Antennal Oligomery in Heteroptera

Abstract

Puttarudriah and Channabasavanna¹ state “…so far as we are aware, no reference occurs of an insect possessing antennæ with unequal number of joints [sic] on the two sides, affecting its bilateral symmetry”. In fact, antennal oligomery is a common phenomenon in the Heteropterous family Lygæidæ. Butler² records its occurrence in twenty of the sixty-six British Lygæidæ known to him, and in certain genera, for example, Scolopostethus Fieber, it occurs frequently. However, I have reported³ examining 208 specimens of Ischnodemus sabuleti ssp. palustris Carayon (stated by Butler to exhibit oligomery) without finding an oligomerous individual. Butler does not include Heterogaster urticœ (F.) among the oligomerous species, but I have a male with normal 4-segmented left antenna and 3-segmented right antenna; this was the sole abnormal specimen in a catch of 75 of both sexes.