An entomopathogenic fungal strain was originally isolated on artificial medium from the corpse of a pea aphid (Acyrthosiphon pisum Harris) collected at Jingzhou, China (N30°21′18.15″, E112°08′41.63″). Based on tests of the morphological, physiological and biochemical characteristics and analysis of internal transcribed spacer (ITS) sequences, it was considered to be a strain of Lecanicillium attenuatum Zare & W. Gams. Therefore, the strain was designated L. attenuatum YZU 151121. The activity of the biological agents under study was determined at 26 °C and 90% relative humidity. The number of A. pisum killed was increased by increasing the concentration of L. attenuatum. The results demonstrated that L. attenuatum YZU 151121 showed a high efficacy against 3rd-instar nymphs (LC50 = 2.91 ± 0.365 × 105 conidia/ml) and adults (LC50 = 3.12 ± 0.398 × 106 conidia/ml) after 6 days of exposure. Crude extract from this strain was tested for contact toxicity and showed high activity in 3rd-instar nymphs and adults, with LC50 values of 251.34 ± 49.54 and 315.46 ± 87.66 mg/l, respectively. In addition, crude extract at a concentration of 200 mg/l could significantly reduce fecundity in adults. These results revealed that the strain YZU 151121 may be useful in biopesticides for controlling pea aphid.

In the black chafer Holotrichia kiotonensis Brenske (Coleoptera: Scarabaeidae), mating behavior was observed between 1940 and 2010 hours at < 0.1 lx in both the laboratory and the field. In the laboratory, an ether extract of female abdominal glands induced a series of pre-mating behaviors such as short-distance orientation and abdominal bending. When the extract was fractionated by silica gel column chromatography, the active fraction was eluted with 50% ether in hexane and 100% ether. Gas chromatography–mass spectrometry analysis revealed that both active fractions contained anthranilic acid (2-amino-benzoic acid) as a major compound. The amount of this compound was determined to be ca. 600 ng/female by high performance liquid chromatography analysis with a fluorescence detector. In the field, male chafers were observed to land on cotton balls impregnated with 10 mg of authentic anthranilic acid. When a white ball treated with anthranilic acid was placed 2–10 cm away from an untreated black ball, males were observed to land significantly more frequently on the latter. These results suggest that males could recognize white balls below 0.1 lx and landed on black balls. When a treated black ball was placed beside an untreated black ball, more males landed on the former. The difference was significant when the distance between the two lures was 5 or 10 cm, but not significant when it was 2 cm. These observations demonstrated that anthranilic acid was the sex-attractant pheromone for the black chafer H. kiotonensis and that the males located and landed on a pheromone source by using olfaction in conjunction with visual orientation. The importance of visual orientation in this nocturnal species is discussed in comparison with the congeneric diurnal species Holotrichia loochooana loochooana.

Serangium japonicum Chapin (Coleoptera: Coccinellidae) chiefly attacks whiteflies. This study monitored the adult occurrence of the ladybird and the citrus whitefly Dialeurodes citri (Ashmead) (Hemiptera: Aleyrodidae) in citrus groves in central Japan using sticky traps, thereby examining temporal relationships in their abundance. Many S. japonicum adults were captured in a pesticide-free grove where D. citri adults were very abundant, with few adults in neighboring (organic, reduced pesticide, and conventional) groves harboring small numbers of D. citri. The whitefly adults exhibited a large peak in numbers in late May to early June. Two peaks of the ladybird adult numbers were detected in late May to early June and late June to mid-July, −6 to 7 days, and nearly 1 month after the peak in whitefly adult numbers, respectively. The ladybird adults found during the first peak period would be those that visited citrus trees mainly for oviposition, and the adults caught during the second peak period would be those that newly emerged after consuming immature whiteflies at the larval stage. Based on a yearly change in adult numbers in the pesticide-free grove, i.e., a large increase in S. japonicum numbers followed by a rapid decline in D. citri numbers, the ladybird’s role in controlling the whitefly is discussed.

The influence of the fungus Metarhizium robertsii Bischoff, Rehner and Humber on the mortality of four water bug species, Cymatia coleoptrata (Fabricius), Sigara assimilis (Fieber), Ilyocoris cimicoides cimicoides (Linnaeus), and Notonecta reuteri Hungerford, and bloodsucking mosquito Anopheles messeae Falleroni, was investigated under various concentrations of conidia and different treatment types. We found that the mortality of adults of the water bug species was similar or higher than that of A. messeae, with C. coleoptrata and S. assimilis being more susceptible to M. robertsii than N. reuteri, I. c. cimicoides, and the mosquito A. messeae. Treatment with dry conidia at concentrations of 5 × 104 and 5 × 105 conidia/ml caused higher mortality of the water bug species than did treatment at the same concentrations with conidia in an aqueous suspension. In contrast, higher concentrations (5 × 106 conidia/ml) led to higher mortality after treatment with the aqueous suspension, relative to treatment with dry conidia. Our studies showed that water bugs exhibited the classical development of a mycosis with hemocoel colonization, mummification, and conidia formation on cadavers directly on the surface of the water. Possible changes in invertebrate communities in aquatic ecosystems after treatment with Metarhizium are discussed.

The stinkbug Plautia stali Scott is a notorious agricultural pest whose posterior midgut hosts specific bacteria essential for its growth and survival, highlighted as an experimental model for symbiosis studies. Some symbiotic bacteria of P. stali are cultivable, found free-living in and acquired from the environment, and, furthermore, some free-living environmental bacteria are potentially capable of establishing symbiotic association with P. stali. In this context, it is expected that such environmental bacteria may occasionally contaminate and infect the experimental insects maintained in the laboratory, which could potentially affect the functional analyses of the symbiosis. Here we report that such contamination events do occur under a laboratory rearing conditions for P. stali. When symbiont-deprived newborn nymphs from surface-sterilized eggs were reared in sterilized plastic containers with autoclaved water, most of them died as nymphs presumably as a result of aposymbiosis, but only a small fraction could attain adulthood and the adult insects were all infected with γ-proteobacteria allied to Pantoea and Enterobacter. A variety of bacteria, mainly Bacillus and also Pantoea and Enterobacter, were detected from peanuts and soybeans provided as food for P. stali. Autoclaving of peanuts and soybeans eradicated these bacteria but negatively affected the host survival, whereas ethanol sterilization of peanuts and soybeans removed Pantoea and Enterobacter, but not Bacillus, without negative effects on the host survival. On the basis of these results, we established a practical procedure for aseptic rearing of P. stali, which will enable reliable and strict analyses of host–symbiont interactions in the model symbiotic system.

With a view to improving the establishment of Aphidius gifuensis Ashmead, a potential natural enemy for suppression of aphids on vegetables, the effects of host deprivation and honey feeding before release on the parasitoid’s egg load and reproduction were studied under laboratory conditions. Host deprivation significantly affected mummy production and survival rate of female parasitoids. A. gifuensis produced more mummies when exposed to a short period (1 and 2 days) of host deprivation, but when host deprivation lasted for 3 days, their mummy production sharply decreased. Offspring produced by parasitoids that had been deprived of hosts for 2 days were much heavier than those produced by parasitoids deprived of hosts for 1 and 3 days. However, host deprivation did not affect emergence rate or offspring sex ratio; the emergence rate was always above 80%, and the offspring sex ratio was always female biased irrespective of whether the host-deprivation period was 1, 2, or 3 days. Honey feeding greatly increased egg load, longevity and decelerated oosorption of A. gifuensis when hosts were absent, and significantly increased parasitoid mummy production in late age. We discuss the results in the context of augmentative biological control, with the view to understanding how to increase parasitoid performance after they are released.

The Chinese weevil, Hylobitelus xiaoi Zhang, is a major pest affecting the pine industry throughout southern China, but its dispersal is still poorly understood. We aimed to investigate its dispersal by assessing the genetic structure of seven geographical populations, using the distribution of two mitochondrial genes (cytochrome c oxidase subunit I and cytochrome b). A 1212-bp fragment of the two mitochondrial genes was sequenced for 70 individuals from seven geographical populations. The gene sequences included 861 conserved sites, 351 variable sites, 254 parsim-info sites, and 97 singleton sites. These polymorphic sites defined 24 haplotypes with a haplotype diversity of 0.825. Nucleotide diversity was low (0.04568). The differentiation parameter (0.619) was much greater than the coefficient of genetic differentiation (0.285). An analysis of molecular variance suggested that most of the variation was due to within-population differences (61.68%). This molecular data also demonstrated that there is significant divergence among the seven sampled populations of H. xiaoi. This is probably due to habitat fragmentation, preventing effective gene flow between sites. Our molecular evidence supports the view that the Chinese weevil is a native pest, and that outbreaks of H. xiaoi are caused by large plantations of the exotic slash pine.

Asian hornet, Vespa velutina Lepeletier nests were discovered in 2007 in Andernos-les-Bains on the south-west coast of France, 3 years after the first reported sightings in France. The number of nests increased in the commune over the following 7 years, despite local authorities enacting a destruction policy. The nests existed in close proximity to one another leading to a high density of over 10 nests per square kilometre in urban areas. New information on the chosen habitat for nests is presented, and the differences between primary and secondary locations are evident, with primary nests mostly occupying buildings and man-made structures, while secondary nests were found on trees. Using Bayesian inference methods, we fit a basic model to the observational data, which allows us to estimate key demographic parameters. This model fit is highly informative for predicting V. velutina spread and colonisation of other at-risk regions, and suggests that local control has a limited impact on the spread of V. velutina once established within a region.

The invasive red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae) has become the main pest of palms. Because of the cryptic habits of the adult, little is known about the precise movements on palms and the actual dispersal capability in a population. Such data would help to improve risk assessment and management. Miniature radio tags have been increasingly used to monitor movements of animals. In this study, we evaluated the resistance of passive radio frequency identification (RFID) and active radio-transmitters (comprising an antenna) to the burrowing behavior of the insect and their effects on the flight activity. Tagged weevils were placed in boxes filled with fibrous plant material. After 1 week, ca. 90% of insects kept the tag but 83% of the radio-transmitters had a broken antenna. In a screen cage, 100% of insects equipped with RFID flew normally, in contrast to the 17% of insects equipped with active tags. RFID-tagged insects inserted in palm tissue could be easily identified. RFID glued to the thorax affected neither mating behavior nor oviposition. In conclusion, RFID tags appear to be the most efficient tool for tracking the displacement of the weevil in young palms and present new opportunities for promoting studies about gregarious behavior of the red palm weevil on young infected palms.