Allozyme analysis and phyletic relationships of two new stick‐insects from north‐west Sicily: Bacillus grandii benazzii and B. rossius‐grandii benazzii (Insecta Phasmatodea)

Two new Sicilian stick‐insects have been discovered within the genus Bacillus. Evidence concerning the subspecific differentiation of Bacillus grandii benazzii and the hybrid constitution of B. rossius‐grandii benazzii by means of allozyme analysis is given, and is consistent with morphological and karyological data on the differentiation of these two north‐west Sicilian morphs from south‐eastern B. g. grandii and B. whitei. B. g. benazzii is more polymorphic than B. g. grandii and B. rossius‐g. benazzii embodies its genetic variability, thus differing sharply from the south‐eastern parallel hybrid B. whitei ( = B. rossius × B. g. grandii). Reproductive mechanisms also appear to be different in the two interspecific hybrids, involving parthenogenesis in the latter and hybridogenesis in the former. Finally, the phyletic relationships among all Sicilian Bacillus taxa are summarized in a revised scheme, which also takes into account new evidence that B. atticus has contributed to hybrid constitution of the triploid B. lynceorum. Copyright © 1991, Wiley Blackwell. All rights reserved