Dry grain legume seeds possessing αAI-1, an α-amylase inhibitor from common bean (Phaseolus vulgaris), under the control of a cotyledon-specific promoter have been shown to be highly resistant to several important bruchid pest species. One transgenic chickpea and four cowpea lines expressing αAI-1, their respective controls, as well as nine conventional chickpea cultivars were assessed for their resistance to the bruchids Acanthoscelides obtectus (Say), Callosobruchus chinensis L. and Callosobruchus maculatus F. All transgenic lines were highly resistant to both Callosobruchus species. A. obtectus, known to be tolerant to αAI-1, was able to develop in all transgenic lines. While the cotyledons of all non-transgenic cultivars were highly susceptible to all bruchids, C. chinensis and C. maculatus larvae suffered from significantly increased mortality rates inside transgenic seeds. The main factor responsible for the partial resistance in the non-transgenic cultivars was deduced to reside in the seed coat. The αAI-1 present in seeds of transgenic chickpea and cowpea lines significantly increases their resistance to two important bruchid pest species (C. chinensis and C. maculatus) essentially to immunity. To control αAI-1 tolerant bruchid species such as A. obtectus and to avoid the development of resistance to αAI-1, varieties carrying this transgene should be protected with additional control measures.

The brown planthoppers (BPH) Nilaparvata lugens (Stål) and the white-backed planthoppers (WBPH) Sogatella furcifera (Horváth) annually migrate from tropical and subtropical regions to temperate regions in Asia, including Japan, Korea and northern China. To elucidate the genetic divergence based on geography of planthoppers and to estimate their migration route on the basis of molecular data, we analysed a part of their mitochondrial genome sequences. Sequences of cytochrome oxidase subunit I (cox1) – transfer RNA for Leu (trnL2) – cox2 were determined for 579 BPH (1,928 bp) and 464 WBPH (1,927 bp) individuals collected from 31 and 25 locations, respectively, in East and Southeast Asia. Thirty and 20 mitochondrial haplotypes were detected for BPH and WBPH, respectively. Single populations of both planthoppers included multiple haplotypes, and many haplotypes were shared in some populations and areas. The most frequently detected haplotypes accounted for approximately 50% of all BPH and WBPH individuals. To evaluate gene flow among planthoppers in different regions in Asia, pairwise fixation index (Fst) values were calculated. For BPH, high Fst values (0.580–0.926) were shown between planthoppers in Papua New Guinea (PNG) and the other areas and moderate Fst values (0.176–0.362) were observed between those in southern Philippines and other areas. For WBPH, the Fst value was the highest between Taiwan and southern Vietnam (0.236), and low among the other areas. AMOVA indicated no genetic structure among eight areas, excluding southern Philippines and PNG, for BPH, and among ten areas for WBPH. These data indicate that both planthoppers do not show much differentiation of local populations and/or have genetically intermixed Asian populations. These data also indicate that it may be difficult to distinguish regional planthopper populations on the basis of differences in mitochondrial sequences.

In insect, fat body plays major roles in insect innate immunity. Phenoloxidase (PO) is an important component in insect innate immunity and is necessary for acclimatization. In our study, two prophenoloxidase (PPO) subunits were obtained from fat body of Catantops pinguis (Stål). The full-length cDNA sequence of one PPO (CpPPO1) consisted of 2347 bp with an open reading frame (ORF) of 2187 bp encoding 728 amino acids, while the other subunit (CpPPO2) had a full length of 2445 bp, encoding 691 amino acids. Both the PPO gene products are predicted to possess all the structural features of other PPO members, including two putative tyrosinase copper-binding motifs with six highly conserved histidine residues and a thiolester-like motif. Tissue distribution analysis showed that both PPO mRNAs were abundantly expressed in the fat body among 11 tissues examined, and they were transiently up-regulated after Escherichia coli infection, consistent with them being immune-responsive genes. Total levels of CpPPO1 and CpPPO2 mRNA transcripts were much higher in first instar larvae and adults. A much higher transcript level of CpPPO1 was detected in several months, while there were extremely high mRNA expression levels of CpPPO2 in January, July, October, and December. The above results suggested that PPO from fat body might also bring significant function during the processes of development and acclimatization for C. pinguis.

To estimate the net effect of climate change on natural populations, we must take into account the positive and negative effects of temperature oscillations and climate variability. Warming because of climate change will likely exceed the physiological optima of tropical insects, which currently live very close to their thermal optima. Tropical insects will be negatively affected if their optima are exceeded otherwise warming may affect them positively. We evaluate the demographic responses of the cowpea aphid, Aphis craccivora, to summer warming in subtropical and tropical Taiwan, and examine the effects of diel temperature oscillation on these responses. Aphids were reared at four temperatures (current summer mean, +1.4, +3.9 and +6.4 °C), the latter three simulating different levels of warming. At each average temperature, aphids experienced constant or oscillating (from −2.9 to +3.6 °C of each mean temperature) regimes. As the simulated summer temperatures increased, so did the negative effects on life-history traits and demographic parameters. Compared with aphids reared in constant temperatures, aphids reared in oscillating temperatures developed more slowly and had a longer mean generation time, but their net reproductive rate was higher. These findings demonstrate that climate warming will affect demographic parameters and life-history traits differentially. Studies that use constant temperatures are unlikely to accurately predict biotic responses to climate change.

Lycorma delicatula (White) was identified in 2004 as an invasive pest in South Korea, where it causes serious damage to vineyard crops. To investigate the population structure and dispersal pattern of L. delicatula in South Korea, we estimated the population genetic structure and gene flow among nine locations across the country using seven microsatellite markers. Although L. delicatula spread throughout most of its geographical range in South Korea within 5–7 years following invasion, its populations show evidence of genetic structuring across the range with a low but significant global FST (genetic differentiation across all populations) of 0.0474. Bayesian-based clustering analysis indicates the presence of at least three genetically unique populations in South Korea, including populations in northeastern South Korea, which show a distinct genetic background. However, isolation by distance suggests that populations in South Korea have not yet reached genetic equilibrium. Estimates of the historical rate of gene flow (Nem) indicate that relatively high rates of flow have been maintained among populations within the western region, which may indicate recent range expansion. A population assignment test using the first-generation migrant detection method suggested that long-distance dispersal of L. delicatula may have occurred over large areas of South Korea. More complex dispersal patterns may have occurred during L. delicatula invasion of heterogeneous landscapes in South Korea.

The greenbug, Schizaphis graminum (Rondani), is a major pest of cereals in some parts of the world and is of particular concern because it can be resistant to some insecticides and overcome the resistance of crops. In the UK, it has never been found on crops, but two rather little-known and closely-related species (Schizaphis holci and Schizaphis agrostis) are associated with the wild grasses, Holcus lanatus and Agrostis stolonifera. Since 1987, winged (alate) aphids morphologically resembling the greenbug have been found in increasing numbers in 12.2 m high suction-trap samples of the Rothamsted Insect Survey (RIS); hence, studies were undertaken to establish their identity. Clones (=asexual lineages) established from populations collected from H. lanatus in southern England showed strong preference for Holcus over Agrostis and Hordeum in laboratory tests and produced sexual morphs when transferred to short-day conditions, the males being apterous, as expected for S. holci. Multivariate morphometric comparisons of alatae caught in UK RIS suction traps in 2007 and 2011 with named specimens from museum collections, including S. graminum from many countries, indicated that the suction-trapped alatae were mostly S. agrostis and S. holci. Cytochrome c oxidase subunit I (COI) mtDNA obtained from 62 UK specimens from suction-traps had 95.4–100% sequence identity with US specimens of S. graminum. Two of the UK specimens had identical COI sequence to the US sorghum-adapted form of S. graminum, and these specimens also had 100% identity with a 640 bp fragment of nDNA CytC, indicating that this form of S. graminum may already be present in the UK. Present and future economic implications of these results are discussed.

Trissolcus basalis has been used as a biological control agent of its main host, Nezara viridula, in many countries. However, estimations of its functional and numerical responses in the field are lacking. We estimated the density of N. viridula eggs, the proportion of parasitized N. viridula eggs, and the number of T. basalis adults/trap in the field. We transformed relative parasitoid density to an absolute density, and estimated the parasitoid's attack rate, a, and the mutual interference parameter, m, in two ways: following Arditi & Akçakaya (1990) and using the Holling–Hassell–Varley model with two iterative techniques. The attack rate estimated by both methods were a=1.097 and a=0.767, respectively. Parameter m varied less between methods: m=0.563 and m=0.586, respectively, and when used to calculate the number of parasitized N. viridula eggs per m2, differences with the observed values were not significant. The numerical response of T. basalis was affected by the sex allocation of their progeny and the proportion of adult parasitoids trapped decreased with field parasitoid population density. Theoretical models show that 0<m<1 is a stabilizing factor and previous re-analysis of field data showed a mean m value of 0.8. The Holling–Hassell–Varley model leads to a flexible description of the functional response allowing to predict acceptable weekly host parasitism. The pre-imaginal parasitoid survival and the change in sex ratio as a function of parasitoid density adequately describe the numerical functional response of the parasitoid.

We report the occurrence of Lysiphlebus orientalis in Serbia, an aphid parasitoid from the Far East that is new to Europe and has the potential to become invasive. Our finding based on morphological characters is confirmed by analyses of mitochondrial cytochrome oxidase subunit I sequences. An increase in number and an expansion of the host range were observed during field studies over the past two years, and it is determined that the current host range encompasses nine aphid hosts on 12 different host plants, forming 13 tri-trophic associations. A host range determined for European populations of L. orientalis appears wider compared with that in its Far Eastern native habitats where Aphis glycines Mats. is the sole known host. Moreover, it overlaps considerably with the host ranges of European parasitoids that play an important role in the natural control of pest aphids.

Pesticide applications have a strong impact on biodiversity in agroecosystems. The present study aimed to assess the impact of pest control strategies on the arthropodofauna of Parus major nests built within nestboxes installed in orchards. Unlike many studied groups, these arthropod communities are not in direct contact with pesticide sprays (on account of their being sheltered by nestboxes) and are also unable to move away from the treated area. In this pilot study, we estimated the prevalence and the taxonomic and ecological diversities of arthropodofauna sampled in the nests and assessed the extent to which the whole and nest-specific arthropodofauna were affected by pest control strategies. Sixteen different insect and arachnid Primary Taxonomic Groups (PTGs, order level or below) were found in nests. The best represented PTGs (⩾10% occurrence in years 2007 and 2008) were Psocoptera (Insecta, detritivorous/saprophagous), detritivorous/saprophagous Astigmata (Acari) and hematophagous Mesostigmata (Acari). Pest control strategies had a large impact on the prevalence of arthropods in nests, with higher proportions of nests hosting arthropods in organic orchards than in conventional orchards and with intermediate proportions in nests in Integrated Pest Management orchards. In contrast, pest control strategies had no significant effect on the composition of the arthropod communities when only nests hosting nidicolous arthropods were considered.

The aphid sex pheromone component (4aS,7S,7aR)-nepetalactone is considered to be a potential tool for enhancing biological control of aphids. Studies have confirmed its potential to attract parasitoids, increase parasitism rates in the field and also alter the spatial distribution of parasitoids. An important aspect that has been overlooked is the impact that the introduction of nepetalactone may have on aphid populations already present in field or glasshouse environments. The most prevalent pest aphid populations in glasshouse and field environments are the asexual morphs, which are capable of exponential growth if populations are not controlled. The short-term implications of the sex pheromone on asexual aphids were observed through their behavioural response. Using Y-tube olfactometry, it is shown that virginoparae of the peach-potato aphid, Myzus persicae, are repelled by high concentrations of nepetalactone. Long-term effects of the pheromone which may span the aphid's life, or even generations, were assessed via mean relative growth rate (MRGR) and the intrinsic rate of natural increase (rm). Electroantennography also demonstrated that asexual female aphids are able to detect aphid sex pheromone components. To our knowledge, this is the first time it has been reported that M. persicae virginoparae are able to detect aphid sex pheromone components or that their behavioural response and/or performance has been studied. The implications of these results and their significance in understanding semiochemical communication are discussed.

Diverse agroecosystems offer phytophagous insects a wide choice of host plants. Myzus persicae is a polyphagous aphid common in moderate climates. During its life cycle it alternates between primary and secondary hosts. A spatial genetic population structure may arise due to environmental factors and reproduction modes. The aim of this work was to determine the spatial and temporal genetic population structure of M. persicae in relation to host plants and climatic conditions. For this, 923 individuals of M. persicae collected from six plant families between 2005 and 2008 in south-eastern Spain were genotyped for eight microsatellite loci. The population structure was inferred by neighbour-joining, analysis of molecular variance (AMOVA) and Bayesian analyses. Moderate polymorphism was observed for the eight loci in almost all the samples. No differences in the number of alleles were observed between primary and secondary hosts or between geographical areas. The proportion of unique genotypes found in the primary host was similar in the north (0.961 ± 0.036) and the south (0.987 ± 0.013), while in the secondary host it was higher in the north (0.801 ± 0.159) than in the south (0.318 ± 0.063). Heterozygosity excess and linkage disequilibrium suggest a high representation of obligate parthenogens in areas with warmer climate and in the secondary hosts. The FST-values pointed to no genetic differentiation of M. persicae on the different plant families. FST-values, AMOVA and Bayesian model-based cluster analyses pointed to a significant population structure that was related to primary and secondary hosts. Differences between primary and secondary hosts could be due to the overrepresentation of parthenogens on herbaceous plants.

The ladybird beetle, Eriopis connexa (Germar) (Coleoptera: Coccinellidae), is one of the commonest predators of aphids (Hemiptera: Aphididae) in the cotton agroecosystem and in many other row and fruit crops in Brazil, and has been introduced into other countries such as the USA for purposes of aphid control. In addition, the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most serious cotton pest where it occurs, including Brazil. Controlling boll weevils and other pests such as cotton defoliators still tends to involve the intense application of insecticides to secure cotton production. The pyrethroid insecticide lambda-cyhalothrin (LCT) is commonly used, but this compound is not effective against aphids; hence, a desirable strategy would be to maintain E. connexa populations in cotton fields where LCT is applied. Using populations of E. connexa resistant (Res) and susceptible (Sus) to LCT, we compared behavioural responses on treated cotton plants and under confinement on partially and fully treated surfaces, and assessed the insects' survival on treated plants compared with that of the boll weevil. The E. connexa resistant population caged on treated plants with 15 and 75 g a.i. ha−1 exhibited ≫82% survival for both insecticide concentrations compared with ≪3% and ≪17% survival for susceptible E. connexa populations and boll weevils, respectively. The response of E. connexa Res and Sus populations when released, either on the soil or on the plant canopy, indicated avoidance towards treated plants, as measured by elapsed time to assess the plant. When compared with susceptible individuals, resistant ones took longer time to suffer insecticide knockdown, had a higher recovery rate after suffering knockdown, and spent more time in the plant canopy. Based on behavioural parameters evaluated in treated arenas, no ladybird beetles exhibited repellency. However, irritability was evident, with the susceptible population exhibiting greater irritability compared with the resistant population and a subgroup comprising resistant individuals that had recovered from knockdown. The outcomes for the E. connexa Res population indicate a promising strategy for its maintenance when using the insecticide LCT in integrated pest management schemes to control boll weevil or other non-target pest of ladybird beetles in cotton fields.