Sterility and lethality in crosses involving two translocation heterozygotes of the German cockroach,Blattella germanica (L.)

Summary Productivity in crosses involving two independent reciprocal translocations inBlattella germanica are reported. Lethal effects alone could not account for the reductions in hatch since completely unproductive crosses occurred frequently. The latter are attributed to the inability of reduced numbers of viable embryos to force open the egg case. The implications for genetic control of the joint dominant effects from embryonic trapping and translocation semisterility are discussed.Acknowledgment. This research was supported in part by Naval Facilities Engineering Command Contract No. N00025-74-C-0014 and a grant from Johnson's Wax Fund, Inc. The data on the translocation heterozygote and the wild-type matings were obtained byNancy L. Ross, and their use is gratefully acknowledged.