PEST IN CUCURBITATIOUS VEGETABLES – CUCUMBER, WATERMELONS, SQUASH AND PUMPKIN, GUARDS – Free Online Studymaterial

Insects
family of chiefly herbaceous tendril-bearing vines (order Campanulales) that are characterized by an inferior ovary and anthers usually united and that include food plants (as the cucumber, melon, squash, and pumpkin), drug plants (as the colocynth), and ornamental plants (as the gourds)


Fruit flies (Tephritidae: Diptera)

Bactrocera dorsalis: 

Adult is a reddish-brown fly with lemon-yellow curved vertical markings on thorax and fuscous shading on outer margins of wings.

Bactrocera cucurbitae:

It is often a polyphagous pest attacking melons, gourds, cucumbers and pumpkins. Adult fly is bright brown or ferrugineus-brown with hyaline wings and two round dark-brown spots on fourth abdominal segment.

  • Fruit fly attacks fruits of all types of cucurbits and is a very serious pest.
  • Maggots tunnel and feed within fruits and cause damage. 
  • Infested fruits decay aided by bacterial action. They rot and drop down. 
  • Fly prefers tender fruits. 
  • Adult also causes injury by making oviposition puncture on the soft and tender fruits through which fruit juice oozes out. 
  • More than 50 per cent loss is caused to vegetables by this fly. 
  • Eggs are laid in the fruit in a cavity 2-4 mm deep, singly or in clusters of 4-10 and sealed with a gummy secretion from ovipositor. 
  • Egg period lasts from 1 day in summer to 6-9 days in winter. 
  • Maggot bores into fruit feeding on the internal contents. 
  • Larval life varies from 3 days to 3 weeks. 
  • When full fed, maggot falls to ground to pupate in soil. Pupal period is 6-15 days. 
  • Fly breeds throughout the year under equable climates and except during January and February when it is very cold in North India. 
  • Flies congregate under leaves of plants in winter; they become active when warm weather approaches. 
  • Peak population is observed during rainy months of July and August and generally low during dry period. 



semilooper Plusia peponis

(Noctuidae: Lepidoptera)

  • This is a serious leaf feeder of snake-gourd all over the country. 
  • Adult is a stout dark-brown moth with golden sheen.
  • Eggs are laid singly on the tender leaves.
  • Larva is a greenish semilooper. It is humped on its anal segment. It hides within a leaf fold and feeds on the leaf blades.
  • Pupation takes place in a leaf fold within a thin cocoon. 

Pumpkin beetles (Galerucidae: Coleoptera)


Red pumpkin beetle- Aulacophora foveicollis 

Grey pumpkin beetle- A. cincta 

Blue pumpkin beetle– A. intermedia

  • Adults feed voraciously on leaf lamina and make round to irregular holes. 
  • Grub bores into roots, stems and later into the leaves and fruits lying on the ground. 
  • Damage is caused mainly by adult beetles, which feed extensively on leaves, flowers and fruits making holes and cause death or retardation of growth. 
  • Seedlings, when infested, are totally destroyed. 
  • Damage done by grub to the seedling also is serious. 
  • Freshly hatched grubs of all three species are dirty white and full-grown are creamy yellow. It is the most destructive pest of all cucurbitaceous vegetable crops. 
  • Adults lays spherical eggs singly or in batches in the moist soil around the base of the host plants. 
  • As many as 300 eggs laid by a female. 
  • It undergoes four instars entering soil each time to moult. 
  • Mature larva enters soil and pupates. 
  • Adults live for more than one month.
  • They hibernate under old cucurbitaceous creepers, grasses, weeds and in soil. 


Stem borer or clear winged moth, Melittia eurytion (Aegeriidae: Lepidoptera) 


  • Moth is clear winged with fan-like tufts of hairs on hind legs. 
  • Larvae bore into the main stems producing long galls
  • Frass comes out of the gall through a hole made on it. 
  • Attacked plants are stunted with poor foliage. 
  • Larva is white. It drops to ground and pupates in an earthen cocoon.


 Pumpkin caterpillar, Diaphania indica (Pyraustidae: Lepidoptera)

  • It is a destructive pest on melon, cucumbers, gourds and other cucurbits. 
  • Adult has transparent whitish wings with broad and dark marginal patches and a thick and orange-coloured anal tuft of hairs in the female. 
  • Eggs are laid singly or in groups on the lower surface of leaves. 
  • Larva is elongated, bright green with a pair of thin white longitudinal lines mid-dorsally. 
  • It binds together the leaves and feeds upon them. 
  • Ovaries and young developing fruits are also eaten up or damaged. Affected flowers bear no fruits and infested fruits become unfit for consumption. Pupation takes place in a cocoon spun among the leaves. 

Stem boring grey beetle, Apomecyna saltator (Cerambycidae: Coleoptera)

  • In South India, it attacks Coccinea vines, which die as a result. 
  • Adult female is a white spotted greyish- brown longicorn beetle and the male is smaller and black. Eggs are laid singly on internodes below the bark
  • Grubs bore into the long trailing stems at or near a node and tunnel inside. 
  • Adult beetles gnaw the leaf petioles and soft parts of the stem. 


Leaf footed bug Fabrictilis australis (Coreidae: Hemiptera) 

  • Adult is a long black bug. Its adults and nymphs suck sap as a result of which tender vines die, leaves dry up and tender fruits wither and get malformed.

Stink bug Cordius janus Pentatomidae: Hemiptera) 

  • It is a large red and black bug found clinging to the leaves and tender shoots in large numbers. Nymphs and adults suck sap from the tender parts and thereby devitalize the plants and retard their growth. They also emit a characteristic buggy smell. 

Stem gall fly Neolasioptera falcata (Cecidomyiidae: Diptera): 

  • Maggot feeds within distal stems of bitter-gourd, ribbed and smooth gourds causing formation of elongated galls in between nodes Gall formation causes stunting of plants. 

Flower feeder Mylabris pustulata (Meloidae: Coleoptera): 

  • Beetle feeds on pollens, petals of flowers and flower buds, as a result, fruit setting is affected. 
  • It has three black and three reddish orange bands running horizontally and alternately on elytra. 
  • When disturbed, beetle exudes an acrid yellow fluid which contains cantharidin, which is irritant to touch and causes blisters on human skin-hence the name.

Red spider mites Tetranychus neocaledonicus (Tetranychidae: Acarina)

Plume moth Sphenarches caffer (Pterophoridae: Lepidoptera)

Aphids Aphis gossypii (Aphididae: Hemiptera)

Spotted leaf beetle Epilachna vigintioctopunctata (Coccinellidae: Coleoptera)

Serpentine leaf miner, Liriomyza trifolii (Agromyzidae: Diptera)

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