Jackfruit Insect Pests

Shoot and fruit borer

Biology

• Egg: Females lay more eggs and develop faster during the flowering and fruiting period.
• Larva: The caterpillar is reddish brown with black spots and bores into the tender shoots and developing fruits, occasionally causing substantial damage.
• Adult: The adult moth is pale brown with a number of dark brown spots, and orange stripes outlined in dark brown, on each wing

Life cycle:

Damage symptoms:

• The fruit borer causes about 30─40% damage in jackfruit from flower bud formation up to fruit ripening.

Natural enemies of shoot and fruit borer :

Parasitoids: Bracon sp.,chelonus sp., Systasis sp.

Spittle bugs

Biology:

• Eggs: Pine spittlebugs overwinter as eggs inserted in dead twigs or slits cut into the bark of living stems. The eggs hatch in early May and the young nymphs migrate to the tender one-year-old growth.
• Nymphs: The nymphs begin to produce the frothy spittle from their anus. The spittle apparently protects the nymphs from predators, parasites and dry weather. As the spittle drops onto lower branches, black sooty mold may cover the needles. The young nymphs are yellowish with black markings; older nymphs become more brown. Several nymphs may join together in one large spittle mass and the nymphs constantly abandon old masses to make new ones. The nymphs mature by July and soon leave the spittle in order to molt into the winged adult.
• Adults: The adults do not form spittle masses but quickly jump and fly if disturbed. The adults are mottled gray with two faint parallel lines running across the wings.

Life cycle:

Damage symptoms:

• Larvae feeds on twigs of the tree

Mealy bug

Biology:

• Eggs: Females lay their eggs directly on the host in a fluted ovisac that is attached to the body of the adult female. Inseminated eggs produce hermaphrodites and uninseminated eggs produce males.
• Nymphs: The first instar nymphs are also called as crawlers, which are mobile. They settle on the plants, start sucking the sap and form the colonies.
• Adults: Females actually are hermaphrodites that frequently inseminate themselves. Adult males mate with females, but it is not clear if their sperm are used for reproduction.

Life cycle:

Damage symptoms:

• The adult bugs are covered with whitish powder and colonize between bark of tree trunk, young shoots and panicles.
• The nymphs’ ascent the trees and settle on inflorescence causing flower drop, affecting fruit set.
• They also excrete honey dew, a sticky substance, which facilitates development of sooty mould.

Natural enemies of mealybug:

Predators: Menochilus sexmaculatus, Rodolia fumida, Cryptolaemus montrozieri

Bud weevil

Biology:

• Egg: The egg is pearly white, smooth and oblong oval measuring on an average 0.42mm.in length and 0.28mm. in width.
• Grub:The eggs hatch in 3 to 4 days and the newly hatched legless grub is pale white with a pale brown head and measures 0.56mm in length. It bores through the tissue in all directions and becomes mature in 12 to 15 days. The full-grown grub is whitish in color measuring 4-9mm. in length. It head is light brown but darker at the frontal region and much narrower than thorax and with a conspicuous dark line in frons.
• Pupae: The pupal stage lasts for 5 to 6 days. The adult emerges by boring a hole on the outer skin.
• Adults: The adult is a small, active, greyish brown weevil measuring 3.5mm. in length and 1mm. in breadth, with the whole body thinly clothed with fine setiform golden scales and set with suberect setae and elytra bearing numerous irregular and ill-defined small bare spots. It is often found in groups feeding on the tissue inflorescence.

Life cycle:

Damage symptoms:

The bud weevil (Ochyromera artocarpi) is a specific pest of jackfruit. The small whitish grubs bore into tender flower buds and fruits, and induce premature drop. These greyish brown adult weevils are found nibbling the leaves

Bark eating caterpillar

Biology:

• Egg: Females lay about 2000 eggs in clusters of 15-20 on the bark of the host tree. Eggs hatch in 8-10 days.
• Larvae: Caterpillars are about 50-60 mm long with dark brown heads and with dirty brown bodies. Larvae become full grown by December but continue to feed slowly until April.
• Pupae : Pupae are 16-20 mm long, stout, reddish brown with two rows of spines on each abdominal segment. Pupation takes place in April and pupal period varies between 21-31 days.
• Adults : Adults are pale brown with head and thorax dark brown, abdomen, fore-wings pale reddish brown with numerous dark brown bands.

Life cycle:

Damage symptoms:

The newly hatched larvae nibble the bark of the tree and after 2-3 days bore into the same and feed. This disturbs the continuity of flow of sap which results in poor growth and less fruiting. Silk webs which consist of excreta and chewed wood particles can be seen, more commonly at the junction of two branches, hanging on the bark of infested trees.

Aphid

Biology:

• Eggs: Eggs are white in colour and laid along the veins of leaves.
• Nymphs: There are four nymphal stages (instars). The general appearance of each stage is similar except for increase in size during subsequent instars. The first, second, third and fourth nymphal stages last 1-2, 2, 2, and 3 days respectfully.
• Adults: Aphids are small, soft-bodied, pear-shaped insects that have a pair of cornicles (waxsecreting tubes) projecting out from the fifth or sixth abdominal segment.Wingless, female, aphids are yellowish green, gray green or olive green with a white waxy bloom covering the body. The winged, female, adult aphids have a dusky green abdomen with dark lateral stripes separating the body segments and dusky wing veins.Male aphids are olive-green to brown in color. The aphid attacks generally during 2nd and 3rd week of December and continues till March.

Life cycle:

Damage symptoms:

• Both nymph and adults suck the sap from leaves, buds and pods.
• Curling may occur for infested leaves and at advanced stage plants may wither and die.
• Plants remain stunted and sooty molds grow on the honey dew excreted by the insects.

Leaf webber

• Eggs: The eggs are minute, measuring only about 0.4–0.6 mm in width and 0.8 mm in length. The shape varies from spherical to flattened. Their color is white initially, but changes to yellow after about 24 hours. The eggs are distributed in small clusters, usually two to seven per cluster. They are deposited principally on the buds, flowers, and other actively growing portions of the plant. Hatching occurs in about four days. Egg production to be 300–400 eggs per female.
• Larva: There are five instars. Total larval development time averages 14 days. Mean duration (range) of each instar is about 2.5 (2-3), 2 (1-3), 2 (1-3), 2.5 (2-3), and 5 (4-7) days, respectively. Prior to pupation larvae tend to turn a dark copper color. When mature, larvae often attain a length of 2.5 cm.
• Pupa: Pupation usually occurs in a leaf fold; often dead, dry material is used. There is only weak evidence of a cocoon, usually just a few strands of silk. The pupa is elongate, measuring about 13 mm in length and 4 mm in width. It is light brown to dark brown in color, and tapers to a point at both ends. Pupation usually lasts about eight to nine days.
• Adult: Emerging moths fly during much of the evening hours, but most flight occurs three to five hours after sundown, with peak flight at approximately midnight . he female moth produces a pheromone that attracts males, with peak production occurring at five to seven hours after sunset.

Life Cycle:

Stem borer

Biology:

• Egg: The female cuts the tree bark and lays eggs singly into these cuts, laying a total of up to 200 eggs. Egg is a brownish-white cylinder, 6.2 mm, with narrowly rounded ends. On hatching the larvae start to tunnel into the sapwood of the trunk or branches.
• Larva: Larval development takes about 2 years. As a very large species, the larval tunnel measuring 2 or 3 centimeters in width that is correspondingly large and very damaging to the tree. The larvae tunnel through the sapwood and because of their size, they make large tunnel which interfere with sap flow and affect foliage and fruit production.
• Adult: The adult beetle emerges by a short tunnel running to the exterior and ending in a circular exit-hole. The maximum life recorded for the adult is eight months.

Life cycle:

Damage symptoms:

• Grub tunnels in the sapwood on the trunk or branches
• Grub bore into the sap wood and making irregular tunnels.
• Feeding the vascular tissues
• interruption of nutrient and water transport on the tissue
• Drying of terminal shoot in early stage
• Frass comes out from several points and sometimes sap oozes out of the holes
• Wilting of branches or entire tree

Castor capsule borer

Biology:

• Egg: The female moths lay eggs on the tender parts of the plant.
• Larva: Pale greenish with pinkish tinge and fine hairs with dark head and prothoracic shield. The caterpillar that hatches out bores into the shoot if the plant is young and knit the planting materials capsules if the plant is old. The full-grown caterpillar is stout, reddish brown in colour and measures 15 to 25 mm. long. It pupates in a silken cocoon.
• Adult: Adults have yellow wings with black dots

Damage symptoms:

• The caterpillars bore into shoot and planting materials capsules and cause extensive damage to the tree and characteristic webbing of capsules along with excreta is seen.
• Capsules with bore holes
• Damaged capsules webbed together
• Peduncle and capsules having galleries made of silk and frass.

Natural enemies of shoot and capsule borer:

• Parastioids : Bracon brevicornis, Brachymeria euploeae
• Predators : Chrysoperla zastrowisillemi, ladybird beetle, reduviid bug, spider, fire ant, robber fly, black drongo (King crow), common mynah, big-eyed bug (Geocoris sp), earwig, ground beetle, pentatomid bug (Eocanthecona furcellata), preying mantis etc.

IPM for Jackfruit

To know the IPM practices for Jackfruit, click here.

Source: NIPHM; Directorate of Plant Protection, Quarantine & Storage