EFFECTS OF COMPOUND EYE REMOVAL ON THE PHOTOPERIODIC RESPONSE OF THE BAND LEGGED GROUND CRICKET, PTERONEMOBIUS-NIGROFASCIATUS

The band-legged ground cricket Pteronemobius nigrofasciatus shows a cl ear photoperiodic response at 25 degrees C with respect to the control of the induction of embryonic diapause. When crickets were reared und er a short-day (LD 12 : 12) photoperiod and then transferred to a long -day (LD 16 : 8) photoperiod upon adult emergence, the adults mainly l aid nondiapause eggs. However, adults maintained continuously under sh ort-day conditions laid dispause eggs. When compound eyes were bilater ally removed after adult emergence, the crickets mainly laid nondiapau se eggs, irrespective of the photoperiod. Thus, the adults completely lost their sensitivity to photoperiod after bilateral removal of their compound eyes. Unilateral removal of the compound eye also affected t he crickets under a short-day photoperiod, and the incidence of diapau se eggs was intermediate between that laid by intact adults and that l aid by adults after the bilateral removal of compound eyes. The incide nce of diapause eggs in sham-operated crickets was not significantly d ifferent from that in intact crickets under both sets of photoperiodic conditions. These results show that P. nigrofasciatus perceives the p hotoperiod through its compound eyes.