Seasonal de-alation of the macropterous morph of the wing-dimorphic bug Ischnodemus sabuleti (Hemiptera: Heteroptera: Blissidae): accumulation of injuries or active autotomy?

Wing autotomy is known to occur sporadically in some heteropteran families but undocumented in the superfamily Lygaeoidea. The regular and seasonal partial de-alation of the macropterous form of the wing-dimorphic blissid bug Ischnodemus sabuleti is documented in this paper. All macropterous adults of both sexes stay full winged after emergence during the late summer and autumn and during the hibernation. Breaking down of the forewing membrane and the serious damage to the hindwings happens in the spring and coincides with the onset of the reproductive behaviour. Very likely the bugs mutilate their wings by rubbing them with the hind legs (active autotomy); however, this should be confirmed with observations. Heteropteran wing autotomy might have evolved several times independently from the normal wing-cleaning behaviour and might be triggered by natural wing injuries. Phylogenetically, the supposed wing autotomy of I. sabuleti is probably an apomorphic character. Most, if not all, heteropteran species known to mutilate their wings are the macropters of wing-dimorphic species, which fact represents another aspect of the phenomenon called 'migratory syndrome'. Concerning the possible adaptive value of I. sabuleti's supposed wing autotomy, some mutually non-exclusive hypotheses are presented and discussed. These might be also relevant to the documented wing autotomy of some other heteropteran species. [ABSTRACT FROM AUTHOR]