Eggplant Under Protection: How to Identify and Neutralize the Main Pests

How to Identify the Pest

• Adult beetle — oval, convex, 9–11 mm long. Elytra reddish‑yellow with five black stripes (Fig. 24b in Akhatov et al., 2013). Pronotum covered with black spots.
• Eggs — smooth, yellow, elongated‑oval, about 2 mm long. Females lay them in groups of 15–100 on the underside of leaves. The fecundity of one female can reach 2000 eggs, although usually no more than 300.
• First‑instar larvae (about 2 mm long) — black. Older larvae (four instars) — brick‑red, with two rows of black dots on the sides. The larva before pupation reaches 15 mm in length.
• Pupae — orange‑red, develop in soil at a depth of 5–10 cm.

Life Cycle and Behavioural Features

The Colorado potato beetle overwinters in soil at a depth of 20–30 cm (sometimes up to 50 cm) in a state of diapause (winter dormancy). In spring, when the soil warms up, beetles emerge to the surface, start feeding, and then lay eggs. Notably, the beetle has several forms of dormancy: winter diapause, multi‑year diapause (can last 2–3 years), and summer aestivation (hibernation in hot weather). This greatly complicates control, as part of the population may “drop out” of the season and appear unexpectedly (Akhatov et al., 2013).

During the season, in regions with warm climates, 2–3 generations develop. In greenhouses, the Colorado potato beetle can produce several overlapping generations. Larval development lasts on average 18–25 days, after which it goes into the soil to pupate. It is important to remember that on plants, eggs, larvae of all ages, young (with soft elytra) and overwintered (with hard elytra) beetles can be present simultaneously.

Signs of Damage

Both beetles and larvae gnaw irregular‑shaped holes in leaves, eat flower stalks and young shoots. The greatest damage to eggplants is caused by older larvae—they are extremely voracious and can completely destroy the leaf surface, leaving only veins. At high pest numbers, plants die. Damage symptoms can easily be confused with the activity of other chewing pests, but the mass presence of bright orange larvae with black dots leaves no doubt.

Control Methods

Summary

The Colorado potato beetle is the most dangerous pest of eggplant, capable of destroying the entire crop in a few days. Success depends on an integrated approach: crop rotation, manual collection, biological preparations against young larvae, and, if necessary, targeted use of chemicals with rotation of active ingredients. Remember: on small gardens, daily inspection of plants and timely removal of egg masses and young larvae, preventing their mass development, is most effective.

How to Identify Aphids

• Glasshouse aphid — wingless females oval‑ovoid, yellowish‑green, light green or pinkish, 1.5–2.5 mm long. Antennal tubercles well developed, antennae equal to body length. Eyes brown‑red. On eggplant, aphids reach maximum size (larger than on tomato) due to dense pubescence, which hinders predator movement (Akhatov et al., 2013).
• Potato aphid — also wingless and winged forms, usually light green or yellowish, slightly smaller than glasshouse aphid. Less common but also dangerous.
• Winged individuals appear when the colony is overcrowded and disperse to neighbouring plants.

Signs of Damage

Aphids colonise the underside of leaves, young shoots, flowers, and even ovaries. As a result:

• Leaves curl, yellow, and fall prematurely.
• Plants become covered with sticky honeydew (excrement), on which sooty mould then develops—this impairs photosynthesis and the marketable appearance of fruits.
• Fruits located below the aphid focus become contaminated with cast skins and sooty mould, losing marketability.
• Under severe infestation, ovaries and young fruits may drop.

The most dangerous aspect of aphids is their role as virus vectors. For example, the glasshouse aphid transmits tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), and potato Y‑virus, causing mosaic, necrosis, and leaf deformation (Akhatov et al., 2013). Yield losses from viral infections spread by aphids can reach 30–50%.

Biology and Life Cycle

In greenhouses and southern regions, aphids develop incompletely — without host alternation, parthenogenetically (viviparous). Females give birth to larvae, which in 7–10 days become adults and start reproducing. At optimal temperature (24–25°C), one female's fecundity reaches 150 larvae. At high numbers, winged individuals appear and disperse to new plants.

Aphids tolerate short‑term frosts down to –5°C and high temperatures up to +45°C, but the optimal range for development is 20–25°C. In open ground, aphids are active throughout the growing season, producing up to 10–15 generations.

Control Methods

Specifics of Aphid Control on Eggplant

The dense pubescence of leaves hinders the penetration of contact insecticides to the feeding site of aphids (underside of leaves). Therefore, preference is given to systemic preparations (Aktara, Confidor) or biopreparations with adjuvants (soap, silicone surfactants). Spraying should be abundant, thoroughly wetting the lower leaf surface.

Summary

Aphids on eggplant are a dangerous pest that can not only weaken the plant but also infect it with viruses. The main protective measures are prevention (weed control, balanced fertilisation), attracting entomophages, and timely application of biological products or systemic insecticides at high numbers. Regular inspection of plants (especially young shoots and the underside of leaves) allows detection of colonies at an early stage and prevents mass reproduction.

How to Identify the Pest

• Adult female — oval body, 0.5 mm long, 0.3 mm wide. Skin folds on the back bear wide‑angled festoons with rounded apices. Young females yellowish‑grey with translucent green‑black spots. Ovipositing females become greenish‑black (colour depends on the contents of the caecum—chloroplasts). Ageing females fade.
• Male smaller (0.31 mm), with body tapering toward the rear end.
• Eggs — perfectly spherical, 0.13 mm in diameter. Colourless in the first day, then become cloudy, acquire a pearly hue, and before hatching the reddish eyes of the embryo are visible through the shell.
• Larvae and nymphs — yellowish‑grey with a greenish tinge.

Signs of Damage

The first symptoms appear on the underside of leaves as tiny silvery or yellowish dots — sites of puncture and sap sucking. Gradually the discoloured areas merge, leaves turn yellow, dry out and fall off. Under severe infestation, leaves become covered with a fine web visible to the naked eye (Akhatov et al., 2013).

The web serves for dispersal: mites crawl along it to neighbouring plants and can be carried by air currents over considerable distances. At high colony density, mites concentrate in the upper tier of plants, as they prefer young leaves. Under particularly favourable conditions (hot, dry weather), mites move to flowers and even fruits, damaging them.

Biology and Life Cycle

The spider mite develops very quickly in warm and dry weather. Optimum temperature — +30°C, optimum air humidity — 45–55%. At humidity 25–35% almost all eggs and over 50% of larvae die; at 98–100% 30–60% of eggs survive (Akhatov et al., 2013).

Overwintering fertilised females remain in the soil, under plant debris, in greenhouse crevices. In spring they emerge and lay eggs on the underside of leaves. During the season in open ground they produce 4–8 generations, in greenhouses up to 12. Development of one generation under optimal conditions takes 7–10 days.

Important: mites reproduce especially actively on plants receiving excess nitrogen fertilisation (tissues become more succulent). Conversely, excess phosphorus reduces mite numbers (Akhatov et al., 2013).

Why is the Mite So Dangerous for Eggplant?

• Eggplant has large, succulent leaves, which are an ideal environment for mite reproduction.
• In hot and dry weather, when other pests are less active, mites reach peak numbers, causing premature wilting of leaves.
• Mite‑damaged plants lose resistance to other stresses (drought, diseases), fruit set decreases, fruits become smaller.
• In greenhouses, mites spread especially quickly due to optimal temperatures and the absence of natural enemies.

Control Methods

Summary

The spider mite is one of the most dangerous and difficult‑to‑eradicate pests of eggplant in hot and dry weather. Success depends on a combination of measures: increasing humidity (watering, air humidification), regular plant inspection, use of biological products, and (if necessary) specialised acaricides with rotation of active ingredients. Remember: the key in mite control is to prevent mass reproduction, as at later stages of infestation it is extremely difficult to cope with the pest.

How to Identify Whitefly

• Adult insect (imago) — small (1.0–1.5 mm) gnat with white waxy wings without spots, pale yellow body. Female larger than male. At the slightest touch to the plant, whiteflies fly up, forming a white cloud — this is one of the most characteristic signs (Akhatov et al., 2013).
• Eggs — elongated, about 0.25 mm long, initially light yellow, then after 8–9 days darken to black. Females lay them on the underside of young leaves.
• Larvae after hatching (0.3 mm) are mobile, but after finding a suitable place, they attach to the leaf and lose legs. They then appear as flat, pale‑green or translucent scales. In the third instar, larvae reach 0.5 mm, in the fourth (nymphal) — 0.75–0.80 mm. Nymphs are greenish‑white, surrounded by a wax fringe, covered with waxy powder.
• On the underside of the leaf all stages can be seen simultaneously: eggs, larvae of different ages, nymphs, and adults.

Signs of Damage

• Leaves become sticky due to the excretion of honeydew, on which sooty mould then develops — a black coating that impairs photosynthesis and the marketable appearance of plants.
• Under mass reproduction, whitefly suppresses growth, leaves turn yellow and dry out.
• The most important danger: whitefly is a vector of many viruses, including cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), tomato mosaic virus (ToMV) and potato X‑virus. Viral infection multiplies the harmfulness of this pest (Akhatov et al., 2013).

On eggplant, symptoms of viral diseases transmitted by whitefly appear as leaf curling, yellows, chlorosis, mosaic, which are often confused with other diseases or nutrient disorders.

Biology and Life Cycle

Whitefly is a tropical species; in northern regions it lives in protected cultivation, in warmer areas it can overwinter on weeds. Females overwinter, less often eggs and nymphs. Over the year, up to 10–15 generations develop in greenhouses, 4–6 in open ground (Akhatov et al., 2013). One generation at optimal temperature (21–25°C) develops in 20–30 days. Fecundity of one female — from 30 to 500 eggs, on average 100–200.

An important feature: on different tiers of the same plant, all developmental stages are present simultaneously, greatly complicating control, as most products act only on mobile stages (adults and young larvae). The proportion of eggs in the population is 55–95%, larvae and nymphs — 27–36%, and adults — only 0.5–5% (Akhatov et al., 2013). Therefore, a single treatment is never sufficient — repeated applications are needed.

Specifics of Whitefly on Eggplant

Although whitefly prefers cucumbers, tomatoes, and flower crops, eggplant also serves as a host plant. Interestingly, on eggplant, adults lay many eggs, but only a small part completes the full cycle — due to dense leaf pubescence and natural mortality (Akhatov et al., 2013). However, this does not mean the pest is safe: at high density, whitefly still weakens plants and transmits viruses.

Control Methods

Summary

Whitefly is a dangerous pest of protected cultivation and southern regions, capable of rapid reproduction and virus transmission. The main protective measures are prevention (disinfection of greenhouses, weed control, yellow traps), biological methods (Encarsia), and, if necessary, the use of systemic insecticides or biopreparations with mandatory rotation. The greatest effectiveness is achieved through an integrated approach, especially in greenhouse conditions where whitefly is most harmful.

How to Identify Thrips

Thrips are microscopic insects 1.0–1.5 mm long, with narrow elongated bodies and fringed wings. Colour varies from straw‑yellow to dark brown or black. Due to their small size, they are difficult to see with the naked eye, but characteristic leaf damage indicates their presence.

• Larvae of thrips are wingless, yellowish or greenish, slightly smaller than adults. Like adults, they feed on the underside of leaves, sucking sap from epidermal cells.
• Eggs are very small, whitish, laid in leaf tissues, petioles, and flowers, making them practically inaccessible to contact pesticides.

Signs of Damage

• On eggplant leaves, small silvery spots and streaks of irregular shape appear — these are feeding marks of thrips. The silvery hue is due to the insects sucking out cell contents, causing air to fill the voids and the tissue to become light‑reflecting (Akhatov et al., 2013).
• The surface of the spots is covered with dark‑brown dots of excrement — their size is larger than those of spider mites, which helps distinguish the damage.
• Under severe infestation, leaves become deformed, curled, and brittle.
• On flowers and ovaries, necrosis and deformations appear. Damaged buds may drop or produce misshapen fruits.
• Unlike spider mites, thrips do not leave webs.

Important feature for eggplant: eggplant leaves are covered with complex trichomes (hairs) that impede thrips movement. The hairs have a vertical needle and several horizontal ones, causing insect death when they attempt to move. Therefore, thrips concentrate along the veins, where trichomes are fewer, and at the leaf base. Since the highest pubescence is on the underside of the leaf, the pest is less common there (Akhatov et al., 2013).

Biology and Life Cycle

Thrips develop very quickly. At optimal temperature (25–30°C), one generation develops in 10–14 days. They produce 5–10 generations per season in open ground and up to 15 in greenhouses. Adults overwinter in soil, plant debris, under tree bark (onion thrips) or in greenhouses (western flower thrips).

The danger of thrips is not only direct damage but also virus transmission. For example, the western flower thrips is the main vector of tomato spotted wilt virus (TSWV), which affects eggplants, tomatoes, peppers, and many other crops. The virus causes necrosis, ring spots, and plant death. Onion thrips can also transmit TSWV and other viruses (Rubatzky & Yamaguchi, 1997).

Specifics of Thrips on Eggplant

Although eggplant is one of the hosts of thrips, their harmfulness on this crop is often lower than on pepper or tomato. This is due to the strong pubescence of leaves, which serves as a natural barrier. However, if breeders, in pursuit of smooth leaves (to facilitate care and reduce allergic reactions), create varieties with minimal pubescence, thrips damage may increase significantly (Akhatov et al., 2013).

Control Methods

Summary

Thrips on eggplant are dangerous pests, especially in greenhouses and southern regions. Their harmfulness increases due to their ability to transmit viruses. However, due to the strong leaf pubescence of eggplant, thrips are often less damaging on this crop than on pepper or tomato. The main control measures are regular monitoring, biological control (predatory mites and bugs), and, if necessary, the use of chemical insecticides with mandatory rotation. Remember that thrips eggs are inside tissues, so repeated treatments are required.

How to Recognise Damage

• Irregular holes and gnawed edges appear on leaves — slugs eat soft tissues, leaving large ragged edges. Unlike caterpillars, they do not leave excrement.
• On the leaf and fruit surfaces, silvery slime trails are visible, which dry and gleam in the sun. This is the most reliable sign of mollusc presence.
• Young seedlings and transplants may be eaten completely at the base, leading to plant death.
• Eggplant fruits are less often damaged, but at high numbers slugs gnaw depressions in the flesh, making fruits unsuitable for sale.

Biology and Conditions Favouring Reproduction

Slugs and snails prefer moist, cool weather and lack of direct sunlight. They are most active at 15–20°C and high humidity (above 80%). During dry periods, they retreat into the soil or under cover and enter a state of torpor. Eggs are laid in moist soil, under plant debris. One to two generations can develop per season (up to 3–4 in warm regions). The main species damaging vegetable crops are the grey field slug (Deroceras reticulatum), the Lusitanian slug (Arion lusitanicus), and various snail species.

Control Methods

Controlling slugs and snails requires an integrated approach, as they are very mobile and quickly recover numbers.

Specifics on Eggplant

Since eggplants are often grown on mulched beds (especially with polyethylene film), this creates favourable conditions for slugs, as moisture is retained under the film. Reflective mulch (white or silver) is recommended — it reduces surface humidity and repels molluscs. Also ensure that fruits do not touch the ground (use supports or staking).

Summary

Slugs and snails are dangerous pests of eggplant under high humidity. Successful control depends on comprehensive prevention: removal of plant debris, soil loosening, creation of barriers, and use of traps. At high numbers, biological products (nematodes) or chemical molluscicides are used, observing waiting periods. Regular manual collection is a simple and effective method on small plots.

How to Identify Wireworms

• Larvae — thin, 10–25 mm long, yellow or brownish, with a hard chitinous covering resembling a piece of wire (hence the name). The body has 13 segments, the head is flat, and the last segment has characteristic outgrowths.
• Adult click beetles — elongated, 8–15 mm long, colour from black to brown. Characteristic feature: when turned on its back, the beetle makes a click and jumps to turn over (hence the family name).
• In the soil, wireworms can be found during digging — they curl into a ring when touched.

Signs of Damage

Wireworms feed on underground parts of plants:

• Root damage — larvae gnaw roots and root collars, leading to stunted growth, yellowing, and wilting of plants.
• Stem damage at the base — especially dangerous for young seedlings, which wireworms can completely cut off.
• Fruit damage — when in contact with the soil, larvae can penetrate eggplant fruits, especially if they lie on the ground (Swiader & Ware, 1992). In fruits, wireworms make deep narrow tunnels, reducing marketable quality and creating entry points for rot‑causing bacteria and fungi.
• Reduced yield and plant death at high pest numbers.

Biology and Life Cycle

Click beetles lay eggs in the soil (at a depth of 3–5 cm) in spring and early summer. After 15–30 days, larvae emerge and develop in the soil for 2 to 5 years, passing through several instars. During this time, they cause significant damage to several generations of crops. Both larvae and adults overwinter in the soil at a depth of 10–40 cm. Pupation occurs in summer, and after 2–3 weeks young beetles emerge, which remain to overwinter in the soil and emerge to the surface only the following spring.

Factors increasing the risk of wireworm occurrence:

• Plots where cereals (wheat, rye, oats), maize, sunflower, or potatoes were previously grown.
• Weed‑infested areas, especially with couch grass — wireworms prefer its roots.
• Acidic soils (pH below 5.5), where wireworms are more common.
• Lack of crop rotation and continuous cultivation of solanaceous crops in the same place.

Control Methods

Wireworm control is difficult due to its long development in soil and ability to migrate to depths of 50–60 cm depending on moisture and temperature.

Specifics on Eggplant

Wireworms are particularly dangerous for young eggplant seedlings, as they damage delicate roots and stems at the base. Using seedlings with well‑developed root systems and planting in warm soil reduces the risk. Also, prevent fruits from contacting the soil — use supports, staking, or mulching film.

Summary

Wireworms are dangerous soil‑dwelling pests whose larvae live in soil for 2–5 years and damage roots and stems of eggplants. Control requires patience and an integrated approach: deep soil cultivation, liming of acidic soils, weed control (especially couch grass), use of traps, and crop rotation. At high numbers, soil insecticides or biopreparations based on entomopathogenic nematodes are used. The most effective measure is a long (3–4 years) break in growing solanaceous crops on infested land, combined with liming and sowing legumes to improve soil health.

The next pest — eggplant fruit borer (Leucinodes orbonalis), which is characteristic of Asia and Africa. We will write chapter 9?

How to Identify the Eggplant Fruit Borer

• Adult moth — small, with a wingspan of 20–24 mm. Wings whitish with brown and black spots, resembling other members of the family Pyralidae. Active at dusk and at night.
• Eggs — small (0.5–0.8 mm), oval, cream‑white, laid singly or in small groups on the underside of leaves, on stems, and on fruit calyces.
• Caterpillars — the main damaging stage. Young caterpillars whitish or pale pink, with a dark head. Mature caterpillars reach 15–20 mm in length, become pink or reddish, with well‑visible dark spots (spiracles) on the sides. They actively crawl inside shoots and fruits.
• Pupae — found in thin cocoons inside damaged shoots or in the soil, colour from yellow‑brown to dark brown.

Signs of Damage

The damage caused by caterpillars is very characteristic and noticeable:

• Wilting of terminal shoots (shoot dieback). Caterpillars bore into young stems and shoots, eating tunnels. Damaged stems stop growing, showing small holes with excrement. This leads to branching and loss of plant productivity (Prohens & Nuez, 2008).
• Fruit damage — caterpillars penetrate into fruits, usually through the calyx or directly through the skin. At the entry points, small holes surrounded by excrement are visible. Inside the fruit, the caterpillar eats the flesh and seeds, filling the tunnels with excrement. Damaged fruits become unfit for consumption and quickly rot.
• Symptoms — drying of shoot tips, presence of entry holes (with excrement) in stems or fruits, premature dropping of buds and ovaries.

Life Cycle and Biology

The fruit borer is a moth with complete metamorphosis. Over one season in the tropics, 4–5 generations can develop, and under favourable conditions (warm, humid weather) up to 7–8 generations (Prohens & Nuez, 2008). Development of one generation at 25–30°C takes 3–4 weeks.

• Egg — 3–5 days.
• Caterpillar — 12–16 days. During this time, it passes through several instars, increasing in size and causing increasing damage.
• Pupa — 6–8 days inside a cocoon, often in a damaged shoot or in the soil.
• Moth — lives 3–6 days, laying up to 100–200 eggs.

Overwinters as pupae (sometimes caterpillars) inside dry stems and fruits left in the field, or in soil at a depth of 2–5 cm. Therefore, control must begin with removal and destruction of plant residues after harvest.

Control Methods

Because caterpillars spend most of their lives inside plant tissues (shoots and fruits), controlling the fruit borer is a difficult task. A pesticide must either penetrate the plant (systemic) or the caterpillar must be destroyed before it bores inside. Therefore, the key to success is an integrated approach combining prevention, agronomy, biological, and chemical methods.

Specifics on Eggplant

Since the fruit borer is the most dangerous pest of eggplant in Asia, transgenic (Bt) eggplant varieties resistant to caterpillars have been developed specifically to combat it (Prohens & Nuez, 2008). In some countries, they are approved and successfully used; however, in most regions (and in organic farming), preference is given to integrated protection methods. It is also important to consider that in areas with high pest numbers, eggplants should be planted early (before mass moth flight) or use early‑maturing varieties that complete fruiting before the pest peak.

Summary

The eggplant fruit borer (Leucinodes orbonalis) is a major pest in Asia and Africa, whose caterpillars penetrate shoots and fruits, making them unfit for consumption. Control is difficult due to the hidden lifestyle of caterpillars. The basis of protection is an integrated approach: regular sanitary pruning of damaged shoots and fruits, removal of plant residues, use of pheromone traps, biopreparations (Bt), and, if necessary, systemic insecticides. Regular monitoring and timely treatments during egg‑laying are the key to saving the crop.

How to Identify Leafminer Flies and Their Damage

• Adult flies — very small (1.5–3 mm), greyish‑black or yellow‑black, with transparent wings. They can be seen on leaves, especially in the morning. Females puncture the leaf with their ovipositor, feeding on sap, and leave small light dots (punctures) on the leaf surface.
• Eggs — whitish, translucent, about 0.2–0.3 mm long, laid inside the leaf blade under the epidermis.
• Larvae — worm‑like, legless, whitish or yellowish, up to 2–3 mm long. They live inside the leaf, eating soft tissues and leaving characteristic winding tunnels (mines).
• Mines — the main diagnostic sign. They appear as narrow, winding, gradually widening light streaks on the leaf surface. Inside the mines, dark dots — larval excrement — are visible. Under severe infestation, mines coalesce, and the leaf becomes translucent, brown, and dries out.
• Puparia — yellowish‑brown, oval, about 1.5–2 mm long. They may be found inside the mine or fall to the soil to pupate.

Signs of Damage

• Reduced photosynthetic activity — damaged leaves lose chlorophyll, leading to plant inhibition, stunted growth, and reduced yield.
• Premature leaf drop — under severe infestation, leaves turn yellow and fall, exposing stems, especially dangerous for young plants.
• Cosmetic damage — for fruit crops, leaf damage may not directly kill plants but reduces vigour and yield, especially if more than 30–40% of leaf surface is affected (Rubatzky & Yamaguchi, 1997).
• Entry points for diseases — damaged leaves become more susceptible to fungal and bacterial infections.

Biology and Life Cycle

Leafminer flies develop very quickly, especially in warm conditions. At 25–30°C, one generation can develop in just 2–3 weeks. They produce from 4 to 10 generations per season in open ground and up to 12–15 in greenhouses (Akhatov et al., 2013). Adults, less often pupae, overwinter in plant debris, in the soil, or in greenhouses.

• Egg — 2–5 days.
• Larva — 5–10 days (3 instars).
• Pupa — 5–12 days (in soil or in leaf).
• Adult fly — lives 2–4 weeks, female lays up to 200–300 eggs in her lifetime.

Adult flies feed on plant sap, leaving punctures on leaves that also damage tissues and promote water loss.

Specifics of Leafminer Flies on Eggplant

Eggplant is one of many host plants for leafminer flies. However, its dense pubescence can somewhat hinder oviposition, so damage often begins on lower, older leaves where pubescence is less, or on leaf margins. In greenhouses, where humidity and temperature are optimal for the pest, leafminer flies can pose a serious threat, especially when eggplants are grown without crop rotation.

Control Methods

Control of leafminer flies is complicated because larvae are protected from contact products by leaf tissues. Adults are more vulnerable, but they are difficult to eradicate completely as they disperse over large distances. Therefore, emphasis is placed on prevention and integrated methods.

Summary

Leafminer flies are small but dangerous pests whose larvae mine inside eggplant leaves, reducing photosynthesis and overall plant vigour. The main protective measures are prevention (weed control, removal of infested leaves, crop rotation, yellow traps), biological methods (parasitic wasps), and the use of systemic insecticides or biopreparations based on avermectins, taking into account rapid resistance development. It is important to combine several methods and conduct regular monitoring.

Root‑knot Nematode (Meloidogyne spp.)

This is the most widespread and dangerous nematode species on eggplants, especially in southern regions, in greenhouses, and on light sandy soils. The most harmful species are M. incognita, M. javanica, and M. arenaria (Akhatov et al., 2013; Prohens & Nuez, 2008).

Stem Nematode (Ditylenchus dipsaci)

This species is less common but can also infect eggplants, especially under high humidity and cool weather. It lives and reproduces inside stem, leaf, and root tissues, causing deformation, thickening, and cracking. Plants are stunted, stems become bent, leaves curl and turn yellow. Under severe infestation, plants die.

Control Methods

Nematode control is extremely difficult due to their protection inside plant tissues and soil. The main methods are prevention and agronomy; chemical products are rarely used due to their toxicity and high cost.

Specifics on Eggplant

Eggplant is one of the most susceptible solanaceous crops to root‑knot nematodes. In warm regions (southern Russia, Ukraine, Moldova, Central Asia, the Caucasus), nematodes are a serious problem. In protected cultivation, the risk of infestation is especially high, as greenhouse conditions (warmth, humidity, repeated plantings) favour their reproduction.

Summary

Root‑knot and stem nematodes are hidden but extremely dangerous pests of eggplant, reducing yield and weakening plants. Control is difficult, so the main emphasis is on prevention: crop rotation (4–5 years), use of resistant varieties and rootstocks (especially Solanum torvum), removal of plant residues, deep ploughing, maintaining optimal soil pH and moisture. In greenhouses, the use of biopreparations based on Pasteuria penetrans, steam treatment, or soil replacement is effective. Chemical nematicides are used only as a last resort, with great caution.

12.1. Cutworms (Noctuidae) — Armyworms and Fruitworms

Cutworms are nocturnal moths whose caterpillars are active at dusk and at night, hiding under plant debris or in soil during the day. On eggplants, the most common are:

• Turnip moth (Agrotis segetum) — caterpillars cut stems of young plants at the base, causing lodging and death. Especially dangerous for seedlings.
• Cotton bollworm (Helicoverpa armigera) — caterpillars damage fruits, eating flesh, leading to rot and loss of market quality (Akhatov et al., 2013; Rubatzky & Yamaguchi, 1997).
• Cabbage moth (Mamestra brassicae) and cabbage armyworm (Lacanobia oleracea) — caterpillars eat leaves and young shoots, leaving large ragged holes and excrement.

Signs of damage: ragged holes on leaves, eaten stems at the base, damaged fruits with characteristic round entry holes, presence of large (up to 3–5 cm) greyish‑green or brown caterpillars on plants (especially in the morning and evening).

Control measures: agronomy (deep ploughing, weed control, crop rotation); biopreparations based on Bacillus thuringiensis (Bt) against young caterpillars; pheromone traps for monitoring moth flight; at high numbers — use of approved insecticides (pyrethroids, organochlorines) with waiting periods.

12.2. Stink Bugs and Plant Bugs (Hemiptera)

Various bugs (e.g., berry bug Dolycoris baccarum, green vegetable bug Nezara viridula, tarnished plant bug Lygus spp.) can damage young shoots, buds, flowers, and ovaries of eggplant (Swiader & Ware, 1992; Rubatzky & Yamaguchi, 1997). They feed on plant sap, piercing tissues and injecting digestive enzymes, causing fruit deformation (“beaks”, spots), bud drop, and reduced yield.

Signs of damage: characteristic punctures and discoloured areas on fruits, misshapen fruits, wilting of shoot tips. Adult bugs and their nymphs can be seen with the naked eye on the underside of leaves and on fruits.

Control measures: maintaining cleanliness, weed removal; use of insecticides at high numbers (pyrethroids, organophosphates) with waiting periods and safety for pollinators.

12.3. Leafhoppers (Cicadellidae) and Psyllids (Psyllidae)

Leafhoppers (e.g., beet leafhopper) and psyllids can be vectors of phytoplasma and viral diseases, such as stolbur and yellow dwarf virus. They feed on plant sap, sucking it from leaves and shoots (Akhatov et al., 2013). Under mass reproduction, they cause yellowing and curling of leaves, growth inhibition.

Control measures: weed control (especially field bindweed, the main reservoir for leafhoppers); use of insecticides (systemic or contact) during mass flight; use of yellow sticky traps for monitoring.

12.4. Mole Cricket (Gryllotalpa gryllotalpa)

The mole cricket is a large (up to 5 cm) soil‑dwelling insect that burrows in the soil and damages roots, root collars, and stems of eggplants, especially young seedlings. The pest prefers moist, organic‑rich soils (Swiader & Ware, 1992).

Signs: characteristic tunnels in the soil, wilting of plants, damaged roots and stems at the base. Adults and larvae can be found during digging.

Control measures: deep autumn ploughing; use of poisoned baits (grain, boiled potato with insecticide); traps (jars with water and kerosene buried in the soil); soil insecticides (diazinon, imidacloprid) in planting holes.

12.5. Chafer Grubs (May Beetle and Other Scarabaeidae)

Larvae of the May beetle and other chafers (genera Melolontha, Amphimallon) — large, thick, C‑shaped cream‑coloured larvae. They live in the soil and feed on roots and underground parts of eggplants, causing stunting and death, especially on plantations near shelterbelts or fallow areas (Swiader & Ware, 1992).

Control measures: deep ploughing, collection of larvae during digging, crop rotation, application of entomopathogenic nematodes (Heterorhabditis, Steinernema) to the soil.

12.6. Earwigs (Dermaptera)

The common earwig (Forficula auricularia) can damage leaves and young shoots of eggplant, especially in greenhouses. It is active at night and hides in crevices and under plant debris.

Control measures: maintain cleanliness, set traps (tubes, boards filled with damp hay), at high numbers — spray with approved contact insecticides.

12.7. Caterpillars of Other Lepidoptera

On eggplants, caterpillars of cabbage white (Pieris brassicae), diamondback moth (Plutella xylostella), fall webworm (Hyphantria cunea), and other leaf‑eating pests may also occur, especially near fields with cabbage and other brassicas. They eat leaves, leaving characteristic holes and excrement.

Control measures: biopreparations (Bt, lepidocide), pheromone traps, if necessary — insecticides.

General Recommendations for Controlling “Other” Pests

1. Regular monitoring — inspect plantings every 5–7 days, paying attention to leaf, fruit, and plant condition.

2. Maintain high agronomic background — healthy, well‑fed and watered plants are more resistant to damage and recover better after pest attacks.

3. Observe crop rotation — alternating crops reduces the accumulation of specific pests in the soil.

4. Destroy weeds and plant debris — deprives pests of shelters and reservoirs.

5. Attract beneficial insects — planting nectar‑bearing plants (dill, phacelia, buckwheat) and using biopreparations supports natural enemies of pests.

6. Use insecticides — only when the economic threshold is exceeded, with mandatory rotation of active ingredients and waiting periods.

Next chapter — Methods of Controlling Eggplant Pests (summary). Shall we write it?

13.1. Preventive and Agronomic Methods (Foundation of Protection)

These are the most important, accessible, and environmentally safe measures. They aim to create conditions unfavourable for pests and to strengthen the plant itself.

• Crop rotation. Do not plant eggplants and other solanaceous crops (potato, tomato, pepper) on the same plot for more than 2–3 years in a row. Return the crop to the same place no earlier than after 4–5 years. Best predecessors are legumes (peas, beans), alliums (onion, garlic), cereals, brassicas, and cucurbits. This reduces the accumulation of specific pests (nematodes, wireworms, pathogens) in the soil (Akhatov et al., 2013; Swiader & Ware, 1992).

• Soil cultivation. Deep autumn (fall) ploughing to 25–30 cm destroys overwintering stages of many pests (Colorado potato beetle, wireworms, cutworms, mole crickets, leafminer pupae). Spring harrowing and loosening destroy eggs and young larvae in the topsoil. Liming of acidic soils (to pH 6.0–6.5) reduces wireworm and root‑knot nematode numbers, which prefer acidic conditions.

• Weed control. Weeds serve as reservoirs and intermediate hosts for many pests (aphids, whitefly, thrips, leafhoppers, nematodes, slugs). Particularly dangerous are Solanaceae (black nightshade), Chenopodiaceae, field bindweed, and couch grass. Regular weeding and mowing around the plot and between rows deprive pests of shelter and food sources.

• Use of resistant varieties and rootstocks. Choose varieties resistant to the main pests and diseases in your region (e.g., to Colorado potato beetle, nematodes, viruses). In southern regions and greenhouses, rootstocks resistant to root‑knot nematodes and Fusarium (Solanum torvum, S. sisymbriifolium, S. aethiopicum) are effective. Grafted plants better withstand stress and produce higher yields (Prohens & Nuez, 2008).

• Balanced nutrition. Excess nitrogen makes plant tissues loose, succulent, and particularly attractive to aphids, mites, and whitefly. Do not over‑fertilise eggplants with nitrogen. Prefer complex fertilisers with a predominance of phosphorus and potassium, which strengthen cell walls and increase plant resistance.

• Correct watering. Avoid waterlogging and stagnation, which promote slugs and soil pathogens. Water in the morning so that the soil surface dries by evening — this reduces slug activity. In dry weather, regular watering increases plant resistance to spider mites.

• Mulching. Black or reflective mulching film not only conserves moisture and heat but also inhibits weed growth and reduces fruit contact with soil (reducing the risk of wireworm and slug damage). White or silver mulch reflects light and reduces numbers of aphids, whitefly, and thrips.

• Traps and barriers. Yellow sticky traps attract adults of whitefly, aphids, leafminer flies, and other flying pests (place them at plant level). Blue traps are effective against thrips. Boards, cardboard, damp cloths serve as slug shelters — regularly collect and destroy them. Barriers of ash, lime, tobacco dust, or eggshells around plants repel molluscs.

• Remove plant residues. After harvest, carefully remove and burn all plant debris (stems, leaves, roots, damaged fruits), as they are overwintering and breeding sites for many pests and diseases. This is one of the most important preventive measures.

13.2. Biological Methods (Environmentally Safe and Effective)

Biological methods use natural enemies of pests — parasites, predators, and pathogens of insects. They are especially valuable in greenhouses and organic plots.

Entomophages — predatory and parasitic insects.

• Ladybirds (coccinellids), green lacewings, hoverflies — destroy aphids, thrips, Colorado potato beetle eggs, and other pests. Attract them by planting nectar‑bearing plants (dill, phacelia, buckwheat, marigold).
• Predatory mites Phytoseiulus and Neoseiulus — effectively control spider mites, especially in greenhouses.
• Parasitic wasps Encarsia formosa (against whitefly), Diglyphus and Dacnusa (against leafminer flies), Aphidius (against aphids) — widely used in protected cultivation. They can be purchased from biolaboratories and released into greenhouses at the first signs of pests.
• Predatory bugs Orius and Macrolophus — destroy thrips, aphids, whitefly.
• Predatory ground beetles and rove beetles — eat eggs and larvae of wireworms and other soil pests. Conservation of their populations is achieved by limiting chemical pesticide use and leaving buffer zones.

Microbiological preparations (biopesticides).

• Based on the bacterium Bacillus thuringiensis (Bt, Lepidocide, Bitoxybacillin) — effective against cutworm caterpillars, fruit borer, diamondback moth, and other Lepidoptera. Act on young larvae.
• Based on avermectins (Fitoverm, Aktofit) — affect mites, thrips, aphids, leafminer flies, and other sucking pests. Have a short waiting period (2–3 days).
• Based on entomopathogenic fungi (Beauveria bassiana — Boverin) — effective against whitefly, thrips, aphids, Colorado potato beetle.
• Based on entomopathogenic nematodes (Steinernema, Heterorhabditis) — used against wireworms, mole crickets, chafer grubs, slugs. Watering soil with nematode suspension in warm, wet weather gives good results.
• Based on the bacterium Pasteuria penetrans — a specific parasite of root‑knot nematodes, applied to soil to reduce their numbers.

• Pheromone traps. Used for monitoring and mass trapping of male fruit borers, cutworms, diamondback moths, Colorado potato beetles, and other pests. They allow detection of the start of moth flight and timely application of other protection methods (Prohens & Nuez, 2008).

13.3. Mechanical and Physical Methods (Manual Work)

These methods are labour‑intensive but indispensable on small plots and in organic farming.

• Manual collection of pests. Regularly inspect plantings, collect and destroy Colorado potato beetles and their egg masses, caterpillars, slugs, snails, leafminer larvae in damaged leaves. Under mass reproduction, this can give a noticeable effect.
• Washing with water. A strong jet of water washes aphids, spider mites, whitefly off leaves, especially in greenhouses.
• Pruning and removal of damaged organs. Cut and burn shoots and fruits damaged by fruit borer, leafminer flies, cutworms. This reduces pest numbers and prevents their spread.
• Barriers and covers. Non‑woven covers (agrospan, lutrasil) protect young seedlings from flying pests (whitefly, thrips, aphids) and from slugs. They are removed during flowering for pollination.

13.4. Chemical Methods (Last Resort)

Chemical insecticides and acaricides are used only when the economic threshold of harmfulness is exceeded (when pest damage becomes significant and other methods are no longer effective). Remember: chemicals kill not only pests but also beneficial insects, can contaminate fruits and the environment. Therefore, their use must be deliberate, minimal, and strictly regulated.

Choice of product. Products are divided into groups:

• Contact (act on contact with the insect) — effective against openly living pests (aphids, thrips, whitefly, caterpillars, Colorado potato beetle). Examples: Actellic, Karate, Decis.
• Systemic (penetrate plant tissues and circulate through the vascular system) — effective against sucking pests (aphids, whitefly, thrips) and pests living inside tissues (fruit borer, leafminer flies, root‑knot nematodes). Examples: Aktara, Confidor (imidacloprid, thiamethoxam), Mospilan.
• Acaricides (specific products against mites) — Neoron, Apollo, Sanmite, Oberon.
• Nematicides (against nematodes) — Oxamyl, Nematode (use as a last resort due to high toxicity).
• Molluscicides (against slugs) — based on metaldehyde (Groza, Meta) or iron phosphate (Ferramol).

Application rules:

• Strictly follow the dosage and concentration stated on the label.
• Treat plants in dry, calm weather, early morning or late evening, to avoid sunburn and bee deaths.
• Pay special attention to the underside of leaves, where many pests (aphids, mites, whitefly) concentrate.
• Always observe waiting periods (time from last treatment to harvest) to avoid accumulation of toxic substances in fruits.
• Alternate products from different chemical groups to avoid resistance development in pests. Do not use the same product (or products with the same active ingredient) several times per season.
• Use tank mixtures (compatible according to instructions) to broaden the spectrum of action, but do not mix more than two or three components without checking compatibility.

Safety. Use personal protective equipment (respirator, gloves, goggles). After work, shower, wash clothes. Do not treat in the presence of children and pets. Strictly observe waiting periods before re‑entering the plot.

13.5. Integrated Pest Management (IPM)

IPM is a strategy that combines all the above methods into a single system, considering the specific conditions of the plot, season, weather, and pest population dynamics. Its essence:

1. Monitoring. Regularly inspect plantings, use traps, count pests. Determine when pest numbers reach the damage threshold.

2. Priority of prevention. First apply agronomic methods (crop rotation, variety choice, fertilisation, watering, mulching, removal of plant residues).

3. Biological control. Attract and release entomophages, apply biopreparations.

4. Mechanical methods. Use traps, barriers, manual collection, pruning of damaged organs.

5. Chemical methods — only as a last resort. If other methods do not work and the pest threatens the crop, apply selective chemical products with all safety and rotation rules.

6. Evaluate effectiveness. After treatments, re‑inspect to assess results and adjust the plan if necessary.

This approach minimises pesticide use, preserves beneficial fauna, reduces costs, and protects the environment.

Mistake 1. Ignoring Prevention

Many gardeners start thinking about pests only when plants are already severely damaged. Unfortunately, at that stage it is often very difficult or even impossible to save the crop.

How to avoid: Make prevention a habit. Crop rotation, choice of resistant varieties, timely weeding, removal of plant residues, balanced fertilisation, use of mulch — these are not “extra” chores, but the foundation of a healthy garden. Regular inspection of plantings (at least every 5–7 days) allows pests to be detected early, when they can be easily removed by hand or treated with biopreparations.

“Prevention is the basis of integrated pest management. The less chemistry we use, the more healthy and beneficial insects remain on the plot, which themselves regulate pest numbers” (Akhatov et al., 2013).

Mistake 2. Incorrect Pest Diagnosis

Gardeners often confuse one pest with another and apply inappropriate means. For example, against spider mites they use ordinary insecticides (which do not affect mites), and against caterpillars they use acaricides. Or they mistake thrips damage for drought or disease.

How to avoid: Learn to distinguish pests by characteristic signs:

• Spider mite — tiny dots, webs on leaves, yellowing. Feeds on sap, damages in dry, hot weather.
• Aphids — curled leaves, sticky coating, colonies on the underside.
• Thrips — silvery streaks and spots with black excrement dots.
• Colorado potato beetle — bright yellow‑black beetles and orange larvae with rows of black dots.
• Leafminer flies — winding light tunnels inside the leaf.
• Root‑knot nematode — swellings (galls) on roots when the plant is dug up.
• Slugs — eaten leaves and silvery slime trails.

When in doubt, use a magnifying glass, photograph the damage, and compare with descriptions from reliable sources. If that fails, consult a local agronomist or plant protection service.

Mistake 3. Using the Same Product Without Rotation

This is one of the most dangerous mistakes. Pests (especially aphids, spider mites, Colorado potato beetle, and leafminer flies) develop resistance very quickly to products used repeatedly. As a result, after 2–3 treatments the product stops working, and the pest multiplies with renewed vigour (Rubatzky & Yamaguchi, 1997; Prohens & Nuez, 2008).

How to avoid: Always rotate products with different active ingredients. Do not use the same insecticide or acaricide more than twice per season, and do not apply products from the same chemical group consecutively. Keep records (or at least a mental note) of which products and when you applied them. Pay attention not to the trade name but to the active ingredient — it determines the chemical group.

Examples of different groups by active ingredient:

• Neonicotinoids (imidacloprid, thiamethoxam — Aktara, Confidor)
• Pyrethroids (cypermethrin, deltamethrin, lambda‑cyhalothrin — Decis, Karate)
• Organophosphates (pirimiphos‑methyl, malathion — Actellic, Karbofos)
• Avermectins (abamectin — Fitoverm, Aktofit)
• Spinosyns (spinosad — Conserve)
• Ovicides and specific acaricides (clofentezine, fenpyroximate — Apollo, Neoron)

Mistake 4. Not Following Treatment Timing

Many treat plants after the pest has already caused serious damage, or at the wrong developmental stage of the pest. For example, products based on Bacillus thuringiensis (Bt) are effective only against young caterpillars that are actively feeding. If you delay by 2–3 days, the caterpillars become older and Bt no longer works. Or against leafminer flies: contact products are useless if the larva is already inside the leaf — systemic products applied before mass egg‑laying are needed.

How to avoid: Study the life cycles of the main pests in your region and treat plants at the right stage. Use pheromone traps to track the start of moth flight. Apply treatments regularly (at intervals specified in the instructions), not sporadically. Remember: the best protection is timely.

Mistake 5. Neglecting the Underside of Leaves

Many pests (aphids, spider mites, whitefly, thrips, leafminer larvae) live and feed mainly on the underside of leaves. Treating only the upper side is practically useless.

How to avoid: Direct the sprayer from bottom to top, thoroughly wetting the lower surface of all leaves. This is especially important during the active growth phase, when leaves have not yet closed. Add adjuvants (soap, silicone surfactants) to working solutions — they improve wetting of the waxy coating and pubescence of eggplant leaves.

Mistake 6. Applying Chemicals Too Early or Too Late

• Too early (before pests appear) — leads to unnecessary product use, death of beneficial insects, and resistance development.
• Too late (when pests have already multiplied heavily) — requires multiple treatments, increases costs, and contaminates produce.

How to avoid: Apply chemical products only when the economic threshold is exceeded (when the number of pests on a plant reaches a level at which yield losses become economically significant). For each pest, this threshold differs (e.g., for aphids — 5–10 individuals per leaf, for spider mites — 2–3 individuals per leaf). Use biopreparations at early stages, and chemicals only as a last resort.

Mistake 7. Ignoring Crop Rotation and Proximity to Other Crops

If you plant eggplants year after year in the same place, or next to potatoes, tomatoes, and peppers, you create ideal conditions for the accumulation of pests, especially soil‑dwelling ones (nematodes, wireworms) and Colorado potato beetles.

How to avoid: Observe a 4–5‑year crop rotation, returning solanaceous crops to their original place. Avoid planting solanaceous crops next to each other. Use spatial isolation: potatoes and eggplants should be separated by a strip of other crops (e.g., legumes or onions).

Mistake 8. Improper Storage and Use of Pesticides

Storing products in rooms with high temperature and humidity, expired shelf life, incorrect dosage — all reduce treatment effectiveness and sometimes make them dangerous to humans and plants.

How to avoid: Store pesticides and biopreparations in a dry, cool, dark place, separate from food, drinking water, and feed. Strictly follow expiration dates. Prepare working solutions only immediately before use, in the amount needed for one treatment. Use measuring utensils for accurate dosing. Do not mix incompatible products without consulting an agronomist.

Mistake 9. Destroying Beneficial Insects

The use of broad‑spectrum insecticides kills not only pests but also their natural enemies (ladybirds, lacewings, parasitic wasps, predatory mites). After that, pests multiply with doubled strength, and control becomes even more difficult.

How to avoid: Prefer selective products (biopreparations, specific insecticides that act only on certain pest groups). Try not to use chemicals during mass flowering (dangerous for bees) and during active flight of entomophages. Attract beneficial insects by planting nectar‑bearing plants (dill, phacelia, buckwheat).

Mistake 10. Violating Waiting Periods (Time from Treatment to Harvest)

This is the most dangerous mistake for your health. If you treat plants with insecticide 1–2 days before harvest, toxic substances may remain in the fruits and cause poisoning.

How to avoid: Carefully read the product label — it always states the waiting period in days (e.g., 7, 14, 20 days). Plan treatments so that you meet this period. For treatments close to harvest, use biopreparations with short waiting periods (Fitoverm — 2–3 days, Aktofit — 2 days, Bt products — 1–2 days).

Summary

Most pest control mistakes arise from a lack of understanding of pest biology, lack of a systematic approach, and haste. Remember: plant protection is not a war, but a partnership with nature. Healthy, strong plants grown with crop rotation and balanced nutrition resist pests themselves. Regular inspection, timely prevention, correct choice and rotation of products, respect for beneficial insects, and strict observance of waiting periods — that is the recipe for success. Be attentive, patient, and caring towards your garden, and it will reward you with a bountiful harvest of tasty and healthy eggplants!