RESPONSE TO SELECTION FOR DIFFERENT WING FORMS IN THE PYRRHOCORID BUG, PYRRHOCORIS-SIBIRICUS (HETEROPTERA, PYRRHOCORIDAE)

The pyrrhocorid bug, Pyrrhocoris sibiricus, which is a ground-dwelling seedfeeder, shows a wing polymorphism producing brachyptery and macro ptery. A selection experiment for different wing forms was carried out at 30 degrees C under 12L-12D to investigate whether or not the wing form of this species is a heritable trait. In the macropterous selecte d line, the incidence of macroptery reached a plateau at around 70% in females and at 80% in males after the 4th generation. ON the contrary , in the brachypterous selected line, almost not macropters were produ ced after the 6th generation in either sex. These responses to selecti on for the two wing forms clearly showed that wind form is a heritable trait in P. sibiricus. Realized heritabilities for the two wing forms were estimated by the degree of response to wing form selection in bo th sexes. The realized heritability for macroptery was estimated to be 0.48 for females and 0.78 for males. On the other hand, the realized heritability for brachyptery was estimated to be 1.57 for females and 1.54 for males.