For more information:Contact N.S. Talekar, Entomologist, AVRDC.E-mail: talekar@netra.avrdc.org.tw

2003

Other recommended publications:Development of an Integrated PestManagement Strategy for Eggplant Fruit andShoot Borer in South AsiaSocio-economic Parameters of EggplantPest Control in Jessore District ofBangladesh

Department forInternational DevelopmentDFID

The production of this publication was fundedby the UK Department for InternationalDevelopment (DFID). However, the viewsexpressed are not necessarily those of DFID.

Acknowledgment:

AVRDCThe World Vegetable Center

P.O. Box 42, Shanhua, Taiwan 741Tel: ++886-6-583-7801Fax: ++886-6-583-0009Website: www.avrdc.org

Introduction

Eggplant or brinjal, as it is called in South Asia, isone of the most important vegetables in Asia. Itis susceptible to several pests, especially the egg-plant fruit and shoot borer, the current control ofwhich entails enormous misuse of pesticides.

This pictorial guide contains information on themajor insect and mite pests causing damage toeggplant in South and Southeast Asia. The guideis written for eggplant growers and extension spe-cialists. It gives information on damage symptomsand characteristics of pest insects. We trust thisinformation will help farmers identify pest prob-lems and take suitable control measures. For pestcontrol, we strongly urge farmers to seek the ad-vice of technical professionals.

We have also included pictures and informationon natural enemies found in the field. The naturalenemies depicted here are readily found but rarelyappreciated for their importance in keeping pestinsects under check. This information is providedin the hope that farmers will realize the impor-tance of natural enemies and refrain from theunnecessary use of pesticides that will kill them.

This publication is one in a series of tools meantto promote integrated pest management (IPM)of eggplant fruit and shoot borer with minimumor no use of chemical pesticides, a project fundedby UK Government’s Department for InternationalDevelopment.

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Eggplant fruit andshoot borer

Damage symptomsPlant shoots wilt and dry. Small holes appearbelow the calyx of fruits. Fruits are filled with frass.

Insect characteristicsFully grown larvae are 15–18 mm long, dull whitein color turning light pink as it matures. The moth,which is active only at night and hides under plantcanopy during day, is white with a pink or bluishtinge and brownish markings on its wings.

Where to lookLook for larvae inside wilting shoots. Fruit dam-age will not be obvious. The first indication is asmall hole just below the calyx where the insecthas entered. Cut the fruit near this entry hole andyou will find where the larva has tunneled.

Life cycleCreamy white eggs are laid singly on leaf under-sides, stems, flower buds, or the base of the fruit.Newly hatched larva bore into fruits or tendershoots. After feeding, larva pupate in soil amongfallen debris. Several overlapping generations oc-cur in warm climates. This pest can survive insidepartially dried plant stubble during off-season.

Scientific name: Leucinodes orbonalis

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Exit holein shoot

Exit holesin fruits

Adult moth

Wilted shoot

Larva andinternal damage

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Leafhopper

Damage symptomsInfested leaves curl upwards along the margins.Outer leaf areas appear yellowish or burned.Leaves remain small and show a mosaic patternof yellowing. Fruit-set may be very low.

Insect characteristicsLeafhoppers infest the lower surface of theleaves. Commonly, if disturbed, they move veryrapidly sideways and hop. They are usually 1–3mm long, greenish yellow with slender, taperedbodies, with two distinct black spots on the pos-terior end of the wings. Legs have rows of sharpspines.

Where to lookAdults and immatures are readily found on theundersides of leaves. Their highly active behav-ior makes them difficult to catch.

Life cycleLeafhopper breeds practically throughout the yearbut are more prevalent during dry periods. Minuteeggs are laid in leaf lamina on the underside ofleaves. Tiny nymphs feed on the underside ofleaves before becoming adults. Total life cyclecan last 5–7 weeks and there are overlapping ofgenerations during the season.

Scientific name: Amrasca biguttula biguttula

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Damage

Close-up of damage

Adults

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Epilachna beetle

Damage symptomsLeaf tissue is eaten between the veins. The leavesmay be completely stripped to the mid-veins, andsmall areas eaten out and or shallow holes presenton the fruit surface.

Insect characteristicsAdults and larvae are often seen living together.Adults look like common lady beetles, but ladybeetles do not eat plants. Epilachna beetles areoval-shaped with brownish with black spots ontheir backs. Larvae are pale yellow and havebranched spines covering their backs and sides.

Where to lookLook on both sides of leaves. Adults fall to theground or fly when you disturb them. The youngnormally stay in place.

Life cycleAdult females lay yellow cigar-shaped eggs,mostly on the underside of leaves. Eggs hatchinto yellow spiny grubs that feed on the lower epi-dermis of leaves. They have four larval instarsand full-grown larvae are 6 mm long. The pupaeare darker and found on the leaves or stems.The life cycle is completed in 15–20 days andthere may be several generations in a season.

Scientific name: Epilachna spp.

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Beetle (12-spotted) ondamaged leaf

Larvaeeating tissuebetweenleaf veins

Beetle (28-spotted)

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Eggplant leaf roller

Damage symptomsYoung leaves are rolled lengthwise. Rolled leavesare brown and eventually dry. In heavy infesta-tions entire portions of plants appear brown andleaf drop occurs.

Insect characteristicsCaterpillars are purple-brown with many cream-colored hollow bumps and long hairs on the backand sides. The adult is an olive green moth thatis active at night.

Where to lookInspect the young leaves for signs of silken web-bing and rolled/leaves. Open these leaves andlook for the caterpillar and signs of chewing dam-age on the leaf surface.

Life cycleThe female adult lays eggs in masses on theyoung leaves. Each egg mass may have 8–22eggs. The caterpillar feeds for about four weeksand then pupates inside the rolled leaf. In favor-able climates there may be three to fourgenerations each year.

Scientific name: Eublemma olivacea

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Rolled leaf(larva hidden inside)

Exposed larva

Severedamage

Adultmoths

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Red spider mite

Damage symptomsMite feeding results in large chlorotic patches onleaves. Often these damaged leaves curl whenthe infestation is concentrated on middle part oflower leaf surface. Severe infestation causes ex-tensive yellowing and browning of entire leavesand eventually leaves drop.

Insect characteristicsMites are not true insects (for example, they haveeight legs, not six), but cause damage similar tomany tiny insects such as thrips and whiteflies.They are very tiny red in color and barely seenby the naked eye.

Where to lookRed spider mites are found mainly on lower sur-face of leaves. Only when the population is veryhigh can you find some individuals crawling onthe upper leaf surface or on stems and flowers.

Life cycleMites lay very tiny eggs not readily visible by thenaked eye on the lower leaf surface. Tiny orangenymphs hatching from these eggs feed on lowersurface of eggplant leaves. Within a week,nymphs turn into dark orange to red color adults,which look like tiny spiders crawling on lower sur-face of leaves.

Scientific name: Tetranychus urticae10

Mites feedingon leaf

Close-upof mites

Damage

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Thrips

Damage symptomsBrown, dry areas appear on the underside of lowerleaves. In severe cases, the entire leaf dries. Simi-lar damage is seen along the mid-vein on the upperleaf surface.

Insect characteristicsThese insects are very small, about the size of aflea, and just visible to the naked eye. Adults aredarker yellow with two pairs of narrow fringedwings and two brownish strips down their backs.The young are either yellow or white.

Where to lookStart by looking at the upper surface of the lowerleaves, then look along the mid-vein for damageon either side. This is where you should see thesetiny insects. Turn the leaf over and carefully lookat the sections with healthy tissue that borderareas of brown or damaged tissue. If you focuswell, you will notice the tiny insects moving.

Life cycleAdults lay eggs within leaf tissues and the younghatch after several days. Adults are excitable andfly if disturbed. Pupation occurs in the soil usu-ally at the base of the plant. This pest alsodamages watermelon, muskmelon, bottle gourd,cucumber, chili pepper, tomato, and potato crops.

Scientific name: Thrips palmi12

Adult

Damageto leaf

Damage to fruit

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Aphid

Damage symptomsAphids attack eggplant during the cool dry sea-son. Initially, damaged leaves show generalyellowing. Young leaves become curled whenaphids are numerous. Plants become covered witha black sooty mold and remain stunted.

Insect characteristicsAphids are tiny soft-bodied insects, 1.0–1.5 mmin length. They are yellowish and have two tubesprojecting from their abdomens. Aphids piercethrough the leaf surface and suck the plant’s juice.They secrete a sugary substance, which falls onleaves and on which a sooty black mold fungusgrows. Older aphids sometimes develop wings.

Where to lookLook on the lower surface of leaves. Initially theyare always on lower leaf surfaces, but if the popu-lation increases rapidly they can move to upperleaf surfaces, stems, and flowers.

Life cycleUnlike most insects, aphids do not lay eggs. Theygive birth directly to tiny aphids of which all arefemales, at least temporarily. These baby aphidsbecome adults in a week’s time and start produc-ing a new generation. Aphids feed on numerouscrops including tomato, bell pepper, and cotton.

Scientific name: Aphis gossypii

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Close-up ofadults

Sooty molddamagesymptom

Adults onleaves

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Whitefly

Damage symptomsWhitefly feeding causes chlorotic spots on leaves.If the insect population is high, these chloroticspots coalesce until the leaf appears yellow withgreen veins. Nymphs secrete a sticky honeydewsubstance when feeding, which covers leaf sur-faces and flowers. Plant growth is stunted.

Insect characteristicsAdults live on the lower leaf surface, flying shortdistances when disturbed. Minute circular eggshatch into flat oval scale-like nymphs, which arestationary when feeding. Nymphs are less than 1mm long and adults slightly over 1 mm long.

Where to lookThe easiest way to find whiteflies is to brush orshake the leaves and look for the whitefly adultsthat fly off. Inspect the undersides of the leavesfor the stationary immatures.

Life cycleEggs are laid on the lower leaf surface usually ingroups. Eggs hatch into nymphs, which feed bysucking plant sap. Female adults may lay up to160 eggs each, leading to a rapid increase in popu-lation, especially since each generation iscompleted in only 10–15 days. There may be upto 15 generations per cropping season.

Scientific name: Bemisia tabaci

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Whiteflies on leaves

Nymphs and winged adult

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Natural enemies

In nature, insects are plagued by numerous liv-ing organisms that feed upon them. These arecalled natural enemies or beneficials and are ofgreat value to eggplant growers. Natural enemiesinclude predators such as mantids, lady beetles,earwig, green lacewing, and spiders. Thesebeneficials can be seen during the day feastingon a wide variety of pests and other insects inthe field. In addition, there are tiny wasps calledparasitoids, the larvae of which feed on the pestinsect and kill it from within. Many natural en-emies look similar to insect pests and they shouldnot be mistaken.

Care should be taken to allow beneficials to thrivewhenever possible. Chemical pesticides used inkilling pest insects will also kill most beneficialinsects. Sometimes natural enemy populationsbuild up slowly and a resurgence of the pest aftera pesticide application can occur. In addition,when the natural balance between the beneficialand pest complexes is disrupted, a different, pre-viously minor, pest species can unexpectedlycause major damage. Therefore, utmost careshould be taken to use a pesticide that targetsthe pest insect and does not harm the naturalenemies, if possible.

Bacteria, fungi, nematodes, viruses, and proto-zoans also kill insect pests. Each of these is animportant component of the natural biologicalcontrol system.

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Ladybird beetle larva and adult

Mantid

Predatory bug

Spider

Earwig

Trathalaflavo-orbitalis

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Removinginfested shoots

Pheromone trapPublication oncontrol of EFSB

How to control insectpests of eggplant

Eggplant fruit and shoot borer (EFSB) is by farthe most destructive pest of eggplant in Southand Southeast Asia. The combination of weeklycutting and destruction of pest-damaged shoots,using sex pheromone-baited traps, and withhold-ing the use of chemical pesticides has proven tobe a very effective and economical strategy in con-trolling this pest on a sustainable basis. For moreinformation, refer to AVRDC publication “Control-ling eggplant fruit and shoot borer” or visit ourwebsite at <www.avrdc.org>. For the control ofother eggplant insect pests, please read and fol-low local government recommendations in yourarea.

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Pest control notes

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