[en] The studies of population fluctuation of male oriental fruit fly, (Dacus dorsalis Hendel) and [Dacus zontanus (Saunders)] and micro climate at Royal Ang Khang Highland Research Station Chiang Mai in 1983 were conducted. It was found that population of Dacus zonatus was rather high and almost seemed equal to that of Dacus dorsalis. Population of these two species increased at the beginning of February. Population of Dacus zonatus increased rapidly and reached the peak in the middle of May and of June. The number at peaks were 103 males and 87 males/trap/day respectively. However, the population of Dacus dorsalis increased slowly and followed the pattern of Dacus zonatus until the beginning of June, after that, the population increased rapidly and reached the peak in the middle of July. The number at peak was 240 males/trap/day. Later on they dropped rapidly in the middle of August, then the population of the two species fluctuated together. Finally they decreased down to near zero in November, December and January of the following year. In summary, population density of the said two species adult flies were rather high from the end of winter (the beginning of February) to the middle of raining season (July) and this period coincided with the time of fruit development in many introduced varieties (peach, persimmon, apple, pear and plum)

[en] The development of pink bollworm, Pectinophora gossypiella (Saunders) was compared on rearing on used-diet or the medium remaining after larval use, with no supplements added versus used-diet with 100 percent supplement of vitamins, choline chloride and the heat sensitive antimicrobial agents (Fumidil B, Aureomycin and formaldehyde). In another evaluation of used diet it was mixed at 0, 25, 50, and 75 percent with the new diet and compared to 100 percent new diet. Used diet with no supplement and used diet with 100 percent supplement of vitamins and heat sensitive antimicrobial agents had no significant effect on the development of the pink bollworm except in adult emergence. Some pupae which developed from unsupplemented used-diet died before moth emergence. Used diet mixed with 75 percent new ingredients was the best rate for reclamation of the used diet and produced the same results in pupal production rate pupal weight, adult emergence, adult longevity and egg production of female pink bollworm when compared to those from diet prepared with 100 percent new ingredients. The other rates supplemented with 0,25 and 50 percent new ingredients were significantly poorer by most criteria

[en] Effect of gamma radiation on each growth stage of meal worm (Tenebrio molitor Lin.) were conducted at 27+-2⁰C and 75+-2% relative humidity. LD₅₀ and LD₉₉ of 5-day old eggs at 5 days after irradiation were 76 and 367 gray. The survived larvae could live no longer than 5 days and seldom moved or without feeding. LD₅₀ and LD₉₉ of last instar larvae at 10 days after irradiation were 662 and 1,367 gray. No pupation occurred in larvae after irradiation. Dead larvae caused by radiation turned blackish, liquid oozed out from the body, and survived no longer than 5 days. Some irradiated larvae had incomplete molting and died. LD₅₀ and LD₉₉ of 6-day-old pupae at 3 days after irradiation were 874 and 1,492 gray. Abnormal irradiated pupae, some abnormal pupae were underdeveloped wing and abdominal pupal characteristic was still remained. Pupal legs could develop to adult legs only and could survive no longer than 1 week. Unfortunately pupae irradiated at low dosage of radiation would develop to be complete adult head, but could survive no longer than 2 weeks with slow movement and no oviposition. LD₅₀ of male adults and female adults was checked in 7 days postirradiation and it was estimated as 788 and 786 gray while LD₉₉ was estimated as 1,375 and 1,350 gray respectively. Results of male adults and female adults checking in 10 days post-irradiation found that LD₅₀ was estimated as 533 and 598 gray and LD₉₉ was estimated as 1,227 and 1,229 gray respectively. The remained survivors of both sexes could survive no longer than 10 days without feeding and mating

[en] The army worm, Spodoptera exigua Hb. was reared for 6 more generations in an artificial medium containing Mung bean as a major component. By improving the rearing temperature and humidity conditions, better rearing results were obtained. The average percentage of development from eggs to pupae, from eggs to adults, and from pupae to adults was 41.7+-4.93, 38.44+-6.32 and 88.1+-1.48 respectively. The pupal weight was also calculated. In sterilization studies, the 3-day-old male pupae were subjected to gamma rays at 0, 5 and 10 krads. Upon emerging into adults, they were mated with non-irradiated female moths. Male moths emerged from pupae subjected to 10 krads of gamma rays could significantly induce infertility in eggs deposited

[en] Commercial packages of fragrant rice, 50 kg each, were used to determine the efficiency of an industrial gamma irradiator, Model JS-8900. The maximum product throughput was 6,300 kg in 1 hr 27.12 min with the overall average absorbed dose in the product carrier of 1.0 kGy. Fragrant rice irradiated at 0, 0.5, 0.9 and 1.1 kGy were used for sensory acceptability evaluation. The panel accepted the color, the taste and the texture of steamed-fragrant rice, regardless of radiation doses. In addition, the odor and the color of raw-fragrant rice irradiated at 0.9 and 1.1 kGy were accepted