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Antheraea pernyi Guerin-Meneville eggs have become an important host for rearing Trichogramma and are the preferred host for mass production of Trichogramma dendrolimi Mausumura, a widely used natural enemy in pest control practices. However, the effects of fertilization of host eggs on their mass production remains unclear. In this study, we evaluated parasitism and biological parameters for T. dendrolimi reared on A. pernyi eggs with five different treatments under the laboratory conditions. The five treatments were manually-extracted unfertilized washed eggs (MUW), naturally-laid unfertilized washed eggs (NUW) and unwashed (NUUW) eggs, naturally-laid fertilized washed eggs (NFW) and unwashed (NFUW) eggs. Our results showed that T. dendrolimi preferred MUW eggs to other treatments, although all treated A. pernyi eggs were accepted by T. dendrolimi . Generally, T. dendrolimi parasitized more washed eggs than unwashed eggs, and a greater number of unfertilized than fertilized eggs. On MUW eggs, the highest number of adults emerged per egg coupled with the shortest pre-emergence time and longest longevity of offspring. Those T. dendrolimi adults emerging from unfertilized eggs exhibited a higher number per egg, shorter pre-emergence time and longer adult longevity than those from fertilized eggs. There was no significant difference in percentage of female progeny, time to adult death, hind tibia length and egg load across all treatments. Our results demonstrate that MUW eggs of A. pernyi are most suitable for mass production of T. dendrolimi .

Cardinium and Wolbachia are maternally inherited bacterial symbionts of arthropods that can manipulate host reproduction by increasing the fitness of infected females. Here, we report that Cardinium and Wolbachia coinfection induced male-killing and cytoplasmic incompatibility (CI) when they coexisted in a cryptic species of whitefly, Bemisia tabaci Asia II7. Cardinium and Wolbachia symbionts were either singly or simultaneously localized in the bacteriocytes placed in the abdomen of B. tabaci nymphs and adults. Cardinium-Wolbachia coinfection induced male-killing and resulted in a higher female sex ratio in the intraspecific amphigenetic progeny of Asia II7 ICWH and ICWL lines; interestingly, male-killing induction was enhanced with increased Cardinium titer. Moreover, single infection of Wolbachia induced partial CI in the Asia II7 IW line and resulted in reduced fecundity, higher embryonic mortality, and lower female sex ratio. The uninfected Asia II7 IU line had significantly higher fecundity, lower embryonic and nymphal mortalities, and a lower level of CI than both the Wolbachia-infected Asia II7 IW line and the Cardinium-Wolbachia-coinfected Asia II7 ICWH line. Our findings indicate that Cardinium-Wolbachia coinfection induced male-killing, which may have had antagonistic effects on Wolbachia-induced CI in the Asia II7 whiteflies. For the first time, our study revealed that B. tabaci Asia II7 reproduction is co-manipulated by Cardinium and Wolbachia endosymbionts.

The life table is a type of research tool that is frequently used in many studies involving population and community ecology. They are the basis for many comprehensive studies in pest management, pesticide resistance, predator-prey relationships, biological control, mass-rearing and harvesting of insects, plant resistance, etc. Because the morphology, physiology, survival, fecundity, and predation/consumption rate of most arthropods will vary significantly depending on their developmental stage and sex, precise description of stage differentiation and inclusion of both sexes are critical for attaining realistic and accurate life table analyses and correctly evaluating the overall fitness of populations. Since traditional female age-specific life tables ignore the male individuals in a population and are incapable of describing the unique and important feature of stage differentiation (i.e., metamorphosis) that is a defining characteristic of insects and mites, their application to data analysis involving these groups will inevitably result in miscalculations and limit the practical application of these life tables. On the other hand, the age-stage, two-sex life table (hereafter referred to as the two-sex life table whenever appropriate), can precisely delineate stage differentiation and includes both sexes in data analysis, description, and interpretation, and in practical applications. In this review, the problems of female age-specific life tables are examined, followed by a discussion of the advantages of using the two-sex life table. Finally, applications of the two-sex life table in various types of entomological research are discussed and accompanied by examples.

In insects, neuropeptides and their receptors not only play a critical role in insect physiology and behavior but also are the potential targets for novel pesticide discoveries. Aphidius gifuensis is one of the most important and widespread aphid parasitoids, and has been successfully used to control aphid. In the present work, we systematically identified neuropeptides and their receptors from the genome and head transcriptome of A. gifuensis. A total of 35 neuropeptide precursors and 49 corresponding receptors were identified. The phylogenetic analyses demonstrated that 35 of these receptors belong to family-A, four belong to family-B, two belong to leucine-rich repeat-containing GPCRs, four belong to receptor guanylyl cyclases, and four belong to receptor tyrosine kinases. Oral ingestion of imidacloprid significantly up-regulated five neuropeptide precursors and four receptors whereas three neuropeptide precursors and eight receptors were significantly down-regulated, which indicated that these neuropeptides and their receptors are potential targets of some commercial insecticides. The RT-qPCR results showed that dopamine receptor 1, dopamine receptor 2, octopamine receptor, allatostatin-A receptor, neuropeptides capa receptor, SIFamide receptor, FMRFamide receptor, tyramine receptor and short neuropeptide F predominantly were expressed in the head whilst the expression of ion transport peptide showed widespread distribution in various tissues. The high expression levels of these genes suggest their important roles in the central nervous system. Taken together, our study provides fundamental information that may further our understanding of neuropeptidergic signaling systems in the regulation of the physiology and behavior of solitary wasps. Furthermore, this information could also aid in the design and discovery of specific and environment-friendly insecticides.

A small-sized c-MYC promoter G-quadruplex selective fluorescent BZT-Indolium binding ligand was demonstrated for the first time as a highly target-specific and photostable probe for in vitro staining and live cell imaging and it was found to be able to inhibit the amplification of the c-MYC G-rich sequence (G-quadruplex) and down-regulate oncogene c-MYC expression in human cancer cells (HeLa).

Serangium japonicum Chapin (Coleoptera: Coccinellidae) is a predominant predator with a preference for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). To date, the orientational behavior of S. japonicum toward B. tabaci-infested plants has seldom been reported. In this study, greenhouse cage experiments and bioassays with wind tunnels, a Y-tube olfactometer and B. tabaci-induced plant volatiles were executed to clarify this behavior. In greenhouse cage experiments, B. tabaci adults significantly preferred eggplant, cucumber and tobacco to cotton and tomato, whereas S. japonicum adults preferred B. tabaci-infested eggplant, cucumber and cotton to tobacco and tomato. In wind tunnel bioassays, B. tabaci showed a clear preference for eggplant, cucumber and tobacco. Compared with B. tabaci-infested eggplant, cucumber or cotton, B. tabaci-infested tobacco was rarely visited by S. japonicum. In Y-tube bioassays, S. japonicum did not distinguish between B. tabaci-infested and uninfested eggplant. Nine common plant volatiles were detected in different plant species, suggesting that these volatiles may play an important role in the process by which S. japonicum looks for prey. In light of the current results, we discuss the implications of our findings and put forward to a new strategy&mdash, i.e., an eggplant + B. tabaci + S. japonicum system&mdash, to control B. tabaci damage in the integrated management of whitefly.

Chrysoperla nipponensis (Okamoto), which has the unique diapause phenotype distinguishable from nondiapause adult, is an ideal model organism for studying the mechanism of reproductive diapause. However, there is no reliable and effective reference genes used for the reproductive diapause study of C. nipponensis. Therefore, in this study, we evaluated the expression stability of 10 candidate reference genes (Tub1, Arpc5, EF1a, 128up, RpS5, RpS26e, GAPDH, Arp3, Actin, α-Tub) in adults under diapause and nondiapause induction conditions using four statistical algorithms including GeNorm, NormFinder, Bestkeeper, and ∆CT method. Results showed that Arp3 and Tub1 were the most stable reference genes in all samples and in the adult tissues group. Arp3 and RpS5 were the most stable reference genes in the development degree group. α-Tub and EF1a were unstable reference genes under the conditions of this study. Meanwhile, to verify the reliability of the reference genes, we evaluated the relative expression levels of Vg and VgR in different treatments. Significant upregulation and downregulation in expression level of two genes in response to diapause termination and diapause fat body tissue was, respectively, observed when using Arp3 as the reference gene but not when using an unstable reference gene. The reference genes identified in this work provided not only the basis for future functional genomics research in diapause of C. nipponensis and will also identify reliable normalization factors for real-time quantitative real-time polymerase chain reaction data for other related insects.

PubMed ID: 29992315, The development, survival, and fecundity data of Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae) reared on chestnut (Castanea mollissima Blume), maize (Zea mays L.), sunflower (Helianthus annuus L.), hawthorn (Crataegus pinnatifida Bunge), and apple (Malus domestica Miller) were collected at 25 ± 1°C and 70 ± 5% RH. Raw data were analyzed and compared by using the age-stage, two-sex life table. The mean fecundity (F) was the highest (282.3 eggs per female) when larvae were reared on chestnut. The lowest mean fecundity (19.2 eggs per female) occurred on apple. The net reproductive rates (R 0) were 134.52, 106.77, 30.29, 27.61, and 8.63 offspring on chestnut, maize, sunflower, hawthorn, and apple, respectively. The intrinsic rates of increase (r) were 0.1359, 0.1326, 0.0807, 0.0811, and 0.0448 d -1 on chestnut, maize, sunflower, hawthorn, and apple, respectively. Computer projections based on the age-stage, two-sex life table revealed the stage structure and variability of the population growth of C. punctiferalis. Our results demonstrated that although chestnut and maize were the most suitable host plants for C. punctiferalis, the moths were also able to develop and reproduce on sunflower, hawthorn, and apple. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved.

The influence of fluctuating temperatures on the development and fecundity of two aphids, Megoura crassicauda Mordvilko and Aphis craccivora Koch, were determined by collecting life table data at a constant temperature (22 °C) and two fluctuating temperatures (22 ± 3 °C and 22 ± 5 °C). The longevity of M. crassicauda decreased significantly at 22 ± 3 °C and 22 ± 5 °C, while there was no significant difference in the longevity of A. craccivora among the three treatments. The fecundity and intrinsic rate of increase (r) of M. crassicauda decreased significantly at both fluctuating temperatures, while A. craccivora showed the opposite tendency. These results showed that the fluctuating temperatures had negative impacts on the life history traits of M. crassicauda, but were beneficial for A. craccivora. Data obtained under constant temperatures may not reveal accurately enough the biotic responses of pests in the field.

The oriental fruit moth, Grapholita molesta, is an important pest in many commercial orchards including apple, pear and peach orchards, and responsible for substantial economic losses every year. To help in attaining a comprehensive and thorough understanding of the ecological tolerances of G. molesta, we collected life history data of individuals reared on apples under different constant temperature regimes and compared the data with moths reared under a variable outdoor temperature environment. Because G. molesta individuals reared at a constant 25°C had the heaviest pupal weight, the highest survival rate from egg to adult, highest finite rate of increase, and greatest fecundity, 25°C was considered as the optimum developmental temperature. The G. molesta population reared at a constant 31°C had the shortest development time, lowest survival rate and fecundity, resulting in population parameters of r < 0, λ < 1, lead to negative population growth. The population parameters r and λ reared under fluctuating temperature were higher than that reared under constant temperatures, the mean generation time (T) was shorter than it was in all of the constant temperatures treatments. This would imply that the outdoor G. molesta population would have a higher population growth potential and faster growth rate than indoor populations raised at constant temperatures. G. molesta moths reared under fluctuating temperature also had a higher fertility than moths reared under constant temperatures (except at 25°C). Our findings indicated that the population raised under outdoor fluctuating temperature conditions had strong environment adaptiveness.

The life table of the green lacewing, Chrysopa pallens (Rambur), was studied at 22 degrees C, a photoperiod of 15:9 (L:D) h, and 80% relative humidity in the laboratory. The raw data were analyzed using the age-stage, two-sex life table. The intrinsic rate of increase (r), the finite rate of increase (lambda), the net reproduction rate (R0), and the mean generation time (T) of Ch. pallens were 0.1258 d(-1), 1.1340 d(-1), 241.4 offspring and 43.6 d, respectively. For the estimation of the means, variances, and SEs of the population parameters, we compared the jackknife and bootstrap techniques. Although similar values of the means and SEs were obtained with both techniques, significant differences were observed in the frequency distribution and variances of all parameters. The jackknife technique will result in a zero net reproductive rate upon the omission of a male, an immature death, or a nonreproductive female. This result represents, however, a contradiction because an intrinsic rate of increase exists in this situation. Therefore, we suggest that the jackknife technique should not be used for the estimation of population parameters. In predator-prey interactions, the nonpredatory egg and pupal stages of the predator are time refuges for the prey, and the pest population can grow during these times. In this study, a population projection based on the age-stage, two-sex life table is used to determine the optimal interval between releases to fill the predation gaps and maintain the predatory capacity of the control agent.

Photoperiod is an important factor influencing many biological processes including population dynamics of many insect species in temperate zones. To determine the population response of Chrysoperla nipponensis under altered conditions (high temperature and short photoperiod) and to test whether the short photoperiod was suitable for artificial storage, the life table data of C. nipponensis were collected at 25 °C under a long photoperiod, 15:9 h (L:D), and a short photoperiod, 9:15 h (L:D) and analyzed using the age-stage, two-sex life table approach. We found that C. nipponensis developed faster under the long photoperiod than under the short photoperiod. The shorter developmental time, higher fecundity, and higher proportion of females found during the long photoperiod resulted in higher intrinsic and net reproductive rates, but a shorter mean generation time and life expectancy compared to those reared during the short photoperiod. Individuals reared under the short photoperiod also had a high reproductive value. Population projection demonstrated that C. nipponensis reared at the long photoperiod would complete four generations in 150 d, while reared under the short photoperiod would just be entering the second generation. Our results demonstrated that the different fitness values obtained for C. nipponensis individuals by varying photoperiod lengths, were readily distinguishable when using the age-stage, two-sex life table. High winter temperatures would be detrimental to a diapausing population, and diapause induced by the short photoperiod would be beneficial to the storage of natural enemies.

Effects of eight insecticides on Diadegma insulare (Cresson), a parasitoid of the diamondback moth, Plutella xylostella L., were evaluated under the laboratory conditions. The insecticides were three azadirachtin-based products (Ecozin, Agroneem and Neemix), two Bacillus thuringiensis (Bt) products (Xentari and Crymax), indoxacarb, spinosad, and λ-cyhalothrin. When D. insulare pupae were treated, none of the insecticide treatments except λ-cyhalothrin significantly reduced adult emergence, with 76–90% adults emerged from the treated pupae. In the λ-cyhalothrin treatment, only 10% D. insulare pupae produced adult wasps. Indoxacarb, spinosad, and λ-cyhalothrin caused 100% D. insulare adult mortality in 24 h in Petri dishes sprayed with insecticides in the contact bioassays, and 95.8, 100 and 95.8% adult mortality in 24 h in the ingestion bioassays, respectively. In contrast, all three azadirachtin-based insecticides and the two Bt-insecticides caused only 0–10.4% mortality of D. insulare adults after ingest...

Photoperiodic sensitivity for diapause induction of the green lacewing, Chrysoperla sinica (Tjeder) was examined at 22°C. The adult diapause of C. sinica was induced by short-day photoperiods, and the critical photoperiod for its induction was between 12.5L-11.5D and 13L-11D. Adults developed without diapause under long-day conditions, and entered diapause under short-day conditions. The adult stage was the uppermost sensitive stage for adult diapause induction, adults could go into diapause only when the emerging adults were under diapause-inducing short-day photoperiods. The short-day photoperiodic experience by transferring between 15L: 9D and 9L: 15D at preimaginal stages did not result in adult diapause under 15L: 9D photo regime, although some treatments extended the pre-oviposition period in adult stage. The results showed that the 3rd instar larvae and pre-pupae were more sensitive to the photoperiodic change from 15L: 9D to 9L: 15D photo regime than the other preimaginal stages.

To evaluate the influence of different host plants including apple, wild jujube, jujube, pear and hawthorn on the cold-tolerance substances in overwintering larvae of the peach fruit moth Carposina sasakii Matsumura, we measured the larvae super-cooling capacity, the water content (W), total fat content (TFC), total protein content (TPC) and total glycogen content (TGC) in the body. Results showed that the mean super-cooling point (SCPs) and freezing point (FPs) of overwintering larvae from the 5 host plant fruits differed significantly, ranging from -15.53 to -8.50 degrees C and -11.31 to -4.04 degrees C, respectively. The overwintering larvae fed on hawthorn owned the highest SCP, FP, TGC and the lowest W, while those fed on apple had the lowest SCP, FP, TFC and TGC but the highest W and TPC. The fresh mass (FM) of the overwintering larvae fed on pear was the highest, while those fed on jujube was very low. Those fed on jujube accumulated the highest TFC but the lowest TPC.

In order to understand the effects of fluctuating thermal regime (FTR) on the cold tolerance of female and male Aphidius gifuensis adults in the mummies of Schizaphis graminum and to explore the variation patterns of the biochemical substances in the adult body, this paper determined the supercooling point (SCP), freezing point (FP), and the water, fat, protein, and carbohydrate contents of the adults after FTR treatments. Compared with that at constant temperature (20 degrees C), the cold tolerance of the adults at 4 degrees C 22 h/20 degrees C 2 h and 4 degrees C 46 h/20 degrees C 2 h after 1 week enhanced significantly. The SCP and FP after FTR presented a downtrend, being the lowest (-26.38 degrees C and -25.51 degrees C, respectively) for the female adults after 1 week of 4 degrees C 22 h/20 degrees C and the lowest (-26.82 degrees C and -26.38 degrees C, respectively) for the male adults after 1 week of 4 degrees C 46 h/20 degrees C 2 h. After FTR, the carbohydrate and protein contents of the female and male adults increased while the fat and water contents were in adverse, with distinct changes after 1 week of 4 degrees C 22 h/20 degrees C 2 h and 4 degrees C 46 h/20 degrees C 2 h. The results indicated that FTR could enhance the cold tolerance of A. gifuensis adults, which was closely related to the variations of the biochemical substances in the adult body, and the treatments 4 degrees C 22 h/20 degrees C 2 h and 4 degrees C 46 h/20 degrees C 2 h for 1 week were most advantageous to the survival and practical application of A. gifuensis.

The determinations of super-cooling ability and body' s water and fat contents of overwintering Hyphantria cunea pupae showed that during overwintering, the female and male H. cunea pupae had the similar change patterns in their cold-resistance ability, i.e., increased with decreasing air temperature, but their body's water and fat contents, super-cooling point (SCP), and freezing point (FP) differed at different overwintering stages. The SCP was significantly lower at pre- and mid-overwintering stages than at late-overwintering stage, while FP had less difference among the stages. The body's water content was significantly higher at mid-overwintering stage than at pre- and late-overwintering stages. Comparing with non-overwintering pupae, the overwintering pupae had significantly lower SCP and FP, but significantly higher body's water and total fat contents. Regression analysis showed that there was a negative relationship between the water content and the SCP of female and male pupae (P0.05).