• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.115-123
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• 2003

Oviposition and egg laying is an important physiological and behavioural event in the life cycle of the silkworm, Bombyx mori (L). Oviposition and egg laying is dependent on a number of intrinsic and extrinsic factors viz., neural, hormonal, environmental, physical, behavioral etc for the perpetuation of population. Although, the virgin female moths have fully developed embryos but active egg laying begins under the influence of mating which provides essential copulation stimulus for oviposition. After mating drastic biochemical changes occurred that incites egg laying under the influence of optimum environmental conditions. Weight of pupae as well as larval density has significant role on oviposition and egg laying behaviour in the silkworm wherein high pupal weight and inadequate rearing space affects not only the biology, morphology and physiology but also the oviposition and egg laying. Surface topography, plane of inclination, mating length, age of male moth, temperature and photoperiod etc has significant effect on reproductive physiology of silkworm. An attempt has been made in this review article to elucidate briefly the works carried out on mating behaviour, direct and indirect copulation stimulus, vitellogenesis, influence of environmental factors besides effect of weight of pupae and or pharate adult and larval density on oviposition and egg laying behavior in the silkworm, B. mori and its significance in silkworm seed production.

• 한국응용곤충학회지
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• 제52권1호
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• pp.29-33
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• 2013

화살깍지벌레 여름성충의 산란수를 항온조건에서 조사하였다. 총 산란수는 온도가 증가함에 따라 $29^{\circ}C$까지는 증가하였고 그 후 감소하였다. 최대 산란수는 암컷당 평균 $29^{\circ}C$에서 254.5개로 나타났다. 성충은 주기적인 산란활동을 보였으나, 그 형태는 온도에 따라 달랐다. 처리온도 $25^{\circ}C$와 $29^{\circ}C$에서는 3개 이상의 산란주기가 나타났다. 다른 온도에서는 두 번째 산란주기가 불완전하거나 확실하지 않았다. 첫 번째 산란주기 산란수는 온도에 따라 유의한 차이를 보였으며 $25^{\circ}C$와 $29^{\circ}C$에서 많았다. 또한 이후 산란주기의 산란수도 $13^{\circ}C$, $17^{\circ}C$ 및 $21^{\circ}C$에서는 $25^{\circ}C$와 $29^{\circ}C$ 보다 낮았다. 부화약충의 암컷 : 수컷 성비는 $13^{\circ}C$, $17^{\circ}C$, $25^{\circ}C$, $29^{\circ}C$, $33^{\circ}C$에서 각각 1 : 0.48, 1 : 4.79, 1 : 2.48, 1 : 1.85, 1 : 0.56로 조사되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제30권1호
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• pp.26-30
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• 2015

Tropical Tasar culture is forest and agro-based activity that covers agricultural and industrial activity. Tasar silk is produced by the silkworm, Antheraea mylitta which is polyphagous in nature. A large number of pests are reported to attack both the host plant as well as silkworm. As the rearing is conducted outdoor silkworms are exposed to attack of various pests during their life cycle. Eocanthecona furcellata (Hemiptera: Pentatomidae) is the major predator of tasar silkworm during young age rearing. Both nymphs and adults of the stink bug suck the heamolymph of silkworm leading to death. The present work was undertaken to study the life cycle of E. furcellata on larvae of vapourer tussock moth which is a major pest of tasar host plants. The incubation period, nymphal duration and total developmental period from egg to adult was $8.0{\pm}0.45d$, $16.0{\pm}3.24$ and $22.0{\pm}4.20d$, respectively. Pre-oviposition, oviposition and longevity of male and female stink bug was $3.20{\pm}0.38$, $17.60{\pm}1.86$, $42.40{\pm}1.94$, $37.00{\pm}3.18d$, respectively. Analysis of the data revealed no significant difference in life cycle of the predator when provided silkworm and vapourer tussock moth larvae as hosts. Which clearly indicates that E. furcellata can multiply on vapourer tussock moth larvae during non rearing periods. Adoption of recommended pest control measures for defoliators of tasar host plants during non-rearing periods will help in reducing the incidence of host plant pests and also in reducing the incidence of stink bug during rearing season. During the study it was also observed that larvae semilooper, boll headed caterpillar and nymphs of leaf hopper serve as alternate/secondary hosts to E. furcellata during non rearing seasons.

• International Journal of Industrial Entomology and Biomaterials
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• 제38권2호
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• pp.38-50
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• 2019

We investigated the developmental characteristics and life cycle of the lawn cutworm, Spodoptera depravata (Lepidoptera: Noctuidae), which is one of the most important pests causing economic damage in grass production. For larval culture, we provided the zoysiagrass at $25^{\circ}C$ and $60{\pm}5%$ humidity. The durations of the developmental stages were as follows: $4.11{\pm}0.19$ days for eggs, $25.17{\pm}3.02$ for larvae, $8.80{\pm}0.28$ for pupae, and $7.57{\pm}0.95$ for adults. We grew the larvae to the 7th instar stage, unlike previous studies, in which it was assumed that the 6th instar was the final age. There was a significant positive correlation between the body length and head capsule width of each instar larvae. In terms of morphology, the eggs changed from light green immediately following oviposition to black as they developed, and the grass-fed larvae changed from light yellow immediately after hatching to green as development continued. We observed a pattern of black spots at regular intervals on the dorsal sides of the abdomens of the final instar larvae. Furthermore, we detected two notable designs on the dorsal side of the front of the head. The pupal colors changed from light brown and green immediately after pupation, to dark brown as the pupal cuticle hardened. The wingspans of the adults were similar in both sexes. However, the forewings of the males had obvious outer lines and eyespots with dark gray-brown backgrounds, whereas the corresponding features on the female forewings were less obvious. The oviposition preperiod was 2.11 days, the oviposition period was 4.2 days, the average fecundity per female was approximately 341 eggs, and the hatching rate was approximately 76.1%.

• Journal of Ecology and Environment
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• 제36권1호
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• pp.11-17
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• 2013

The life cycle of butterflies is closely related to the growth of food plants and, through a prolonged coevolutionary process, has undergone an ecological adaptation. So, it is important that control the egg-laying number and place to secure enough food plant by female adult to guarantee the survival of the larvae. To study whether oviposition control of the Luehdorfia puziloi takes into greater consideration food plant leaf biomass or leaf abundance, correlation among the egg cluster size, the leaf size, and the number of leaves around egg clusters was investigated. According to the results, the egg clusters size exhibited positive correlation with the leaf size of food plants on which eggs had been laid but did not do so with the number of surrounding leaves. In addition, the number of egg clusters laid exhibited positive correlation with the number of surrounding food plant leaves but not with the leaf size on which eggs had been laid. Consequently, for the Luehdorfia puziloi, the females' recognition of the leaf size seems to be the most important factor in the egg cluster size, and the number of egg clusters had positive correlation with food plant density per unit area.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1565-1571
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• 2003

Physiological mechanisms, involved in unusual ovulatory sequences in domestic hen are remaining undefined. One hundred individually caged white leghorn birds were divided into two equal groups viz. control and treatment, and 2-bromo-$\alpha$-ergocryptine, was administered to birds in the treatment group to modulate prolactin (PRL) secretion from anterior pituitary gland. The effect of modulation of PRL concentrations on egg production, sequence length and intersequence pause length were studied by analysis of oviposition records of the birds from 24 to 72 weeks of age. The surviving 48 birds in the control and treatment groups averaged $34.58{\pm}1.7$ and $25.67{\pm}1.15$ sequences of oviposition, with a mean sequence length of $9.92{\pm}0.63$ and ${\pm}1.12$ days respectively. Most of the birds had a single characteristically long sequence during the entire reproductive cycle, which averaged $46.04{\pm}3.09$ days in the control birds and $59.33{\pm}4.44$ days in the treated birds. 2-bromo-$\alpha$-ergocriptine treatments had significantly decreased (p$\leq$0.01) the circulating concentrations of PRL compared to the birds of the control group. This resulted in a significant increase (p$\leq$0.01) in the number of laying days in birds of the treatment group with a concomitant decrease in the intersequence pause length. The decreased PRL levels during prime sequences in birds of the both groups, reveals the negative role of the circulating PRL levels on egg production with concomitant shorter intersequence pause length. Hence, modulation of PRL with dopamine agonist may enhance the reproductive efficiency of hens later in life.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.686-691
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• 2005

Prolactin is considered to influence the taking of pauses in between ovulatory sequences in White Leghorn hens. Therefore modulating concentrations of prolactin using bromocriptine - a dopamine agonist during early life (17 to 36 weeks of age) could overcome the inhibitory effects of high concentration of prolactin on ovarian activity. The effect of modulation of prolactin concentration on egg production, sequence length and inter sequence pauses were studied by analyzing the oviposition records from 19 to 72 weeks were studied and compared with untreated controls. Bromocriptine administered subcutaneously (100 $\mu$g kg$^{-1}$ body weight or orally through feed (640 $\mu$g day$^{-1}$ bird$^{-1}$) resulted in a steady and sustained decrease in prolactin levels (p<0.01) during and after the withdrawal of treatment up to one reproductive cycle (72 weeks of age). The treated birds had comparatively longer sequences (p<0.01) and fewer pauses (p<0.01). Egg production increased (p<0.01) by fourteen per cent through subcutaneous administration and eleven per cent through oral feeding, over the control birds. It is concluded that the physiological pauses that occur during ovulatory sequences can be disrupted effectively using bromocriptine. Prolactin levels are modulated which may interfere with the follicular recruitment and subsequent oviposition thereby improve egg laying potential of the bird.

• Journal of Ginseng Research
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• 제14권3호
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• pp.421-426
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• 1990

Field and laboratory works were conducted to Investigate the life history, ginseng damage and chemical control effect of the field slug, Deroceras varians A. Adams. D. varians laid eggs from April to June, but a small number of eggs were also found from July to September in the field. Most young slugs grew through the slimmer months to maturity by October. overwintered beneath the moist soil surface, and began feeding and egg-laying in the following April. indicating that D varians have a life cycle in a year. Damage of ginseng plants by D. varina occurred mainly from late April to mid May in the 3rd to 5th year ginseng fields with rice-straw mulching. It seems that this damage is caused by the adults in oviposition periods and related to rice-straw mulching of ginseng fields. In the experiment, ethoprop 5% granule and metaldehyde 6% bait showed relatively high effectiveness in the control of D. varians adults. Bordeaux mixture was more effective when the chemical was sprayed after infestation of the slug than before the infestation and when the 6-12 mixture was used.

• 한국응용곤충학회지
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• 제51권2호
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• pp.141-148
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• 2012

본 실험은 2011년 전남 구례지역의 산수유, 감, 밤 등에 대발생하여 피해가 심한 갈색날개매미충의 기주식물, 산란특성, 형태적 특징, 생활환을 조사하고 친환경 방제자재 선발을 위하여 수행하였다. 갈색날개매미충의 기주식물은 목본류 32종, 초본류 19종을 포함한 51종이였으며, 산란 선호식물은 산수유, 감나무, 밤나무, 두충나무, 때죽나무였다. 알은 길이 1.24 mm, 폭 0.55 mm 의 장타원형으로 1년생 가지 속에 난괴 당 평균 28.8개의 알을 산란하였다. 약충은 4회 탈피하는데 항문 주변에 x자 모양의 흰색 또는 노랑색 밀납물질을 형성한다. 전남 구례지역에서 연 1세대 발생하며 알로 월동하여 부화시기는 5월 중순~6월 상순, 약충시기는 5월 중순~8월 중순, 성충은 7월 중순~11월 중순이며 알은 8월 중순부터 산란한다. 갈색날개매미충은 산란에 의한 1년생 가지 고사, 양분흡즙으로 인한 생육저해, 그을음병 유발에 의한 상품성을 하락시키는 피해를 준다. 갈색날개매미충 약충과 성충 방제에 효과적인 친환경자재는 고삼추출물제와 천연식물추출물제로 살충율이 80% 이상이었다.

• 한국응용곤충학회지
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• 제53권4호
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• pp.381-389
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• 2014

매실의 낙과 피해를 일으키는 복숭아씨살이좀벌은 경기도, 충청남북도, 전라남북도 지역의 매실과 살구, 그리고 중국산 복숭아 종자에서 확인되었다. 복숭아씨살이좀벌은 땅에 떨어진 핵과류의 핵 속에서 유충 상태로 월동하고, 노숙유충은 4월 중순까지, 번데기는 3월 하순에서 4월 하순까지 관찰되었으며, 성충은 4월 하순~5월 상순 사이에 90% 이상이 우화하는 것으로 조사되었다. 암컷 성충은 핵이 경화되기 이전 씨앗이 액상일 때 과실 씨앗의 외피 바로 밑에 산란하였으며, 산란관의 길이가 5 mm를 넘지 않아 산란이 가능한 매실의 크기는 직경이 2 cm를 넘지 않았다. 하나의 과실에 최대 5개의 알이 관찰되었으며, 알 기간은 2일을 넘지 않았다. 부화한 유충은 먼저 고형화되는 배로 이동하여 이를 섭식하면서 성장하는데 이 과정에서 유충들 사이의 경쟁으로 인해 한 마리의 유충만 생존하였다. 6월 상순경 피해를 받은 과실의 대부분이 부패증상을 보이며 낙과하였다. 땅에 떨어진 과실의 핵 속에서 이듬해 봄까지 노숙유충으로 월동하였다.