The susceptibility values for field-collected (BG-BG) and laboratory (KS-BG) strains of German cockroaches, Blattella germanica (L.) to 5 synthetic pyrethroids and 3 organophosphates were assessed by topical application. Both KS-BG and BS-BG demonstrated the highest levels of susceptibility to deltamethrin. The KS-BG demonstrated the lowest susceptibility level to fenthion, while the BS-BG field population showed the lowest susceptibility to bifenthrin. The BS-BG field population showed resistance levels of 50 to 640 fold higher against the eight pesticides evaluated compared to the KS-BG. The resistance ratios (RR) of the eight pesticides were compared using populations of B. germanica that were collected from the same locality during 2007 and 2014. The field population of B. germanica collected during 2014 demonstrated significantly high resistance to an organophosphate and all pyrethroids when compared with those collected during 2007, but RR values were < 10 except for chlorpyrifos-methyl and chlorpyrifos with RR values of 74 and 104, respectively.

The susceptibility of the Blattella germcanica (L.) in the Republic of Korea (ROK) to insecticides was evaluated under laboratory conditions using 12 insecticides currently used by the local public health centers and/or pest control operators in the ROK. The insecticides included seven pyrethroids and five organophosphages. Based on their LD50values, the order of susceptibility of B. germanica adults to the insecticides was chlorpyrifos-methyl, profenofos, and chlorpyrifos with the values of 0.07, 0.29, and 0.88 ㎍/♀, respectively. The least susceptibility was obtained with tetramethrin at LD50 of 7.39 ㎍/♀. In the comparative resistance test, the resistance ratios (RR) of 12 insecticides were compared to each other using field collected B. germanica adults in Seoul between 1993 and 2007. Blattella germanica demonstrated higher RRs to pyrethroids such as λ-cyhalothrin, and low RRs among the organophosphates. Among the pyrethroids, λ-cyhalothrin had the highest RRs of 111 and 129 fold differences at LD50 and LD90 values, respectively. Among the organophosphates, profenofos was observed to have the highest RRs of 4 and 15 fold differences at LD50 and LD90 values, respectively. However, there were no significant differences in susceptibility to tetramethrin, chlorpyrifos, and fenitrothion. Blattella germanica was more susceptible to pyridafenthion showing a 0.7 fold difference in a resistance rate (RRLD50), respectively. Resistance ratio of tetramethrin was low, but susceptibility was also not high.

5.0% micro-capsuled fenitrothion, 2.0% hydramethylnon, 또는 0.8% chlorpyrifos가 주요 활성 물질인 독먹이 제제의 방제효과를 알아보기 위하여 바퀴, Bfattella germanica (L)가 번식하고 있는 15개의 식당에서 8주동안 야외실험을 실시한 결과는 다음과 같다. 바퀴 성충에 대한 방제효과는 mIcro-capsuled fenitrothion 제제 (평균 82.8%)가 chlorpyrifos 제제 (평균 68.4%)보다 유의성 있게 높았으나 hydramethylnon 제제 (평균 86.1%)와는 거의 같은 효과를 보였다. 또한, 바퀴 자충에 대한 방제효과는 3가지 독먹이 제제가 거의 같은 유효성(평균 74.9- 82.8%)을 나타내였다. 독먹이 소모량을 조사한 결과, 8주 동안에 서식 바퀴에 의한 micro-capsuled fenitrothion 제제의 소모량은 0.11 g으로, 평균 90% 이상 남아 있었으나, hydramethylnon 제제는 바퀴에 의한 소비량(O.72g)이 현격하게 많아서 잔여량이 평균 57%로 나타났다. 이러한 결과는 hydramethylnon의 살충 기작의 특성, 유인먹이의 재료, 서식 바퀴의 밀도와 관계가 있는 것으로 추정되었다.