scholarly journals Environmental Controlling Factors of Tasar Silkworms Antheria mylitta Drury (Lepidoptera : Saturniidae)

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 115-118
Author(s):  
Amit Ranjan ◽  
Anjana Poddar ◽  
S.P. Roy

The paper deals with the ovipositioin, hatchability, fecundity larval and pupal performances of a tropical variety of tasar silkworms Antheria mylitta Drury (Lepidoptera : Saturniidae). The Tasar silkworms have been cultured feeding on the leaves of Arjun (Terminalia arjuna) in the laboratory at temperature 30°C and humidity 86% which has been recorded congenial for the hatching of the larvae. It was estimated that a potent female laid 285 eggs which are all variable and hatched into first instar larvae i.e. of 7 days each. Such a high reproductive potential of tasar silkworms will be beneficial for tasar production which has high value in the trade and commerce.DOI: http://dx.doi.org/10.3126/on.v10i1.7771

1959 ◽  
Vol 37 (4) ◽  
pp. 429-446 ◽  
Author(s):  
Roderick C. Fisher

Horogenes chrysostictos Gmelin, a common parasite of lepidopterous larvae, was reared in the laboratory in larvae of Ephestia cautella Walk., E. elutella Walk., E. sericarium Scott, Hofmannophila pseudospretella Staint., Endrosis sarcitrella L., Galleria mellonella L., and Achroia grisella Fab. The size and coloration of the adult and period of preimaginal development are regulated by the size and species of the host and environmental temperature. The duration of the egg stage and of the five larval instars are recorded over the viable temperature range. Characters are given which distinguish the first and fifth larval instars from those of Nemeritis canescens Grav., also a parasite of E. sericarium, and the rates of development of both species are compared over the range 15° to 30 °C. H. chrysostictos develops more quickly at all temperatures. Its sex ratio is usually 3 males: 2 females; the reproductive potential is highest at 25 °C with a mean of 39.4 progeny per female. The adult behavior in mating, host finding, and oviposition is described. Two modes of combat occur between supernumerary larvae in competition for the possession of their host: fighting with the mandibles between young first instar larvae, and combat by humoral inhibition which occurs between young first instar larvae and those in later instars. In both cases the older parasite survives competition.


2020 ◽  
pp. 43-50
Author(s):  
N.V. Didenkul ◽  

According to recent studies, in the vitamin D deficiency state (VDD), pregnancy can be complicated and the optimal level of VD in the blood is one of the conditions for the realization of reproductive potential. The objective: the possibility to preventing calcitriol-associated pregnancy complications by the correcting VD deficiency at the preconception period. Materials and methods. 57 women with VDD were examined. A history of all women had a pregnancy complicated by placental dysfunction (PD); 27 of them were observed from the preconception period (main group – IA) and 30 – from the 1st trimester of pregnancy (comparison group – IB). The VD status by the blood level of the 25-hydroxyvitamin D by ELISA was determined. Women of both groups, in addition to the vitamin-mineral complex (VMC) were prescribed supplementation colecalciferol at a dose of 4.000 IU per day. Pregnant women of both groups received VMCs up to 16 weeks. After optimizing the level (3–4 months), women continued to take VD at a dose of 2.000 IU per day throughout pregnancy. Results. At the initial study, the VD level was 15.72±2.59 ng/ml in ІА and 16.1±1.99 ng/ml in ІВ group (U=883; p>0.05); after treatment increased to 38.31±3.29 ng/ml and 36.13±2.99 ng/ml (U=900; p>0.05). In group IA, the course of pregnancy was characterized by a lower frequency of complications: PD was diagnosed in 22.2% in group IA and 50% in group IB (F=0.0001; p<0.01); fetal distress in 3.7% and 10% (F=0.16; p<0.05): signs of amnionitis – in 18.5% and 33.3% (F=0.035; p<0.05); placental hypertrophy or hypotrophy – in 7.4% and 36.7% (F=0.00001; p<0.01), preeclampsia in 3.7% and 6.7% of women (F=0,54; p<0.05). The frequency of cesarean section in the comparison group was significantly higher (40% VS 25.9%, F=0.034; p<0.05). Conclusions. During pregnancy, which occurred in conditions of VDD, the frequency of some pregnancy complications, including preeclampsia, the threat of miscarriage, placental dysfunction was in 2–4 times higher than in women with optimized VD status. One of the directions of the individual management plan for women with a negative obstetric history can be the determination of the level of VD in the blood and correction of the VDD at the preconception period. This approach is a pathogenetically substantiated and promising direction for the prevention of some pregnancy complications and improvement of perinatal outcomes. Keywords: pregnancy, deficiency vitamin D, placental dysfunction, preconception period.


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