Effects of Peganum harmala L. Seed Extract on Culex pipiens (Diptera: Culicidae)

Mosquito-borne diseases result in the loss of life and economy, primarily in subtropical and tropical countries, and the emerging resistance to insecticides is increasing this threat. Botanical insecticides are promising substitutes for synthetic insecticides. This study evaluated the larvicidal and growth index of Culex pipiens of four solvent extracts of Terminalia chebula, Aloe perryi, and Peganum harmala against Cx. pipiens. None of the 12 extracts exhibited larvicidal potential against third instars except the ethyl acetate extract of P. harmala. After 24 h of exposure, the LC50 value was 314.88 ppm, and the LC90 value was 464.19 ppm. At 320 ppm, the hatchability was 25.83%, and it resulted in 100% mortality. In addition, the eggs treated with the EtOAc extract of P. Harmala exhibited a long larval period compared with the control. The larval period continued for 12 days, and the pupal period took three days in the treatment groups. The growth index data also exhibited a decrease (0.00–7.53) in the treated groups compare with 8.5 in the control. The transformation of eggs into adults decreased with increasing concentrations. This paper is the first report on the development and growth index of Cx. pipiens potential using P. harmala seeds.

Unstable Indicators of Temperature and Humidity in Large-Scale Special Worm Rearing Houses and the Negative Consequences of Feeding Worms in Them

This article reveals the information on rearing houses for silkworms. It has been observed that the larger the size of silkworm rearing houses, the more difficult it is to maintain a comfortable temperature, relative humidity and other environmental factors, and as a result, the development of silkworms, cocoon spinning processes vary, and the process implementation of agro-technical measures is disrupted. As consequently, scientifically based data show that the viability of industrial cocoons was 14.5-24.5%, and the duration of the larval period was 2-8 days.

Early ontogeny of Clarias gariepinus and its features under artificial cultivation at different temperature conditions

The influence of different temperature regimes (28 ° C and 25 ° C) on the early ontogeny of Clarias gariepinus was studied. Heterochronism in the development of the main systems has been provided: the central nervous system and the digestive system are actively developing, the formation of the cardiovascular, respiratory and genitourinary systems occurs more slowly. The duration of embryonic development within the membranes was 18-22 hours. The initial stages of development changed insignificantly with decreasing temperature. The duration of the larval period was 14 days at 28 ° C and 15 days at 25 ° C. The fry period lasted 30 and 32 days, respectively. In terms of the duration of embryogenesis and the timing of the release of free embryos, the indicators did not go beyond the norm. The percentage of ugly embryos (underdevelopment of the operculum, underdevelopment of the tail, head and fins) was small and amounted to 3.2%, in the first and 4% in the second temperature regime. Incubation at temperatures below the optimum temperature of this species makes it possible to obtain viable offspring, adapted to the change in temperature regime.

Biology of Attagenus fasciatus Thunberg (Coleoptera: Dermestidae) on four different diets of animal origin

Biology of dermestid beetle, Attagenus fasciatus was studied on four different diets of animal origin included dried silkworm pupae and moths of Bombyx mori, feathers of white leghorn and on an equal mixture of fur of goat and sheep under laboratory conditions, to know the dietary effect on the developmental process. The mean incubation period was 12-16 days. There were 10-12 larval instars. The life-cycle on four different diets of animal origin varied. On dried silkworm pupae, total larval period ranged from 243 to 298 days and total life-cycle 267-326 days; on dried silk moths, total larval period was 251-307 and total life-cycle 272-330 days; on feathers of white leghorn, total larval period was 264-329 and total life-cycle was 288-355 days, and on an equal mixture of fur of goat and sheep, total larval period was 273-317 and total life-cycle was 297-343 days.

Competition Between The Tadpoles of Toads Versus Frogs: A Study of Four Japanese Anuran Taxa

Competition within and among species can play a key role in structuring the assemblages of anuran tadpoles. Previous studies have reported that tadpoles of the invasive cane toad (Rhinella marina) are more strongly disadvantaged by the presence of native frog tadpoles than by the same number of conspecific toad tadpoles. That effect might arise from a lack of coevolution of the invasive toad with its competitors; and/or from a generalized superiority of frog tadpoles over toad tadpoles. To clarify those possibilities, we conducted experimental trials using the larvae of a native rather than invasive toad (Bufo japonicus formosus in Japan) exposed to larvae of native anurans (the sympatric frogs Rana japonica and Rana ornativentris and the parapatric toad Bufo japonicus japonicus). In intraspecific competition trials, higher densities of B. j. formosus prolonged the larval period and reduced size at metamorphosis, but did not affect survival. In interspecific competition trials, the effects of the other anuran species on B. j. formosus were similar to the effects of the same number of conspecific larvae. This similarity in impact of interspecific versus intraspecific competition argues against any overall competitive superiority of frog larvae over toad larvae. Instead, the vulnerability of larval cane toads to frog tadpoles may result from a lack of coevolutionary history.

Antibiosis to Spodoptera frugiperda (Lepidoptera: Noctuidae) in chickpea genotypes

Chickpeas (Cicer arietinum L.) belong to the Fabaceae family and are one of the most grown crops in the world and an important source of protein for humans. Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) is a polyphagous pest that causes significant crop damage. The objective of this study was to examine antibiosis to S. frugiperda in chickpea genotypes. The following genotypes were studied: Jamu 96 and Blanco Sinaloa 92 (Mexico); Nacional 29 (Cuba); BG 1392 (Spain), and BRS Kalifa, BRS Cristalino, BRS Toro, Nacional 27, 004UP, 003UP, BRS Cícero, and BRS Aleppo (Brazil). The chickpea genotypes influenced the biological parameters of S. frugiperda, of which larval period, larval weight, and pupal period were most affected. Nacional 29 caused high mortality in the larval and pupal stages of S. frugiperda. The larvae on BRS Aleppo had the longest larval stage, lowest weight, and longest pupal stage. The genotypes Nacional 29, Nacional 27, and BRS Cícero showed antibiosis resistance to S. frugiperda. These genotypes could be used as a source of resistance to S. frugiperda in conjunction with other methods of pest control in integrated pest management programs for chickpea crops. These resistant genotypes could also be used as donor sources in breeding programs for insect resistance.

Habitat ephemerality affects the evolution of contrasting growth strategies and cannibalism in anuran larvae

Ephemeral streams are challenging environments for tadpoles; thus, adaptive features that increase the survival of these larvae should be favored by natural selection. In this study, we compared the adaptive growth strategies of Bombina orientalis (the oriental fire-bellied toad) tadpoles from ephemeral streams with those of such tadpoles from non-ephemeral streams. Using a common garden experiment, we tested the interactive effects of location (ephemeral vs. non-ephemeral), food availability, and growing density on larval period, weight at metamorphosis, and cannibalism. We found that tadpoles from ephemeral streams underwent a shorter larval period compared with those from non-ephemeral streams but that this difference was contingent on food availability. The observed faster growth is likely to be an adaptive response because tadpoles in ephemeral streams experience more biotic/abiotic stressors, such as desiccation risk and limited resources, compared with those in non-ephemeral streams, with their earlier metamorphosis potentially resulting in survival benefits. As a trade-off for their faster growth, tadpoles from ephemeral streams generally had a lower body weight at metamorphosis compared with those from non-ephemeral streams. We also found lower cannibalism rates among tadpoles from ephemeral streams, which can be attributed to the indirect fitness costs of cannibalizing their kin. Our study demonstrates how ephemeral habitats have affected the evolutionary change in cannibalistic behaviors in anurans and provides additional evidence that natural selection has mediated the evolution of growth strategies of tadpoles in ephemeral streams.

Biology of white grub Anomala dimidiata (Hope) (Coleoptera: Scarabaeidae) in agricultural ecosystem, Doon Valley, (U.K.), India

Present study was carried out to know the biology of white grub Anomala dimidiata (Hope) (Coleoptera: Scarabaeidae) collected from agricultural ecosystem with reference ecological conditions of Doon Valley. Anomala dimidiata (Hope) is a dominant species among the scarabaeid beetles and commonly distributed throughout India. Emergence of beetle is begun at the end of May when first pre-monsoon rain occurred, but peak emergence was observed in the second and third week of July after heavy rainfall. Maximum numbers of beetles were trapped during second and third week of July. Grubs were found throughout the year, causing severe damage to host plants. The males of this species show marked territorial behavior and chase the intruding conspecific females. During the study period, it was observed that the eggs are elongated, cylindrical and laid in clusters in. The observed copulation period was 40.0±14.14 min. The oviposition period was 8.0±1.41 days. The incubation period of eggs was 14.60±0.72 days. Larval period remained for 248 to 278 days. The pupal stage lasts for 14.70±0.62 days. The adult female is broadly oval, less convex shape and slightly larger than male. The stage lasts for 27.75±4.74 days.

Effects of thiourea on the skull of Triturus newts during ontogeny

Background In amphibians, thyroid hormone (TH) has a profound role in cranial development, especially in ossification of the late-appearing bones and remodeling of the skull. In the present study, we explored the influence of TH deficiency on bone ossification and resulting skull shape during the ontogeny of Triturus newt hybrid larvae obtained from interspecific crosses between T. ivanbureschi and T. macedonicus. Methods Larvae were treated with two concentrations of thiourea (an endocrine disruptor that chemically inhibits synthesis of TH) during the midlarval and late larval periods. Morphological differences of the cranium were assessed at the end of the midlarval period (ontogenetic stage 62) and the metamorphic stage after treatment during the late larval period. Results There was no difference in the ossification level and shape of the skull between the experimental groups (control and two treatment concentrations) at stage 62. During the late larval period and metamorphosis, TH deficit had a significant impact on the level of bone ossification and skull shape with no differences between the two treatment concentrations of thiourea. The most pronounced differences in bone development were: the palatopterygoid failed to disintegrate into the palatal and pterygoid portions, retardation was observed in development of the maxilla, nasal and prefrontal bones and larval organization of the vomer was retained in thiourea-treated larvae. Conclusions This implies that deficiency of TH caused retardation in development and arrested metamorphic cranium skeletal reorganization, which resulted in divergent cranial shape compared to the control group. Our results confirmed that skull remodeling and ossification of late-appearing bones is TH–dependent, as in other studied Urodela species. Also, our results indicate that TH plays an important role in the establishment of skull shape during the ontogeny of Triturus newts, especially during the late larval period and metamorphosis, when TH concentrations reach their maximum.