Adult Female Longevity Research Articles

Toxicity and Sublethal Effect of Chlorantraniliprole on Multiple Generations of Aedes aegypti L. (Diptera: Culicidae)

Due to the quick development of insecticide resistance, it is crucial to optimize management programs by understanding the sublethal effects of effective insecticides like chlorantraniliprole on Aedes aegypti L. populations. Using age-stage and two-sex life tables, we investigated the sublethal impacts of chlorantraniliprole on Ae. aegypti. Larval duration in the progeny of exposed parents was reduced by 0.33–0.42 days, whereas, the longevity of male and female adults was decreased by 1.43–3.05 days. Similarly, the egg-laying capacity of F1 and F2 progeny of the exposed parents was significantly reduced from 27.3% to 41.2%. The mean generation time (T) increased up to 11.8% in exposed populations, and the net reproduction rate (Ro) decreased by 51.50–55.60%. After 24 h of chlorantraniliprole treatment, there was a significant increase in cytochrome P450 activity. Contrarily, the activity of glutathione S-transferase (GST) initially declined but started increasing after 48 h of treatment. This research highlights the importance of chlorantraniliprole in mosquito management, as well as the importance of considering sublethal effects when developing strategies to handle them. Having a thorough understanding of the harmful effects of insecticides on mosquito populations can greatly enhance the effectiveness of insecticide-based interventions, while also minimizing the risk of pest resurgence.

Fitness Cost Associated with Diamide-Resistant Population of Brinjal Shoot and Fruit Borer <i>Leucinodes orbonalis</i> Guenee

Brinjal shoot and fruit borer, Leucinodes orbonalis is a serious pest of brinjal and has evolved resistance to commonly used diamide insecticides such as flubendiamide and chlorantraniliprole. Lifetable parameters of the field populations of L. orbonalis, collected from brinjal fields of Kullarayanpalayam (Palakkad) (PKD) and Anchal (Kollam) (KLM), Kerala, reported resistance to diamides was studied and compared with that of laboratory-reared susceptible population of L. orbonalis (Lo-S) procured from ICAR- NBAIR, Bengaluru to determine the fitness cost associated with diamide resistance. The results revealed that the PKD population was found to have a significantly longer larval period with 12.7± 0.82 days as compared to the Lo-S population (10.6± 2.71 days), while the KLM population showed a larval period of 11.1± 0.87 days. The pupal duration was significantly longer in both KLM and PKD populations with 10.3± 0.48 and 11.8± 0.63 days respectively; whereas, the Lo-S population showed only 9.6± 0.69 days. The longevity of female adults of PKD population was (3.80± 0.63 days), while KLM and Lo-S populations showed 4.20± 0.63 and 4.40± 0.51 days respectively. The fecundity of KLM (178.9± 6.08 eggs/ female) and PKD (171.40± 5.64 eggs/ female) populations were significantly lower when compared with the Lo-S population (194.1± 4.38 eggs/ female). Only 89.11% eggs hatched in the PKD population while 89.34± 2.73and 91.87± 4.01% of eggs hatched in KLM and Lo-S populations, respectively. However, the fitness parameters like the incubation period, pupation rate, adult emergence rate, female ratio, and male longevity were not significantly different. The PKD and KLM populations showed both negative and positive biological trade-offs exhibiting a relative fitness of 0.74 and 0.82 respectively compared to the Lo-S population (1).

The Food Source and Gut Bacteria Show Effects on the Invasion of Alien Pests-A Case of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae).

How alien pests invade new areas has always been a hot topic in invasion biology. The spread of the Bactrocera dorsalis from southern to northern China involved changes in food sources. In this paper, in controlled conditions, we take Bactrocera dorsalis as an example to study how plant host transformation affects gut bacteria by feeding it its favorite host oranges in the south, its favorite host peaches and apples in the north, and feeding it cucumbers as a non-favorite host plant, thereby further affecting their fitness during invasion. The result showed that, after three generations of feeding on cucumbers, Bactrocera dorsalis took longer to develop as a larva while its longevity and fecundity decreased and pre-adult mortality increased. Feeding it cucumbers significantly reduced the overall diversity of gut microbiota of Bactrocera dorsalis. The relative abundance of Enterobacter necessary for survival decreased, while the Empedobacter and Enterococcus increased, resulting in decreased carbohydrate transport and metabolism and increased lipid transport and metabolism. Feeding Bactrocera dorsalis Empedobacter brevis and Enterococcus faecalis resulted in a 26% increase in pre-adult mortality and a 2-3 d increase in adult preoviposition period (APOP). Additionally, Enterococcus faecalis decreased the longevity of female and male adults by 17 and 12 d, respectively, and decreased fecundity by 11%. We inferred that the shifted plant hosts played an important role in posing serious harm to Bactrocera dorsalis invading from the south to the north. Therefore, after an invasion of Bactrocera dorsalis into northern China, it is difficult to colonize cucumbers for a long time, but there is still a risk of short-term harm. The findings of this study have established that the interactions between an insect's food source and gut bacteria may have an important effect on insect invasions.

Silence of Aminopeptidase N 2gene reveals the trade-offs for acquiring Cry1Ac resistance in Plutella xylostella.

Bacillus thuringiensis (Bt) is widely used as a biopesticide worldwide. To date, at least eight pest species have been found to be resistant to Bt in the field. As the first pest that was reported having resistance to Bt in the field, considerable research has been done on the mechanisms of Bt resistance in Plutella xylostella. However, whether the acquisition of Bt resistance by P. xylostella comes at a fitness cost is also a valuable question. In this study, Aminopeptidase-N 2 (APN2), a Cry toxin receptor gene of P. xylostella, was knocked down by RNA interference, resulting in improved resistance to Cry1Ac. It was also found that larval mortality of APN2 knockdown P. xylostella was significantly higher than that of the control, while the pupation rate, pupal weight, eclosion rate, fecundity (egg/female), hatchability, and female adult longevity were significantly lower in APN2 knockdown P. xylostella than in the control. These results illustrate that if Cry1Ac resistance was obtained only through the reduction of APN2 expression, P. xylostella would need to incur some fitness costs for it.

Biology and Morphometrics of Fall armyworm (Spodoptera frugiperda) in Chitwan, Nepal

The Fall armyworm (FAW) Spodoptera frugiperda, native to the Americas, is an important invasive and polyphagous pest threatening cereal production. Abiotic and biotic factors, including climatic uncertainty and insect pests like S. frugiperda, pose threats. Detected in East Africa in 2016 and reported in Nawalpur, Nepal, on May 9, 2019, FAW has led to a 34% decline in maize yields. Studying FAW's biology and morphometrics is crucial for understanding its habitat and ecology, essential prerequisites for adopting integrated management strategies. Biological parameters such as incubation period, larval and pupal duration, pre-oviposition and, oviposition periods, male and female adult longevity, larval and pupal mortality, sex ratio (male: female), and morphometrics of egg, larvae, pupa, and adult were measured. The incubation period (2-3 days), larval and pupal periods (13-18 and 9-12 days) with overall life duration (31-45 days) were recorded in maize. Head capsule width of the first, second, third, fourth, fifth, and sixth instar were recorded as 0.52±0.05, 0.73±0.05, 1.1±0.05, 1.74±0.12, 2.04±0.15, and 2.91±0.23 mm respectively. Mean body length of different larval instars were recorded as 3.33±0.26, 6.92±1.07, 13.11±1.45, 16.82±1.57, 28.68±1.75, and 34.56±1.99 mm for the first, second, third, fourth, fifth, and sixth instar respectively.

Sublethal and transgenerational effects of broflanilide on the citrus red mite, Panonychus citri.

The citrus red mite, Panonychus citri is a serious pest of the citrus industry and has developed resistance to many acaricides. Broflanilide is a novel meta-diamide insecticide that binds to a new site on the γ -aminobutyric acid receptor with high potency against pests. However, little information has been reported about its effect on the citrus red mite. Broflanilide exhibited higher toxicity to female adults and eggs of a laboratory strain of P. citri The median lethal concentration (LC50), 9.769 mg/L and 4.576 mg/L, respectively) than other commonly used acaricides and was also toxic to two P. citri field strains. Broflanilide treatment with LC10, LC20, and LC30 significantly decreased the fecundity and longevity of female adults of F0 P. citri compared with the control. The duration of larva, protonymph, deutonymph and adult, and total life span in the F1 generation were significantly reduced after treatment of F0 with broflanilide. Population parameters, including the intrinsic rate of increase (r) and finite rate of increase (λ), were significantly increased, and the mean generation time (T) of F1 progeny was significantly reduced in the LC20 treatment. The predicted population size of F1 increased when parental female adults were treated with sublethal concentrations. Broflanilide had high acaricidal activity toward P. citri, and exposure to a sublethal concentration significantly inhibited the population growth of F0. The transgenerational hormesis effect is likely to cause population expansion of F1. More attention should be paid when broflanilide is applied to control P. citri in citrus orchards. © 2024 Society of Chemical Industry.

Effect of storage period on trichocards parasitized by Trichogramma chilonis Ishii under laboratory conditions

The present study aimed to find the suitable storage duration for parasitized trichocards without affecting much the biological parameters of T. chilonis adults such as adult emergence, adult longevity and egg parasitization. The results revealed that biological parameters viz., adult emergence, adult longevity and egg parasitization were inversely proportional to the storage period. Maximum adult emergence (87.63%), female longevity (5.57 days), male longevity (4.53 days) and egg parasitization (85.67%) were observed at 5 days storage period. Further, adult emergence declines to 56.13 per cent when trichocards are stored for 25 days. Whereas, less than 50 per cent egg parasitization in F1 generation was observed when trichocards were stored for 35 days. However, there was no egg parasitization by a female in the F1 generation noticed for 45 and 50 days storage period this might be due to short adult female longevity and lowest adult emergence. Hence, it can be concluded that trichocard could be effectively stored for up to 25 days at low temperatures under refrigerator conditions(4°C temperature and 50-60% relative humidity) by considering at least 50 per cent adult emergence with 4.13 days of female longevity as well as 63.00 per cent egg parasitization during the mass production program. Therefore, effective and right time augmentation of T. chilonis could be achieved under field conditions.

Colonization of Piriformospora indica enhances rice resistance against the brown planthopper Nilaparvata lugens.

Piriformospora indica is an endophytic fungus that can promote the growth and confer resistance against diverse stresses in host plants by root colonization. However, the effects of P. indica colonization on improving plant resistance to insect pests are still less explored. The brown planthopper (BPH) Nilaparvata lugens is a serious monophagous pest that causes extensive damage to rice plants. Here, we aimed to evaluate the effects of P. indica colonization on rice resistance against BPH. The colonization of P. indica in rice roots resisted damage from BPH. Age-stage, two-sex life table analyses showed that feeding on P. indica-colonized rice plants affected BPH's female adult longevity, oviposition period, fecundity, population parameters and population size. BPH female adults feeding on P. indica-colonized plants excreted less honeydew. P. indica colonization remarkably increased the duration of np, N2, and N3 waveform, as well as the occurrences of N1 and N2, and decreased the duration of N4-b for BPH on rice plants. Meanwhile, the weight of BPH on the colonized plants was significantly lower than the control. In addition, the feeding and oviposition preferences of BPH to P. indica-colonized plants were reduced. qRT-RCR analyses revealed that P. indica colonization induced the expressions of jasmonic acid (JA)- and salicylic acid (SA)-related genes in rice plants. P. indica colonization can reduce BPH performance on rice plants with potential inhibitory effects on population growth. Collectively, these results support the potential for endophytically colonized P. indica as an effective strategy to improve insect resistance of crops. © 2024 Society of Chemical Industry.

The link between functional response and longevity of Trichogramma evanescens strains indigenous to Türkiye: A comparative assessment of parameters

AbstractA previous comprehensive survey in the Mediterranean and Southeastern regions of Türkiye investigating the natural egg parasitism of lepidopteran maize pests, Sesamia spp, (Lepidoptera: Noctuidae) Ostrinia nubilalis Hbn. and Chilo partellus (Swinhoe; Lepidoptera: Crambidae) by Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) yielded successful establishment of laboratory cultures of six strains molecularly clustering into two main groups. In this study, the functional response and adult longevity of the strains reared and tested on a factitious host, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were investigated to provide insights into their potential as candidate biocontrol agents under constant laboratory conditions. The functional response modelling process consisted of two main sequential steps: model selection using polynomial logistic regression and parameter estimation using an iterative maximum likelihood estimation method. The functional response of two strains showed negative linear parameters (type II): HAP068M and HAP268S. Although their attack rate did not differ, the handling time of HAP268S was longer than that of HAP068M. In contrast, four strains had positive linear and negative quadratic parameters (type III) in their functional response: HAP044S, HAP070S, HAP210S, and HAP258M. The strains exhibiting type III functional response did not differ in their handling time, while HAP044S had a higher attack coefficient than HAP070S, HAP210S, and HAP258M. The longevity of both female and male adults significantly differed between strains. More importantly, the females belonging to strains exhibiting type II functional response presented a shorter longevity, compared to those with type III functional response. Males also showed a similar trend in their longevity. This paper discusses the differences in functional response types and estimated parameters of the strains in relation to their relevance for biological control programs and reveals a link between their functional response and longevity as potential reciprocal predictors.

Lethal and sublethal effects of fluralaner on the citrus red mite, Panonychus citri (McGregor).

The citrus red mite, Panonychus citri (McGregor) is a globally distributed agricultural pest. Of late, resistance to common acaricides has raised concerns that chemical control of P. citri is an inefficient means of control. Fluralaner, a highly toxic isoxazoline insecticide used to treat various ectoparasites, presents one potential alternative. However, little information has been reported about the effect of fluralaner on the citrus red mite. This study aims to evaluate the toxicity, sublethal and transgenerational effects of fluralaner on P. citri. In both laboratory and field populations of P. citri, we found fluralaner to be more toxic than conventional alternatives, including fenpropathrin, bifenazate, azocyclotin and chlorpyrifos. Interestingly, fluralaner proved more toxic to female adults than to the eggs of P. citri, with median lethal concentrations (LC50) of 2.446 and 122.7 mg L-1, respectively. Exposure to sublethal concentrations of fluralaner (LC10, LC20 and LC30) significantly reduced the fecundity and longevity of female adults P. citri individuals. Although concentrations of fluralaner applied to the parental female adults (F0) led to some changes in the developmental parameters, there were no significant changes in most of the life table parameters or population growth of the F1 generation. Our results indicate that fluralaner is highly toxic to P. citri, and a significant sublethal effect on F0 could suppress the population growth of P. citri, but not for F1. Fluralaner may be considered as a pesticide for the future management of the citrus red mite. © 2024 Society of Chemical Industry.

Low concentrations of cyantraniliprole negatively affects the development of Spodoptera frugiperda by disruption of ecdysteroid biosynthesis and carbohydrate and lipid metabolism

In addition to the acute lethal toxicity, insecticides might affect population dynamics of insect pests by inducing life history trait changes under low concentrations, however, the underlying mechanisms remain not well understood. Here we examined systemic impacts on development and reproduction caused by low concentration exposures to cyantraniliprole in the fall armyworm (FAW), Spodoptera frugiperda, and the putative underlying mechanisms were investigated. The results showed that exposure of third-instar larvae to LC10 and LC30 of cyantraniliprole significantly extended larvae duration by 1.46 and 5.41 days, respectively. Treatment with LC30 of cyantraniliprole significantly decreased the pupae weight and pupation rate as well as the longevity, fecundity and egg hatchability of female adults. Consistently, we found that exposure of FAW to LC30 cyantraniliprole downregulated the mRNA expression of four ecdysteroid biosynthesis genes including SfNobo, SfShd, SfSpo and SfDib and one ecdysone response gene SfE75 in the larvae as well as the gene encoding vitellogenin (SfVg) in the female adults. We also found that treatment with LC30 of cyantraniliprole significantly decreased the whole body levels of glucose, trehalose, glycogen and triglyceride in the larvae. Our results indicate that low concentration of cyantraniliprole inhibited FAW development by disruption of ecdysteroid biosynthesis as well as carbohydrate and lipid metabolism, which have applied implications for the control of FAW.

Effect of Elevated Temperature on the Bionomics of <i>Aenasius arizonensis</i> Girault

An experiment was conducted to know the effect of thermal stress on the biological attributes of the parasitoid Aenasius arizonensis Girault of the cotton mealybug Phenacoccus solenopsis Tinsley. The results revealed that temperature showed a significant effect on the biological fitness traits of the A. arizonensis; when exposed to 32°C, parasitisation, fecundity, female sex ratio and adult longevity. At 32°C these viz., parasitisation (77%), sex ratio (63.46) and days taken from oviposition to mummy formation (6.4) were found to be the highest. Other fitness traits like fecundity (142.8) and developmental duration (11.2 - males, 12.6 - females) were found to be the highest at 27°C. These parameters gradually decreased with increasing temperature, indicating a negative relationship. Morphometrics of adults revealed that mean length and breadth of mummies, total length and breadth of adult male and females, total width of head, total length of antenna and total hind tibial length were maximum at 27°C as compared to those observed with high temperature treatments. Thus high temperature was observed to have an adverse effect on the growth and development of the parasitoid.

Importance of wildflowers in Orius insidiosus (Heteroptera: Anthocoridae) diet

Abstract The addition of non-crop floral resources is known to improve the fitness of many beneficial arthropods. Orius insidiosus (Say; Heteroptera: Anthocoridae) is a predator of several economically important pests and is known to feed on pollen. Spanish needles, Bidens alba L., and Leavenworth’s tickseed, Coreopsis leavenworthii Torrey & Gray (both Asteraceae), are two Florida native wildflowers that may serve as sources of pollen beneficial to O. insidiosus. The current study investigated the effects of adding flowers from C. leavenworthii and B. alba to the diet of captive O. insidiosus on longevity, nymphal development time, and cannibalism. A mixed diet of flowers and thrips prey increased O. insidiosus adult female longevity. Nymphal development time was reduced when B. alba was added to thrips when compared to a diet of thrips alone. Interestingly, cannibalism was low in all instances, suggesting a negligible effect of cannibalism on O. insidiosus except perhaps in extreme situations. These results indicate that B. alba and C. leavenworthii flowers can increase longevity and fitness of O. insidiosus, thus providing support for the use of these plants to enhance natural enemy services.

Impact of artificial diets on the biological and chemical properties of red palm weevil, Rhynchophorus Ferrugineus Olivier (Coleoptera:Curculionidae).

One of the most common palm pests is the red palm weevil, Rhynchophorus ferrugineus Olivier. Five artificial diets were evaluated to rear RPW, and to facilitate its behavioral and biological studies. The developmental of R. ferruginus was studied on the tested artificial diets based on primarily composed of sugarcane stem pieces (1st diet; control), sweet pumpkin (2nd diet), ground sugarcane + sweet pumpkin (3rd diet), sweet potato (4th diet) and ground sugarcane + sweet potato (5th diet) under rearing room (28 ± 1 °C and 75 ± 5 RH%) at Faculty of Agriculture in Benha district. The biological aspects, pre-oviposition, oviposition, larval & pupal durations, the longevity of male and female adults and the generation period of R. ferrugineus have all been estimated. Moreover, the impact of these artificial diets on the quantities of total proteins, carbohydrates and lipids were determined in the full-grown larvae. Obtained results showed that the insect manifested the shortest larval and pupal periods and the longest longevity for males and females when rearing of R. ferruginus took place on an artificial diet based on sweet potato as a successful and economical for mass rearing of the red palm weevil under laboratory conditions. Larvae fed on diet 4 (sweet potato) was exhibited the shortest duration (114.80 days), while 1st diet (Sugarcane stem pieces) was recorded the longest period (125.00 ± days). Similarly for pupation and both male and female longevity, the shortest periods resulted from larvae feeding on 4th diet (14.65, 49.40 and 48.0 days, respectively). Contrariwise, the longest pupal period was reported with 5th diet (15.70 days). The highest of eggs hatchability % (96.53%) resulted from the rearing nof R. ferruginus larvae on the 4th diet. Chemical analyses of the full-grown larva were indicated that the highest contents of total carbohydrates (45.57 µg/g), lipids (28.46 µg/g) and proteins (20.01µg/g) were obtained in case of larvae reared on 1st and 4th diets, respectively. Consequently, the development of R. ferruginus stages was slightly lower on both 1st and 4th artificial diets. So that, both of them were a successful and economic artificial diet for RPW development under laboratory conditions. Therefore, this study added valuable alternative ingredients to prepare more practical and economical feeding substrate for weevil rearing to help for proposal of its management and conservation in palm plantations.

Larval diet and temperature alter mosquito immunity and development: using body size and developmental traits to track carry-over effects on longevity

BackgroundEstimating arbovirus transmission potential requires a mechanistic understanding of how environmental factors influence the expression of adult mosquito traits. While preimaginal exposure to environmental factors can have profound effects on adult traits, tracking and predicting these effects remains challenging.MethodsUsing Aedes albopictus and a structural equation modeling approach, we explored how larval nutrition and temperature jointly affect development rate and success, female body size, and whether these metrics capture carry-over effects on adult female longevity. Additionally, we investigated how larval diet and temperature affect the baseline expression of 10 immune genes.ResultsWe found that larval development success was primarily determined by diet, while temperature and diet both affected development rate and female body size. Under a low larval diet, pupal wet weight and wing length both declined with increasing temperature. In contrast, responses of the two morphometric measures to rearing temperature diverged when females were provided higher larval nutrition, with pupal wet weight increasing and wing length decreasing at higher temperatures. Our analyses also revealed opposing relationships between adult female lifespan and the two morphometric measures, with wing length having a positive association with longevity and pupal weight a negative association. Larval diet indirectly affected adult longevity, and the time to pupation was negatively correlated with longevity. The expression of eight immune genes from the toll, JAK-STAT and Imd pathways was enhanced in mosquitoes with higher nutrition.ConclusionsOur results highlight deficiencies from using a single body size measure to capture carry-over effects on adult traits. Further studies of larval development rate under varying environmental conditions and its potential for tracking carry-over effects on vectorial capacity are warranted.Graphical

CRISPR/Cas9-mediated mutagenesis of the white gene in an ectoparasitic wasp, Habrobracon hebetor.

The ectoparasitic wasp Habrobracon hebetor (Hymenoptera, Braconidae) can parasitize various species of lepidopteran pests. To maximize its potential for biological control, it is necessary to investigate its gene function through genome engineering. To test the effectiveness of genome engineering system in H. hebetor, we injected the mixture of clustered regularly interspaced short palindromic repeats (CRISPR) -associated (Cas) 9 protein and single guide RNA(s) targeting gene white into embryos. The resulting mutants display a phenotype of eye pigment loss. The phenotype was caused by small indel and is heritable. Then, we compared some biological parameters between wildtype and mutant, and found there were no significant differences in other parameters except for the offspring female rate and adult longevity. In addition, cocoons could be used to extract genomic DNA for genotype during the gene editing process without causing unnecessary harm to H. hebetor. Our results demonstrate that the CRISPR/Cas9 system can be used for H. hebetor genome editing and it does not adversely affect biological parameters of the parasitoid wasps. We also provide a feasible non-invasive genotype detection method using genomic DNA extracted from cocoons. Our study introduces a novel tool and method for studying gene function in H. hebetor, and may contribute to better application of H. hebetor in biocontrol. © 2023 Society of Chemical Industry.

Studies on Reproductive Biology of Yellow Stem Borer, Scirpophaga incertulas Walker (Lepidoptera: Pyralidae) in the Changing Climate Scenario

Studies on reproductive biology of yellow stem borer, Scirpophaga incertulas walker in the changing climate scenario conducted at Agriculture Research Station, Gangavathi during 2020-22.Results on post eclosion behavior of yellow stem borer revealed that the maximum female moths emerged between 18:00 and 21:00 hrs from among the emerged moth the female calling was observed between 23:00 and 02:00 hrs. The time of mating commenced after the calling period and was observed between 23:00 and 03:00 hrs. The average pre-oviposition period, oviposition period and post-oviposition period were completed in 1.09 ± 0.09, 1.28 ± 0.17 and 0.85 ± 0.25 days, respectively. The longevity of adult females and males was about 3.23 ± 0.29 and 2.66 ± 0.33 days, respectively. The total number of eggs laid varied from 68 to 221 in number with an average of 146.95 ± 43.98 per female. The Operational and intrinsic sex ratio of YSB were observed to be female-biased with 1:1.35 and 1:1.44 of male to female moths, respectively.

Biology and integrative taxonomy of leaf folder, Helcystogramma hibisci (Stainton, 1859): a pest of musk mallow, Abelmoschus moschatus (L.) Medik.

Abstract The leaf folder, Helcystogramma hibisci (Stainton, 1859) (Lepidoptera: Gelechiidae) is an oligophagous pest of different malvaceous plants. In this study, attempts have been made to study the biology and taxonomy of the insect infesting musk mallow (Abelmoschus moschatus), an aromatic cum medicinal plant in India, following an integrative approach based on external morphology, internal genitalia structures, and molecular taxonomy. In the initial stage, the larva scrapes the tender surface of the leaves, and later, grown-up larvae web the leaves by folding them longitudinally. The entire inner content of the leaves is eaten by the larvae and ultimately the leaves get dry. The identity of the pest species is confirmed through dissecting of the male and female genitalia of the pest species and molecular confirmation (GenBank accession number ON545806). By studying the biology of the insect, the egg incubation period, larval period, and pupal period were determined to be 4.70 ± 0.64, 13.66 ± 0.86, and 6.46 ± 0.61 (male), and 7.60 ± 0.71 days (female), respectively. The average fecundity and adult longevity of males and females were 61.20 ± 11.68 eggs/female, 4.93 ± 1.38 days (male), and 8.06 ± 1.56 days (female), respectively. During their fourth instar, male larvae have dark-colored gonads that are easily visible on the dorsal integument of the abdominal segment distinguishing them from female larvae. Further confirmation of the identification was done by keeping the larvae in separate vials until emergence; larvae with this dark-colored character could be confirmed to be males, while other the larvae developed into female moths. The head capsule width of the larval instars was 0.26 ± 0.02, 0.47 ± 0.04, 0.66 ± 0.03, 0.83 ± 0.06, and 1.13 ± 0.14 mm, respectively. The information is useful for proper identification and management of this pest in such a valuable and popular plant as musk mallow in India. To our best knowledge, this is the first description of this pest species from the Indian region along with molecular confirmation.

Developmental Diet Alters the Fecundity-Longevity Relationship and Age-Related Gene Expression in Drosophila melanogaster.

The standard evolutionary theory of aging predicts a negative relationship (trade-off) between fecundity and longevity. However, in principle, the fecundity-longevity relationship can become positive in populations in which individuals have unequal resources. Positive fecundity-longevity relationships also occur in queens of eusocial insects such as ants and bees. Developmental diet is likely to be central to determining trade-offs as it affects key fitness traits, but its exact role remains uncertain. For example, in Drosophila melanogaster, changes in adult diet can affect fecundity, longevity, and gene expression throughout life, but it is unknown how changes in developmental (larval) diet affect fecundity-longevity relationships and gene expression in adults. Using D. melanogaster, we tested the hypothesis that varying developmental diets alters the directionality of fecundity-longevity relationships in adults, and characterized associated gene expression changes. We reared larvae on low (20%), medium (100%), and high (120%) yeast diets, and transferred adult females to a common diet. We measured fecundity and longevity of individual adult females and profiled gene expression changes with age. Adult females raised on different larval diets exhibited fecundity-longevity relationships that varied from significantly positive to significantly negative, despite minimal differences in mean lifetime fertility or longevity. Treatments also differed in age-related gene expression, including for aging-related genes. Hence, the sign of fecundity-longevity relationships in adult insects can be altered and even reversed by changes in larval diet quality. By extension, larval diet differences may represent a key mechanistic factor underpinning positive fecundity-longevity relationships observed in species such as eusocial insects.

Toxic effect of cyanobacterial (blue–green algae) extracts as natural pesticides for the control of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

BackgroundThe Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a cosmopolitan polyphagous pest that feeds on nearly 80 species of plants The pest can cause upto 100% damage to crops if neglected. It is also resistant to the most of the chemical molecules available in the market, so it is necessary to identify alternate technology to combat this pest.ResultsThe crude cyanobacterial extracts of hexane, petroleum ether, ethanol and methanol extracts of Spirulina sp. and Nostoc muscorum were evaluated against second instar larvae of S. frugiperda through diet overlay method of bioassay. The results revealed that N. muscorum hexane extract and N. muscorum petroleum ether extract recorded the lowest LC50 value of 49.09 and 61.37 ppm, respectively. This was followed by Spirulina hexane extract, Spirulina petroleum ether extract, N. muscorum ethanol extract, N. muscorum methanol extract, Spirulina ethanol and methanol extract which were recorded 173.16, 227.22, 530, 730, 970 and 1000 ppm, respectively. Further, their potential effects on different biological parameters of S. frugiperda, viz. larval duration, pupal duration, percent pupation, pupal weight, pupal malformation, adult malformation, percent adult emergence, fecundity, and male and female adult longevity, were studied. The significant effects on different biological parameters were recorded by N. muscorum hexane and petroleum ether extract, followed by Spirulina hexane and petroleum ether extract. Similarly, an experiment was repeated for the confirmation of the first set of results, which followed by a similar trend. The first-ever novel study on S. frugiperda concluded that crude extracts of Spirulina sp. and N. muscorum extracts showed significant effects in causing larval mortality and affecting different biological parameters.ConclusionsThe experimental results can be recommended as a potential source of natural pesticides for the control of S. frugiperda.