New Approach for the Control of Cockroaches Utilizing the Entomophilic Nematode DD-136 in Conjunction with Attractants

摘要

The pathogenicity of the entomogenous nematodes, Neoaplectana carpocapsae (DD-136 strain) and Neoaoplectana glaseri, was tested for the German cockroach, Blattella germanica, under laboratory conditions. All developmental stages, including oothecae, were tested for susceptibility. Infection dishes consisted of standard size petri dishes lined with filter paper, to which were added 3 ml of a nematode suspension containing infective juveniles at a concentration of 1000, 5000, 10,000 and 20,000 per ml. The dishes were examined for cockroach mortality at 24 hour intervals for a period of 5 days. Both German cockroach adults and nymphs were very susceptible to infection by N. carpocapsae. Significant mortality was recorded after 3 days for all concentrations of infective juveniles. Data were gathered to test three hypotheses concerning the function of the aggregation behavior of the German cockroach, (Blattella germanica (L.) (Orthoptera: Blattidae). The first is that aggregation serves to ameliorate in a harsh environment and promote individual survival. Group and individual rearing experiments demonstrated a possible reduction of survival and growth rates with increased group size, in contrast with the increases suggested in previous literature.