PESTS OF TOMATO

Dr. Jamba Gyeltshen

7/05/10

Adult moth Helicoverpa armigera (Lepidoptera:

Noctuidae)

Host range

• tomato

• peppers

• okra

• eggplant

• beans

• maize

Damage

• Feed on tomato leaves and fruit. • Larvae may also bore into stalks or

midribs. • When fruit is present, larvae enter it soon

after hatching. They prefer green fruit and will enter it usually at the stem end, causing extensive direct damage and result in decay.

Young egg

Mature egg

Egg

• Eggs are tiny, hemispherical, and slightly flattened on top with coarse striations or ribs running from base to tip.

• Fruitworm eggs are laid singly on both upper and lower surfaces of the leaves usually in the upper part of the plant.

• When first laid they are creamy white, but develop a reddish brown ring after 24 hours.

Young larva

Colour variation

• The young larvae are yellowish-white with a brown head and conspicuous black tubercles and hairs

Management

• Monitor eggs and small larvae. Choose leaves located below the highest open flower.

• Avoid planting tomato along with maize or near maize fields to prevent heavy pest infestations

• Insecticides: fenvalerate, cypermethrin and chlorpyrifos.

Blister beetle (Epicauta spp)

• Blister Beetles - slender gray or black beetles with red head, 1/2 to 3/4 inch long.

Blister beetle damage

Blister beetle damage

Lifecycle

• The adults eat the leaves of the plants and skeletonize the plants but the larvae feed on grasshopper eggs and are therefore somewhat beneficial.

• They usually arrive late in the season (July-August) as mature adults that overwintered in the soil.

• Each adult can lay 50-300 eggs in the soil which hatch 10-21 days later.

• The larvae eat and molt thru 7 stages before returning to the soil for the winter.

• They can be hand-picked but wear gloves as they extrude a caustic fluid in self-defense. Chemical controls include pyrethrins and 5% Sevin.

Green peach aphid

Myzus persicae (Sulzer) (Insecta: Hemoptera: Aphididae

Description

• Soft-bodied and pear-shaped, ranging from 1.6 to 2.4 mm long

• The wingless green peach aphid adult is pale-yellow to green. In the fall, color may range from pale- to dark-green to pink or red.

• The winged migrant form has a yellowish green abdomen with a dark dorsal blotch.

• Both forms have a pair of tailpipe like appendages known as cornicles.

• Nymphs are slightly smaller than the adult but similar in shape. They are pale yellow-green with three, dark lines on the abdomen.

Distribution and host range

• Cosmopolitan

• Infests a wide range of crops (tomato, chilli, potato, tobacco, cabbage, leafy green vegetables, legumes) and trees of Prunus spp. (Peach, plum, nectarine)

Description of the pest

• The green peach aphid is recognized by three longitudinal dark green stripes on the pale green body.

Damage

• The green peach aphid has piercing sucking mouthparts, and feeds by inserting these mouthparts into plant tissue and sucking out the sap.

• The aphids injures plants in three ways. • First, feeding interferes with proper nutrient

transfer in the plant. • Second, the green peach aphid can transmit

over 100 plant diseases, including cucumber mosaic virus on peppers.

Damage

• Finally, aphids produce a large amount of excrement called honey dew because of its high sugar content. Honey dew sticks to the leaves and often becomes a substrate for fungus, which causes smutting of leaves and fruit.

• Plants injured by aphid feeding will have leaves that appear curled, distorted and discolored.