EFFECT OF PHOTOPERIOD ON FLIGHT ACTIVITY IN GRAPHOSOMA-LINEATUM (HETEROPTERA, PENTATOMIDAE)

Flight activity in a pentatomid bug, Graphosoma lineatum, was measured under different photoperiodic conditions. Insects started flying 3 da ys after adult ecdysis and the percentage of flying adults became high est about 1 week after the ecdysis, regardless of the photoperiod. Und er long day (18L : 6D), high flight activity was continued, whereas un der short day (12L : 12D), most adults stopped flying when diapause wa s induced. In both photoperiods, a small number of adults showed fligh t of a long duration, longer than 30 minutes. Thus, no evidence was fo und relating the long flight to diapause. It is suggested that diapaus e adults of G. lineatum do not overwinter far from their breeding site s and thus there is no migration to hibernation sites. Also, the long flight is probably only a foraging flight, enabling the bugs to find t heir dispersed host plants.