Biology and feeding potential of Coccinella septempunctata (Linn.) against Lipaphis erysimi (Kalt) at different temperature regimes

Biology and feeding potential of Coccinella septempunctata (Linn.) were studied in laboratory on 3rd instar nymphs of mustard aphid (Lipaphis erysimi Kalt.) at two different temperature regimes. At 30± 20C, fecundity, oviposition period, hatchability of eggs, male and female longevity (232±70.46, 12.8±3.91, 82.87±6.66, 22.70 ± 2.21and 26.60 ± 4.45, respectively) were higher and incubation period, pre-oviposition period, total grub duration and pupal duration (2.6±0.51, 6.5±3.53, 8.7 ± 1.63 and 5.1 ± 1.10, respectively) were lesser in comparison to 25± 20C where fecundity, oviposition period, hatchability of eggs, male and female longevity, incubation period, preoviposition period, total grub duration and pupal duration were 169.8±61.12, 7.9±1.37, 71.68±4.08, 16.2 ± 1.31 and 21.50 ± 1.95, 2.9±0.73, 7.7±2.49, 11.1 ± 1.52 and 5.8 ± 0.918, respectively . At 27± 2 0C, total mustard aphid consumption by a grub of C. septempunctata during the whole life span, was 424.4±2.78 mustard aphids in comparison to 272.64±1.79 mustard aphid at 23± 20C. Similarly an adult male and female consumed 103.2±1.52 and 116.6 ±1.46 aphids per day respectively at 27± 2 0C in comparison to 65.6 ± 1.02 and 71.8 ± 1.60 at 23± 20C. Thus, at both temperatures aphid consumption increased gradually till 4th instar and 30±20C was found to be most suitable temperature as compared to 25±20C for the life history of C. septempunctata. Hence, it could be concluded that C. septempunctata might play a suitable role in biointensive Integrated Pest Management programme because of better longevity and high predatory potential against the mustard aphid

Population dynamics of potential bioagents of mustard aphid, Lipaphiserysimi(Kaltenbach) on different cultivars of rapeseed-mustard

Field experiment was conducted to study the population dynamics of potential bioagents of mustard aphids on 9 different cultivars which included: Brassica alba cv. PSB-I, Eruca sativa Mill cv. T-27, Brassica campestriscv. BSH-I, Brassica napuscv. Sheetal, B. carinataBraun cv. CCN-06- 1, B. junceaL. cv. Varuna, B. nigraKoch. cv. PBR-I, Brassica campestriscv.YST-151 and Brassica campestriscv. PT-30. Population of aphid and natural enemies was recorded at weekly intervals. The results indicated that the first appearance of coccinellids and syrphids has been observed during 4th standard week, which gradually build up population and attained peak during 9th (pooled mean 1.42 coccinellids/ plant and 0.122 syrphid larva/plant) and 8th standard week (pooled mean 3.96 coccinellids/plant and 0.228 syrphid larva/plant) in 2008-09 and 2009-10 respectively, followed by a declining trend in the following weeks. Similarly first appearance of parasi-tization has been found to occur from 4th standard week followed by a gradual increase in the following weeks with maximum parasitization on PT-30 (33.32%) and BSH-1 (35.25%) during 2008-09 and 2009-10 respectively. Correlation between abiotic factors and these natural enemies was also studied. It has been observed that with the increase of aphid population the population of natural enemies also increased. The population dynamics of mustard aphids and its natural enemies var-ied according to climatic situations and between host plant species. So by computing population trends of both natu-ral enemies and aphids with meterological records would generate information on relative abundance and would certainly help in formulating sound pest management strategies against mustard aphid

Effect of high day and night temperature regimes on tomato (Solanum lycopersicum) genotypes

Five tomato (Solanum lycopersicum L.) genotypes, including heat tolerant (Pusa Sadabahar, Booster, Pusa Sheetal), one F1 combination (Pusa Sheetal × Pusa Sadabahar ) and one susceptible genotype (Pusa Rohini) were grown under phytotron under four temperature regimes, i.e. 20/24, 22/26, 24/32, 27/37°C night (11 hours)/day (13 hours) temperature, respectively. Pusa Sadabahar and Booster recorded high value of relative water content (RWC) and low value of membrane injury index (MII) both at normal and high temperature conditions. High value of chlorophyll a and chlorophyll b ratio was recorded in Pusa Sadabahar and Pusa Sheetal×Pusa Sadabahar under all the temperature regimes showed their tolerance to high temperature. Normal (more than 80 percent) flowering and fruiting was recorded in all the genotypes at 20/24°C & 22/26°C. However at 24/32°C Pusa Sadabahar recorded 65 per cent fruit set and other genotypes 25 to 49 percent fruit setting only. None of the genotypes could record fruit set at 27/37°C, except Pusa Sadabahar which could set few small fruits (19%). Pollen germination was maximum (ranging from 21.8 - 62.9%) in Pusa Sadabahar under all temperature regimes. The susceptible genotype, Pusa Rohini recorded exerted stigma in 100% flowers at 27/37°C temperature whereas it was 75% in tolerant genotype Pusa Sadabahar. Night/day temperature 22/26°C was optimum for fruit set, pollen viability and normal stigma development in tomato. High night temperature (³ 26°C ± 2°C) at flowering was the major factor in reducing fruit set in tomato than the day temperature. The study showed that day temperature of ³ 35°C and night temperature of ³ 26oC may be used for screening tomato against high temperature tolerance

All India Co-ordinated Research Project on Biological Control of Crop Pests

Not AvailableSurveys were undertaken to document the fauna of insects, spiders and entomopathogenic nematodesacross India despite the travel restrictions due to COVID-19. The expeditions undertaken yielded several species of natural enemies viz.,Chalcididae (66.32%), Eulophidae (19.94%), Pteromalidae (4.14%) and Encyrtidae (3.37%) of Hymenoptera and 14 species of trichogrammatids representing 7 genera. The predominant genera of hymenopteran insect parasitoids were identified as Dirhinus Dalman (30.47%) followed by Brachymeria Westwood (27.73%), Hockeria Walker (22.27%) and Antrocephalus Kirby (18.75%). Revisionary studies of the braconid parasitoid, Apanteles sp. ater-group including subgroup eublemmae of the genus (Hymenoptera: Braconidae) of the Oriental region was carried out with an illustrated key, in which a total of 97 species were recorded and illustrated. Three species of tachinid flies, Peribaea orbata on larva of Spodoptera litura, Halidaia luteicornis on larva of Parnara sp., Sturmiopsis inferens on larva of Sesamia inferens and Carcelia sp. from the larvae of Helicoverpa armigera (Noctuidae) were identified and described. The spider fauna of rice ecosystem was documented, where six species of long jawed orb weaver, Tetragnatha species have been described of which T. keyserlingi was the predominant species across the surveyed locations in Tamil Nadu. The species, Tetragnathanitens collected from Tamil Nadu and Telangana was the first report from India. The spitting spider, Scytodes fusca Walckenaer of family Scyotidae was redescribed with documentation of variations in the vulval pattern of the female and theory about the introduction of this Pantropical species to India.Not Availabl

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe

Vijay Madanlal Choudhary : An Affirmation of ED’s Unbridled Powers or Harbinger of Hope?

Essa

Intraguild predation on Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) by the generalist predator Geocoris ochropterus Fieber (Hemiptera: Geocoridae)

Abstract Intraguild predation (IGP) is common in food web when two natural enemies share the same resources and prey. It may affect the success or failure of a biological control attempt. The role of intraguild predation by Geocoris ochropterus Fieber (Heteroptera: Geocoridae) on Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) developed on eggs of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) was evaluated under laboratory conditions. In choice experiments, both fifth instar nymph and adult of G. ochropterus preferred to predate on unparasitized eggs of H. armigera and C. cephalonica over parasitized eggs. In no-choice experiments, G. ochropterus nymph consumed 58 and 67% of unparasitized H. armigera and C. cephalonica eggs, compared to 3.33 and 7.38% of parasitized ones. A similar trend was observed in no-choice experiments with adult predator. Additional semi-field and field studies are required to explicate the consequences and intensity of intraguild predation in agro-ecosystem

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Not AvailableInsects can be a problem or an opportunity. Though the proportion of useful and harmful insects is low within the class Insecta, it is now widely acknowledged that interactions in the insect community impact the density and diversity of economically important insects. Generally the emphasis is on economically important insects as they visibly and directly influence mankind, while the number of agriculturally important insects that need to be documented far outweighs the mere quantum of economically important insects. Insect biodiversity is instrumentally important not only for the production of food, but for other ecological services as well, including the recycling of nutrients, regulation of microclimate and suppression of undesirable organisms. In the United States alone, pollination by bees accounts for over US$9 billion of economic revenue and some estimates indicate that over ⅓ of the human diet can be traced directly or indirectly to bee pollination. There are two key gaps in understanding and utilizing the positive aspects of insect diversity: a general neglect of insects in biodiversity research and an overemphasis on their negative impacts in all other biological research areas. Promising species/strains of macrobials and microbials have been identified for several of the notorious pests and diseases infesting crops. Simple and novel farmer friendly technologies have been standardised by NBAIR for the production of these potential bio-agents. At this juncture, armed with these technologies, focus should be on popularising the concept of biological control among farmers and motivating them to adopt this eco-friendly bio-approach as an important component of IPM.Not Availabl

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Not AvailableTrichogrammatid egg parasitoid widely used in the biological control of lepidopteran pests. The great diversity of Trichogramma have been reported worldwide over 230 species parasitizing the different eggs of over 200 insect species belonging to 70 different families. Among, Trichogramma and Trichogrammatoidea are amenable for laboratory mass production on factitious hosts. Development of a tolerant strain for the different stresses, though genetic improvement considered very useful which improved their survival and performance to manage the insect-pests in field conditions. This development made easy to integrate trichogrammatids with other method of control and component in the integrated pest management practices. The present studies information pertaining to the information on most utilized species of trichogrammatids and their utilization have been discussed.Not Availabl

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Not AvailableThe biology and predatory efficiency of Geocoris ochropterus Fieber (Hemiptera: Geocoridae) has been studied extensively against many insect pests, but information on functional response of different stages of G. ochropterus to Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is lacking so far. The functional response of different stages of G. ochropterus to varying densities of eggs of H. armigera was investigated in the laboratory at 26 ± 2°C, 65 ± 2% RH and 12 L: 12D. Immature stages i.e. 3rd, 4th, 5th instar and adult predator exhibited type II functional response. Handling time decreased with increasing predator’s developmental stage. Adult G. ochropterus followed by fifth instar exhibited highest egg consumption and attack rate compared to other stages. Functional response parameters indicate that the adult and fifth instar of G. ochropterus were more voracious and efficient than other juveniles and might be useful as promising biocontrol agent against H. armigera.Not Availabl