Leaf Eating Beetle

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Leaf Eating Beetle

Epilachna vigintioctopunctata

Insect


In a Nutshell

  • Feeding damage appears on the leaf tissue between the veins.
  • Skeletonization of the leaves occurs.
  • Shallow holes can appear on fruit surfaces.
  • Seedlings can be destroyed.
  • Infestation leads to stunted plants and heavy defoliation.

Hosts

Eggplant

Symptoms

Both adults and larvae feed on the leaves and can cause serious damage. Feeding damage of the green tissue between the leaf veins is the initial symptom. Later, a characteristic pattern of damage called skeletonization occurs whereby only the hard parts of the leaves (main veins and petioles) are left. There may be shallow holes on fruit surfaces, too. Seedlings can be destroyed and the growth of more mature plants can be stunted. The pest can lead to heavy defoliation and high yield loss and is therefore one of the most dangerous eggplant pests.

Trigger

The adults are oval, dull orange in color with 28 black spots and short soft hairs on the back. The female beetle lays oval, yellow eggs (0.4-1 mm) upright and in small groups usually on the lower side of the leaves. After about 4 days the pale yellow-whitish larvae with long, dark-tipped split spines on the backs hatch. The larvae grow to about 6 mm within about 18 days, depending on temperature. They then move to the underside of the leaves and pupate. After an additional 4 days, the new generation of adult beetles emerges from the cocoons. During the reproduction period (March-October), cooler temperatures favor lifecycle and population growth. The beetles can overwinter in the soil and in piles of dry leaves.

Biological Control

Parasitoid wasps of the Pediobius family can be used to control the pest. These wasps also attack beneficial ladybirds, so it is important to identify the pest carefully before using them. Pathogenic microorganism can help to control the population of leaf eating beetle, too. Biopesticides containing the bacterium Bacillus thurengiensis or the fungus Aspergillus spp. can be used as foliar spray applications. Leaf extracts of Ricinus communis (castor oil), Calotropis procera and Datura innoxia can be sprayed foliarly. Applying ash can effectively reduce the infestation in early stages.

Chemical Control

Always consider an integrated approach first. If insecticides are needed, products containing dimethoate, fenvelarate, chloropyriphos, malathion can be applied on the foliage.

Preventive Measures

Plant resilient, tolerant or resistant varieties available in your area.,Avoid planting eggplant in or next to infested fields.,Remove or avoid planting alternative hosts in the vicinity of your field.,Use thorough irrigation to minimize an increasing pest population.,Check your plants or field for any sign of the pest.,Handpick and destroy larvae and adults found in the seedbeds or fields.,Remove or destroy infested plants and your waste by burning.