Big-eyed bugs (Geocoris spp.) are small insects that are cosmopolitan in occurrence. They are generally regarded as beneficial because they are generalist predators of many kinds of insect and mite pests of turf, ornamental, and agricultural crops. Big-eyed bugs are small, oblong-oval insects. Their heads are more broad than long, and their large prominent eyes curve backward and overlap the front of the beak. They are stout-bodied and somewhat flat and are usually black with silver wings.
Survival And Spread
Development time from egg to adult averages about 30 days. Nymphs hatching from eggs develop through five stages before becoming winged adults. Immature stages (nymphs) resemble adults but do not have fully developed wings.
Big-eyed bugs prey upon aphids, plant bugs, thrips, and the eggs and young larvae of various worms and can be effective predators of soft-bodied insects. On the downside, their prey occasionally include beneficial species such as Orius spp. Nymphs have been documented to consume an average of 47 mites, and adults an average of 83 “red spider” mites on cotton per day.
Like many beneficial insects, big-eyed bugs are very susceptible to broad-spectrum pesticides, so growers should scout crops to verify their presence and avoid the use of such products to preserve beneficial populations. Populations can also be encouraged by creating a refuge by planting sunflowers along field margins and windbreaks, which can serve as a food source in lean times.