Objective　Attracting effect of fecal extract of the Blattella germanica of different ages and genders on themselves was measured in the present study in order to provide more effective guidance on the chemical control of B. germanica. Methods　B. germanica feces were immersed in organic solvents to produce the extract, of which the attracting effect was measured by a four?arm olfactometer. Results　The ethanol fecal extract of early nymphs was the best to attract early nymphs, late nymphs, male adults and female adults, with the attraction rates of 39.72%, 40.56%, 38.33% and 34.17%, respectively, followed by fecal extract of late nymphs, the attraction rates of which were 30.56%, 30.56%, 27.22% and 26.11%, respectively. The extracts of male and female adult feces were the worst at attracting, though the one of male adult feces had an attraction rate of 22.22% to female adults, and that of the female adult fecal extract reached 24.72% to male adults, both higher than the effect of nymph fecal extracts and that between the same gender. The effectiveness of toxic baits increased significantly when added a certain amount of the ethanol extracts of early or late nymph feces; the 24 h kill rate of deltamethrin baits increased from 26.00% to 54.00% and 48.00%, respectively; the 24 h kill rate of phoxim baits increased from 20.00% to 48.00% and 40.00%, respectively. Conclusion　The fecal extract of early nymphs had a favorable attracting effect on the nymphs of all ages and male and female adults, while the fecal extract of a certain gender satisfyingly attracted the opposite. Mixed with the ethanol fecal extract of early and late nymph, the toxic baits demonstrated improvement in the killing efficiency.

Objective　To determine the attractiveness of different foods and identify an effective attractant that can act as a toxic bait for chemical control for Blattella germanica. Methods　The four?arm olfactometer was used to sort out strongly attractive foods from a variety of edible materials for B. germanica. The candidate was then prepared with insecticides into toxic baits. Results　The strongest attractants identified from four groups were fried soybean powder, cabbage juice, bananas and glucose, with attracting rates of 63.33%, 59.44%, 63.33% and 42.78%, respectively. The four best attractive ingredients were subject to the optimal luring test, which showed that fried soybean powder had the greatest attracting effect on B. germanica with the attracting rate of 45.66%, followed by bananas (25.83%). Combined with deltamethrin or Phoxim, bananas could act as the most efficiently attractive toxic bait. Conclusion　The screening study showed that soybean powder and bananas had strong attractiveness for B. germanica. Bananas can be used to produce the most effective toxic bait.

　　【Abstract】　Objective　Activities of carboxylesterase，glutathione S-transferase and acetylcholinesterase from German cockroach (Blattella germanica) treated with sublethal doses of deltamethrin and phoxim were measured. Methods　Enzyme activities were measured in vitro by spectrophotometry and DPS was used for statistical analysis. Results  Activity of carboxylesterase reduced to the lowest level at 24 h after treated with sublethal doses of phoxim. The activity decreased 79.33％ compared with that before treatment, then recovered gradually and at 168 h reached 37.10% of that of before treatment. Activity of carboxylesterase reduced slightly after treated with sublethal doses of deltamethrin. For glutathione S-transferase, activities declined slightly and were 74.97% and 79.77% after treatment for 72 h , respectively. Activity of acetylcholinesterase increased within 24 h after treated with sublethal doses of deltamethrin, then declined gradually. Activity reduced slightly after treated with sublethal doses of phoxim. Conclusion　Compared with before treatment, the enzyme activity of German cockroach changes with the difference of time after treated with sub-lethal doses of deltamethrin and phoxim.

　  【Abstract】　Objective　To study activity variance of carboxylesterase，glutathione S?transferase and acetylcholinesterase in different development stages and gender adults of German cockroach (Blattella germanica). Methods　Enzyme activities were measured by spectrophotometry in vitro and the data were analyzed with software DPS. Results　The activities of carboxylesterase and acetylcholinesterase in the first?instar nymphae were the highest and the activities values were （0.3741±0.0077）μmol/（mg pro·min） and  （61.7586±9.2400）nmol/（mg pro·min）, respectively. The differences among different development instars were significant. The activity of carboxylesterase in male adults was higher than that in female adults, and the difference between them was significant. For acetylcholinesterase, the activity in male adults was higher than that in female adults, but the difference was not significant.  The  activity  of  glutathione  S?transferase  among  different  development  stages  and  gender  adults  had  almost  no difference. Conclusion　The activity differences of carboxylesterase and acetylcholinesterase among different development stages and male, female adults were significant whereas that  of glutathione S?transferase was not significant.

　　【Abstract】　Objective　To assay the toxicities of deltermethrin and cypermethrin to male, female adults and the first, third, fifth instar nymphae of Blattella germanica, and to provide the effective instruction for chemical control of B.germanica. Methods　The  insecticide  films  in  jar  was  used  in this study. Results　There was significant difference for the tolerance of B.germanica to deltamethrin and cypermethrin  among different instars and different sexes. The tolerance of the first instar nymphae to deltamethrin and cypermethrin was the lowest with the KT50 values of 7.1743 min and 10.0015 min respectively. The KT₅₀ of the fifth instar nymphae to these two chemicals were 14.1624 min and 24.6041 min respectively, highest in all the instars. The tolerance level of nymphae increased gradually with the development of instars. The tolerance level of male adults was higher than that of female adults. The KT₅₀ of male adults to the two tested chemicals were 9.6157 min and 11.7492 min respectively. Conclusion　The KT₅₀ of the fifth instar nymphae to deltermethrin and cypermethrin was the highest. The KT₅₀ of male adults to deltermethrin and cypermethrin was higher than that of female adults.