The big-eyed bugs, Geocoris spp., are small insects (approximately 1/6 inch long) that occur in many parts of the world. They are generally regarded as beneficial because they prey upon numerous kinds of insect and mite pests of turf, ornamental and agricultural crops. Big-eyed bugs are among those insects receiving research attention in Florida (and elsewhere) for their value as predators. To aid in identification of big-eyed bugs in Florida, a key to adults and late instar nymphs is provided in this publication.
Big-eyed bugs are small, oblong-oval lygaeids having the head broader than long, and prominent eyes that curve backward and overlap the front of the pronotum. The stylus has a longitudinal groove. These features can be seen on nymphs as well as adults and serve to separate big-eyed bugs from similar bugs. A distinguishing feature of adult big-eyed bugs is the very short or absent claval commissure. Lygaeids such as chinch bugs, Blissus spp.; false chinch bugs, Nysius spp.; and pamera bugs, Neopamera spp. are sometimes confused with big-eyed bugs, but these genera have a claval commissure (Fig 5.) approximately half as long as the scutellum. Also, the head has more of a triangular shape in these lygaeids. Caplan (1968) emphasized the need for turf specialists to distinguish between big-eyed bugs and chinch bugs. Misidentification could result in a chinch bug spray directed against geocorines, resulting in needless loss of money and beneficial insects.