The Turkestan cockroach (Blatta lateralis) - an emerging urban pest in the Southwest

The Turkestan cockroach, Blatta lateralis, was first recorded in California in 1978 and in Arizona in 1984. Pest management professionals in New Mexico and west Texas also report treating for this species. It has been reportedly displacing the oriental cockroach, Blatta orientalis as the major species around structures. Little is known about the biology of this invasive species. We under took life history studies and water loss studies to determine what factors might be contributing to its success. At 26.7°C, there are 6 nymphal instars that require about 8 months to develop into adults. The fifth and sixth instars requiring slightly longer to develop than the first four instars. Females produce their first ootheca within 2 weeks. Each ootheca contains about 16-18 nymphs. The developmental life cycle of B. lateralis is significantly shorter than B. orientalis. Adult male B. lateralis and orientalis have similar cuticular permeability values at 26.7°C, 11.5 and 13.6 µg water lost/h/cm2/mmHg, respectively. The 3rd instar nymphs had higher, but similar water lost patterns. At 26.7°C, the adult males lost about 8-10% of their body water at 24 hours. Both species appear to be well adapted to the arid climates of urban areas in the southwest.