• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.243-264
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• 2013

Antheraea mylitta Drury is a commercial silk producing forest insect in India and Xanthopimpla pedator Fabricius is its larval-pupal endoparasitoid, which causes pupal mortality that affects seed production. Effects of host plants, rearing season and their interactions on parasitic behaviour of X. pedator were studied here, as influence of these factors on biological success of X. pedator is not known. Seven forest tree species were tested as food plants for A. mylitta, and rate of pupal parasitization in both the rearing seasons were recorded and analysed. Results showed that rearing season and host plants significantly affected the rate of pupal parasitization in both the sexes. Pupal mortality was found significantly higher (14.52%) in second rearing season than the first (2.89%). Likewise, host plants and rearing seasons significantly affected length, diameter, and shell thickness of cocoons in both sexes. Out of all infested pupae, 85.59% were found male, which indicated that X. pedator chooses male spinning larva of A. mylitta for oviposition, but we could not answer satisfactorily the why and how aspect of this sex specific parasitic behaviour of X. pedator. Multiple regression analysis indicated that length and shell thickness of male cocoons are potential predictors for pupal parasitization rate of X. pedator. Based on highest cocoon productivity and lowest pupal mortality, Terminalia alata, T. tomentosa, and T. arjuna were found to be the most suitable host plants for forest based commercial rearing of A. mylitta in tropical forest areas of Uttarakhand state, where it has never been reared earlier. Sex and season specific interaction of X. pedator with its larval-pupal host, A. mylitta is a novel entomological study to find out explanations for some of the unresolved research questions on parasitic behaviour of X. predator that opens a new area for specialised study on male specific parasitization in Ichneumonidae.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.228-231
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• 1983

In order to eradicate harmful insect by use of sterile male techniques, it is necessary to disperse about 10 times as many male insect as in wild condition. However, it is so difficult to discriminate male insect in pupal stage that usually the population are likely to be contaminated by female insect when that are released in field. The present study was conducted to establish a useful method capable of differenciating the male pupae of Stomawys calcitsans by means of measuring the pupal weight and length. The results were summarized as follows; 1. Male pupa was lighter and shorter than female and high correlation existed between length and width of pupa. 2. There was significant relationship between the length of pupa and width of adult 3. When the pupal sex of stable ay was identified by median of mean length and mean weight of the pupae, the Ratio of female to male was 1 : 1. 4 and 1 : 2. 2, respectively. Therefore, median of pupal weight seemed to be applicable for obtaining more number of male pupae.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.197-202
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• 2009

The Luciola lateralis larva took 5.3 days from climbing on the land to the pupal cocoon formation. It took 6.6 days for a larva to eventually transform to a pupa after building a pupal cocoon. The size of pupal cocoon was 10.1 mm in length, 4.7 mm in width and its wall thickness was 1.3 mm. The mean pupal period was 10.5 days. The adult stayed 6.8 days in the pupal cocoon before escaping the cocoon. The peak adult emergence appeared around 9 p.m., and decreased after 10 p.m. The optimal soil temperature for emergence was $23.4^{\circ}C$. The female adult of the natural population (Nat-type) lived shorter, laid fewer eggs, and the oviposition frequency was fewer than that of the Lab-type individuals. However, a few individuals from the natural population laid 200-400 eggs. The less number of oviposition in the natural population may be due to the fact that the female adults might lay eggs before the collection for the experiment.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.126-132
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• 2012

Two different feed(bran and swine feed) effect was tested on development of Tenebrio molitor at $25{\pm}5^{\circ}C$, $65{\pm}10%RH$. There was no significant feed effect on larval developmental periods(80.0 ~ 83.7 days), pupal length (18.1 ~ 18.7 mm) and fecundity(44.3 ~ 55.3 eggs) during first two days. However, fecundity was significantly affected by the pupal weight(P < 0.05), such that the number of eggs 172.3, 191.2, 215.0 gradually increased as pupal weight rose from 0.12 g, 0.15 g to 0.18 g, respectively. During the first two weeks of oviposition was 51.8%, which gradually decreased for further days. Longevity was $27.1{\pm}6.9$, $30.1{\pm}7.8$, $27.4{\pm}8.5$ days with increasing pupal weight of 0.12, 0.15, 0.18 g, respectively. Larval densities of 100, 300, 500 and 700 individuals reared in the container ($16{\times}21.5{\times}7cm$) resulted 67.9% of the T. molitor pupation during first three weeks. Pupal weight was decreased $146.9{\pm}6.5$, $142.1{\pm}8.3$, $122.0{\pm}9.6$, $118.5{\pm}5.2mg$ when it was reared at different larval densities of 100, 300, 500 and 700 individuals, respectively in size of($16{\times}21.5{\times}7cm$) rearing container.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.101-108
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• 2009

For biological control of larva of Cnaphalocrocis medinalis and Naranga aenescens do considerable damage to crops by folding and scraping the leaf tissue of rice, a large number of Bacillus thuringiensis isolates have been obtained from soil samples in Korea and the pesticidal activity was assayed against two insect pest species described above. Among 53 Bt isolates tested in bioassay, 18 and 13 isolates showed over 90% mortality against C. medinalis and N. aenescens, respectively. Some isolates (11 isolates including CAB141) presented dual activity against C. medinalis and N. aenescens. These isolates showed over 96% control effect in pest control in laboratory against larvae of C. medinalis. Also, it was investigated that pupation, pupal length, and adult emergence of larvae exposed to Bt suspension decreased. Especially, the pupal length of C. medinalis after being fed corn seedling leaves treated Bt suspension for 10 days, were much smaller than that of control.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.67-71
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• 2002

The implications of temperature (25,30 and 35$^{\circ}C$) and relative humidity (60, 70 and 80%) on the pupation patterns were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB4D2 and their hybrid, PM ${\times}4 NB4D2 were reared under experimental conditions under natural day photoperiodic (LD 12: 12) condition. The three developmental marker events viz., larval ripening, pharate pupal formation and pupal formation occurred at or around the beginning of the photo-phase. The computed of mean vector (equation omitted), based on the circular statistics, also confirmed the above. However, the length of mean vector, r and the mean vector angular variance, s varied according to temperature and humidity conditions imposed; the variations being non-significant. Extreme temperature and humidity conditions, however, resulted in reduction in pupation rate (%) for PM and PM ${\times}4 NB4D2. On the other hand, in NB4D2 pupation percentage reduced below the economic level. The temperature and humidity together seems to exert synergic impact on the pupation rate at least in the silkworm Bombyx mori, L.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.45-49
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• 2006

The present investigation was conducted to know the effects of host age on development and morphological characteristics of Nesolynx thymus, a gregarious ectopupal parasitoid of the uzi fly, Exorista bombycis, a serious en do-larval parasitoid of the silkworm, Bombyx mori L. For experimentation, 3 - 11 day-old pupae of E. bombycis were exposed to 2 day-old adults of N. thymus at $25{\pm}2^{\circ}C\;and\;60{\pm}10%$ RH. A highly significant negative correlation between host age and the following development and morphological characteristics of the parasitoid was observed: number of pupae parasitised, total adult recovery, sex ratio and recovery, longevity, body length, wing span, abdomen length, and abdomen width of females. The findings of the present study clearly demonstrate that various development and morphological parameters of N. thymus are influenced by the age of E. bombycis pupae.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.39-44
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• 2011

To evaluate the growth rate of larval and pupal parameters of silkworm Bombyx mori fed with Silver Nanoparticles (AgNps) treated $MR_2$ mulberry leaves, the following works have been considered. The AgNp was synthesized by chemical reduction method, it was diluted by different concentrations such as 25%, 50%, 75% and 100% (without dilution). Fresh mulberry leaves (Morus alba L.) were sprayed by each concentration and were fed to silkworms, from $3^{rd}$, $4^{th}$ and $5^{th}$ instar, five feedings/day. Group $T_1$ larvae received $MR_2$ mulberry leaves sprayed with distilled water and served as control, group $T_2$, $T_3$, $T_4$ and $T_5$ larvae received 25%, 50%, 75% and 100% AgNps sprayed mulberry leaves, respectively. Silkworm larvae fed on M. alba ($MR_2$) leaves sprayed with 25% concentration of AgNps (group $T_2$) was significantly increased the larvae and cocoon length, width and weight as compared to those fed on control (group $T_1$) $MR_2$ mulberry leaves and other groups ($T_3$, $T_4$ and $T_5$). Hence, 25% AgNps dose was fixed as an effective dose. It has been observed from the present study that 25% AgNps treated (group $T_2$) leaves fed by silkworms have enhanced the larval and pupal growth and quantity of silk production than control.

• International Journal of Industrial Entomology and Biomaterials
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• v.38 no.2
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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%.

• Biomedical Science Letters
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• v.29 no.4
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• pp.330-335
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• 2023

The corazonin (Crz) gene showed two subtypes of different length at laval and pupal stage. The long subtype fade out in adult central nerve system (CNS) but the short one survive through all the life cycle from larva to adult. The short subtype has the same base sequences with mature Crz mRNA and detected in both brain and ventral nerve cord (VNC). The long one, on the contrary, was detected only in the brain tissue. As observed in above results, Crz neurons develop in different pattern in the CNS of scuttle fly and the Crz gene expresses two different subtypes. These results suggest that this neurotransmitter may perform differential neurophysiological functions in the scuttle fly. Variation in the amino acid composition of the final active undecapeptide supports in strong those possibilities. We expect further studies on the relationship between neurophysiological functions of Crz and behavioral characteristics of the scuttle fly.