톱다리개미허리노린재(Riptortus pedestris Fabricius)는 지역에 따라 사과에 심각한 경제적 피해를 야기하고 있지만, 사과에서 톱다리개미 허리노린재 친환경 방제에 대한 연구는 전무한 실정이다. 따라서, 이번 연구에서는 톱다리개미허리노린재의 집합페로몬 성분 중 (E)-2-hexenyl (Z)-3hexenoate (E2HZ3H)이 노린재검정알벌(Gryon japonicum Ashmead)과 노린재깡충좀벌(Ooencyrtus nezarae Ishii)에 미치는 영향을 조사하였다. 사과 과수원에서 E2HZ3H는 전체 과수원에 발생하는 2종의 포식기생자의 밀도에는 직접적으로 영향을 주지 않았고 이들 포식기생자의 공간분포도 변화시키지 않았다. 그러나, E2HZ3H 루어가 설치된 지역 주변에서는 2종의 포식기생자 모두 제한적으로 유인하는 것을 확인하였다. 따라서, E2HZ3H 루어는 사과 과수원 내에서 정밀방제를 목적으로 친환경 방제에 고려될 수 있을 것으로 생각된다.

As a broad-spectrum insecticide azadirachtin may cause acute toxicity and alter behavior of natural enemies. We evaluatedthe toxicity of azadirachtin on two egg parasitoids of Riptortus pedestris (Fabricius) (Hemiptera: Alydidae), Ooencyrtusnezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Platygastridae), by pre-treatinghost eggs with five concentrations, i.e., 15, 10, 7.5, 5, and 2.5 mL/L. Azadirachtin significantly reduced parasitism byG. japonicum in 15 and 10 mL/L concentrations than other lower concentrations. Similar effect was also observed inO. nezarae. The parasitism reduction capacity (R) for G. japonicum was 40.8 and 33.1% in 15 and 10 mL/L concentrations,but it was 81.6 and 71.4% in O. nezarae, respectively. Based on the IOBC guideline, azadirachtin can be slightly ormoderately harmful to O. nezarae and slightly harmful or harmless to G. japonicum.

From our previous studies in a farm in Songcheon, Andong where a series of crops was cultivated in 2008 and 2009, occurrence patterns of Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) and its egg parasitism by Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae) were reported. With an objective to verify the trend of the occurrence pattern, a year long monitoring of R. pedestris and its egg parasitism was continued in 2010 in the same location where barley, sesame, and soybean were cultivated in series. We placed four aggregation pheromone traps added with 50 refrigerated eggs of R. pedestris each along the perimeter of the field from 11 April to 31 October. Weekly occurrence patterns of R. pedestris and its parasitism in 2010 were generally similar to the patterns of previous years. Riptortus pedestris population first appeared in the last week of April, peaked after the third week of August, and declined in October. Parasitism by G. japonicum was recorded up to 64% in July, 2010 which was much higher than previous years. This study verifies that G. japonicum is the first colonizer that appears as early as May and remains active until September. Ooencyrtus nezarae, however, starts to occur late from the last week of August and exist in the field until October.

Gryon japonicum (Ashmead), an egg parasitoid of Riptortus clavatus (Thunberg) is an economically important pest of various crops. As a conservational biological control, non-viable refrigerated eggs of R. clavatus were released to enhance parasitism by the parasitoid in soybean field. Since fenitrothion is an insecticide broadly used against R. clavatus, we investigated the effect of fenitrothion on the parasitization of refrigerated host eggs by G. japonicum. The acute toxicity of fenitrothion was compared with seven pesticides by topical application, exposure to residue, and oral ingestion. Fenitrothion, spinosad, cyfluthrin, carbosulfan and thiamithoxam caused 100% mortality within 24 hours by topical application. Fenitrothion was also highly toxic to G. japonicum when ingested orally. In sublethal effects of fenitrothion on G. japonicum in refrigerated and fresh host eggs, adult emergence of G. japonicum decreased by 12% and 34%, respectively, compared to control when the fenitrothion was applied on 8th day after parasitization. Parasitism on refrigerated eggs after a day of fenitrothion spray was higher as compared to the fresh eggs. However, parasitism on both refrigerated and fresh eggs significantly reduced when the parasitoids were provided with the fenitrothion sprayed eggs after an hour. In conclusion, there is no negative effect of fenitrothion on the parasitization by G. japonicum.

The kairomonal activity of the aggregation pheromones of Riptortus clavatus for the egg parasitoid, Gryon japonicum , were investigated in soybean field. The parasitism rate of G. japonicum gradually decreased when the distances between pheromone traps and egg sites were increased from 0 to 15 m. The active distance of pheromone source for parasitoid attraction was estimated to be ca. 15 m. Under field conditions, the parasitoid wasp population peaked during the late August and early September, and the parasitism rate increased when the number of pheromone traps was increased from one to three per 165 ㎡. However, insecticide-treated plots, the level of parasitism recorded is relatively low. Sex ratios in field populations of G. japonicum were female-biased.