eChapters

Diamond back moth: Plutella xylostella: Plutellidae
 
The adults of this moth are small, greyish brown having pale whitish narrow wings and with inner margins yellow. There are three pale whitish triangular markings on hind margins of each forewing. At rest, when both forewings come together, they form a dorsal median patch of three diamond shaped yellowish white spots that give them their name diamond back moth. Hind wings have a fringe of long hairs.

Shoot and fruit borer: Leucinodes orbonalis: Pyraustidae

The pest is active throughout year, but more during monsoon period. Heavy losses up to 60% can occur.

The adult is a greyish brown medium sized moth with white and hyaline wings, having triangular brown and red markings on forewing. A crescent shaped mark facing outside at the apical margin is typical for the species. About 150-250 creamy white eggs are laid singly on leaves, tender shoots, flowers and developing fruits. Egg period is 3-5 days and the hatched larva completes its life in 15 days with 5 instars.

Shoot and fruit borer: Earias vitella (=E.fabia), E. insulana: Noctuidae

This is a pest on cotton, bhendi, hibiscus, holly hock and other malvaceous vegetables. The damage is due to the larva that bores into tender terminal shoots in the vegetative stage and flower buds;  flowers and young fruits in the fruit formation stage.  The damaged shoot drops, wither and dry up.  The infested fruits have bore holes, are deformed and become unfit for consumption.  Bore holes are plugged with excreta.

Amaranthus stem weevil: Hypolixus truncatulus :Curculionidae
 
It is an important pest of amaranthus and is widely distributed in India. It attacks both wild and cultivated amaranthus, especially the leafy varieties with large leaves. Hence, management involves destruction of unwanted, weedy wild amaranthus plants, to reduce the breeding place for the weevil. Adults are ash-grey in colour, with elbowed antennae and brown elytra. Females lay eggs singly in holes made on the stem, branches, petioles or midribs. Eggs are smooth, oval and pale yellow in colour. Incubation period is 3 to 8 days.

Sweet potato weevil: Cylas formicarius: Apionidae

It is a specific pest of sweet potato and the most important one. Adult weevils are ant-like, slender bodied having elongated snout-like bluish-brown head with geniculate antenna, bright red thorax and leg tips and bluish-brown elytra. Females make small cavities on the tubers or stems and lay eggs singly. Each female lays 180-200 eggs. Grubs are elongate, legless, pale-yellowish white in colour with smaller brown head. Pupation takes place in larval tunnels in the tuber. Incubation, grub and pupal stages last for 5 to 8, 14 to 17 and 4 to 5 days respectively. Life cycle is completed in 4-5 weeks and adults live for 95-110 days. The grubs bore into stems, tunnel inside and feed on soft tissues. Grubs and adults bore into tubers both in field and storage godowns. Affected tubers develop dark patches, which later start rotting. Feeding holes and adult emergence holes can be seen on vines and tubers.  In severe infestation the collar region of the plants shows unusual thickening due to proliferation and hypertrophy of tissues causing a characteristic terpenoid odour.  Even the slightly damaged tubers are unsuitable for cooking and consumption.  Hence yield loss in practice may come to 100% in many cases.

Aphids: Myzus persicae, Lipaphis erysimi and Brevicoryne brassicae Aphididae
 
Aphids suck the sap from potato foliage, causing wrinkling, cupping and downward curling of young leaves. The older leaves will become yellow, wilt and fall off.  They also excrete honeydew on which sooty mould develops covering affected parts with a thin superficial black coating that hinders photosynthetic activity of leaves resulting in stunted growth of plants. In addition, they also act as vectors, for transmitting potato leaf roll virus. Major damage by M.persicae and A. gossypii is through transmission of potato leaf roll virus.

Leaf-and shoot folders: Hymenia recurvalis : Pyraustidae

Pycnarmon cribrata;Phostria piasusalis

Cassava scale : Aonidomytilus albus: Diaspididae

White elongated scales appear in colonies on stems. Plants die in the field and under storage.  Stem becomes weak and dry, causing side branching to give bushy appearance.  Viability of planting material is reduced, resulting in poor establishment.

Aphids: Aphis gossypii :Aphididae

The aphids congregate on growing points and suck the sap. Honey dew secreted by the aphids can cause sooty mould in severe infestation. Attack leads to yellowish speckling and curling of leaves.
 
Thrips: Caliothrips indicus: Thripidae

Characteristic silvery white specks with black dots which are mostly faecal pellets, develop on leaves. Consequently, the leaves dry up.

Pollu beetle: Longitarsus nigripennis:Chrysomelidae

This pest is monophagous to pepper and no alternate host has been reported so far.

Nature of Damage

Adult is a shining blue flea beetle with yellow head and thorax and has thick enlarged femur and tibia. The adult beetle is only the size of a pin head.  The infested berries dry up and turn dark in colour. Berries become hollow and crumble when pressed and such hollow berries are called “Pollu” meaning empty. The eggs are laid on the berries @ 1-2 eggs in each hole. Eggs hatch in 5-8 days. The grub period extends for 30-32 days. The emerging grubs feed on the berries of pepper and consume the internal contents.

Thrips: Thrips tabaci: Thripidae

The nymphs and adults of the thrips desap from the narrow spaces between the inner leaf axils. Leaves are faded, with curled tips and shining silver streaks or brown spots.  Many minute yellow or white insects are seen moving, generally near the base or middle of leaves and they suck the sap from the plants.  Plants are faded and the yield is reduced.

Scale insects:Pseudaulacaspis cockerelli, Parasaisettia nigra:Coccidae

Attack Adults and nymphs feed on plant sap and cause wilting and drying of seedlings and young plants.
 
Brown soft scale: Lecanium sp. (=Coccus) hesperidum : Coccidae

Grasshoppers: Mecopoda elongata :Tettigonidae; Oxya velox: Acrididae

These pests occur both in nurseries and plantations. Both adults and nymphs feed on leaves by scrapping and eating outer tissues and margins. The emerging leaves are nibbled and the spot holes appear when the leaf unfurls. In severe conditions the entire leaf is eaten leaving behind only the midrib.

Shoot borer: Conogethes punctiferalis: Pyraustidae

The main damage done by the caterpillar of this pest is to bore holes in the pseudostem and to plug it with excreta, causing dead hearts. Larva is pale greenish with pinkish tinge and dark head and has fine hairs on the body with a pro thoracic shield. Adult is a medium sized moth, pale yellowish with small black spots on the fore and hind wings.

Management involves spraying dimethoate or malathion 1.5 ml/lit or phosphamidon 0.75 ml/lit of water. This is mainly intended to manage the adults flying in the crop canopy and the first instar caterpillars that are seen on the outside of the plants and before thsy enter the pseudostem. The spray has to be given at the very first spotting of dead haearts.

Coriander aphid: Hyadaphis coriandri: Aphididae

Coriander aphids are yellow-green in color, dusted with grayish wax. They have short, dusky, slightly swollen, siphunculi (or cornicles). The Aphids form dense, damaging colonies on leaves, heads, and stems of their host plants.

In its native land, Florida, USA, the life cycle of the coriander aphid is similar to that of other host-alternating aphids. Overwintering eggs occur on other hosts.  A fundatrix (or stem mother) hatches from the egg in the spring. Her offspring are parthenogenetic, and the winged-females are spring migrants. They colonize summer host plants in the family Umbelliferae.

Stem-borer: Sahyadrassus malabaricus: Hepialidae

Presence of the pest is understood when chewed tissue is seen at at the col­lar region. The mouth of the tunnel in which the borer feeds show pieces of bark, wood and frass particles held together by silk. The saplings break off at the point of injury. When the main stem is attacked, there is mat-like frass at basal region of stem. Larvae girdle main stem and bores downward killing the tree.

Adult moth is peculiar and hangs vertically down by the support of two pairs of legs. Egg period is for 7-10 days, and larvae live for about 10 months inside the larval tunnels. They pupate for 3-5 weeks.

Cinnamon butterfly: Chilasa clytia clytia : Papilionidae

Larvae defoliate plants. The larvae are pests on many crop plants and weeds and are common in the plains. The larvae are jet black at hatching. They develop a series of broad white patches. The adult is a common butterfly rich velvety brown, and spotted with white dots. The hind wings have arrow shaped streaks and crescent shaped spots.

Cardamom thrips: Sciothrips cardamomi: Thripidae

Thysanoptera

This thrips attacks other crops like amomum,  tea, colocasia, grapevine, castor, cotton, ginger and turmeric also. The thrips are minute greyish brown insects with fringed wings. They breed on unopened leaves, spindles, leaf sheath, flower bracts and floral tubes .

Scale insect: Lepidosaphes sp.: Diaspididae

The mature scale is elongated and oval in shape and dark grey in colour. They infest the stems, leaves and petioles, causing shriveled leaves due to sucking of the sap. The affected parts wither and dry up. In severe infestation leaves dry up and give sticky look and gradually the vine wilts.

Tea tortrix/flushworm: Homona coffearia:Tortricidae

The tortrix is  an important pest of tea leaves. The larvae make leaf nests by webbing the leaves using silken threads and feed from inside. A single caterpillar makes several cases. Young larvae prefer tender leaves, while the older larvae are seen in mature leaves. The economic produce being the leaves, and since chemical control is not advised, especially during the picking phase, the pest becomes a management problem.

Spindle bug: Carvalhoia arecae :Miridae

Nymphs and adult bugs suck the plant sap from spindle leaf and tender leaves.  Feeding marks are seen as necrotic lesions in the spindle and fully opened leaves.  The pest is seen in the nursery plants round the year but incidence is high during rainy season.

Coffee is an important cash and export crop for small-scale farmers. The crop suffers heavy yield losses due to damage caused by a wide range of insect pests
 
White stem-borer : Xylotrechus quadripes : Cerambycidae

This is one of the important and serious pests of arabica coffee. Other types are also attacked to a slightly lesser extent. The adult is a dark-brown longicorn beetle having several white markings on the elytra and thorax.

Though the coconut palm is subjected to attack by a number of insect and non insect pests although only 8-10 species of insect pests are considered to be important. Others assume importance, once in a while at isolated locations.

Major pests

The major pests of coconut include the rhinoceros beetle, red palm weevil, black headed caterpillar, root grub and the perianth mite.

Cacao Mealy Bug : Planococcus lilacinus : Pseudococcidae

The adult female mealy bug is 3.9 mm in length and 2.25 mm in width. Eggs are laid on the plant parts within a mass of tangled waxy strands, a female laying 50 to 300 eggs. The eggs hatch in less than 6 hours and the nymphs feeding on the plant juice become full-grown in 20-25 days with a mean of 23 days in the case of females and 17 to 20 days for the males. The male nymph assumes a pupal period which lasts for 4 to 6 days and the adult male is winged. They live for 2-3 days while the adult female has longevity of 12 -16 days. The females dominate the population, 67.6 per cent of the crawlers developing into female mealy bugs.

The Tea mosquito bug : Helopeltis antonii : Miridae

The host range of this bug also includes tea, neem, moringa and guava. The attack can cause inflorescence blight, terminal drying of young shoots and heavy yield loss. The adult is a reddish brown bug with black head, red thorax, and black and white abdomen. The easiest identifying character for this pest is a pin like process on the scutellum mid dorsally on the thorax. It is reddish brown, erect and knobbed, and would seem as a pin inserted into the scutellum.

Spindle bug: Carvalhoia arecae :Miridae

Spindle bug is a serious pest multiplying rapidly with the close of monsoon. The adults are red and black and nymphs are greenish in colour with reddish brown patches. Both these stages colonize the top-most leaf axils at the base of the spindle. Adults and nymphs suck the sap from emerging spindle, tender leaves and other tender parts. For feeding they move out and later return to the axils again. At the site of feeding a longitudinal narrow, decolourised zone develops rapidly on either side of the puncture, along the length of the leaf blade. The decolourised patch gradually turns yellowish, then brownish, become stunted, twisted and malformed in a few days and dries up. In this way the tissues may break away and drop off in the wind leaving shot holes on the leaves. In cases of severe infestation the leaves get shred, stand erect and the palms become stunted.

Thrips: Thrips tabaci : Tuberose thrips Franklinella schultzei: Thripidae

These minute insects, preferring hot humid weather, rasp and suck the cell sap, causing bronzing, withering and drying up of leaves and flowers. This is the most serious pest on tuberose. Damage to young plants results in stunted growth.

Hard Red scale: Aonidiella aurantii :Diaspididae

Both adults and young scales suck the sap from the stem and cause spot yellowing and loss of vigour of the plant. Infested shoots bear reddish brown encrustations of the scale and in case of severe damage the shoots dry up.

Biosduval Scale/Orchid scale : Diaspis boisduvalii : Diaspididae

These scales are round flat and yellow in colour. Only the first instar crawlers move. The others are sedentary. The young and mature scales suck the juice from the leaves, petioles and shoots and also inject toxins into the plant. Affected plants turn yellow in patches, lose vigour and get stunted.

Bud caterpillars : Helicoverpa armigera : Noctuidae

Eggs are laid singly on young buds.  Larvae feed on developing flowers by damaging florets. They can also eat the leaves.

Leaf webber : Phycita sp. : Phycitidae

Larvae of Phycita sp. feed on heads of buds and flowers.

Bud-worm : Hendecasis duplifascialis : Pyraustidae

This pest is serious on J.sambac. The larvae are dark green with black head which bores into immature buds.  They make a hole on the buds, and feed inside, leaving behind faecal pellets entangled in few silk strands. Webbing is seen in severe infestation and pupation takes place in soil.

Thrips : Taeniothrips simplex : Thripidae

Yellow coloured nymphs and black adults damage leaves and spikes by rasping tissues and sucking the sap.  Affected leaves and spikes develop silver streaks, turn brown, get deformed and dry when attack is severe.  Corms in storage are also attacked. Infested corms are sticky, get shriveled and produce weak plants.

Spikeborer : Helicoverpa armigera : Noctuidae

Larvae of this polyphagous moth feed on the spikelets, flowers and developing seeds. The young larvae bite holes into the spikelets and the grown up ones attack the mature spikes

Chrysomelid beetle : Aulacophora foveicollis : ChrysomelidaeAphids : Macrosiphoniella  sanborni; Myzus  persicae; Brachicaudus  helichrysi; Aphis  gossypi; Aphis fabae; Aulocorthum circumflexum: Aphid

Chrysanthemum   is infested by different species of aphids. Aphids are small, soft bodied insects and their colour varies with species. Both nymphs and adults cluster on the growing stem tips and under surface of leaves. As a result, the plants show loss of vigor, distortion of leaves and flowers, yellowing, premature leaf fall and stunted growth. The damaged plants bear only undersized buds and they remain unopened. Peak damage period is November-December. Secretion of honeydew by the aphids favor development of sooty mould which hinders photosynthesis and the plants become stunted. They are also vectors of virus diseases.

Chrysomelid beetle : Aulacophora foveicollis : Chrysomelidae

Adults cut tender shoots and feed on leaves resulting in holes and loss of leaf. Grubs feed on roots and underground stems leading to yellowing,wilting and drying of attacked plants.

Aphids: Myzus persicae : Aleyrodidae

Aphids are considered as the most serious pest of carnation. Both adults and nymphs suck sap from the leaves and debilitate the plants. They transmit carnation ring spot and carnation mosaic virus disease. They are thus more important as vectors. Regular monitoring for the incidence of the aphid and spot spray-ings of contact insecticides on the shoot tips can easily manage the pest.

Thrips – Chaetanaphorothrips  orchidii, Thripidae: Thysanoptera

It is a polyphagous feeder that attacks other ornamentals, herbs, fruits, vegetables, grasses, and weeds, but shows preference for Anthurium species. It is a widely distributed species infesting green houses and out door landscapes.

Both adult and immature thrips start feeding within unopened Anthurium spathe. Damage appears as white streaks on the upper and lower surface of the spathe, resulting in deformed spathe and bronzing of the injured tissue with age. In severe cases, spathe  fails to open and the foliage may be deformed with streaming and bronzing and thereby reduced plant growth.

Scale: Saissetia coffeae: Coccidae

Scale insects

Brownish black scale infests lower surface of leaves along with mid ribs and mid veins.They also cover petioles and tender shoots.  Due to draining of sap, leaves turn yellow and drop, plants become stunted.

Sphingid larva: Dilephila nerii :Sphingidae

The large larvae cause severe damage to plants by feeding extensively on leaves, buds and flowers.They are very big and can easily be hand picked and killed or fed to poultry.

Leaf webber: Syngamia abruptalis :Pyralidae
 
Caterpillars feed extensively on tender foliage leaving veins alone and the growth of the plants are affected.

Leaf roller: Psara stullalis: Pyralidae

Larvae of these small moths are also leaf Webbers and rollers, and rolls the leaves and feed inside causing browning and drying of affected leaves. Inspect the crop for the pest incidence and remove the initial attacks systematically.

Cut worms: Agrotis suffusa: Noctuidae

Adult moth lays eggs in moist soil or on lower side of leaves.  Dark brown larvae cut young plants at ground level and shoot of grown up plants. Damage results in growth retardation of plants and reduced yield.

Cabbage semilooper: Thysanoplusia orichalcea :Noctuidae

Eggs are laid singly on lower surface of leaves.  The emerging larvae feed as a scraper initially and then feed voraciously on the leaves. The larva is greenish and hence not easily noticed initially. But when patches of damage occur in the crop, examine for the larvae and remove and destroy all the larvae. Chemical control is not advisable, and spraying extracts of other aromatic plants can deter egg laying very well.

Shoot borer: Chilo infuscatellus : Pyralidae

This pyralid is more commonly known as a pest of sugarcane. Eggs are laid in batches on lower side of leaves.  The emerging larvae move down and cut a hole at the ground level and enters the stem.  Due to feeding of larva, the central shoot begins to wilt and dry causing dead heart. The yield of the crop is affected.New tillers may develop but will not have the physiological maturity and oil content at the time of harvest.

The cotton aphid: Aphis gossypii: Aphididae

Symptoms of Damage

Both nymphs and adults cause the damage by sucking the plant sap from shoot tips, pods and leaves. Severe infestation may result in complete drying of affected parts. Attacked leaves curl up, wither and fall. These are yellowish green or brown coloured aphids. The total life cycle from first instar nymph to adult occupies an average of 8-10days. It reproduces parthenogenetically and viviparously. The female may produce 10-30 young ones in a life span of 10-12 days. The nymphs transform into adult in 5-8 days after passing through four moults. 

The cotton aphid :Aphis gossypii: Aphididae

Both nymphs and adults cause the damage by sucking the plant sap from shoot tips, flowers and leaves.  Severe infestation may result in complete drying of affected parts.  Attacked leaves curl up, wither and fall. These are yellowish green or brown coloured aphids.  The total life cycle from first instar nymph to adult occupies an average of 8-10days.  It reproduces parthenogenetically and viviparously.  The female may produce 10-30 young ones in a life span of 10-12 days.  The nymphs transform into adult in 5-8 days after passing through four moults.

Thrips : Thrips flavus : Thripidae

Infestation of thrips is generally during hot months with high night humidity.  The attack by thrips leads to discolouration, bronzing and drying of affected leaves.

Semilooper : Thysanoplusia orichalcea  : Noctuidae

Bluish green or grey coloured eggs are laid singly on lower surface of leaves.  Larvae feed voraciously on leaves and defoliate plants.

Semilooper: Thysanoplusia(Plusia) orichalcea : Noctuidae

Bluish green or grey coloured eggs are laid singly on lower surface of leaves.The larvae are semi loopers and feed voraciously on leaves and cause defoliation of the plants.

Lace wing bug: Monantha globulifera : Tingidae

Eggs are inserted slantingly into leaves and other tender foliage.  Black spiny nymphs and lace winged adults suck the sap from leaves. Attacked leaves develop yellow patches become brown, shrivel and dry up in severe cases.

Leaf feeder : Helicoverpa armigera : Noctuidae

The female moth lays eggs on tender foliage. Young larva feeds on tender foliage and starts infesting the older ones in later instars. A single caterpillar can destroy many leaves

Withania somnifera, also known as Ashwagandha, Indian ginseng, Winter cherry, Ajagandha, Kan-aje Hindi, Amukkara in Tamil and Samm Al Ferakh, is a plant in the Solanaceae or nightshade family.

Grasshoppers : Trilophida an- nulata : Acrididae

The nymphs and adults of this grasshopper feed on the margins of leaves of Aswagandha. It is only a minor pest, nibbling on the leaves.

Spotted boll  worms/ Shoot and fruit borer: Earias vitella (=E.fabia), E. insulana: Noctuidae

This is a pest on cotton, bhendi, hibiscus, holly hock and other malvaceous vegetables. Moths lay eggs singly in leaf axils, bracts and leaf veins and on under surface. Larvae bore into tender shoots, buds, flowers and fruits and feed on internal contents.  Damage results in drooping of shoots and shedding of buds and flowers. The infested fruits have bore holes, are deformed and become unfit for consumption.  Bore holes are plugged with excreta.