Pupal Mortality Research Articles

Impact of Seed Blend and Structured Maize Refuge on Helicoverpa zea (Lepidoptera: Noctuidae) Potential Phenological Resistance Development Parameters in Pupae and Adults.

Helicoverpa zea, an economic pest in the southeastern U.S., has evolved practical resistance to Bt Cry toxins in maize and cotton. Insect resistance management (IRM) programs have historically required planting of structured non-Bt maize, but because of its low adoption, the use of seed blends has been considered. To generate knowledge on target pest biology and ecology to help improve IRM strategies, nine field trials were conducted in 2019 and 2020 in Florida, Georgia, North Carolina, and South Carolina to evaluate the impact of Bt (Cry1Ab + Cry1F or Cry1Ab + Cry1F + Vip3A) and non-Bt maize plants in blended and structured refuge treatments on H. zea pupal survival, weight, soil pupation depth, adult flight parameters, and adult time to eclosion. From a very large sample size and geography, we found a significant difference in pupal mortality and weight among treatments in seed blends with Vip3A, implying that cross-pollination occurred between Bt and non-Bt maize ears. There was no treatment effect for pupation depth, adult flight distance, and eclosion time. Results of this study demonstrate the potential impact of different refuge strategies on phenological development and survival of an important pest species of regulatory concern. This article is protected by copyright. All rights reserved.

Effects of geographic origin and temperature on survival, development, and emergence of the managed pollinator Osmia lignaria

IntroductionThe blue orchard bee,Osmia lignaria, is a widespread North American native pollinator that can be employed for commercial fruit and nut crop production. The largest supplies of these bees are collected in the wildlands ssssof Utah and Washington, United States. HowO. lignariafrom different geographic regions respond to current recommended management practices or translocation to novel environments is not fully understood.MethodsUtah- and Washington-originatedO. lignariawere reared in laboratory incubators under two thermal regimens: (1) constant temperatures used to manage bees through immature development, adult winter dormancy, and for spring emergence, and (2) hourly fluctuating temperatures programmed to mimic the natural daily (24 h) thermal cycles of the nearest cherry orchard growing region through their life cycles.ResultsIn comparison to rearing bees at orchard temperatures, we found that rearing bees at a constant temperature increased survival and shortened egg–adult development periods. Washington bees were more adversely affected by the consistent warm rearing temperatures than were Utah bees, possibly due to their adaptations to Washington’s relatively moderate climate. At orchard temperatures, Utah bees suffered high prepupal and pupal mortality, while Washington bees suffered high pupal and adult mortality. These late life stages coincided with the hottest maximum temperatures in their respective thermal regimens. Adult females from both states naturally emerged in synchrony with local bloom time, but their emergence period overall was prolonged compared to bees in the constant thermal regimen that were induced to emerge at orchard bloom times.DiscussionOur data support that bees originating from cool montane habitats of different U.S. states suffer from the warmer climatic conditions at lower altitudes of their respective crop-growing regions. A better understanding of optimal management temperatures forO. lignariafrom different geographic regions and the effect of bee origin and temperature on survival and development timing is needed for best managing these pollinators when they are translocated or when climate change results in increased temperatures during bee development periods.

Growth Optimization and Rearing of Mealworm (Tenebrio molitor L.) as a Sustainable Food Source.

As a sustainable food source for humans, mealworms (Tenebrio molitor) have a great deal of potential, due to the fact that they have a very favorable nutritional profile and a low environmental impact. For meal production, feed formulation and optimization are important. The mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) is the most consumed insect in the world. Mealworms were given a variety of diets, including wheat bran as constant diet supplemented with different levels of Ospor (Bacillus clausii) at 0.002 g, 0.004 g, 0.006 g, and 0.008 g; imutec (Lacticaseibacillus rhamnosus) at 0.2 g. 0.4 g, 0.6 g, and 0.8 g; fungi (Calocybe indica) at 250 g, 500 g, and 750 g; yeast (Saccharomyces cerevisiae) at 50 g, 100 g, and 150 g; and wheat bran (standard diet) were examined in complete randomized design (CRD). Different parameters, i.e., the larval, pupal, and adult weight, size, life span, and nutritional profile of mealworm were studied. When compared with other insect growth promoters, only wheat bran was discovered to be the most efficient. It generated the heaviest and longest larvae at 65.03 mg and 18.32 mm, respectively, as well as pupae weighing 107.55 mg and 19.94 mm, respectively, and adults weighing 87.52 mg and 20.26 mm, respectively. It was also determined that fungi (C. indica) and ospor (B. clausii) promoted faster larval development than yeast (S. cerevisiae) and imutec (L. rhamnosus). Larval mortality was also greater in the imutec (L. rhamnosus) and yeast (S. cerevisiae) diets than the others. No pupal mortality was recorded in all diets. Furthermore, the protein content of Tenebrio. molitor raised on a diet including fungi (C. indica) was the highest at (375 g), with a content of 68.31%, followed by a concentration of (250 g) with a content of 67.84%, and wheat bran (1 kg) (normal diet) with the lowest content at 58.91%. T. molitor larvae fed a diet supplemented with bacterial and fungal had lower fat and ash content than bran-fed T. molitor larvae (standard diet). Wheat bran (normal diet) had the highest fat at 16.11%, and ash at 7.71%. Hence, it is concluded that wheat bran alone or diet containing fungi (C. indica) and ospor (B. clausii) performed better in terms of growth, and these diets and protein content are recommended for the mass rearing of mealworms.

Insecticidal potential of organic extracts of Calotropis procera to Spodoptera frugiperda

This study evaluated the toxic effects of organic extracts of Calotropis procera leaves on the survival, development, and reproduction of Spodoptera frugiperda. Solutions of crude methanol extract and hexane and methanol fractions of C. procera leaves were added at 1.15% and 2.14% concentrations to the artificial diet of S. frugiperda. The mortality and duration of larval and pupal phases, weights of female and male pupae, deformations of pupae and adults, the reduction of adults able to reproduce, pre-oviposition and oviposition periods, the number of postures per female, and the fecundity and fertility of S. frugiperda females were also evaluated. The extracts harmed the survival, development, and reproduction of S. frugiperda. The ingestion of extracts and fractions by caterpillars affected adults by decreasing the oviposition period, the number of postures, fecundity, and fertility. The crude MeOH extract at a 2.14% concentration harmed the evaluated parameters of the insect, except for pupal mortality, female pupae weight, and pre-oviposition period. The MeOH fraction at 2.14% caused a 50.0% mortality of caterpillars and 16.0% deformation in pupae and 33.0% in adults, reducing by 72.0% the population able to reproduce. The MeOH fraction at the 2.14% concentration caused 25.0% and 38.0% of pupal mortality and deformation, respectively. Calotropis procera has promising insecticidal properties for a biological insecticide, a convenient and sustainable strategy for protecting plants against S. frugiperda.

Bt cotton and modern insecticide adoption decreases Helicoverpa spp. population recruitment in a subtropical cropping system

AbstractExtensive crop sampling for Helicoverpa spp. pupae was undertaken (2017–2021) to provide insights as to how pest population dynamics have altered in a subtropical cropping system following the introduction of transgenic Bt cotton and newer generation insecticides for pulse production. Previously (1996–1999), a pattern of year‐round population cycling and build‐up was identified to occur between summer cotton (non‐Bt) and winter chickpea, enabled by widespread resistance to broad‐spectrum insecticides used at the time. Current pupae sampling was unable to recover pupae from Bt cotton, suggesting this crop had become a population sink rather than a source for Helicoverpa spp. Pupae were less abundant in pulses, with monthly counts varying from 0 to 3192/ha in chickpea being a fraction of previous densities that ranged from 10,000 to 100,000/ha whilst pupae were not detected in mungbean crops. Poor survival (0%–39.5%) of pupae collected from chickpea, likely due to sub‐lethal insecticide exposure during the larval stage, further limited population recruitment. The highest densities of pupae (up to 18,666/ha) were routinely recovered from unsprayed pigeon pea grown as refuges for Bt cotton resistance management, although Tachinid spp. parasitoids caused increasing pupal mortality with refuge age. This study suggests that the high control efficacy afforded by transgenic Bt traits incorporated into cotton and newer insecticides used on pulse crops has provided a form of area‐wide management that may explain suppression of Helicoverpa spp. pupae densities compared to levels previously recorded across the cropping system.

Toxicity of some Biocides in the Tomato leaf Miner Tuta Absoluta Meyrick (Lepidoptera: Gelechiidae) in Laboratory

The experiment was conducted in the Entomology Laboratory/Plant Protection Department/College of Agriculture and Forestry/Mosul University/Iraq in the year 2021, to evaluated the toxicity of biocides, Beauveria bassiana (Bals.) Vuill, (conc. 1, 3, 5 g/L) Bacillus thuringiensis var. kurstaki (conc. 1, 3, 5 g/L), Spinosad (conc. 0.15, 0.30, 0.60 ml/L) and Neem plant extract (Azadirachta indica) (conc. 0.25, 0.50, 1.00 ml/L) on the third larval instar and pupal stage of tomato leafminer (TLM) under laboratory conditions, 25 - 27 °C, and the average relative humidity was 60 - 65%. The results of the study showed that the treatment with Spinosad at a concentration of 0.60 mm/L was significantly superior compared to the rest of the biocides, with an average mortality of 86.67% and 90.67% for larvae and pupae, respectively. All biocides differed significantly compared to the control, which amounted to 0.00%, and the highest mean of larval mortality was 71.67% for the reading after ten days of treatment, which differed significantly compared to the reading after one and three days of treatment, which amounted to 23.89 and 50.56%, respectively. While the reading after nine days of treatment outperformed significantly, and recorded the highest average of pupal mortality, which amounted to 68.00%, compared to the lowest average reading after seven days of treatment, which amounted to 44.00%. The treatment with the biocides B. thuringensis at a concentration of 1, 3 and 5 g/L was superior, with the lowest average percentage of transformation of larva to pupal stage reaching 15.56, 2.22 and 0.00%, respectively, compared to the rest of the concentrations of other biocides and the control, which was 73.33%. The biocides B. thuringensis was significantly superior to the rest of the biocides, and the lowest average percentage of emergence was recorded, as it reached 6.67% in the third concentration 5 g/L, which did not differ significantly compared to the third concentration of the rest of the biocides, however, it differed significantly compared to the rest of the concentrations of other biocides, and the control, as the highest mean of the percentage of emergence rate was 76.67%. It is noted from the study that all biocides had a significant effect on their toxicity to TLM compared to the control, and that the toxicity of biocides for the third larval instar and pupa of TLM increased with increasing concentration and number of days after treatment, and led to a decrease in the average percentage of adult emergence with an increase in concentration used compared to the control. From the results of this study, it is possible to introduce these pesticides in the integrated pest management programs for TLM in open fields and protected cultivation.

Insecticidal Activity of Some Plant Extract Against Greater Wax Moth Larvae (Galleria mellonella L.)

Galleria mellonella L. (Lepidoptera: Pyralidae) is a significant international pest and the most devastating pest throughout the world of beeswax. Natural pesticides must be replaced with synthetic materials since they are more ecologically friendly. This study aims to determine alternative methods of controlling the larger wax moth by assessing the efficacy of several plant-based biocides for this purpose various ethanolic plant extracts such as rosemary (Rosmarinus officinalis L), Clove (Syzygium aromaticum), Eucalyptus (Eucalyptus sp) and Cinnamon (Cinnamomum verum) where used with four extraction rates (5,10,15 and 20) against the late instar larvae of Galleria mellonella in vitro after 24,48 and 72 hr. Obtained results revealed that the pupal mortality increased when the concentration increased and the highest accumulative mortality percentage of wax moth larvae during the experiment, it was demonstrated that all studied plants were efficient at suppressing Galleria mellonella larvae. The result shows that three days after application treatment of rosemary 20% gave the maximum total mortality percentage (%100) followed by (%96.58, %92.66 and %64.86) for Eucalyptus, Cinnamon and clove after 24,48 and 72 hr. respectively. It may be suggested that spraying natural products is a good option on new wax combs to protect them against infestation by wax moth larvae

Larvicidal and pupicidal effects of some essential oils against Musca domestica Linnaeus, 1758 (Diptera:Muscidae)

Essential oils (EOs) from plants can provide an eco-friendly alternatives to traditional synthetic insecticides. This study aimed to evaluate the effects of six different essential oil (Foeniculum vulgare, Cinnamomum verum, Allium sativum, Capsicum annum, Mentha piperita, Urtica dioica) against Musca domestica. Larvicidal and pupicidal, efficacy of six EOs were evaluated by contact toxicity method at four different doses (1%; 2.5%, 5%, and 10%) in 5 replications. The research was performed at 60 ± 1.5% humidity and 27 ± 0.5 0C temperature at the Animal Physiology Laboratory of Ondokuz Mayıs University. The LC50 and LC90 values were determined by probit analysis. The effects of treatment and concentrations on different exposure periods, larval and pupal survival and development time were analyzed by a two-way analysis of variance. The larval toxicity of six EOs increased significantly with increased exposed periods. The larval and pupal mortality percent was also increased as the concentration increased for testing all essential oil. The highest larval mortality percent (100.0%) was observed at the (10%) concentration of six essential oils, and all concentrations of Cinnamomum verum oil. Besides, the lowest larval mortality percent (46%) was caused by the 1% concentration of Foeniculum vulgare. The highest pupicidal effect was shown by 10, 5, 2.5% Cinnamomum verum EOs (100% mortality) and 1% Cinnamomum verum EOs (97.36%). The present study revealed that tested essential oil had significant potential for affecting biological parameters of M. domestica. The Cinnamomum verum EOs can be used as an eco- friendly product for the control of housefly larvae and pupae.

Efficacy of a native entomopathogenic nematode Heterorhabditis bacteriophora (isolate Z-1) against potato tuber moth (Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) in Turkey

BackgroundPotato tuber worm (PTM) [Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)] is one of the most significant and widespread pests of potato. PTM damages potatoes both in the field and in potato storage areas. Control of the pest is getting harder as it is developing resistance to pesticides. Several entomopathogenic nematode (EPN) species have been reported to successfully control numerous agricultural pests worldwide. The main aim of the study was to isolate native nematode/s as a biological control agent against P. operculella. Morphometric measurements of the infective juvenile (IJ) and sequencing and characterization of the internal transcribed spacer (ITS) region was used to identify the nematode isolate to species level. The efficacy of EPN isolate Z-1 obtained from Zonguldak province, Turkey was tested against different life stages of the pest. Experiments were conducted in 150 ml plastic pots containing sterile soil mixture. Four EPN concentrations (i.e., 0, 250, 500 and 1000 IJs/ml) were applied to the soil. Data relating to the mortality of different life stages were collected daily till 6 days after inoculation.ResultsMolecular analyses based on the ITS sequence and morphometric data revealed that isolate Z-1 was Heterorhabditis bacteriophora. Mortality rates of PTM larvae exposed to 250, 500, and 1000 IJs/ml concentrations of native EPN were 62.9 ± 9.8, 74.0 ± 3.7, and 92.5 ± 3.7%, respectively. There were non-significant differences among tested EPN concentrations for pupal mortality and the highest concentration (i.e., 1000 IJs/ml) caused 25.6% mortality.ConclusionsThe results revealed that the native H. bacteriophora isolate was effective against late-stage larvae of PTM under laboratory conditions. Therefore, it can be used as an alternative management option of the pest.

Combining the virulent Beauveria bassiana (Balsam) Vuillemin LCB289 and nematode strains to control pupae of Ceratitis capitata Wiedemann

ABSTRACT Entomopathogenic fungi (EF) and nematodes (EPN) can infect pupae of C. capitata Wiedemann in the soil, where they are protected from most control measures. This study evaluated infective juvenile (IJs) density to achieve high control efficiency, the residual effect of commercial strains of Heterorhabitidis bacteriophora (Poinar) and Steinernema carpocapsae (Weiser), and their combined application with Beauveria bassiana (Balsam) Vuillemin LCB289 on pupae mortality. Applying 106 IJs m−2 of both EPN species to columns with sandy Yellow Ultsol at laboratory temperature (24.0 ± 2°C) caused pupae mortality higher than 80%. Probit analysis showed that the curves for the EPN species had statistically similar slopes, with LC50 of 3.57 × 106 for H. bacteriophora and 2.12 × 106 for S. carpocapsae. The former showed a median potency 36% higher than H. bacteriophora. Microscope observations showed that infection by both species resulted in the melanization of pupae and no visual differences in the EPN growth in the cadavers. In a long-term experiment in greenhouse conditions (T = 26.5 ± 4.2°C; Ru = 62.7% ± 22.5), a single application of S. carpocapsae in columns with sandy Ultisol showed a residual effect of 21 days, while for H. bacteriophora it was lower than 15 days. Concomitant application of S. carpocapsae and the virulent EF strain B. bassiana LCB289 in columns with sandy soil in a greenhouse experiment in the same conditions (T = 26.5 ± 4.2°C; Ru = 68.5% ± 23.3) increased the median potency of the BCAs, resulting in a lower lethal concentration applied (LC50).

Study on Phytochemical Profiling of Euphorbia cyathophora Leaf Extracts and Their Potential Antimicrobial, Larvicidal, and Pupicidal Properties Against Earias vittella

Earias vittella is a serious polyphagous agricultural pest that can directly or indirectly damage crops and stored products worldwide. Using synthetic chemicals in pest control has resulted in physiological resistance and adverse environmental effects. However, this alternative to plant-based pest control systems is ecologically friendly and biodegradable. Moreover, Euphorbia cyathophora is a medicinal plant used for many therapeutic activities. Therefore, the present study is aimed at E. cyathophora leaf extract evaluation of the phytochemical, in vitro antimicrobial, larvicidal, and pupal activity of E. vittella. A preliminary phytochemical screening of E. cyathophora leaf extracts revealed numerous bioactive components such as alkaloids, flavonoids, sterols, terpenoids, anthraquinones, carbohydrates, and essential oils. GC-MS analysis of E. cyathophora leaf different extracts revealed the presence of 29 phytochemicals. Among the extracts tested, the methanolic leaf extract showed the highest range of growth inhibition against gram-positive bacteria Streptococcus iniae (15 ± 0.26) and gram-negative bacteria Aeromonas hydrophila (13 ± 0.6), while antifungal activity against Aspergillus flavus (14 ± 0.2) and Aspergillus niger (12 ± 0.36) compared to other solvent extracts. In addition, the bioefficacy of E.Cyathophora leaf extract treated against IV instar larvae and pupae of E. vittella; however, the highest larval and pupal mortality was observed in the methanol extract at 750 ppm, followed by acetone and chloroform against E. vittella. Larvicidal activity of E. cyathophora leaf extracts showed LC50 and LC90 values: methanol 298.64 ppm (708.14); Acetone 362.61 ppm (848.56), and chloroform 415.18 ppm (937.31), respectively. Similarly, thepupicidal effect of E. Cyathophora leaf extracts showed LC50 and LC90 values: methanol 470.25 ppm (958.01); acetone 527.36 ppm (996.35) and chloroform 545.55 ppm (997.88). This study strongly suggests that E. cyathophora leaf extract exhibited significant larval and pupal mortality and potential antimicrobial activity, which can be observed as the development of a new botanical preparation for economic pest control.

Development and Immature Mortality of the Sawtoothed Grain Beetle (Coleoptera: Silvanidae), on Different Sorghum Fractions and Different Temperatures.

Developmental ability of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) was examined on six different sorghum milling fractions: Bran, Shorts, Cgrits, Fgrits, Red dogs, Flour, and also on a standard diet of Oat Flakes. For this purpose, a 1-day-old egg was placed in a vial containing 1 g of one of the sorghum fractions and exposed to three temperatures: 25, 30, or 32°C. All vials were checked daily for pupal and adult emergence and mortality of immatures. The developmental time was significantly affected by the type of sorghum fraction. After two weeks, for most of the temperatures examined, the longest developmental times in most cases for both pupation and adult emergence were observed in Flour and Oat flakes. Increasing the temperature from 25 to 30 accelerated the development, while adult emergence time did not differ between 30 and 32°C for all fractions except Flour. Egg mortality ranged from 11 to 78%, while larval and pupal mortality ranged from 0 to 22 and 0 to 45%, respectively for all sorghum fractions and different temperatures tested. Moreover, the mean overall immature mortality occurred at 30°C was 49.2, 39.7, and 65.1% at 25, 30, and 32°C for all the diets examined. The findings of the present work show that O. surinamensis can develop and survive in sorghum milling fractions and that the optimal temperatures for growth enhancement are 30 and 32°C. The temperatures within sorghum milling facilities could support O. surinamensis development on milling fractions if they are not addressed through phytosanitary measures.

Effects of Excess Insecticide Application on Cowpea (Vigna unguiculata) Seeds by responses of Colonized Cowpea Weevil (Callosobruchus maculatus)

This study was designed to determine the effect of excess insecticide application on stored cowpea (Vigna unguiculata) seeds sourced from Lapai market, Niger State, Nigeria using appropriate standard techniques. The effect quantum was using cowpea weevil (Callosobruchus maculatus) as Biomarker. Result obtained show that lethal concentration of insecticide significantly (P < 0.05) affected duration of immature development, with highest concentration increasing the duration of larval development significantly. Larval and pupal mortality (11.20±1.24 and 67.20±4.65; 8.04±0.44 and 36.20±2.11 for negative control and highest treated concentration respectively) were significantly (P < 0.05) affected by increase in insecticide concentration. Mean temperature and relative humidity (28.77±1.2 and 35.88±5.14 respectively) of the immediate stored cowpea environment were within the ambient condition. Protein and Carbohydrate were the two proximate composition that varied significantly as a result of insecticide application. Cowpea weevil have shown a great potential of serving as a potential bio-markers of insecticide contamination of stored cowpea seeds in storage. Further research on similar and other biological effects of abused insecticide on colonizing weevil should be carried out in and outside laboratory condition.

Sub-lethal effects of indigenous isolate of Spodoptera frugiperda nucleopolyhedrovirus on fall armyworm growth and reproduction in India

BackgroundBaculoviruses are specific pathogens which can lethally infect several lepidopteran pests. However, the sub-lethal effects of baculoviruses are also highly debilitating for the host. The objective of the study was to demonstrate the sub-lethal effects of an indigenous strain of Spodoptera frugiperda nucleopolyhedrovirus (SpfrNPV) infecting fall armyworm in India.ResultsAs a result of larval infection, the larval developmental time was significantly prolonged as compared to the untreated insects. The percentage of pupal mortality ranged from 40.74 to 72.73 at varying doses of SpfrNPV and recorded low pupal weight in all the treatments than control. The fertility and fecundity of infected adult moths was significantly reduced when compared to the untreated insects in a concentration dependent fashion. Sub-lethal effects of baculoviral infection on different biological parameters were studied. Mean developmental period of infected 3rd and 4th larval instars was significantly higher (F = 2.945; F = 18.414; df = 5, 20; P < 0.05) in SpfrNPV infected larvae than the control at all tested viral concentrations. The percentage of pupal mortality ranged from 40.74 to 72.73 in the lowest and highest concentrations of SpfrNPV, respectively. Developmental period of male pupae was found to be significantly longer in infected groups than the uninfected ones. The infected adults had significantly reduced longevity in both males ranged from 3.5 to 5.75 (F = 6.273; P = 0.002) and females ranged from 3.5 to7.00 (F = 13.652; P = 0.001). Further, the mates of virus-treated adults showed a highly reduced egg production (F = 31.255; P < 0.05) ranged from 150.03 to 338.33 and the larval emerging ranged from 71.11 to 227.89 (F = 74.52; P < 0.05), which was again significantly lower than the control. The percentage of egg hatching ranged from 47.40 to 86.41%.ConclusionsThe sub-lethal effect of SpfrNPV has observed on the growth and development and also reduced percentage of egg hatching in the subsequent generation. Hence, this indigenous SpfrNPV strain can be used in the sustainable and resilience IPM program. Further studies under open field conditions are still needed.

THE BISON AND THE BLOW FLY: USING PUPARIA OF THE BLACK BLOW FLY (PHORMIA REGINA: DIPTERA, CALLIPHORIDAE) TO CONSTRAIN THE SEASON OF DEATH AND TAPHONOMIC HISTORY OF AN EARLY HISTORIC-AGE BISON, CARSON CITY, NEVADA, USA

ABSTRACT We report the occurrence of abundant dipteran puparia of Phormia regina, the black blow fly, in association with an early historic-age bison skeleton excavated near Carson City, Nevada. Cut marks on some of the bones indicate that the bison was butchered and probably skinned by humans. Radiocarbon dating provides two possible age intervals for the death of the bison: (1) latest seventeenth to early eighteenth century or (2) early nineteenth to early twentieth century; we consider the more recent age to be more plausible. The purpose of this study is to explore how the presence of puparia of this well-studied, necrophagous fly species can be used to help constrain the season of death and inform the interpretation of the taphonomic history of the bison. The life cycle of P. regina requires a minimum of 8.8 days within a temperature range of 14°C to 35°C, so the bison carcass must have been exposed to the air for at least that long within that temperature range. However, of the thousands of recovered puparia, 35% remain closed and did not produce adult flies; of this cohort, only a tiny percentage exhibit small exit holes attributable to parasitoid wasps. Cold temperatures, and not parasitoid wasps, are the most probable cause of the high pupal mortality. Climate data for the region, along with P. regina temperature constraints and streamflow and flooding records for the Carson River watershed, indicate that the bison died and was colonized by black blow flies in the spring, when night-time temperatures were low. A short time later the skinned and butchered skeleton was buried by floodplain sediments. Blow fly puparia can contribute useful information for the taphonomic analysis of vertebrate fossil sites.

Characterization, expression analysis and RNAi-mediated knockdown of two aquaporin genes in the cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae)

Aquaporins (AQPs) are integral membrane proteins that can transport water and small molecules across cell membranes in organisms. In a previous report, we identified an AQP (SlAQP1) gene of the cotton leafworm, Spodoptera littoralis. In the current study, we identify and characterize two more SlAQP genes and their developmental and tissues expression. Predicted amino acid sequence and phylogenetic analysis revealed that SlAQP2 is a glycerol channel belonging to the insect specific Eglp subfamily, whereas SlAQP3 is a water specific channel belonging to the Prip subfamily. SlAQP2 expression was detected mainly in the first four larval instars and adult males, whereas SlAQP3 was detected in all developmental stages. SlAQP2 gene expression was mainly detected in larval midgut and Malpighian tubules and adult male testes, whereas SlAQP3 was detected in all the tissues tested. RNAi mediated knockdown of each gene separately resulted in deleterious effects including larval and pupal mortality, deformed pupae and adults and prolonged development. Results were confirmed using qRT-PCR, which revealed downregulation of both genes after injection of larvae with gene specific dsRNA. Our results confirm the presence of Prip and Eglp AQPs in S. littoralis and suggest that Eglp has a role in male reproductive ability.

Luminescence Tracking and In Vivo Toxicity Evaluation of TiO2 and Europium Doped TiO2 Nanocrystals during Drosophila Development

Titanium dioxide (TiO2) nanoparticles (NPs) are widely used in industry and commercial products. Thus, their potential risks to the environment and human health must be evaluated. Doping NPs with certain ions makes it possible to mix properties or generate new ones. Thus, in order to track TiO2 NPs in biological assays, doping with europium (Eu3+) ions was performed, which luminesce in red. Here, we synthesized TiO2 and Eu3+-doped TiO2 nanocrystals (NCs) in anatase phase to verify the toxicity at different concentrations in Drosophila melanogaster and track the distribution of these NCs in vivo. We verified that the incorporation of europium improved the biocompatibility in relation to the pure samples. The presence of Eu3+-doped TiO2 NCs in the gut, brain, and fat body of larvae and intestinal cells of adult animals was detected. Eu3+-doped TiO2 NCs caused significant larval and pupal mortality rates, in addition to leading to the formation of reactive species, especially at high concentrations. Therefore, our data demonstrated it was possible to trace the Eu3+-doped TiO2 NCs, but TiO2 and Eu3+-doped TiO2 NCs in anatase phase were toxic to fruit flies at the tested concentrations, and should be used with caution to minimize health risks.

Lifetables of &lt;i&gt;Chilo partellus&lt;/i&gt; (Swinhoe) infesting rabi sorghum

This study on the sorghum spotted stem borer Chilo partellus (Swinhoe) was conducted at the Post Graduate Experimental Field of Department of Agricultural Entomology, College of Agriculture, Campus Latur during 2020-21. The results revealed that C. partellus passed through three generations on rabi sorghum. The mortality in early instar larval stage was observed due to unknown reasons (17.24, 19.05 and 14.51%, respectively), Callibracon sp. (4.16, 11.76 and 8.33%, respectively) and Cotesia flavipes (8.69, 6.67 and 9.65%, respectively) in its first, second and third generations. The mortality in late instar larvae was also found owing to unknown reasons (19.4, 14.28, and 11.36%, respectively), Callibracon sp. (11.76, 12.49 and 11.43%, respectively) and C. flavipes (13.33, 14.28 and 10.26%, respectively) in the first, second and third generations. In first generation, the pupal mortality was not observed, and when noticed it was due to unknown reasons (11.11 and 16.12%, respectively) during second and third generations. The trend index and generation survival were 1.44 and 0.44; 1.48 and 0.38 and; 0 and 0.42 during first, second and third generations, respectively.

Bioefficacy of Leaf Extracts of two underutilized ferns, Azolla pinnata and Polystichum acrostichoides against Malaria Vector, Anopheles gambiae Giles [Diptera: Culicidae

The bioefficacy of Azolla pinnata and Polystichum acrostichoides leaf extracts were evaluated in the laboratory against the immature stages (larvae and pupae) and adults of Anopheles gambiae at a relative humidity of 75±5% and an ambient temperature of 28 ±2°C. The efficacy of the extracts was evaluated in a standard bioassay at different concentration of 15mg/L, 30mg/L, 60mg/L, 120mg/L and 240mg/L using standard methods were tested. The effects of various concentrations of the plant extracts (A. pinnata and P. acrostichoides) used in this study were significantly different (p&lt;0.05) in efficacy on An. gambiae larvae. The mortality rate of An. gambiae caused by the tested plants’ extracts were concentration-dependent. The larvicidal efficacies of A. pinnata and P. acrostichoides at concentrations of 15mg/L, 30mg/L, 60mg/L, 120mg/L and 240mg/L were 40%, 55%, 70%, 95% and 100%, and 27.25%, 42.5%, 57.25%, 85% and 100% after 24 hours exposure, respectively. Pupa mortality of An. gambiae exhibited by the highest concentration of A. pinnata and P. acrostichoides were 100% and 90% respectively after 24 hours exposure. The mortality of the adults caused by the highest used concentration was 70% and 57.5% for A. pinnata and P. acrostichoides respectively after 24 hours exposure. The Probit model analysis revealed that A. pinnata extract was the most effective due to its low lethal concentrations to cause 50% (LC50) and 90% (LC90) mortality of malaria vector (An. gambiae) larvae, pupa and adult. Results from this current study indicate the potentials of A. pinnata leaf extract as a mosquito insecticidal agent.

Effect of temperature on survival of Australian entomopathogenic nematodes and their virulence against the Queensland fruit fly, Bactrocera tryoni

Entomopathogenic nematodes (EPNs) are commonly used biocontrol agents of insect pests, with a wide range of commercially available isolates targeting specific pests. New isolates are, however, required to improve pest control across a wider range of environmental conditions for target pests, including emerging threats. We assessed the effect of temperature on survival and virulence of 17 Australian isolates of five EPN species (Heterorhabditis bacteriophora, Heterorhabditis indica, Heterorhabditis marelatus, Heterorhabditis zealandica and Steinernema feltiae) against larvae and pupae of the Queensland fruit fly, Bactrocera tryoni. All isolates still infected and killed larvae after infective juveniles (IJ) had been kept without insect hosts at 15 °C, 25 °C or 30 °C for two weeks, indicating their potential to remain viable under field conditions. However, the mean LD50 value ranged from 35 to 150 and was generally lower at 15 °C than at 25 °C and 30 °C. Similarly, after IJs had been kept at 25 °C for 1–3 weeks without insect hosts, all isolates infected B. tryoni larvae, with mean LD50 values ranging from 25 to 144. Interestingly, 15 isolates infected and killed B. tryoni pupae after one week, with a mean LD50 value between 130 and 209, but only two isolates after two weeks, with a mean LD50 value between 229 to 209. No pupal mortality was seen after three weeks. In absence of hosts, EPNs survived longer at 15 °C and 25 °C than at 30 °C. Complete EPN mortality occurred after nine weeks at 30 °C, and after 18 weeks at 15 °C and 25 °C, except for some survival in one S. feltiae isolate (Sf.ECCS). Overall, six isolates of H. indica (Hi.HRN2, Hi.LMI2, Hi.QF6), H. bacteriophora (Hb.HIE), H. zealandica (Hz.NAR1) and S. feltiae (Sf.ECCS) performed best and need further testing as potential biocontrol agents against B. tryoni under semi-field and field conditions.