Black Aphids
Black aphid nymphs and adults feed on the base of young shoots, flowers, and fruits of stringbeans.
What are the symptoms
Extensive feeding of black aphids results in the drying of plant parts affected. Sooty mold can also develop due to high levels of secretion of honeydew.
Impact to the crop
Feeding on shoots and flowers directly reduces the potential yield of the crop. Damaged shoots and fruits may not develop due to extensive feeding. Black aphids transmit bean mosaic virus which results in the mosaic appearance of leaves, stunting of crop, reduced fruiting & flowering.
How to control
√ Use of yellow-painted sticky traps and reflective mulches.
√ Allow the population of natural enemies such as coccinelid beetles, syrphids and spiders.
√ Entomopathogenic fungi Neozygites fresenii and Verticillium lecanii can also help in the control of aphids in the field.
√ Apply chemical insecticides that are proven effective in sucking pests like aphids.
Source : Dela Cueva, et. al., 2015
