Coreid bugs
Heteroptera: Coreidae
Coreid or leaf-footed bugs are large insects, belonging to the bug family Coreidae and are reported in many tropical and subtropical countries throughout the world.
Host plants and damage
The majority of the Coreidae are plant feeders, but a few are predaceous. The squash bug Anasa tristis (), a serious pest on cucurbits, is dark brown in color and about 13 mm in length. Coreid bugs feed on many vegetable groups, but they are also found pecking on rice and are pests on some trees. Primary vegetable hosts are Phaseolus (beans), Vigna unguiculata (cowpea), Glycine max (soybean), and V. radiata (mung bean).
Plant growth stages affected
Flowering and fruiting stages are attacked by Coreid bugs
Affected plant parts
Both, nymph and adults attack Fruits/pods, and seeds.
Symptoms
Pods and seeds attacked by Coreid bugs show spots and discoloration. The bugs inject toxic saliva into the plant during feeding which causes leaf tissue breakdown and ultimately leaf death.
Morphology & biology
Eggs are oval in shape and in some species bright green and in other species are brown. The nymphs undergo five instars before entering the adult stage. Adults are up to 20 mm in length and have segmented antennae.
Species in the family Coreidae are separated from those in Alydidae by differences in width and length of their heads relative to the pronotum. Alydids, commonly called broadheaded bugs, have a head that is nearly as wide as and as long as the pronotum.
Monitoring
Adult bugs preferentially colonize larger, more mature plants. Thus, early-planted crops may be especially prone to attack. Numbers are also highest on plants during bloom and fruit set.
The tendency of these bugs to aggregate in sheltered locations can be used for monitoring. Look on undersides of leaves and on pods for both, nymph and adults.
Pest management
Biological control
Coreid bugs emit a strong unpleasant odor and may eject a foul smelling liquid when disturbed. This behavior is deterrent to many possible predators. Natural enemies include birds, spiders, assassin bugs, tachinid flies, and chalcid wasps.
Chemical Control
Several synthetic insecticides are reported to control Coreid bugs effective.
If insecticides are to be applied when blossoms are present, it is advisable to use insecticides with little residual activity.