The bean bug, Riptortus pedestris (=clavatus) Fabricius (Hemiptera: Alydidae) is a serious pest of soybean in many countries. It enters a reproductive diapause in the winter by short day length (＜13.5 h.) in Korea and Japan. The combined effects of temperatures (25℃ and 8℃) and day lengths (10L:14D and 14L:10D) upon the termination of the male"s diapause were studied. The combinations are ① HTLD = 25℃, 14L:10D treatment for 1, 2, 3 weeks and 30 days, ② HTSD = 25℃, 10L:14D treatment for 1, 2, and 3 weeks, ③ LTLD→HTLD = 8℃, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD treatment, ④ LTSD→HTLD = 8℃, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD. The amount of aggregation pheromone components secreted was adopted as the criteria for diapause termination in males. Males did not secrete aggregation pheromone under HTSD conditions. However, the males treated with HTLD for more than 21 days secreted significantly higher amounts of aggregation components, (E)-2-hexenyl (Z)-3-hexenoate and (E)-2-hexenyl (E)-2-hexenoate, compared to the control or HTSD treatments. The three components of the aggregation pheromone were secreted by the 14%, 29%, and 100% males treated with HTLD for 7 days, respectively. However more than 83% of the HTLD-treated males secreted all three components by the 30<SUP>th</SUP> day under the treatment. In comparison, the pheromone amounts secreted by the males treated with LTLD→HTLD or LTSD→HTLD were equal or less than those secreted by males with continuous HTLD treatment.

The bean bug, Riptortus clavatus Thunberg (Hemiptera: Alydidae), is a pest of soybeans and tree fruits. It enters reproductive diapause during winter. We studied the effect of different combinations of temperature, day length, and treatment period on the termination of diapause in R. clavatus using adult females collected in October and November 2006. Ovarian development was used to determine diapause termination. The treatments were: ① HTLD, 25℃, 14L:10D treatment for 1, 2, 3 weeks and 30 days, ② HTSD, 25℃, 10L:14D treatment for 1, 2, and 3 weeks, ③ LTLD, 8℃, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks, and ④ LTSD, 8℃, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks. The HTSD treatments did not affect ovarian development, and resulted in no significant difference in the number of mature eggs in ovaries or the percentage of diapause-terminated females compared to the control females before treatment. The percentage of females that terminated diapause was significantly higher in the HTLD treatment than in the HTSD treatment. The HTLD treatment for more than 14 days increased the percentage of diapause-terminated females, accelerated the development of the ovaries, and increased the number of mature eggs in ovaries. Compared with the HTLD or HTSD treatments, the LTLD or LTSD treatments followed by the HTLD treatment accelerated ovarian development and increased the number of ovipositing females. The pre-LTSD treatment for 1 week was enough to increase the number of eggs oviposited.

In order to establish an indoor-rearing system for A. Alcinous, the effect of temperature and pupal diapause was investigated. Temperature has been suggested as an important factor in determining the developmental rate, Lifespan and mortality in invertebrates. As temperature increase, the developmental period was gradually reduced. The developmental period of A. alcinous larvae was 12.9 days and 25.8 days at 30℃ and 20℃, respectively. And we investigated the effect of different chilling days on diapause termination. Under longday condition(LD 16:8h, 20℃) oxygen consumption gradually increase. But oxygen consumption on the first day of pupa was the highest and rapidly fell down the next day and attained lowest point after 7days, with average value of 1.92mol/min/g under shortday condition(LD 8:16h). Diapause pupae were chilled for 60, 75, 90, 105 days at 8℃ and thereafter subjected to LD 16:8h at 25℃. And emergence rate at 60~90days was 57.1~80.7%.

Temperature effects on diapause termination of Paratlanticus ussuriensis eggs were studied by measuring embryonic development and hatching rates at various conditions of indoor chilling and overwintering temperatures. Diapausing eggs of P. ussuriensis did not hatch at continued incubation at 25℃ and even after chilling for once at either 5℃ or 10℃ for 30, 45 and 60 days. In addition, double chillings at 5℃ with a 90 days interval at 25℃ did not induce hatching of diapausing eggs. However, double chillings at 10℃ induced hatching at 3.6~26.7%. When eggs were incubated at 25℃ after chilling for once at 5℃ for various periods, those weights were not changed but those chilled at 10℃ gradually increased to approximately 1.5 times. When 60-days-old eggs were artificially deposited under the soil at three different mountain sites in September 2007, the hatching rates of the first-overwintered eggs were 11.3, 3.5 and 4.1% and those of the second-overwintered eggs were 25.1, 21.6 and 0.4% at Hoepori, Bitanri and Hwasanri, respectively. Most eggs were hatched from mid-March to mid-April but little bit earlier in southern regions. During the hatching period soil temperatures in three tested locations were around 8 to 12℃. In overall, diapausing eggs of P. ussuriensis were greatly influenced by chilling temperature conditions and those repeated cycles, and may required overwintering for one or two times to hatch for the post-embryonic development.