Pests of Cole Crops & Tomatoes

Imported Cabbage Worm

Crop: Cole Crops – cabbage, cauliflower, kale, broccoli, Brussels sprouts, turnips – mustard family (Cruciferae) Scientific name: Pieris rapae Order: Lepidoptera Family: Pieridae Range: worldwide Mouthparts: Chewing

Whitish/yellow, rocket-shaped eggs are laid singly on the undersides of leaves

Distinguishing Characters: Larvae are green and very hairy, with an almost velvet-like appearance. Older larvae may be up to 25 mm (1 inch) long and often have one faint yellow orange stripe down their backs and broken stripes along the sides.

After 2 to 3 weeks of feeding, larvae pupate attached by a few strands of silk to stems or other nearby objects

Alternate Hosts: nasturtium, sweet alyssum, lettuce Oviposition Site: undersides of leaves Overwintering Stage: pupae Number of generations/year: 2 - 6 Damaging stages: larvae

Typical damage: feed on both the outer and inner leaves, often feeding along the midrib, at the base of the wrapper leaves, or boring into the heads, and drop greenish brown fecal pellets that may contaminate the marketed product.

Non Chemical control measures: Biological control – Natural enemies can be significant. Important parasites include a pupal parasite Pteromalus puparum; the larval parasites Apanteles glomeratus, Microplitis plutella, and several tachinid flies; and egg parasites in the Trichogramma genus. Viruses and bacterial diseases are also sometimes important control factors in the field

Chemical Control Measures: Bacillus thuringiensis is very effective against imported cabbageworms, especially when applied to early-instar caterpillars Spinosad (Success – a bacterial secondary metabolite) - may also combine with treatment for other lep pests with harder chemicals like malathion, diazanon, carbaryl, fenvalerate Current Pest Status: still a major pest

Cabbage Looper

Crop: Cole Crops, also lettuce, spinach, beet pea, celery, potato, tomato Scientific name: Trichoplusia ni Order: Lepidoptera Family: Noctuidae Range: Throughout US, part of Canada and Mexico Mouthparts: chewing

Distinguishing Characters: Larvae - green, usually with a narrow white stripe along each side and several narrow lines down the back. Smooth-skinned with only a few long bristles down the back; up to an inch and a half long distinctive looping movement

ridged and dome-shaped and usually laid singly on the undersurface of leaves

Adults are brownish moths with a distinctive silvery “figure-8” on the front wings

Alternate Hosts: carnations, nasturtium, mignonette Oviposition Site: undersurface of leaves Number of generations/year: 4 or more Overwintering Stage: pupae (though in CA may be active all year) Damaging stages: larvae

Typical damage: Eat ragged holes into leaves, bore through heads and contaminate heads and leaves with their bodies and frass. Young plants between seedling stage and heading can tolerate substantial leaf damage without loss of yield

Cabbage looper damage to leaves

Cabbage looper frass contamination

Non Chemical control measures: Biological control – has a number of effective egg and larval parasitoids – A viral disease may also be important Cultural control – Plow under crop remnants in spring to bury overwintering pupae before the emergence of adults

Cabbage looper killed by a nuclear polyhedrosis virus

Chemical Control Measures: Use Bt sprays when possible to avoid disruption of natural enemies. Also spinosad or Methomyl (lannate) Current Pest Status: still a major pest

Treatment thresholds Prior to heading, well-established plants do not need to be treated unless you find more than 9 small to medium sized larvae per plant. Treat just before heading or at brussel sprouts formation if counts show more than one looper or other caterpillar in 25 plants

Adult vegetable leafminer (Liriomyza spp)

Leafminer mines

Cabbage aphid wingless adult

Cabbage aphid winged adult

Cabbage aphid colony

Large colonies of cabbage aphids can severely distort the growth of cabbage heads

Cabbage maggots damage and destroy root systems of all cole crops, riddling roots with tunnels when infestations are heavy

Diamondback moth

Tomato Pinworm

Crop: Tomato Scientific name: Keiferia lycopersicella Order: Lepidoptera Family: Gelechiidae Range: Throughout Southern CA, sporadically in San Joaquin Valley and along coast Mouthparts: Chewing Distinguishing Characters: Adults are small gray/brown moths.

Early instar larvae are orange, turning purplish black as they mature Early instar larvae are orange, turning purplish black as they mature. Larvae grow to 6 mm (0.25 inch) in length

Alternate Hosts: eggplant, potato, ornamental plants and weeds in the Solanaceae (nightshade family) Oviposition Site: under sepals or on leaves Number of generations/year: 2 - 3 Overwintering Stage: pupae Damaging stages: larvae Typical damage: caterpillar feeds on leaves and creates blotch-type mines but causes most of its damage when it attacks the fruit. Where abundant, the tomato pinworm may seriously damage foliage and infest nearly 100% of the fruit

Tomato pinworm irregular blotch mine (left) and meandering narrow mine of a leafminer (right).

Tomato pinworms bore into solid parts of fruit creating narrow tunnels

Tomato pinworm larva and entry holes are visible on tomato (calyx removed).

Brown frass around the calyx indicates tomato pinworm infestation

Non Chemical control measures: Biological control – Parasites can be important Cultural control – Sanitation – destroy all overwintering plants and fruit by burning or plowing under Mating disruptants

Chemical Control Measures: Combine with mating disruption – Bt, Methomyl, pyrethrin, abamectin Current Pest Status: still a major pest in some areas – varies with season

Tomato Fruitworm

Crop: Tomato, corn, cotton Common Names: Tomato fruitworm, corn earworm, cotton bollworm Scientific name: Helicoverpa zea Order: Lepidoptera Family: Noctuidea Range: Worldwide Mouthparts: Chewing

Distinguishing Characters: larvae are variable in color when young, but later instars usually develop distinct, lengthwise stripes; they also have distinctive tiny spines that cover large portions of their skin Adults - about 38 mm (1.5 inch) wingspan, color variable – forewing orange-ish to gray with darker area near tip

Note setae (“spines”)

Close up of setae

Pupate below surface of soil

Eggs are hemispherical, slightly flattened on top with 12 or more distinct ridges radiating from the top. They are creamy white when laid, but develop a reddish brown ring after 24 hours

Alternate Hosts: vetch Oviposition Site: tender new leaves Number of generations/year: 3 - 4 Overwintering Stage: pupae Damaging stages: larvae Typical damage: Early stage larvae enter fruit at the stem end when it is between 29 - 50 mm (0.75 - 2 inches) in diameter. Caterpillars may emerge from one fruit and enter another. Feeding results in a messy, watery, internal cavity filled with cast skins and feces – also entry point for fungi

Larvae feeding on corn

Larvae feeding on cotton square

Larvae entering cotton boll

Non Chemical control measures: Biological control – Naturally occurring parasites are very important in the biological control of tomato fruitworm, especially in the Delta area and the Sacramento Valley A tomato fruitworm egg parasite, Trichogramma pretiosum, is available from many commercial insectaries. Inundative releases of 100,000 parasites/acre during the period of fruitworm oviposition and when fruit are susceptible to feeding can reduce damage Cultural control – disk under after picking

Trichogramma pretiosum

Parasitized eggs appear blackened

Chemical Control Measures: Esfenvalerate (Asana XL), Fenpropathrin (Danitol), Methomyl   (Lannate), Spinosaod (Success) Current Pest Status: varies with the year

Treatment thresholds For processing tomatoes, sample by picking the leaf below the highest open flower on 30 random plants. If five or more eggs are found, apply a treatment to coincide with hatching. adjust for parasitized eggs

Greenhouse Whitefly

Crop: tomato, cucumber, lettuce, many ornamentals Scientific name: Trialeurodes vaporariorum Order: Hemiptera Family: Aleyrodidae Range: Worldwide Mouthparts: piercing sucking

Distinguishing Characters: Whitefly adults are tiny (1. 5 mm [0 Distinguishing Characters: Whitefly adults are tiny (1.5 mm [0.06 inch] long), with yellowish bodies and white wings. Greenhouse White Fly hold their wings flatter over the back than other whiteflies and there is no space between the wings where they meet in the center of the back. Adult and eggs

greenhouse whitefly pupae have many long waxy filament around the edge and the edge is somewhat vertical where it contacts the leaf surface

Greenhouse whitefly eggs

Alternate Hosts: 200 plant species, mostly in the families Cruciferae, Leguminosae, Malvaceae, and Solanaceae - other crops include avocados, beans, blackberries and other berries, cucumbers, eggplants, grapes Oviposition Site: underside of leaves Number of generations/year: multiple Overwintering Stage: all stages Damaging stages: adults and nymphs

Typical damage: Damage leaves by feeding, which causes leaves to yellow and curl, and by the production of honeydew. GWF has been found to be the vector of tomato infectious chlorosis virus, a virus capable of causing heavy losses

Non Chemical control measures: Biological control – several important parasitoids and predators. Encarsia formosa, has been used successfully to control greenhouse whitefly in greenhouses Cultural control – When possible, plant tomatoes at least one-half mile upwind from key whitefly hosts such as melons, cole crops, and cotton. Maintain good sanitation in areas of winter/spring host crops and weeds by destroying and removing all crop residues as soon as possible

Chemical Control Measures: Imidacloprid (Admire), Oxamyl (Vydate L), Esfenvalerate (Asana XL), Endosulfan (Thiodan) Current Pest Status: still a serious pest

Consperse stink bug

southern green stink bug

Red shouldered stink bug

Say's stink bug

Stink bugs feeding discolors fruit and may introduce decay fungi

Tomato hornworm larvae

Tomato hornworm adult (Sphingidae)