Field Guide     Pest Management     Green Cloverworm

Green Cloverworm

CROPS IMPACTED: alfalfa, clover, soybean, strawberry, raspberry, bean

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Family: Erebidae

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About the Green Cloverworm

Reproduction and Life Cycle

Green cloverworms will usually have 3 generations annually. They overwinter as either fully developed adults or pupa. When the weather begins to warm up in the spring, the adults will emerge and begin mating. The females will then place their eggs on the underside of plant leaves. The eggs will develop and hatch within the week. The hatched larvae go through 6 instars, taking about a month to complete. They then pupate in the soil; this development stage will take about 10 days to complete.

Green Cloverworm Identification and Habitat

Identification

The green cloverworm adult has a wingspan of 25 to 35mm long; however, the males are often larger than the females. Their narrow forewing ranges between gray, black and brown, and can have yellow or orange varying patterns. Their broad hindwing is twice the width of the forewing and is a gray-brown with dark veins and has a lightly coloured marking on the disk. The larvae start off as a pale yellow. They then turn light gray to green with 1 or 2 yellow-white lines running down its entire body. Larvae vary between 1.5 and 30mm long throughout their 6 instars. They also have tiny white bands that surround each segment on the abdomen. Their head is often green to brown. They have 4 proleg sets and they will loop when they walk. If they are disturbed, they will immediately begin to wiggle hastily. The egg is hemispherical and is approximately 0.5mm wide. The pupa’s length is 13mm and is a dark brown.

Habitat

Green cloverworms live in fields, along the edges of woodland, and in gardens. They are nocturnal and typically fly from the months of March to November. They are mainly a concern due to the soybean damage they cause. Young larvae will eat away at the underside of leaves on soybean plants, leaving it skeletonized. As the larvae mature they will change to the colour of the plant it feeds off of, other than its white stripes that will remain. These larvae eat all leaf matter, not just the underside, only leaving the major leaf veins. They have the power to completely defoliate a soybean plant.

Green Cloverworm Management and Control Methods

Management

The green cloverworm often does not reach economically damaging levels because of their many natural enemies, such as parasites, and other insects. If the larvae are infected by these parasites, they will become shrunken, mottled brown bodies, usually found dead attached to the host plants leaves. However, if this is not the case and defoliation reaches 20 percent during bloom, then a chemical control management system should be considered.

Chemical Control

Chemicals that have been discovered to be effective in controlling the green cloverworm: Asana XL, Ambush 2EC, Lorsban 4E, Penncap-M, Pounce 3.2EC, Sevin XLR Plus, and Warrior T. Be sure to carefully read the label for cautions and proper application. It is extremely important to never spray on days that are windy. After applying insecticides it is important to irrigate sprayed area to increase the insect control; however, a large rainfall or irrigation soon after the application can reduce the insecticides concentration.

Latin / Alternative Green Cloverworm Names

  • - Hypena scabra

Sources

http://bugguide.net/node/view/582588

http://ipm.ncsu.edu/AG271/soybeans/green_cloverworm.html