Sitonia lineatus
Crops Affected:
Succulent peas, field legumes (field peas, dry beans, fababeans)
Life Cycle:
- Adults overwinter in alfalfa or perennial crops
- Adults move into annual crops by flying (if temperatures are above 17°C) or by walking short distances
- Adults emerge in spring and females lay many eggs (1000+) near or sometimes on developing plants in May to June
- Adults feed leaf margins and seedling growing points
- Larvae move into the soil to feed on the nodules
- Larvae undergo 5 instars and then pupate in the soil
- New adults may emerge in summer and feed on any pulse crops that they can find before overwintering
- Typically there is only one generation per year
Symptoms:
- Adult feeding on leaf margins results in characteristic notched or scalloped appearance
- Larval feeding on root nodules would not be visible unless plants are pulled up
- Heavy infestations may result in severe defoliation and ragging of leaves
- Damage may have more impact on younger seedlings
- Plants that rely on nitrogen fixed within root nodules may be weakened
Source : Agriculture and Forestry