Broccoli Insect Pests

Diamondback moth

Biology:

• Egg: Each female lays 50-300 small whitish eggs singly along the veins on underside of leaves at night times. Egg hatches in about 3-10 days.
• Larva: Larva is greenish with short thin hairs on the body. Full grown caterpillar measures 1-1.5 cm and its body tapers towards both ends. Larval period is 14 days.
• Pupa: Pupation takes place inside a barrel shaped thin loose mesh of silken cocoon. Pupal period is about 7 days.
• Adult: The moth is greyish brown with narrow wings having pale white triangular markings on inner margin of each forewing which form three diamond shaped white patches dorsally when wings are folded over back at rest. Hence the name, diamondback moth. The pest is active throughout the year. There are 8-12 generation in a year.

Life cycle:

Damage symptoms:

• Caterpillars feed on undersurface of leaves and bite holes in leaves and cause serious damage
• Withered appearance of affected leaves.
• Skeletonized leaves.
• Growing tip damaged no head/curd formation.
• In severe infestation, under-sized curds are formed, and head formation does not take place when infestation is very severe during primordial stage.

Natural enemies of Diamondback moth:

• Parasitoids: Trichogramma sp (egg) Apantele sglomeratus (larval), Bracongelechiae (larval), Bracon sp, (larval), Mesochorus spp. (larval), Brachymeria spp. (larval), Eriborusspp. (larval), Diadegmasemi clausum, (larval) D. fenestralis (larval), Tetrastichus sokolowskii (larval) and Cotesia vestalis (larval), Diadromus collaris (pupal), Diadromus spp. (pupal), Brachymeria excarinata (pupal) etc.
• Predators: Chrysoperla zastrowi sillemi, coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug, praying mantis, fire ants, big eyed bugs (Geocoris sp), pentatomid bug (Eocanthecona furcellata), earwigs, ground beetles, rove beetles etc.
• Fungal pathogens: Paecilomyces spp., Zoophthora radican etc.

Leaf webber

Biology:

• Egg: Female moth lays eggs in masses of 40 -100 on underside of leaves. They hatch in 5 -15 days
• Larva: Caterpillar webs together the foliage and feeds on leaves. It also feeds on flowers and pods in the case of mustard and flower heads in cabbage and cauliflower. Caterpillar bears red head with brown longitudinal stripes and rows of tubercles on the body. Larval period is 24-27 days.
• Pupa: Pupation takes place in a cocoon within the webbed leaves. Pupal period is 14-40 days.
• Adult: Adult is small with light brownish forewings. The total life cycle is completed in 42-84 days.

Life cycle:

Damage symptoms:

• Webbed leaves with fecal matter
• Skeletonized leaves

Natural enemies of leaf webber:

• Parasitoids: Trichogramma sp (egg), Bracon hebetor (larval), Cotesia crocidolomiae(larval), Palexorista solennis(larval), Microbracon nudlus etc.
• Predators: Chrysoperla zastrowi sillemi, coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug, praying mantis, fire ants, big eyed bugs (Geocoris sp), pentatomid bug (Eocanthe conafurcellata), earwigs, ground beetles, rove beetles etc.
• Fungal pathogens: Paecilomyces spp., Zoophthora radican etc.

Cabbage butterfly

Biology:

• Egg: Adult butterfly after mating lays about 100-150 yellowish cigar-shaped eggs in batches. The eggs hatch in 10-16 days in winter and 307 days in summer.
• Larva: The caterpillar is velvety green and measures about 4.2 cm in length. The caterpillars are gregarious initially but disperse as they grow.
• Pupa: Pupation is in damaged leaves.
• Adult: Adult is a butterfly with its fore wings snow white having black distal margins. Hind wings pure white with black apical spots.

Life cycle:

Symptoms of damage:

• They skeletonise leaves and bore into heads of broccoli

Natural enemies of cabbage butterfly:

• Parasitoids: Trichogramma chilonis (egg), T. japonicum (egg), Cotesia glomeratus (larval), Phryxe vulgaris (larval) and Pteromalus puparum (pupal)
• Predators: Lacewings (Chrysoperla zastrowii sillemi), coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug, praying mantis, fire ants, big eyed bugs (Geocoris sp), pentatomid bug (Eocanthecona furcellata), earwigs, ground beetles, rove beetles etc.

Mustard Sawfly

Biology:

• Egg: Eggs are spherical, about 0.5 mm in diameter, light bluish green in colour, inserted singly into leaf tissues.
• Larva: Larva is greenish black with wrinkled body and eight pairs of pro-legs. On slightest touch the larva falls to round and feigns death. The larvae had 6 instars, feed on the leaves, and pupated after 14-16 days.
• Pupa: Pupae look like sand particle and have salivary secretions; the pupal stage lasted 11-12 days. Pupation takes place in thick silken cocoon in soil.
• Adult: Adults are orange bodied with smoky transparent wings. The pest is active during seedling stage of the crop i.e. October - November.

Damage symptoms:

• Initially the larva nibbles leaves, later it feeds from the margins towards the midrib.
• The larvae cause numerous shot holes and even riddle the entire leaves by voracious feeding.
• They devour the epidermis of the shoot, resulting in drying up of seedlings and failure to bear seeds in older plants.
• The yield losses up to 5 to 18 %. In severe case at the seedling stage, the crop have to be resown. Natural enemies of mustard sawfly: Parasitoids:Perilissus cingulator ( larval) Entomopathogen: Bacterium serratiamarcescens

Aphid

Biology:

• Egg: Eggs are white in colour and laid along the veins of leaves.
• Nymph: 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 generally last 1-2, 2, 2, and 3 days respectfully.
• Adult: 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: This pest infests crucifers in cold season. Both the nymphs and adults suck sap from plant causing loss of vigour. Sooty mould develops on excreted honeydew reducing the photosynthesis

Natural ennemies of cabbageaphids:

• Parasitoids: Aphidius colemani (adult and nymphal), Diaeretiella spp. (adult and nymphal), Aphelinus spp. (adult and nymphal) etc.
• Predators: Anthocorid bugs/pirate bugs (Orius spp.), mirid bugs, syrphid/hover flies, green lacewings (Mallada basalis and Chrysoperla zastrowi sillemi), predatory coccinellids (Stethorus punctillum), staphylinid beetle (Oligota spp.), predatory cecidomyiid fly (Aphidoletis aphidimyza) and predatory gall midge, (Feltiella minuta), earwigs, ground beetles, rove beetles, spiders, wasps etc.

Painted bug

Biology:

• Egg: Bagrada bug lays its eggs in clusters on leaves or on the soil underneath host plants. Eggs are barrel shaped, initially white and turn orange with age. A single female can lay as many as 100 eggs within 2 to 3 weeks. The incubation period is 5 to 8 days
• Nymph: Nymph passes through five stages changing colour from bright orange to red with dark markings, gradually acquiring the colouration of the adult. Initially they do not have wings; wings are gradually developed as the nymphs grow. Wing pads are visible in the last instar nymph.
• Adult: The adult bug is typically shield-shaped, 5 to 7 mm long and 3 to 4 mm broad at its widest area. The upper surface has a mixture of black, white and orange markings, which gives the insect its common names harlequin bug or painted bug. The life cycle lasts 3 to 4 weeks and several generations may occur in a year. Period of activity of painted bug starts from September.

Life cycle:

Damage symptoms:

• Adults and nymphs suck sap from all parts of the plant.
• Young plants wilt and wither as a result of the attack.
• Quality and quantity (31% losses) of yield is affected when grown up plants are infected.
• Harvested crop in threshing floor is also infested. Natural enemies of painted bug: Parasitoid: Alophora spp. (Tachinid fly) (eggs).

Cabbage Head borer

• Egg: Female moth lays yellowish shiny eggs on underside of the leaves. Eggs hatch in about 2- 4 days.
• Larva: The caterpillar becomes full grown in about 9 days. Full grown caterpillar is 12-15 mm, greyish yellow with seven purplish brown longitudinal stripes on the body, dark brown head with ‘V’ shaped marking.
• Pupa: Full grown larva pupates in the larval burrow itself or in the soil. Pupal period is about 6 days.
• Adult: Adult is pale yellowish-brown moth having grey wavy lines on the forewing.

Life cycle:

Damage symptoms:

• Caterpillars web the leaves and bore into stem, stalk or leaf veins.
• They bore into the head also making it unfit for consumption. The damage results in Webbed leaves.
• Holes in cabbage head with fecal matter

Natural enemies of cabbage head borer:

• Parasitoids: Trichogramma spp. (egg), Bracon gelechiae (larval), B. hebetor (larval) etc.
• Predators: Chrysoperla zastrowi sillemi, coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug, praying mantis, fire ants, big eyed bugs (Geocoris sp), pentatomid bug (Eocanthecon afurcellata), earwigs, ground beetles, rove beetles etc.
• Fungal pathogens: Paecilomyces spp., Zoophthora radican etc.

Termites

Biology:

• Egg: Dull, kidney shaped and hatches in 30-90 days.
• Nymph: Moult 8-9 times and are full grown in 6-12 months.
• Adult: Creamy coloured tiny insects resembling ants with dark coloured head.

Life cycle:

Damage symptoms:

• Termites damage the crop soon after sowing and sometimes near maturity. They feed on roots, stem of growing plants, even dead tissues of plant feeding on cellulose. The damaged plants dry up completely and are easily pulled out. The plants damaged at later stages give rise to white ears. Infestation is heavy under unirrigated conditions and in the fields where un-decomposed farm yard manure is applied before sowing.

Cutworm

Biology:

• Egg: The egg is white in color initially, but turns brown with age. It measures 0.43 to 0.50 mm high and 0.51 to 0.58 mm wide and is nearly spherical in shape, with a slightly flattened base. The eggs normally are deposited in clusters on foliage. Females may deposit 1200 to 1900 eggs. Duration of the egg stage is three to six days.
• Larva: Neonate larvae are yellow in colou whereas the full grown larvae is dark brown with greasy body. There are five to nine instars, with a total of six to seven instars most common. Head capsule widths are very similar for instars one through four, but thereafter those individuals that display eight or nine instars show only small increments in width at each molt and eventually attain head capsule sizes no larger than those displaying only six or seven instars.
• Pupa: Pupation occurs belowground at a depth of 3 to 12 cm. The pupa is 17 to 22 mm long and 5 to 6 mm wide, and dark brown. Duration of the pupal stage is normally 12 to 20 days.
• Adult: The adult is fairly large in size, with a wingspan of 40 to 55 mm. The forewing, especially the proximal two-thirds, is uniformly dark brown. The distal area is marked with a lighter irregular band, and a small but distinct black dash extends distally from the bean-shaped wing spot. The hind wings are whitish to gray, and the veins marked with darker scales. The adult preoviposition period is about seven to 10 days. Moths select low-growing broadleaf plants preferentially for oviposition, but lacking these will deposit eggs on dead plant material. Soil is an unsuitable oviposition site.

Life cycle:

Damage symptoms:

Larvae can consume over 400 sq cm of foliage during their development, but over 80% occurs during the terminal instar, and about 10% in the instar immediately preceding the last. Thus, little foliage loss occurs during the early stages of development. Once the fourth instar is attained, larvae can do considerable damage by severing young plants, and a larva may cut several plants in a single night. Plants tend to outgrow their susceptibility to injury.

Natural enemies of cutworm:

• Parasitoids: Apanteles merginiventris, Chelonis insularis, Hyposoter exigua, Lespesia archippivora, Cotesia sp, Meterorus sp., Campoleti sp, Bracon kitcheneri, Fileanta ruficanda
• Predators: Broscus punctatus, Liogryllus bimaculatus, lacewings (Chrysoperla zastrowii sillemi), coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug etc.

Leaf eating caterpillars/cabbage looper

Biology:

• Egg: Eggs are hemispherical in shape, with the flat side affixed to foliage. They are deposited singly on either the upper or lower surface of the leaf, although clusters of six to seven eggs are not uncommon. The eggs are yellowish white or greenish in color, bear longitudinal ridges, and measure about 0.6 mm in diameter and 0.4 mm in height. Eggs hatch in about two, three, and five days at 32, 27, and 20°C, respectively, but require nearly 10 days at 15°C.
• Larva: Young larvae initially are dusky white, but become pale green as they commence feeding on foliage. They are somewhat hairy initially, but the number of hairs decreases rapidly as larvae mature. Larvae have three pairs of prolegs, and crawl by arching their back to form a loop and then projecting the front section of the body forward. The mature larva is predominantly green, but is usually marked with a distinct white stripe on each side. The thoracic legs and head capsule are usually pale green or brown. Dorsally, the larva bears several narrow, faint white stripes clustered into two broad white bands. In some cases the mature larva is entirely green. The body is narrower at the anterior end, and broadens toward the posterior. It measures 3 to 4 cm in length at maturity. The number of instars is four to seven, but many authors indicate only five. Larval development required 17.8 and 19.9 days when reared on bean and held at 23 and 32°C, respectively.
• Pupa: At pupation, a white, thin, fragile cocoon in formed on the underside of foliage, in plant debris, or among clods of soil. The pupa contained within is initially green, but soon turns dark brown or black. The pupa measures about 2 cm in length. Duration of the pupal stage is about four, six, and 13 days at 32, 27, and 20°C, respectively.
• Adult: The forewings of the cabbage looper moth are mottled gray-brown in color; the hind wings are light brown at the base, with the distal portions dark brown. The forewing bears silvery white spots centrally: a U-shaped mark and a circle or dot that are often connected. The forewing spots, although slightly variable, serve to distinguish cabbage looper from most other crop-feeding noctuid moths. The moths have a wingspan of 33 to 38 mm.

Life cycle:

Damage symptoms:

• Cabbage loopers are leaf feeders, and in the first three instars they confine their feeding to the lower leaf surface, leaving the upper surface intact.
• The fourth and fifth instars chew large holes, and usually do not feed at the leaf margin. In the case of cabbage, however, they feed not only on the wrapper leaves, but also may bore into the developing head.
• Larvae consume three times their weight in plant material daily.
• Feeding sites are marked by large accumulations of sticky, wet fecal material. Despite their voracious appetite, larvae are not always as destructive as presumed.

Natural enemies of leaf eating caterpillars of cabbage looper:

• Parasitoids: Trichogramma, tachinid, Copidosoma truncatellum
• Predators: Lacewings (Chrysoperla zastrowii sillemi),coccinellids, King crow, common mynah, wasp, dragonfly, spider, robber fly, reduviid bug etc.

Leaf miner

Biology:

• Egg: Eggs are laid singly mostly on leaf tissues. More than one egg may be laid in a single leaf. Incubation period varies from 2-6 days depending upon the weather conditions.
• Larva: Larvae are minute, apodous and yellowish in colour.
• Pupa: Pupation takes place with in galleries and pupal period last for 4-6 days. Adult: Adults are small two winged flies with grayish black meso notum and yellowish forms.

Life cycle:

Damage symptoms:

• Leaves with mines; the attacked leaves wither; vigour of the plant gets reduced. Its damage is often more prominent on the older leaves.

Natural enemeis of leaf miner:

• Parasitoids: Gronotoma micromorpha (larval and pupal), Diglyphus isaea (larval), Halticoptera circulus,Opius phaseoli (pupal) Chrysocharis pentheus (larval), Neochrysocharis formosa (larval).
• Predators: Lacewings, ladybird beetle, spiders, fire ants.

Whitefly

Biology:

• Egg: The gravid females mostly lay eggs near the veins on the underside of leaves. They prefer hairy leaf surfaces to lay more eggs. Each female can lay about 300 eggs in its lifetime. Eggs are small (about 0.25 mm), pear-shaped, and vertically attached to the leaf surface through a pedicel. Newly laid eggs are white and later turn brown. The eggs are not visible to the naked eye, and must be observed under a magnifying lens or microscope. Egg period is about three to five days during summer and 5 to 33 days in winter.
• Nymph: Upon hatching, the first instar larva (nymph) moves on the leaf surface to locate a suitable feeding site. Hence, it is commonly known as a “crawler.” It then inserts its piercing and sucking mouthpart and begins sucking the plant sap from the phloem. The first instar nymph has antennae, eyes, and three pairs of well-developed legs. The nymphs are flattened, ovalshaped, and greenish-yellow in color. The legs and antennae are atrophied during the next three instars and they are immobile during the remaining nymphal stages. The last nymphal stage has red eyes. This stage is sometimes referred to puparium, although insects of this order (Hemiptera) do not have a perfect pupal stage (incomplete metamorphosis). Nymphal period is about 9 to 14 days during summer and 17 to 73 days in winter. Adults emerge from pupariathrough a T-shaped slit, leaving behind empty pupal cases or exuviae.
• Adult: The whitefly adult is a soft-bodied, moth-like fly. The wings are covered with powdery wax and the body is light yellow in color. The wings are held over the body like a tent. The adult males are slightly smaller in size than the females. Adults live from one to three weeks.

Life cycle:

Damage symptoms:

Both the adults and nymphs suck the plant sap and reduce the vigor of the plant. In severe infestations, the leaves turn yellow and drop off. When the populations are high they secrete large quantities of honeydew, which favors the growth of sooty mould on leaf surfaces and reduces the photosynthetic efficiency of the plants.

Natural enemies of whitefly:

• Parasitoids: Encarsia sp, Eretmocerus sp, Chrysocharis pentheus
• Predators: Mirid bug (Dicyphus hesperus), dragonfly, spider, robber fly, praying mantis, fire ants, coccinellids, lace wings, big eyed bugs (Geocorissp) etc.

Mites

Biology: Tetranychus urticae is commonly known as red spider mite or two spotted spider mite. They are minute in size, and vary in color (green, greenish yellow, brown, or orange red) with two dark spots on the body. Eggs are round, white, or cream-colored; egg period is two to four days. Upon hatching, it will pass through a larval stage and two nymphal stages (protonymph and deutonymph) before becoming adult. The lifecycle is completed in one to two weeks. There are several overlapping generations in a year. The adult lives up to three or four weeks.

Damage symptoms:

Spider mites usually extract the cell contents from the leaves using their long, needle- like mouthparts. This results in reduced chlorophyll content in the leaves, leading to the formation of white or yellow speckles on the leaves. In severe infestations, leaves will completely desiccate and drop off. The mites also produce webbing on the leaf surfaces in severe conditions. Under high population densities, the mites move to using strands of silk to form a ball-like mass, which will be blown by winds to new leaves or plants, in a process known as “ballooning.”

Natural enemies of red spider mites:

• Predators: Anthocorid bugs (Orius spp.), mirid bugs, syrphid/hover flies, green lacewings (Mallada basalis and lacewing), predatory mites (Amblyseius alstoniae, A. womersleyi, A. fallacies and Phytoseiulusper similis), predatory coccinellids (Stethorus punctillum), staphylinid beetle (Oligota spp.), cecidomyiid fly (Anthrocnoda xoccidentalis), gall midge (Feltiella minuta) etc.
• Entomopathogen: Beauveria bassiana (entomo pathogen)

Nematodes

Biology:

• Most species of plant parasitic nematodes have a relatively simple life cycle consisting of the egg, four larval stages and the adult male and female. They are microscopic in size.
• Development of the first stage larvae occurs within the egg where the first moult occurs. Second stage larvae hatch from eggs to find and infect plant roots or in some cases foliar tissues.
• Under suitable environmental conditions, the eggs hatch and new larvae emerge to complete the life cycle within 4 to 8 weeks depending on temperature.
• Nematode development is generally most rapid within an optimal soil temperature range of 70 to 80°F.

Life cycle:

Life stages are microscopic in size

Damage symptoms:

• Infected plants in patches in the field
• Formation of galls on host root system is the primary symptom
• Roots branch profusely starting from the gall tissue causing a ‘beard root’ symptom
• Infected roots become knobby and knotty
• In severely infected plants the root system is reduced and the rootlets are almost completely absent. The roots are seriously hampered in their function of uptake and transport of water and nutrients
• Plants wilt during the hot part of day, especially under dry conditions and are often stunted
• Seedlings infected in nursery do not normally survive transplanting and those surviving have reduced flowering and fruit production
• Nematode infection predisposes plants to fungal and bacterial root pathogens

Survival and spread:

• Primary: Egg masses in infected plant debris and soil or collateral and other hosts like Solonaceous, Malvaceous and Leguminaceous plants act as sources of inoculum
• Secondary: Autonomous second stage juveniles that may also be water dispersed

Favourable conditions:

• Loamy light soils

IPM for Braccoli

To know the IPM practices for Braccoli, click here.

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