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        검색결과 48

        41.
        2008.05 구독 인증기관·개인회원 무료
        Temperature-dependent development and oviposition component models were developed for Pseudococcus cryptus Hempel (Homoptera: Pseudococcidae). Egg development times decreased with increasing temperature and ranged from 2.4d at 16℃ to 1.0d at 28℃. Total development times of nymphs reared on citrus leaves decreased from 54.9d at 16℃ to 17.4d at 28℃ and 19.3d at 32℃. As P. cryptus showed an ovoviviparous reproductive behavior, the periods of egg and the 1st nymph were combined. By fitting linear models to the data the lower developmental threshold temperatures for egg-1st nymphs, the 2nd nymphs, the 3rd nymphs, and all nymphs combined were calculated as 8.7, 12.8, 13.1, and 12.1℃, respectively. The thermal constants were 198.6, 84.7, 69.8, and 296.3 degree-days for each of the above stages. The non-linear model based on a Gaussian equation, which fits the relationship between development rate and temperature was well for all stages. Adult longevity decreased with increasing temperature and ranged from 80.4d at 16 to 31.3d at 32.0℃. Also, preoviposition and oviposition periods showed a similar pattern with the longevity. P. cryptus had a maximum fecundity of 111 eggs per female at 28℃, which declined to 102.7 eggs per female at 32℃.
        42.
        2008.05 구독 인증기관·개인회원 무료
        Murgot Looper Moth, Ascotis selenaria, is one of the worldwide pests in citrus plants. They usually damages citrus leaves and often makes young fruits injured. In Jeju, it has been discovered that A. selenaria is a pest of two major geometridae moths being occurred in citrus plant and they also had periodically occurred and damaged bean, asparagus, etc. However, physiological and ecological studies were rarely conducted on this species, which maybe resulted from the limitation of rearing method. Therefore, this study aimed on selecting the diet sources and developing mass-rearing method for A. selenaria, in order to make ease or spur a investigation related with A. selenaria. The major sources, selected among the series of semi-artificial diet, were corn and bean powder and adding yeast makes the larva developed well. Cholesterol, one of the minor sources, enhanced the development rate and lowered the mortality during 1 to 3 larva stage. Consequently the semi-artificial diet, suitable for rearing A. selenaria larva, was composed of 25g agar, 100g corn powder, 100g soybean powder, 30g yeast, 0.5g cholesterol, 2g Vanderzant's vitamin mixture, 2g Wesson's salt mixture, 2g sorbic acid, 2.5g methyl-4-hydroxybenzoate(MPH), 2g Ascorbic acid, and 1000 ml distilled water. A. selenaria larvae has 6 developmental stage and the width of head piece was 0.31 mm (1st instar) , 0.51 mm (2nd), 0.85 mm(3rd), 1.37 mm (4th), 2.14 mm (5th), and 3.19 mm (6th). The development period of A. selenaria, reared at 25℃ and 16L:8D photoperiod, was 4.7 day (egg), 3.58 day(1st instar), 1.88 day (2nd), 1.80 day (3rd), 2.46 day (4th ), 2.59 day (5th), 8.10 day (6th), 11.26 day (pupae) when citrus leaves were supplied to the larva. The larvae, fed with the artificial diet(mentioned above), showed similar developmental periods at each developmental stage as much as the case reared with citrus leaves, although the mortality was sometimes a little bit higher. The weight of pupae were 0.614g (artificial diet) and 0.427g (citrus stuff) and female adult moths lay 1094 eggs (artificial diet) and 1054 eggs (citrus stuff).
        43.
        2008.05 구독 인증기관·개인회원 무료
        Deraeocoris brevis Knight (Hemiptera: Miridae) is a generalist predator and is a key natural enemy in pear orchards in the northwestern United States. Although D. brevis undoubtedly contributes to the regulation of major pear pests, pesticides often disrupt its activity and reduce its effectiveness as a biological control agent. A temperature-dependent stage-structured matrix model was developed to analyse the population dynamics of D. brevis influenced by insecticides. In this study, impacts of acetamiprid on field populations of D. brevis were analysed. The age class of D. brevis was categorized into four stages: eggs, small nymphs (1st to 3rd instar), large nymphs (4th to 5th instar), and adults. Probabilities for each element in the projection matrix were estimated using published temperature-dependent developmental data of D. brevis. Transition probabilities from an age class to the next age class or the probabilities of remaining in the age class were obtained from development rate function of each stage (age classes). The fecundity coefficients of adult population were the products of adult longevity completion rate (1/longevity) and temperature-dependent total fecundity. Also, direct and indirect residual effects of acetamiprid were incorporated into the model. The model results were much overestimated compared with observed actual data from 25d after model running. Such a discrepancy might be occurred from various reasons such as an intra-species competition, successful fecundity rate, etc. Further, the improvement and application of the model were discussed.
        47.
        1993.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        점박이응애(Tetranychus urncae)의 알밀도(10~80), 공간분포〈집중 빛 균일분포) 및 서석면적크기 (3, 9, 16 )에 따른 긴털이리응애(Amblyseius longispinosus)의 가능반응을 연구하여 다음과 같은 결과를 얻었다. 긴털이리웅애의 점박이응애 발견효율은 밀도와 공간분포의 영향을 받았으나, 면적의 영향은 없었다. 포식량과 피식자간의 거리와는 매우 높은 역상관관계를 보였다(r=강.85, p=0.0001). 포식반응은 제2형의 기능반응을 보였다. 긴털이리응애의 기능반응은 random predator equation으로 잘 설명되었으며, 탐색률은 피식자의 집중분포하에서 반응면적에 따라 0.1030 - 0.1504였고 균일분포하에서는 0.0546~0.0276였다.
        4,000원
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