The German cockroach, Blattella germanica (L.), and the closely related species B. bisignata (Brunner) belong to the germanica species group. They are similar in appearance, life history, reproductive cycle, and courtship behavior. The most significant difference is habitat preferences: B. germanica is a household species and lives in crowded conditions, whereas the feral B. bisignata lives outdoors in a solitary manner. Nevertheless, B. bisignata has recently been found in households. A comparison between the two species has shown that B. germanica displays gregarious behavior and produces an aggregation pheromone, whereas both characters are absent in B. bisignata. Mate preference experiments have revealed that B. germanica females accepted only conspecific males, whereas B. bisignata females mated with males from both species, provided that long distance calling was bypassed. In addition, the high reproductive potential of B. germanica outcompeted the other species: when 10 pairs of B. germanica and of B. bisignata were kept together in crowded conditions during 3 mo, B. bisignata was driven into extinction. It is concluded that the chances of B. bisignata becoming a new household species are remote.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 38 • No. 2