• 한국잠사곤충학회지
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• 제40권1호
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• pp.33-37
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• 1998

Two types of sperm, apyrene and eupyrene, are identified in A. mylitta. The sperm in the adult moth are motionless in seminal vesicles. At the time of ejaculation they received a secretion from male ejaculatory duct that renders them motile. The dissociation of eupyrene bundles, eupyrene sperm motility and the sequence of events of sperm migration in both sexes are described in the present paper.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권2호
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• pp.113-119
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• 2007

Tropical tasar silkmoth Antheraea mylilta D. is an economically important insect. The wild nature and above all unsynchronized emergence of moths lead to impairment in reproductive activity. The mating in moths is low (64%-70%), leaving about 30-36% of potential females unused for seed (= egg) production. Delay in mating adversely affects the reproductive performance such as mating behaviour, fecundity and fertility. Females are more severely affected by mating delay than males. Therefore, a study was under taken to develop a method to overcome the problem so that the production of layings can be increased to meet the ever increasing demand. It was revealed from the study that out of 16 possible age combinations (from the age groups of day 0 to day 3), female and male of day 0 (4-8 hours old) excel in their reproductive performance than others (with 94.4% mating success, 284 fecundity and 91.5% hatching). Reproductive performance declined significantly even if one of the parents was older. When either of the mating pair was 1 day old, the mating declined by 28%; fecundity by 32.8%; and hatching by 40.8%. The insemination of eupyrene sperm was declined by 35.2% when both the parents are 1 day old. Mating duration of 8 hours resulted in insemination of $8.3{\times}10^5$ eupyrene sperms, which was declined by 31.6%, 48% and 55% upon lowering of mating duration to 6 hr, 4 hr and 2 hr were maintained respectively.

• 한국연초학회지
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• 제18권1호
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• pp.12-20
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• 1996

The spermatogenesis and chromosome number were investigated in the pupal testes of Helicouerpa assulta Guenee by light microscopy. During the spermatogenesis, each bundle of P8(256) sperms developed by 6 mitotic and 2 meiotic spermatogonial divisions. From the early stage of spermatogenesis, it was distinguishable between two kinds of sperm differentiation, eupyrene and apyrene spermatogenesis, which are characteristic in Lepidoptera, by the differences in nuclear shape and cell distribution in immature spermatocyst. Through the followed spermiogenesis, the spermatocysts were developed into two kinds of mature cyst, a streamline-shaped eupyrene cyst with nucleated sperms of thready head or a long spindle-shaped apyrene cyst with anucleated sperms of cylindrical head. As the results off chromosomal analysis at metaphase of the spermatogonial mitosis and spermatocytic meiosis, the chromosome number were 2n=6a/n=31, respectively, and no variation between individuals.

• International Journal of Industrial Entomology and Biomaterials
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• 제22권2호
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• pp.51-57
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• 2011

Reproductive activity in the economically important insect, Antheraea mylitta is very important because the female reproduces only once in her life time and the aging is very rapid and costly. It is a capital breeder and strictly a monoandrous species. To know how strategically the insect behaves and the male allocates its ejaculate resource more prudently during its successive mating with virgin females to maximize its own fitness and the fitness of the female with whom it mated, both being most important to sericulture industry. So, the present study was undertaken and the results revealed fresh and virgin females always prefer to mate with fresh virgin males (84%) and receives high dose of ejaculates leading to higher hatchability than to virgin males of one day old (13.7%) and one day old males with mating experience (2.3%). The ejaculation size (as referred to eupyrene sperm count in the ejaculation) declined significantly over successive mating (r = -0.9931, P < 0.001), so also the male body weight (r = -0.9560, P < 0.001). The quantity of ejaculate passed to female also dramatically declined during aging (r = -0.9982, P < 0.001). It was found that male weight contribute substantially to the quantum of ejaculate (r = -0.9519, P < 0.001), so also higher fecund females receive relatively more ejaculate than the lower group to reach higher reproductive fitness. The life time fecundity was found to be $334{\pm}31$.