[en] The cotton bollworms, Helicoverpa armigera (Huebner) were reared on an artificial medium consisting of mungbeans, brewer's yeast, vitamins, water, preservatives and antibiotic (Tetracycline hydrochloride) at 26 +- 1 deg C, 70-75% R.H., and 8-hr light duration. The development of this species were not significantly different (p = 0.05) in percent egg hatch, pupal recovery, adult eclosion, and pupal weight in each of 4 successive generations. Effects of gamma irradiation, obtained from Cesium-137 source, on eggs, larvae, pupae and adults of the cotton bollworm were also studied. All sterilizing doses, for various stages of the cotton bollworm, did not reduce the longevity both sexes of the insect. However, sterilized males emerged from eggs, larvae, pupae appeared to mate less frequently than normal males did. In contrast, males sterilized as adults mated as frequently as normal males. The sperms of sterilized males emerged from various stages were probably less motile and possibly less numerous than sperms from normal males. The results of this experiment can be concluded that, it is more effective to control this insect by sterilization in both pupal and adult stages with 150 and 200 gray respectively

[en] Copulation and sperm transfer were observed between wild flies and sterile flies of Bactrocera dorsalis (Hendel) and Bactrocera correcta (Bezzi) in cages. 8-day old pupae of B. dorsalis and B. correcta were irradiated with gamma rays at 90 and 80 gray respectively. Wild flies from infested fruits and sterile flies from artificial diet in the labolatory were used for testing. The experiments were conducted 3 treatments and 3 replications. The ratio of sterile male : wild male: wild female were 3:1:1 by using sterile male of B. dorsalis: wild male of B. correcta : wild female of B. correcta and sterile male of B. correcta: wild male of B. dorsalis: wild female of B. dorsalis as 60:20:20 flies respectively. The experiment found 69 pairs of copulation consisting of 3 mating pairs(4.3%) of wild male with wild female of B. dorsalis, 22 mating pairs (31.9%) of wild male with wild female of B. correcta, 2 mating pairs(2.9%) of sterile male of B dorsalis with wild female of B. correcta, 42 mating pairs(60.9%) of sterile male of B. correcta with wild female of B. dorsalis. The cages which ratio 1:1 consisted of wild B. dorsalis and wild B. correcta (male and female = 50:50 flies) were observed and found that 43 pairs of copulation such as 2 mating pairs (4.6%) of wild male with wild female of B. dorsalis, 26 mating pairs (60.5%) of wild male with wild female of B. correcta, 2 mating pairs(2.9%) of sterile male of B. dorsalis with wild female of B. correcta and 15 mating pairs(34.9%) of wild male of B. correcta with wild female of B. dorsalis. Mated female flies were separated from male flies. Egg hatch and sperm were checked. The hatchability of normal copulation of B. dorsalis and B. correcta were 81 and 90%. The average sperm level in spermathecae of normal copulation of B. dorsalis and B. correcta were 2.2 and 2.3 respectively but had no sperm in their spemathecae of females of interspecific copulations Mating behavior of both species began in the evening before sunset at <500 lux.g

[en] Mating competitiveness of F₁ male moth of cotton bollworm, Helicoverpa armigera from male parents irradiated as mature pupae with normal male and normal female were studied in cages. The ratio of F₁ male : normal male: normal female proposed in this experiment were 0:1:1, 1:0:1, 1:1:1, 3:1:1 and 5:1:1. The result showed that the hatchability were 74.9, 0, 58.8, 49.6 and 37.6% respectively, the average of mating competitiveness value were 0.1-0.3. When the minimum of mating competitiveness value(0.1) was considered, the moths of F₁ male, normal male and normal female were released in the field cages at the ratio of 10:1:1, the releasing number were 100:10:10 moths per cage. The result showed that no significant difference occurred between releasing cage and non-releasing cage by t-test analysist

No abstract available

[en] Effects of gamma radiation on eggs, larvae, pupae and adult stages of the cigarette beetle were studied. The LD₅₀ and LD₉₉ of gamma radiation to the eggs (7±1 days) were 327 Gy and 834 Gy respectively on the 3^rd day after irradiation. At 300 Gy the eggs were able to hatch but died in the pupal stage. None of the eggs hatched when treated with 800 Gy and other doses. The LD₅₀ and LD₉₉ to the last instar larvae (7±1 days) were 505 Gy and 1,547 Gy on the 12^th day after irradiation. The mortality of last instar larvae varied directly with the irradiation dose, no larvae could survive when irradiated at 1,500 Gy and above. At the dose lower than 1,200 Gy, some pupation was observed but no adult emergence occurred. The LD₅₀ and LD₉₉ of gamma radiation to pupae (4±1days) were 548 Gy and 1,578 Gy on the 12^th day after irradiation. The pupal mortality varied directlty with the dose. No adult emergence was obtained after irradiated at 1,500 Gy. At 300 Gy, the adults emerged with deformity and sterility. The LD₅₀ and LD₉₉ to adults (3±1 days) were 931 and 1,746 Gy respectively on the 12^th day after irradiation. The mortality of adults increased when irradiated at higher dose and none of the eggs hatched after treated adults with 300 Gy. The dosage of 300 Gy was high enough to inhibit the development of all stages. Melanization occurred in untreated young larvae after killing by freezing. Some parts of larval body became dark brown to black while the rest of the body was yellow-white or greyed-yellow. In the treated young larvae, non-melanization to slight melanization occurred at 100, 300 and 500 Gy. The degree of melanization in treated young larvae decreased with the increasing doses. In treated old larvae, the melanization increased with the increasing doses