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Dietary change can be a strong evolutionary force and lead to rapid adaptation in organisms. High-fat and high-sugar diets can challenge key metabolic pathways, negatively affecting other life history traits and inducing pathologies such as obesity and diabetes. In this study, we use experimental evolution to investigate the plastic and evolutionary responses to nutritionally unbalanced diets. We reared replicated lines of larvae of the housefly Musca domestica on a fat-enriched (FAT), a sugar-enriched (SUG), and a control (CTRL) diet for thirteen generations. We measured development time in each generation and larval growth and fat accumulation in generations 1, 7, and 13. Subsequently, all lines were reared for one generation on the control diet to detect any plastic and evolutionary changes. In the first generation, time to pupation decreased on a fat-rich diet and increased on a sugar-rich diet. The fat-rich diet increased fat accumulation and, to a lesser extent, the dry weight of the larvae. Multigenerational exposure to unbalanced diets caused compensatory changes in development time, dry weight, and absolute and relative fat content, although pattern and timing depended on diet and trait. When put back on a control diet, many of the changes induced by the unbalanced diets disappeared, indicating that the diet has large plastic effects. Nevertheless, fat-evolved lines still grew significantly larger than the sugar-evolved lines, and sugar-evolved lines had consistently lower fat content. This can be an effect of parental diet or an evolutionary change in nutrient metabolism as a consequence of multigenerational exposure to unbalanced diets. [ABSTRACT FROM AUTHOR]

Body size is a characteristic of many animal species that is correlated with many fitness‐related traits. Parasitoids are important biological control agents of pests; larger parasitoids often have greater fitness and enhanced performance. Host size is a major influence on parasitoid size, which has been explored in the important egg parasitoid Anastatus disparis (Hymenoptera: Eupelmidae), a potential biological control agent for several Lepidopteran pests. Here, we found that the body size of A. disparis females increased with increasing host egg size, while host egg size did not significantly affect male size. In addition, both female and male offspring sizes significantly increased with increasing maternal size, and female offspring produced by younger mothers were also larger. Furthermore, the body sizes of both females and males appeared to increase when the total development time from egg to adult eclosion decreased. Male offspring produced by larger females have shorter development times, while female offspring produced by older females have longer development times. Consequently, our results suggested that the effect of maternal status on offspring size may be mediated by influencing development time. In summary, our results indicated that the body size of A. disparis is determined by multiple factors with differing effects on females and males, and our results provide guidance for its effective mass rearing and its performance in the field. [ABSTRACT FROM AUTHOR]

Background: Insects often show adaptive phenotypic plasticity where environmental cues during early stages are used to produce a phenotype that matches the environment experienced by adults. Many tropical satyrine butterflies (Nymphalidae: Satyrinae) are seasonally polyphenic and produce distinct wet- and dry-season form adults, providing tight environment-phenotype matching in seasonal environments. In studied Mycalesina butterflies, dry-season forms can be induced in the laboratory by growing larvae at low temperatures or on poor food quality. Since both these factors also tend to reduce larval growth rate, larval growth rate may be an internal cue that translates the environmental cues into the expression of phenotypes. If this is the case, we predict that slower-growing larvae would be more likely to develop a dry-season phenotype. Methods: We performed the first experimental study on seasonal polyphenism of a butterfly in the tribe Melanitini. We measured both larval growth rate and adult phenotype (eyespot size and wing shape) of common evening brown butterflies (Melanitis leda), reared at various temperatures and on various host-plant species. We constructed provisional reaction norms, and tested the hypothesis that growth rate mediates between external cues and adult phenotype. Results: Reaction norms were similar to those found in Mycalesina butterflies. We found that both among and within treatments, larvae with lower growth rates (low temperature, particular host plants) were more likely to develop dry-season phenotypes (small eyespots, falcate wing tips). However, among temperature treatments, similar growth rates could lead to very different wing phenotypes, and within treatments the relationships were weak. Moreover, males and females responded differently, and eyespot size and wing shape were not strongly correlated with each other. Overall, larval growth rate seems to be weakly related to eyespot size and wing shape, indicating that seasonal plasticity in M. leda is primarily mediated by other mechanisms. [ABSTRACT FROM AUTHOR]

Aedes albopictus (Skuse, 1895), the Asian tiger mosquito extended globally in just a few decades from Asia showing great adaptability despite temperature-dependent development. The present study revealed the effects of temperature (20 ℃, 26 ℃, 30 ℃, and 35 ℃) on various developmental parameters of Ae. albopictus strains belonging to the desert (Jodhpur, Rajasthan) and the coastal (Kolkata, West Bengal) regions of India. The desert strain developed faster from eggs-adult emergence (7.5 days at 35 ℃ and 14.0 days at 20 ℃) than the coastal strain (7.8 days at 35 ℃ and 16.8 days at 20 ℃). The survival was highest and lowest at 26 °C and 35 ℃, respectively, irrespective of strains and stages. The larval survival trends of both strains were similar to pupae across the temperature range. The wing length of the desert strain was shorter in comparison to the coastal strain. Wing length was found inversely proportional to the temperature being longest at 20 ℃ and the shortest at 35 ℃ for both strains. Male and female wing lengths were larger (25% and 22.7% in the Jodhpur strain and 24.6% and 23.6% in the Kolkata strain) at 20 ℃ compared to 35 ℃, respectively. Significant differences were observed between the male-female sex ratio in the coastal strain. The outcomes of the study suggest consideration of temperature impact on immature developmental attributes that might help in the refining of control measures and a better understanding of ecological adaptations in contrast to ecological conditions. [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda Smith is a major pest of corn plants. Information on the life cycle and survival of this pest is important for proper and effective control. This study was conducted to determine the life cycle and survival of S. frugiperda in several areas in West Java. This study was conducted from June to August 2020. Samples were taken from several areas divided into three categories: highlands in Lembang District (1,100 m asl), middlelands in Jatinangor District (858 m asl), and the lowlands in Tarikolot District (103 m asl). Sampling used the observation method to study the effect of differences in altitude on population, life cycle, and survival. The results showed that there was no significant difference in the development time of S. frugiperda among the three different areas. The average development time of S. fugiperda was 24.55 days (highlands), 24.36 days (middlelands), and 24.07 days (lowlands). The survival percentage of S. frugiperda from highland, middle, and lowland areas in the egg phase was 95.44%, 97.34%, and 96.89%, larval phase 98.46%, 98.65%, and 98.48%, and pupal phase 95.89%, 96.84%, and 94.89%. The sex ratio of S. frugiperda from the highlands was 1:1, from the middlelands was 1:1.28, and from the lowlands was 1:0.89. Location did not affect the width parameter of the head capsule in S. frugiperda. Based on the test results, it is known that the life cycle, survival, and sex ratio of S. frugiperda from several regions do not have significant differences. [ABSTRACT FROM AUTHOR]

This study aims to determine the phenological characteristics of thermal responses in the larvae of a Culex pipiens complex field population at the individual level under the influence of thermal regime of its habitat. The analysis is based on a structured population model quantifying the thermal responses of development time and survival under variable conditions and characterising the variety between the larvae (interindividual variety). During the study performed in Turkish Thrace on a monthly basis between May 2021 and June 2022, a total of 3744 larvae were reared as peer larval cohorts and 2330 larvae as siblings in artificial containers to be fully exposed to the natural thermal condition that was recorded hourly. The development process of larvae was monitored daily from egg to adult. As a result, a total of 4788 adult mosquitoes emerged, with a development period ranging from 8 to 52 days in the females and 7 to 50 days in the males, and the survival rate was found to range from 0% to 100%. Both parameters varied by month and individuals, and the variations manifested itself, particularly in the colder periods. The results indicate that the variation between the individuals in terms of thermal response in the larvae of C. pipiens, along with the thermal acclimation ability, appears to be fate determinant in resisting fluctuating thermal regimes, surviving in concurrent climate change and adapting to new conditions with modifications in the seasonal phenology, such as maintaining reproductive dynamics throughout the winter thanks to global warming. [ABSTRACT FROM AUTHOR]

Voltinism and life‐history traits of the invasive fall armyworm (FAW) Spodoptera frugiperda were investigated under semi‐natural conditions for a period of 2 years. The FAW invaded the corn field in the suburbs of Nanchang (28°46′ N, 115°50′ E) in early summer and produced six complete generations. FAW had the characteristics of short developmental time, high survival rates and strong fecundity. The development time of female pupae was significantly faster than that of male pupae, resulting in the emergence of female pupae earlier than male pupae. Except for the sixth generation in 2021, there was no significant difference between female and male sex ratio, which was close to 1:1. FAW showed male‐bias sexual size dimorphism with male pupae being significantly larger than female pupae. Unlike pupal weight, in most generations, male adult weighed significantly less than females, because the weight loss of male pupae during metamorphosis was significantly greater than that of female pupae. The temporal variation of pupal weight did not conform to the temperature–size rule. Compared with 22.8°C, the 29.2°C high temperature not only significantly reduced the development time of larvae but also significantly increased pupal weight. The adult fecundity feeding on fresh corn leaves was higher than that feeding on live corn plants in most generations. In most generations, pupal weight was positively correlated with larval development time and adult weight was positively correlated with fecundity. In conclusion, climate differences between generations and years have significant effects on developmental time, body weight, sexual size dimorphism and fecundity of the FAW. These results add to the understanding of the evolution of life‐history traits in the FAW and may have important implications for predicting population dynamics of the FAW and optimising control strategies. [ABSTRACT FROM AUTHOR]

Background Insects often show adaptive phenotypic plasticity where environmental cues during early stages are used to produce a phenotype that matches the environment experienced by adults. Many tropical satyrine butterflies (Nymphalidae: Satyrinae) are seasonally polyphenic and produce distinct wet- and dry-season form adults, providing tight environment-phenotype matching in seasonal environments. In studied Mycalesina butterflies, dry-season forms can be induced in the laboratory by growing larvae at low temperatures or on poor food quality. Since both these factors also tend to reduce larval growth rate, larval growth rate may be an internal cue that translates the environmental cues into the expression of phenotypes. If this is the case, we predict that slower-growing larvae would be more likely to develop a dry-season phenotype. Methods We performed the first experimental study on seasonal polyphenism of a butterfly in the tribe Melanitini. We measured both larval growth rate and adult phenotype (eyespot size and wing shape) of common evening brown butterflies (Melanitis leda), reared at various temperatures and on various host-plant species. We constructed provisional reaction norms, and tested the hypothesis that growth rate mediates between external cues and adult phenotype. Results Reaction norms were similar to those found in Mycalesina butterflies. We found that both among and within treatments, larvae with lower growth rates (low temperature, particular host plants) were more likely to develop dry-season phenotypes (small eyespots, falcate wing tips). However, among temperature treatments, similar growth rates could lead to very different wing phenotypes, and within treatments the relationships were weak. Moreover, males and females responded differently, and eyespot size and wing shape were not strongly correlated with each other. Overall, larval growth rate seems to be weakly related to eyespot size and wing shape, indicating that seasonal plasticity in M. leda is primarily mediated by other mechanisms.

The effects of growth and reproduction on the marine Cyclops sp. were investigated using three microalgae as diets. The development period of Cyclops sp. was evaluated at 106 cells/ml in 15ppt salinity to identify the stationary phase. The survival rate of marine Cyclops from nauplius to adult differed according to the microalgal diet. The results showed that the shortest time (14 days) and highest survival (17.6 ± 0.131 %) for Cyclops sp. was achieved with those fed with Nannochloropsis sp. Whereas, it took longest time (37 days) and lowest survival rate (6.40 ± 0.035 %) when fed Chlamydomonas sp. The developmental period from naupli (I - VI) (6.91 ± 0.453 days), copepodite (I - VI) (11.4 ± 0.311days) and naupli to adult (20 ± 1.08 days) appeared significantly longer when fed with Nannochloropsis sp. compared to other treatments. The daily mean naupli production of adult females over 7 days was significantly higher (p ˂ 0.05) in Nannochloropsis sp. compared with Chlamydomonas sp. and Gonyostomum sp. On the 25th day of Nannochloropsis sp. treatment, 99 % of the mature females died. Production (naupli, copepodite adult male and adult female) was significantly higher (p ˂ 0.05) in Nannochloropsis sp. than in other microalgal diets. On the fifteenth day, Nannochloropsis sp. showed a significantly higher (p ˂ 0.05) specific growth rate than other microalgal diets. Nannochloropsis sp. had the highest nauplius survival rate on the sixth day compared to other microalgal diets. With Nannochloropsis sp., the species has a higher hatching rate, and in Chlamydomonas sp. hatching occurs earlier. The average lifespan for Nannochloropsis sp. was 46 days, for Chlamydomonas sp. it was 37 days, and for Gonyostomum sp. it was 32 days.

This study was conducted to determine some biological properties of the potato tuber moth Phthorimaea operculella, a new host of the egg-larval parasitoid Chelonus oculator at different temperatures. The emergence rate, development time, longevity, adult weight, and sex ratio of C. oculator were assessed at three different temperature levels (20±1 ºC, 25±1 ºC, 30±1 ºC), 65±5% humidity and 16:8 light: dark conditions. Forty potato tuber moth eggs, aged 0-24 hours, adhered to the filter papers, were placed into the tubes, and presented to the parasitoids for parasitization for a day. At the end of this period, the parasitized eggs were allowed to develop at the specified temperatures. The study found the highest emergence rate was found at 30 °C, with 20.5%. The longest development period occurred at 20 °C, determined as 49.00±2.00 days in females and 52.27±1.64 days in males. The longest longevity of the parasitoid was found to be 41.71±2.29 and 45.73±3.75 days in males and females, respectively. The highest adult weight was observed at 25 °C for both males and females. The sex ratio was found to be in favor of males as the temperature decreased. It is thought that these results can be used for the biological control of potato tuber moth in the field and storage conditions for release studies. [ABSTRACT FROM AUTHOR]

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Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an invasive alien species that causes major losses in the Chinese tomato industry. Historically, insecticides have been used extensively to control T. absoluta, but resistant populations have been frequently detected. Biological control represents a sustainable and effective method with which to prevent and control T. absoluta. Egg parasitoids from the family of Trichogrammatidae (Hymenoptera) have been identified as potential biological option for controlling of T. absoluta. In the present study, we aimed to identify local dominant Trichogramma species that exhibited the best biological control ability against T. absoluta in China. To accomplish this, we compared the selectivity and number of offspring of three Trichogramma species to T. absoluta by performing host preference experiments in the laboratory. We also evaluated the fitness of Trichogramma against T. absoluta by assessing the parasitic ability and behavior of their offspring on different hosts. Compared with Trichogramma chilonis and Trichogramma dendrolimi, Trichogramma ostriniae exhibited a significantly greater preference to T. absoluta eggs and produced a higher number of offspring. The emergence rate and proportion of female T. ostriniae parasitizing the eggs of T. absoluta was higher than that of the other two Trichogramma species, the rate of T. ostriniae offspring deformity was only 3.00%. In addition, T. ostriniae has shortest immature stage and the longest adult stage among the three species. In conclusion T. ostriniae can be a promising native biological control agent against T. absoluta in China. [ABSTRACT FROM AUTHOR]

The Karner blue butterfly (Lycaeides melissa samuelis) (hereafter Karner blue) is a federally listed endangered species occurring in disjunct locations within the Midwest and Eastern United States. As a hostplant specialist and an ectotherm, the Karner blue is likely to be susceptible to effects of climate change. We undertook warming experiments to explore the temperature sensitivity of various Karner blue life history stages and traits. Over a two-year period, we exposed all Karner blue life stages to temperature increases of + 2, + 4, and + 6 °C above 1952–1999 mean temperatures. We analyzed the effect of these treatments on life history parameters likely related to fitness and population size, including development time, voltinism, degree-day accumulation, body weight, and morphology. Warming treatments resulted in earlier emergence and accelerated development, leading to additional generations. Warming also increased the number of degree-days accumulated during pre-adult development (i.e., egg hatch to eclosion). Results suggest that Karner blues developed in fewer days, in part, by putting on less mass as temperatures increased. As treatment temperature increased, adult body mass, length, and area decreased and voltinism increased. Females with lower adult mass and smaller body size produced fewer eggs. These results suggest a trade-off between accelerated development and decreased body size with decrease in adult mass and abdominal area being associated with reduced fecundity. Implications for insect conservation: Changes in development timing and in voltinism can negatively affect phenological matching between the Karner blue and its obligate host plant, Wild lupine (Lupinus perennis), resulting in population decrease. Poorer phenological matching between insect and hostplant can occur across multiple generations, for example, negatively affecting overwintering population size. With increasing temperatures, smaller females will produce fewer eggs, which can also lead to poorer population outcomes across generations. [ABSTRACT FROM AUTHOR]

Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is a highly efficient parasitoid that has been commercially used for augmentative biological control of the sweetpotato whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The success of control efforts with this parasitoid could be compromised by the use of non-selective pesticides. This study was conducted to determine if acetamiprid, imidacloprid, thiamethoxam, spinetoram, and sulfoxaflor had transgenerational effects on juvenile development of E. mundus. The mean development time from oviposition (OVP) to first sign of parasitism (FSP) for progeny of females treated with control was 9.03 days, which was the shortest compared to the insecticide treatments. After FSP, the control groups reached their pre-pupal (PP) stage in an average time of 3.85 days, while it was in the range of 3.98–4.46 days for insecticide-treated groups. The developmental period from pre-pupal to black-eyed pupal stage ranged from 2.32–2.69 days for parasitoids treated with insecticides, but it was 2.22 days for the control group. The overall mean development time—from oviposition until adult emergence—was 16.24 days for control, which was statistically shorter than all other treatments. Spinerotam and sulfoxaflor prolonged immature development by 2.37 and 1.83 days, respectively, when compared with the control. Male development was slightly shorter than that of female in control, spinetoram, and sulfoxaflor groups, and the opposite was true for the neonicotinoids. Compared to the neonicotinoids, the non-neonicotinoids had more negative effect on juvenile development of E. mundus. [ABSTRACT FROM AUTHOR]

Simple Summary: The brown marmorated stink bug, Halyomorpha halys, is a pentatomid bug that feeds on a wide range of economically important crops. Crop protection in newly invaded areas mainly relies on the use of broad-spectrum chemical insecticides, while little to no information is available regarding a classical biological control approach. The overall purpose of the present study was to estimate the parasitism rate and development time of the native egg parasitoid Ooencyrtus telenomicida Vassiliev (Hymenoptera: Encyrtidae) when offered H. halys egg-masses, taking into consideration several parameters. Specifically, we tested different parasitoid ages and densities on 1–4-day-old H. halys eggs. According to our results, parasitoid density and the age of host eggs significantly affected the parasitism rate of O. telenomicida. High parasitoid density along with younger host eggs led to higher parasitism rates. Likewise, a significant interaction was observed between the parasitoid density and their age. Successful parasitisation occurred with host eggs up to 4 days old, with parasitism rates decreasing as host egg age increased. A three-fold higher parasitism rate of H. halys eggs was observed when they were parasitised by older O. telenomicida females, compared to younger ones. Concerning the development time of O. telenomicida, individuals that developed in younger host eggs displayed a shorter development time. Parasitoid age did not affect the development time of O. telenomicida, nor did the density of parasitoids. Halyomorpha halys (Hemiptera: Pentatomidae) is an invasive pest species that was imported into Greece in 2011 and since then, has caused severe qualitative and quantitative damage to economically important crops. Its management relies mainly on the use of broad-spectrum insecticides, with little to no information available concerning the potential use of native parasitoids in terms of classical biological control. Our study aimed to assess the parasitism rate and development time of the gregarious egg parasitoid Ooencyrtus telenomicida (Hymenoptera: Encyrtidae) on H. halys egg-masses, depending on several factors such as: (i) age of parasitoids, (ii) density of parasitoids, (iii) age of host eggs, and (iv) oviposition experience of parasitoids. According to our results, the younger the host eggs and the more parasitoids, the higher the parasitism rate achieved by adults of O. telenomicida, with the maximum mean value of the parasitism rate observed with 1-day-old host eggs and 4 parasitoid pairs (57.3%). On the contrary, the lowest mean value of the parasitism rate was observed with 4-day-old host eggs and 1 parasitoid pair (6.5%). Similarly, the age of parasitoids significantly affected parasitisation. The older the parasitoids were, the higher the parasitism rate achieved by adults of O. telenomicida, with a three-fold higher parasitism rate observed at 3–4 and 5–6-day-old O. telenomicida, compared to 1–2-day-old (31.8, 32.4, and 12.1%, respectively). Individuals that developed in younger host eggs displayed a shorter development time, and the shortest development time was observed for O. telenomicida laid by 2 parasitoid pairs. Parasitoid age did not affect the development time of O. telenomicida, although there was a tendency for individuals laid by younger female parasitoids to exhibit a shorter development time. Our findings provide valuable information on the potential use of O. telenomicida as a biocontrol agent of H. halys. [ABSTRACT FROM AUTHOR]

In tropical and subtropical countries of the world, Callosobruchus maculatus (F.) is a crucial pest of pulses. After the harvest, pulse beetles in storage cause qualitative and quantitative worsening of legumes. Survival of different geographical strains of cowpea weevil may vary on different host legumes. The research was conducted to examine screening for ovipositional preference, growth and development of cowpea weevil, on nine common legume hosts, viz., cowpea, green gram, pigeon pea, pea, desi chickpea, kabuli chickpea, black gram, soybean and red lentils. In the present study, life phases of Lucknow strain (variant) of C. maculatus, was seen on nine stored pulses at laboratory condition for the assessment of growth and development and better management in storage. The outcome of present studies, indicated that the cowpea weevil favour cowpea, green gram, pigeon pea, pea, for its highest oviposition because the highest number of eggs was found on these legumes followed by desi chickpea, kabuli chickpea while on black gram, soybean and red lentils lowest number of eggs were observed. The developmental time of cowpea weevil was short on cowpea, green gram, pigeon pea, pea, followed by desi chickpea, kabuli chickpea, while the longest developmental period was on the black gram, soybean and red lentils. The percent adult emergence, percent weight loss and growth index was highest in cowpea, green gram, pigeon pea and garden pea, desi chickpea, and kabuli chickpea whereas lowest percent of adult emergence, weight loss and growth index was found in black gram, soybean and lentil after three generations. From this research it was clear that cowpea, green gram, pigeon pea, pea, desi chickpea, kabuli chickpea was most preferred host legumes among all nine examined stored legumes, whereas black gram, soybean, and red lentils were least preferable hosts to the Lucknow strain of C. maculatus. [ABSTRACT FROM AUTHOR]

Telmatometra withei (Bergroth, 1908) is a common water strider found across the Neotropics. Although, the taxonomy of T. withei is relatively well known, the specie's life cycle has not been characterized. We use field surveys and laboratory experiments to describe the life cycle of two populations of T. withei in the Pacific coast of Panama. Specifically, we compared the life cycle between fresh and brackish water populations known to show local adaptation to each environment. We also contrast the life cycle of T. withei with that of other water striders previously reported in the literature. We found that the average life cycle of T. withei is approximately 66.7 days, and this period did not vary significantly between fresh (65.0 days) and brackish (68.3 days) populations. However, these estimates were longer than those reported for other species of water strides. In addition, traits associated with reproductive success such as egg length and fecundity varied significantly between populations, with females from freshwater populations showing larger values. This suggests that salinity can have important consequences for reproductive traits in T. withei, even if the overall life cycle may not be affected by salinity. Thus, characterizing the life history of these Neotropical organisms is crucial to understand the rich freshwater biodiversity of this region, as well as its response to both natural and anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Purpose: Alliances between firms are becoming more common for drug development; however, it is not clear how these alliances affect the time spent on drug development. This study analyzes the effect of firm's alliances on the clinical development time of new drugs by clinical phase. Methods: Datasets of the new drug development program in which the Phase 1 trials were started between 2000 and 2015 were constructed using the Evaluate Pharma's pipeline database. The development time was calculated by measuring the number of days between the initiation dates of a development phase and the date of the subsequent phase, utilizing data from the database. A multiple regression analysis was performed to determine the effect of firm's alliances on the new drug development time at each stage of development, after controlling for the origin of substances, therapeutic indications, drug designation, and firm size. Results: A firm's alliances significantly increased the development times of clinical Phases 1, 2, and 3 by 549.3 days, 617.3 days, and 232.0 days, respectively. However, there was no statistically significant effect on the development time of the approval stage. Conclusion: As a firm's alliances significantly increases the drug development time in the early clinical phases, companies developing new drugs through alliances in the early clinical development stages need to make more efforts to reduce the development time. [ABSTRACT FROM AUTHOR]

Standing genetic variation, and capacity to adapt to environment change, will ultimately depend on the fitness effects of mutations across the range of environments experienced by contemporary, panmictic, populations. We investigated how mild perturbations in diet and temperature affect mutational (co)variances of traits that evolve under climatic adaptation, and contribute to individual fitness in Drosophila serrata. We assessed egg-to-adult viability, development time and wing size of 64 lines that had diverged from one another via spontaneous mutation over 30 generations of brother--sister mating. Our results suggested most mutations have directionally concordant (i.e., synergistic) effects in all environments and both sexes. However, elevated mutational variance under reduced macronutrient conditions suggested environment-dependent variation in mutational effect sizes for development time. We also observed evidence for antagonistic effects under standard versus reduced macronutrient conditions, where these effects were further contingent on temperature (for development time) or sex (for size). Diet also influenced the magnitude and sign of mutational correlations between traits, although this result was largely due to a single genotype (line), which may reflect a rare, large effect mutation. Overall, our results suggest environmental heterogeneity and environment-dependency of mutational effects could contribute to the maintenance of genetic variance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Helicoverpa zea, an economic pest in the south‐eastern United States, has evolved practical resistance to Bacillus thuringiensis (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. RESULTS: 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. CONCLUSION: 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. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The heterotrophic flagellates, Oxyrrhis marina were first suggested to feed Amphiascopsis cinctus, and the effects on the growth and survival rate of Amphiascopsis cinctus were studied. The results showed that the Amphiascopsis cinctus feed on Oxyrrhis marina of different concentrations finished its development and reproduction in different speed. When the Oxyrrhis marina concentrations were 200 ind·mL–1, 800 ind·mL–1, 3200 ind·mL–1 and > 10 4 ind·mL–1 respectively, the increasing concentration of Oxyrrhis marina considerably shorten the development time of Amphiascopsis cinctus between nauplii to copepodid stage from (16.30±0.82) d to (9.06±0.87) d, between copepodid stage to adult stage from (15.94±0.63) d to (10.14± 1.07) d. With the increasing concentration of flagellates, the survival rate of Amphiascopsis cinctus from nauplii to copepodid and from copepodid to adult increased from 36.72% to 70.25% and from 70.88% to 85.62% respectively, but the highest survival rate was found in the group with lower concentration (3200 ind·mL–1 ). With the increasing of food concentration, the brood amount and the hatching rate of Amphiascopsis cinctus increased from7.86 to10.67; 50.83% to 85.30% respectively, and the incubation time decreased from 8.67d to 5.12d. It can be seen that high concentration of Oxyrrhis marina can accelerate the development of Amphiascopsis cinctus and increase their reproduction efficiency. However, high concentration of flagellates reduces the survival rate of the stage from copepodid to adult, which needs further study. [ABSTRACT FROM AUTHOR]

The yellow mealworms (Tenebrio molitor L.) is one of the most valuable and high-nutritional food insects that is used in the animal and human feed industry. In the current study development time of eggs, larvae, pupa, and the entire immature stage, at five constant temperatures of 20, 23, 25, 27, and 30 oC (±1), 60±10% RH was examined under laboratory conditions. The eggs in the same age (less than 24 hours) were randomly selected. The growth was completed at all temperatures of the test. Data showed that the developmental times of males or females on each variety at various constant temperatures differed significantly. The regression and Ikemoto and Takailinear models, in the absence of 27oC described the relationship of developmental rate to temperature for males and females of T. molitor very well. Data were fitted to various nonlinear temperature-dependent models. The model of Lactin-1 and Janisch/Rochat have the best estimate for Tu about 36.79 and 37.36oC. Development time of immature stage was 203.70±2.65, 170.71±3.51, 143.07±2.29, 111.31±0.81 day. The longest development time was recorded at 20o and the shortest growth period at 27o. The results of the variance of the data showed that the development time of the immature stages at different temperatures at a 5% probability level was significant. Although by the increasing in temperature from 20 to 27 development time was declined but that was not associated with increased growth rates.

BackgroundEnvironmental conditions affect the biology of mosquito vectors. Aedes albopictus is a major vector of many important diseases including dengue, Zika, and chikungunya in China. Understanding the development, fecundity, and survivorship of Ae. albopictus mosquitoes in different environmental conditions is beneficial for the implementation of effective vector control measures.MethodsAedes albopictus larval and adult life-table experiments were conducted under natural conditions in indoor, half-shaded, and fully shaded settings, simulating the three major habitat types in Hainan Province, a tropical island in the South China Sea. Temperature, humidity, and light intensity were recorded daily. Larval rearing used habitat water and tap water, with and without additional artificial food. Development time, survivorship, pupation rate, and adult emergence rates were monitored. Adult mosquito survivorship and fecundity were monitored daily and reproductive rates were determined, and age-dependent survivorship and reproduction were analyzed.ResultsThe pupation time and male and female emergence times were significantly shorter in indoor conditions than in shaded and half-shaded conditions for both tap water with added food and habitat water with added food groups. For habitat water with added food, the shaded environment had the lowest pupation rate among the settings. For tap water with added food group, the shaded environment had the lowest pupation rate. The mean survival time of females was 27.3 ± 0.8 days in the indoor condition, which was significantly longer than that in the half-shaded (18.4 ± 0.6 days) and shaded (13.8 ± 1.2 days) conditions. Adult mortality was age-dependent, and the rate of change in mortality with age was not significantly different among different environmental conditions. The mean net replacement rate (R0) of female mosquitoes showed no significant difference among the three conditions, whereas the per capita intrinsic growth rate (r) in the shaded condition was 42.0% and 20.4% higher than that in the indoor and half-shaded conditions, respectively. Female daily egg mass was also age-dependent in all the settings, decaying exponentially with age.ConclusionsOur results imply that half-shaded conditions are likely the best natural condition for adult emergence and female reproduction, and food supply is crucial for larval development and pupation. The results provide new avenues for integrated mosquito management in indoor and outdoor areas, especially in half-shaded areas.

We ask if three decades and over 1,500 generations of divergent life-history selection on age at reproduction has resulted in the evolution of reproductive isolation (RI) between laboratory populations of Drosophila melanogaster. We tested for premating, postmating-prezygotic, and postzygotic reproductive isolation between three replicate population pairs. Large, evolved differences in body size between selection treatments suggested the potential for prezygotic barriers driven by sexual selection or physical incompatibilities between the sexes. Although a simple prediction would be preference for larger size, creating directional isolation, our results from individual mate choice trials indicate that populations from both selection treatments show a marked bias towards homotypic mate choice; indicative of prezygotic RI driven by sexual selection or sexual conflict. Hybridization between the focal populations resulted in the production of viable adult flies with intermediate size and developmental traits. We observed a suggestive but statistically nonsignificant trend of fitness decline in the F2 generation of hybrids, but no significant evidence suggesting the evolution of postmating-prezygotic or postzygotic RI. Our findings are in accord with extant literature that posits that premating RI evolves before postmating forms of RI. [ABSTRACT FROM AUTHOR]

The fall armyworm (FAW) Spodoptera frugiperda (J. E. Smith; Lepidoptera; Noctuidae) has invaded Jiangxi Province, Southeast China for the past 3 years. Although the FAW displays a wide host range, its main host plants in Jiangxi Province are field corn. Understanding the population dynamics of the FAW on different host plants is critical for developing an appropriate control strategy. This study investigated the effects of food plants (corn, peanut, soybean and sugarcane) on life‐history traits of FAW and tested the leaf contents of the total flavonoids, reducing sugars, sucrose and C/N ratio of these host plants. We found that the FAW fed on corn leaves exhibited significantly shorter larval and pupal development times, larger body weight, higher growth rate, lower weight loss, smaller sexual size dimorphism, shorter preoviposition period and higher fecundity than those fed on peanut, soybean and sugarcane leaves. The FAW showed a protogyny phenomenon because the pupal development stage was significantly longer in males than females. Food plants changed the relationships between larval development time and pupal weight and between fecundity and longevity. The corn leaves showed significantly higher contents of reducing sugars and sucrose, lower content of the total flavonoids and a moderate C/N ratio compared with the other leaves, suggesting that the corn leaf tissues are more nutritious. Our results provide the most comprehensive information about the life‐history traits of this newly invasive pest. These findings may help us understand why the FAW mainly infests corn plants and may be critical for the development of strategies to predict infestation levels. [ABSTRACT FROM AUTHOR]

Light pollution is increasingly affecting biodiversity and may also disrupt seasonal adaptations. Even dim artificial light, such as skyglow—which can spread far beyond urban areas—can interfere with using photoperiod as a seasonal cue.Here, we test how light pollution impacts diapause induction and whether urban evolution counteracts it, by using common‐garden experiments with a common, widespread geometrid moth (Chiasmia clathrata). We raised offspring from urban and rural populations from North‐ and Mid‐European countries in treatments with and without dim light at night.The dim light treatment strongly increased direct development overall—with no evidence for urban adaptation to it—but distinctly more so in Mid‐ than in North‐European populations.Because diapause induction is critical for surviving winter, these results indicate that dim but widespread light pollution may have detrimental effects on insect populations, especially so at mid‐latitudes, and may hence explain part of the ongoing, large‐scale insect declines globally.Synthesis and applications. Latitudinal variation in sensitivity to light pollution means that its contribution to insect declines—and its conservation importance—should likewise vary among regions. In mid‐latitude regions, where populations seem more sensitive to light pollution, mitigating light pollution should be a high priority for insect conservation. Reducing skyglow from cities should benefit both urban populations—which were just as susceptible as rural populations in our study—and rural populations—because skyglow extends far beyond the geographic boundaries of cities. [ABSTRACT FROM AUTHOR]

Spodoptera littoralis (Boisduval) is a highly destructive and polyphagous insect pest of great economic importance. It develops throughout the year and the larvae are non-diapausing. Little work has been done on the time taken for food to pass through the gut of S. littoralis. Thus, this study on starving and well fed last instar larvae of S. littoralis aimed to determine the effect of temperature and photoperiod on the time taken for a meal to pass through the gut, defecation and digestion. The results indicate that it depended on temperature, photoperiod and hunger. The time that elapsed between a larva being fed and the production of the first faecal pellet, which is a measure of the time it takes for food pass to pass through the gut (SFP), differed significantly at different temperatures and photoperiods. The SFP was longer at 15°C than at 30°C. At 20°C and under a short photoperiod, SFP was very much shorter than under a long photoperiod (18L : 6D). In addition, at 20°C, the time to defecation was significantly longer under a photoperiod of 12L : 12D than under continuous light. In all the tests > 95% of the larvae produced four faecal pellets per meal. The digestibility values varied significantly in the different tests. This study offers new insights into the passage of food from the crop to the rectum at different temperatures and photoperiods. This might help in understanding the adaptability of S. littoralis and may also help in controlling this important pest.

Male sexual ornaments often evolve rapidly and are thought to be costly, thus contributing to sexual size dimorphism. However, little is known about their developmental costs, and even less about costs associated with structural complexity. Here, we quantified the size and complexity of three morphologically elaborate sexually dimorphic male ornaments that starkly differ across sepsid fly species (Diptera: Sepsidae): (i) male forelegs range from being unmodified, like in most females, to being adorned with spines and large cuticular protrusions; (ii) the fourth abdominal sternites are either unmodified or are converted into complex de novo appendages; and (iii) male genital claspers range from small and simple to large and complex (e.g. bifurcated). We tracked the development of 18 sepsid species from egg to adult to determine larval feeding and pupal metamorphosis times of both sexes. We then statistically explored whether pupal and adult body size, ornament size and/or ornament complexity are correlated with sex-specific development times. Larval growth and foraging periods of male and female larvae did not differ, but the time spent in the pupal stage was ca 5% longer for sepsid males despite emerging 9% smaller than females on average. Surprisingly, we found no evidence that sexual trait complexity prolongs pupal development beyond some effects of trait size. Evolving more complex traits thus does not incur developmental costs at least in this system. [ABSTRACT FROM AUTHOR]

Often, immunity is invoked in the context of infection, disease and injury. However, an ever alert and robust immune system is essential for maintaining good health, but resource investment into immunity needs to be traded off against allocation to other functions. In this study, we study the consequences of such a trade‐off with growth by ascertaining various components of baseline innate immunity in two types of Drosophila melanogaster populations selected for fast development, in combination with either a long effective lifespan (FLJs) or a short effective lifespan (FEJs). We found that distinct immunological parameters were constitutively elevated in both, FLJs and FEJs compared to their ancestral control (JB) populations, and these constitutive elevated immunological parameters were associated with reduced insulin signalling and comparable total gut microbiota. Our results bring into focus the inter‐relationship between egg to adult development time, ecdysone levels, larval gut microbiota, insulin signalling, adult reproductive longevity and immune function. We discuss how changes in selection pressures operating on life‐history traits can modulate different components of immune system. [ABSTRACT FROM AUTHOR]

Development time, survival and final nutrient content of Hermetia illucens L. larvae depends on the substrates in which they develop. Mixing different waste types together can increase the performance and survival of the larvae, as well as their waste reduction. The main objective of this study was to evaluate the effect of different ratios of mixed fruit and vegetable waste with poultry manure on larval development time, size, biomass production, survival, bioconversion and waste reduction. Freshly hatched neonates (90 mg; approx. 6000 individuals) were placed on 12 kg of a mixture of fruit and vegetable waste and fresh, unprocessed poultry manure and held at 28 ± 0.5°C. Inclusion of fruit and vegetable waste varied from 0% to 100% in 10% increments. Initial temperature of the substrate was also measured. The individual mass of larvae increased significantly as more fruit and vegetable waste was included, from less than 81.3 ± 6.6 mg on poultry manure only to an average size of 211.6 ± 6.0 mg at 100% fruit and vegetable waste. After approximately 60% inclusion of fruit and vegetable waste the performance and survival of the larvae increased significantly while development time was reduced. A combination of high fruit and vegetable waste and low initial temperatures resulted in lower development time overall. The mixing of wastes can be applied in industry to further the goals of waste reduction and biomass production while incorporating low‐quality wastes like poultry manure. [ABSTRACT FROM AUTHOR]

Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) is a highly mobile and polyphagous pest known to feed on over 300 cultivated and wild host plant species. Larvae cause significant economic damage to several commercial row crops over multiple generations each growing season. The objective of this study was to compare biological fitness of H. zea on 5 weedy host plants commonly found across the mid-south US. Crimson clover (Trifolium incarnatum L.), white clover (Trifolium repens L.), hairy vetch (Vicia villosa Roth), kudzu (Pueraria montana [Lour.] Merr. (all Fabaceae), and honeysuckle (Lonicera japonica Thunb.; Caprifoliaceae) were evaluated as primary food sources for H. zea under laboratory conditions at 27 ± 0.5 °C, a relative humidity of 60 ± 5%, and a 14:10 h (L:D) photoperiod. This study measures the development, biomass, survival, and fecundity of H. zea when reared on the reproductive tissues of 5 common weeds. Larvae of H. zea successfully developed on all 5 weeds to adulthood, but significant mortality (> 50%) was observed for larvae reared on hairy vetch, honeysuckle, and kudzu. Larval developmental periods ranged from 30 d to 39 d for H. zea reared on honeysuckle and white clover, respectively. Pupal biomass ranged 158.1 mg to 161.2 mg for individuals reared on hairy vetch, followed by 196.2 mg to 202.8 mg on crimson clover, and 204.6 to 217.4 mg for individuals on white clover, honeysuckle, and kudzu collectively. Pupal emergence varied from 92.1% to 61.8% for crimson clover and hairy vetch, respectively. Larval mortality varied from 25.3% on crimson clover to 68.9% for hairy vetch. Average adult longevity ranged from 10 d to 11 d for females and males reared on crimson clover to 4 d on kudzu and 4 d on white clover for female and male, respectively. The average number of eggs laid by females reared on crimson clover, white clover, hairy vetch, honeysuckle, and kudzu were 553.5, 512.3, 288.2, 194.7, and 142.2, respectively. Our findings indicate crimson and white clover were among the most suitable hosts, and kudzu the most unsuitable based on larval mortality and reproductive capability. El objetivo de este estudio fue comparar los parámetros biológicos de Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) en cinco plantas hospederas comunes de mid-south: trébol carmesí (Trifolium incarnatum L.), trébol blanco (Trifolium repens L.), arveja vellosa (Vicia villosa Roth), kudzu (Pueraria montana (Lour.) Merr.) (todos Fabaceae) y madreselva Lonicera japonica Thunb. (Caprifoliaceae) evaluadas bajo condiciones de laboratorio a 27 ± 0.5 °C, 60 ± 5% de humedad relativa y un fotoperíodo de 14:10 (L:O). Se midió el tiempo de desarrollo de huevo, larva y pupa, peso pupal, longevidad y fecundidad del adulto de H. zea. La larva se desarrolló con excito hasta adulto sobre las cinco plantas hospederas, sin embargo, se observo una diferencia significativa de > 50% in larvas criadas en arveja vellosa, madreselva y kudzu. El rango del periodo de desarrollo larval vario de 30 d a 39 d en madreselva y trébol blanco, respectivamente. El rango de biomasa de pupa vario de 217.4 mg para hembras criadas en trébol blanco y 213.6 mg para machos criados en madreselva a 161.2 y 158.1 mg para hembras y machos criados en arveja vellosa. La emergencia de pupa vario de 92.1% a 61.8% para trébol carmesí y arveja vellosa, respectivamente. La mortalidad de larva vario de 25.3% en trébol carmesí a 68.9% en arveja vellosa. El rango promedio de longevidad del adulto vario de 10.3 d a 11.2 d para hembras y machos criados en trébol carmesí a 4 d en kudzu y 4 d en trébol blanco, respectivamente. El promedio de huevos ovipositados por hembras criadas en trébol carmesí, trébol blanco, arveja vellosa, madreselva y kudzu fueron de 553.5, 512.3, 288.2, 194.7 y 142.2, respectivamente. Nuestros resultados indican que los tréboles blanco y carmesí fueron los mas susceptibles comparados con el resto de las plantas hospederas y con base en mortalidad de larva y capacidad reproductiva de adultos, kudzu fue el mas resistente. [ABSTRACT FROM AUTHOR]

Halyomorpha halys (Hemiptera: Pentatomidae) is an invasive pest species that was imported into Greece in 2011 and since then, has caused severe qualitative and quantitative damage to economically important crops. Its management relies mainly on the use of broad-spectrum insecticides, with little to no information available concerning the potential use of native parasitoids in terms of classical biological control. Our study aimed to assess the parasitism rate and development time of the gregarious egg parasitoid Ooencyrtus telenomicida (Hymenoptera: Encyrtidae) on H. halys egg-masses, depending on several factors such as: (i) age of parasitoids, (ii) density of parasitoids, (iii) age of host eggs, and (iv) oviposition experience of parasitoids. According to our results, the younger the host eggs and the more parasitoids, the higher the parasitism rate achieved by adults of O. telenomicida, with the maximum mean value of the parasitism rate observed with 1-day-old host eggs and 4 parasitoid pairs (57.3%). On the contrary, the lowest mean value of the parasitism rate was observed with 4-day-old host eggs and 1 parasitoid pair (6.5%). Similarly, the age of parasitoids significantly affected parasitisation. The older the parasitoids were, the higher the parasitism rate achieved by adults of O. telenomicida, with a three-fold higher parasitism rate observed at 3–4 and 5–6-day-old O. telenomicida, compared to 1–2-day-old (31.8, 32.4, and 12.1%, respectively). Individuals that developed in younger host eggs displayed a shorter development time, and the shortest development time was observed for O. telenomicida laid by 2 parasitoid pairs. Parasitoid age did not affect the development time of O. telenomicida, although there was a tendency for individuals laid by younger female parasitoids to exhibit a shorter development time. Our findings provide valuable information on the potential use of O. telenomicida as a biocontrol agent of H. halys.

Simple Summary: The ladybird Stethorus gilvifrons is an important natural enemy of herbivorous two-spotted spider mites, Tetranychus urticae. Here, we modeled the effect of temperature, which is the most significant abiotic environmental factor, on the development and thermal thresholds of S. gilvifrons. Thermal parameters and developmental trajectories were estimated by fitting two linear and 20 non-linear models to experimental data measured at seven temperature regimes ranging from 15 to 38 °C. Our findings demonstrate that S. gilvifrons is able to complete development at a broad range of temperatures and is well-adapted to temperatures occurring in temperate, Mediterranean, and subtropical climates. The thermal development models presented here represent a significant step towards an in-depth evaluation of S. gilvifrons as a biological control agent of T. urticae under different temperature regimes. The models can be used to predict the phenology of this predator, to forecast its population dynamics in the field, and to optimize mass-rearing efforts. The development rate of the predatory ladybird, Stethorus gilvifrons (Mulsant), fed on Tetranychus urticae Koch, was determined at 15, 20, 25, 27, 30, 34, and 38 °C. The total development time from egg to adult emergence for females was estimated to be 61.4, 31.6, 14.4, 13.3, 12.5, and 11.7 days, respectively. The development time decreased with increasing temperature from 15 to 34 °C, but all eggs failed to hatch at 38 °C. The lower temperature threshold (T0) for the entire development period and the thermal constant (K) for female S. gilvifrons were estimated to be 11.64 °C and 194.50 degree-days (DD) using the common linear model, and 11.96 °C and 187.87 DD using the Ikemoto and Takai model, respectively. Data were fitted to 20 non-linear development rate models and the thermal thresholds (Tmin and Tmax) and optimal temperature (Topt) were estimated. Among non-linear models, the Briere-2 and Ikemoto and Takai linear model provided adequate descriptions of the temperature-dependent development of S. gilvifrons. The upper-temperature threshold was estimated to be about 44 °C using the Logan-10 non-linear model. The estimated thermal development characteristics can be used to predict the occurrence and the population dynamics, as well as to improve the mass rearing and release, of S. gilvifrons for the biological control of T. urticae. [ABSTRACT FROM AUTHOR]

Ongoing climate change has forced animals to face changing thermal and nutritional environments. Animals can adjust to such combinations of stressors via plasticity. Body size is a key trait influencing organismal fitness, and plasticity in this trait in response to nutritional and thermal conditions varies among genetically diverse, locally adapted populations. The standing genetic variation within a population can also influence the extent of body size plasticity. We generated near‐isogenic lines from a newly collected population of Drosophila melanogaster at the mid‐point of east coast Australia and assayed body size for all lines in combinations of thermal and nutritional stress. We found that isogenic lines showed distinct underlying patterns of body size plasticity in response to temperature and nutrition that were often different from the overall population response. We then tested whether plasticity in development time could explain, and therefore regulate, variation in body size to these combinations of environmental conditions. We selected five genotypes that showed the greatest variation in response to combined thermal and nutritional stress and assessed the correlation between response of developmental time and body size. While we found significant genetic variation in development time plasticity, it was a poor predictor of body size among genotypes. Our results therefore suggest that multiple developmental pathways could generate genetic variation in body size plasticity. Our study emphasizes the need to better understand genetic variation in plasticity within a population, which will help determine the potential for populations to adapt to ongoing environmental change. [ABSTRACT FROM AUTHOR]

Simple Summary: We examined the contribution of temperature and daylight to egg-laying behavior by queens of desert ants. Decreasing the temperature had a much stronger negative effect on egg laying than shortening the daylight and queens stopped laying eggs. That said, egg laying is plastic, and increasing the temperature swiftly led to its resumption. Next, we showed that moving the colonies to a cooler temperature after eggs already existed, led to egg disappearance, as they were probably eaten by the colony workers. The longer such colonies experience a warmer temperature after eggs are laid, the higher the probability is of such eggs developing into larvae and later into pupae. The workers' consumption of eggs that fail to develop is evidence of the joint decision of the queen and workers regarding the next generation of workers. Temperature and photoperiod are the two most important factors that affect all aspects of animal life. We conducted two experiments to examine the effect of temperature and photoperiod on egg laying and development in the desert ant Cataglyphis niger. In the first experiment, we examined the effect of decreasing temperatures and shortening daylength on egg-laying behavior. An additional treatment was exposure to natural autumn conditions. Decreasing temperatures impaired egg laying much more than shortening daylength. The effect, however, was rapidly reversible when raising the temperature. When the outdoor treatment was brought inside the lab at a suitable temperature, queens started laying eggs as well. In the second experiment, we first kept the colonies under warmer temperatures and moved them gradually to cooler temperatures, 1–20 days after the eggs were laid. The probability of eggs developing into larvae and pupae under cooler temperatures was positively influenced by the exposure duration to warmer temperatures before the temperature switch. When the eggs developed into larvae, longer exposure to warmer temperatures before the temperature switch led to faster development. However, when the eggs disappeared (and were probably eaten), longer exposure to warmer temperatures before the temperature switch led to slower egg disappearance. We suggest that the decision to lay eggs is reversible to some extent because the workers can consume the eggs if conditions deteriorate. We suggest that this reversibility reduces the cost of laying eggs at the wrong time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Temperature affects the development and survival of Perina nuda. • The life table parameters indicate that the optimum temperatures for rearing Perina nuda are between 24 °C and 28 °C. • The life table parameters were used to simulate the change trend of the population of P. nuda in 120 d at different temperatures. Perina nuda Fabricius (Lepidoptera: Lymantridae) has emerged as a major pest of Ficus spp. Linné (Rosales: Moraceae), exhibiting widespread distribution across southern China. The present study was designed to assess the impact of temperature on the development and lifetime fecundity of P. nuda. We gathered life-history data of P. nuda under four different temperatures (20 °C, 24 °C, 28 °C, and 32 °C) to analyze through the age-stage, two-sex life table methodology. Subsequently, projected population dynamics were made using these data. Results show that a generation can be completed at experimental temperature; the longest mean longevity (72.012 d) was recorded at 20 °C, while the shortest one was 29.126 d at 32 °C. The highest fecundity (219.5 eggs per female), preadult survival rate (90.6 %), and proportion of females (0.494) were observed at 24 ℃. At 20 °C, the intrinsic rate of increase (r) and the finite rate of increase (λ) were found to be much lower than at other temperatures, with 0.0575 and 1.0591 1/d, respectively. Compared to other temperatures, the net reproductive rate (R 0) at 24 ℃ (108.59) was notably higher than other temperatures. The developmental threshold temperatures and effective accumulated temperatures for egg, larva, pupa, and the entire generation were 10.7 °C (128.02 degree-days), 11.53 °C (362.59 degree-days), 11.86 °C (110.4 degree-days), and 10.85 °C (780.98 degree-days), respectively. A higher population growth rate and a larger population number was observed at 24℃, 28℃ and 32 ℃. Predicted generations varied across Guangdong, ranging from 4.68 in Nanxiong to 6.42 in Leizhou. These findings will help understanding P. nuda biology as influenced by temperature and may be used to predict the distribution and infestation risk under climate warming for this pest of banyan trees. [ABSTRACT FROM AUTHOR]

In marine ecosystems, copepods (20°C) and low salinity in August. Predation from large size zooplankton was one of the factors in regulating O. similis abuncance in Jiaozhou Bay. 2) Over the year, the egg production rate, female prosome length, and female carbon mass of O.similis ranged from 0.03 ± 0.02 to 1.21 ± 0.25 eggs female-1d-1, 410 ± 6 to 472 ± 4 μm, and 0.35 ± 0.05 to 0.43 ± 0.03 μg c female-1 respectively. Female prosome length, and female carbon were both significantly negative correlated with temperature(P

Although favorable environmental conditions for tropical cyclone (TC) formation have been known for a long time, physical factors that influence the timing of TC formation remain unclear. Idealized numerical simulations are conducted by placing identical tropical disturbances (TDs) in various locations within the monsoon trough to examine what affects the timing of TC formation. The timing of TC formation is evaluated by the development time of TDs, which ranges from 60 h to 189 h. Vertical misalignment, defined as the vortex tilt between mid-and low-level circulation centers of the TD, is closely related to TC formation timing. The mid-and low-level circulation centers tend to be vertically aligned when TC formation time approaches. Different from previous studies, vertical misalignment does not entirely depend on vertical wind shear. Vertical misalignment is directly induced by inconsistent translation speeds between the mid-and low-level circulation centers. However, the steering flows for the mid-and low-level circulation centers cannot fully explain the differences in translation speeds. Additionally, there is no strong connection between environmental conditions and TC formation timing for the TDs within the monsoon trough. Rossby energy dispersions of TDs and terrain effects have some impacts on TC formation timing but are not decisive in this study.

Spodoptera littoralis (Boisduval) is a highly destructive and polyphagous insect pest of great economic importance. It develops throughout the year and the larvae are non-diapausing. Little work has been done on the time taken for food to pass through the gut of S. littoralis. Thus, this study on starving and well fed last instar larvae of S. littoralis aimed to determine the effect of temperature and photoperiod on the time taken for a meal to pass through the gut, defecation and digestion. The results indicate that it depended on temperature, photoperiod and hunger. The time that elapsed between a larva being fed and the production of the first faecal pellet, which is a measure of the time it takes for food pass to pass through the gut (SFP), differed significantly at different temperatures and photoperiods. The SFP was longer at 15°C than at 30°C. At 20°C and under a short photoperiod, SFP was very much shorter than under a long photoperiod (18L: 6D). In addition, at 20°C, the time to defecation was significantly longer under a photoperiod of 12L: 12D than under continuous light. In all the tests > 95% of the larvae produced four faecal pellets per meal. The digestibility values varied significantly in the different tests. This study offers new insights into the passage of food from the crop to the rectum at different temperatures and photoperiods. This might help in understanding the adaptability of S. littoralis and may also help in controlling this important pest. [ABSTRACT FROM AUTHOR]

In insects, male mating success and female fecundity usually increase with body size. However, natural selection favors faster maturation, reducing the risk of pre‐reproductive death, when the reproductive season is short in habitats located at high altitudes or far from the equator. Also, if males that mature earlier than females under these conditions increase their mating opportunities, protandry may evolve in their populations. Nonetheless, as body size is strongly correlated with maturation time in insects, faster sexual maturation is reached at the expense of having a small body size. We analyzed the differences in adult body size of males and females of the grasshopper Sphenarium histrio Gerstaecker (Orthoptera: Pyrgomorphidae) in three sites across an altitudinal gradient in southern Mexico. We also evaluated the possibility of protandry in these sampling sites using a common garden experiment. Male and female grasshoppers collected from low altitude sites in the field and reared in the laboratory were larger than those from a high altitude, suggesting genetic differentiation. Grasshoppers from a high altitude hatched earlier, had a shorter development time, presented fewer instars, and were smaller than grasshoppers from the other sampling sites. Moreover, development time in the three sampling sites was shorter in males than in females, suggesting protandry. Interestingly, the males from the three sites showed similar growth rates, but the females from low and high altitudes, respectively, had the fastest and slowest growth rates. In general, the adaptive value of the evolution of protandry has been focused on males. However, it may be that the growth rates of females in these sites could modify the degree of protandry as a response to their risk of pre‐reproductive death and the potential benefits associated with multiple matings. [ABSTRACT FROM AUTHOR]

BACKGROUND: The planthopper Pentastiridius leporinus (Hemiptera: Cixiidae) is the main vector of the γ‐3 proteobacterium 'Candidatus Arsenophonus phytopathogenicus' which causes the syndrome 'basses richesses' (SBR) in sugar beet. SBR is a new and fast‐spreading disease in Central Europe that leads to high yield losses. To date, the development of management strategies has been hampered by insufficient knowledge about general life history traits of the planthopper and, most importantly, the year‐round availability of insects reared under controlled conditions. Rearing of P. leporinus has been considered challenging and to date no protocol exists. RESULTS: Here we describe a method for mass rearing P. leporinus on sugar beet from egg to adult that has produced five generations and over 20 000 individuals between June 2020 and March 2022. An alternative host such as wheat is not necessary for completing the life cycle. No‐choice experiments showed that P. leporinus lays 139.1 ± 132.9 eggs on sugar beet, whereas no oviposition was observed on its nymphal host wheat. Head capsule width was identified as a trait that unequivocally distinguished the five nymphal instars. Developmental time from first instar to adult was 193.6 ± 35.8 days for males and 193.5 ± 59.2 days for females. Infection rates of adults were tested with a nested polymerase chain reaction. The results demonstrated that 70%–80% of reared planthoppers across all generations carried the SBR proteobacterium. CONCLUSION: The mass‐rearing protocol and life history data will help overcome an important bottleneck in SBR research and enhance efforts in developing integrated pest management tools. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The developmental times and reproduction of the burdock-infesting aphid, Uroleucon gobonis （Matsumura）, were determined at different temperatures. The developmental zero, effective cumulative temperature, and intrinsic optimum temperature for the development of this aphid were estimated to be 5.27°C, 141.71 degree-days, and 19.22°C, respectively. This species had growth retardation at 27°C, and no nymphs reached the adult stage at 32°C. Like other aphids, it was found to be strong against low temperatures and weak against high temperatures. The intrinsic rate of natural increase of U. gobonis was 0.26 at 12°C, followed by 0.29 at 17°C, and 0.51 at 22°C suggesting that U. gobonis has a higher reproductive ability at low temperatures than other reported aphid species. Assessment of insecticide susceptibility using the leaf and body dipping methods showed that U. gobonis was highly susceptible to the recommended field rates of the 10 insecticides tested. Clothianidin granules（6 kg/10 a）applied to depths of 2 or 5 cm in the soil significantly suppressed aphid densities compared to surface treatment and the nontreated control. Acetamiprid granules（6 kg/10 a）also showed the same effect as clothianidin granules（6 kg/10 a）on the aphid density, and halving the dose showed no reduction in effectiveness. [ABSTRACT FROM AUTHOR]

Group living in gregarious caterpillars may shorten the larval stage, which is thought to reduce predation exposure. In the gregarious caterpillar Battus polydamas archidamas (Papilionidae) we addressed the effects of simulated predation threat on the duration of the larval stage in solitary and gregarious caterpillars. We further evaluated the consequences of group rearing and predation stimuli for pupal mass.We reared caterpillars singly and in groups of ten individuals. Caterpillars were subjected to simulated predation threats (prodding with a paintbrush) and control larvae were untouched. We determined larval stage duration and pupal mass. We also recorded in solitary and gregarious caterpillars the proportion of individuals reacting to predation threats with distinct behavioural responses.Caterpillars in the group completed larval development earlier than solitary caterpillars. This pattern of accelerated development was already evident in the first instar. Simulated predation reduced the duration of both the entire larval stage and the first instar, but only for caterpillars in the group. Pupal mass was not affected by the predation treatment in either solitary or gregarious caterpillars. Solitary caterpillars showed thrashing and osmeterium display + thrashing more frequently than gregarious caterpillars, while individuals in the group reacted with osmeterium display to a greater extent.Accelerated larval development in response to predation risk has been predicted by theoretical models, but–to our knowledge–this is the first report on gregarious caterpillars. This putative adaptive response did not entail a fitness cost in terms of pupal mass. [ABSTRACT FROM AUTHOR]

Coccinella septempunctata is a nontarget beneficial arthropod and an important aphid predator in agricultural crops. In this study, the toxic effects of the neonicotinoid acetamiprid on C. septempunctata were investigated to determine its applicability and efficacy against the aphid predator. The results of the toxicity test showed that the second instar larvae of C. septempunctata were the most sensitive to acetamiprid. The LC50 values of the 1st, 2nd, 3rd, and 4th instar larvae were 15.767, 9.412, 18.850, and 25.278 mg a.i. L−1, respectively. Compared with that of the control, the predation ability of different larval instars was inhibited by sublethal concentrations of acetamiprid. The results of the predatory function test showed that sublethal concentrations of acetamiprid could reduce the consumption of aphids by fourth instar C. septempunctata larvae over a short duration and significantly inhibited the predatory ability of ladybird larvae. The results of the developmental test showed that sublethal concentration of acetamiprid shortened the growth duration of C. septempunctata larvae. Acetamiprid had considerable adverse effects on the different developmental stages of C. septempunctata. Together, our results provide information for implementation in biological and chemical control strategies for the integrated management of aphids. [ABSTRACT FROM AUTHOR]