Pea weavils

Asked December 28, 2012, 10:18 PM EST

Hello, What are the best ways to stop pea weavils on peas? I would prefer organic methods if they yield results. Thank you so much!

Josephine County Oregon fruits and vegetables insect issues horticulture

1 Response

Hi, There is the Pea Leaf Weevil (causes damage to the leaf) and the Pea Weevil that damages the pea. The information below is regarding the latter. I've attached some photo links to confirm you have identified the pest as the pea weevil. There is some cultural control to minimize some of the damage, but no specific organic methods that are listed that are research based and shown to work. I did include the chemical controls also, unfortunately none of them are derived organically. If you want to know more about the chemical controls you can go to: http://npic.orst.edu/ingred/bifenthrin.html

Pictures of the pea weevil:
http://uspest.org/pnw/insects?KGCode_pres.cfm?ID=281
http://uspest.org/pnw/insects?KGCode_pres.cfm?ID=282
http://uspest.org/pnw/insects?KGCode_pres.cfm?ID=278
http://uspest.org/pnw/insects?KGCode_pres.cfm?ID=275

This information is taken from the PNW Insect Management Handbook at http://uspest.org/pnw/insects?22VGTB47.dat

Pea Weevil
Bruchus pisorum) ID photos: Adult Damage Egg Immature
fact page (pdf): pdf fact page about Bruchus pisorum

Pest description and crop damage The adult pea weevil is a chunky beetle about 0.19 inch long with a short, broad snout. It is brown flecked with white, black, and gray patches. The top of the abdomen is exposed behind the wing covers. The larva is C-shaped, up to 0.25 inch long, legless, brown-headed, and cream-color. Adults feed on pea pollen, and the female lays eggs on developing pea pods. The larva burrows directly through the pod, where it feeds and develops in the developing pea seed. While one larva develops in a single seed, nearly every pea may be infested when populations are high.
Biology and life history Adults overwinter with peas primarily in storage but also in the field. The pea weevil emerges about when peas are blooming, feeding on flowers (pollen and petal), leaves, or pods. The elongated yellow eggs are laid on the outside of the pod singly or in pairs. Although one to a dozen eggs are laid per pod, only one larva develops per pea. Hatching is in 1 to 3 weeks. The larva burrows through into the pea and matures in 5 to 6 weeks. Infested peas “heat,” aiding larval development. Pupation takes about 2 weeks, late in summer. Adults may leave the pea immediately or stay inside it all winter. There is only one generation per year.
Scouting and thresholds One weevil in 25 sweeps may result in 10% infested peas at harvest. Take samples along field margins, fence rows, and in the field. The most conservative approach is to apply appropriate insecticides at bloom prior to detecting adult pea weevils.
Management—cultural control
It is very important to destroy crop residues. Do not plant infested seed unless it is fumigated. Careful harvesting prevents shattering that can disperse weevils throughout fields. Destroy volunteer plants. Early planting and harvesting is also desirable.
Management—chemical control: HOME USE
1. bifenthrin
2. carbaryl—Do not apply to plants in bloom.
3. esfenvalerate
4. malathion


Thanks, Amy Jo