To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distinguished based on the correspondence analysis. The first one is related to human modified landscapes (such as urban, rural and industrial sites). A second is composed of species not associated with a specific habitat type, including the now widely distributed Anopheles plumbeus. A third group includes species commonly found in restored natural or bird migration areas, and a fourth cluster is composed of forest species. Outcomes of this study demonstrate the effectiveness of the designed sampling scheme and support the choice of the trap type. Obtained results of this first country-wide inventory of the Culicidae in Belgium may serve as a basis for risk assessment of emerging mosquito-borne diseases.

Despite the potential for phenological and abundance data to improve the reliability of species niche models, they are seldom used. The aim of this study was to combine information on the distribution, relative abundance and seasonal phenology of Natal fruit fly, Ceratitis rosa Karsch (Diptera: Tephritidae), in South Africa to model its potential global distribution. Bucket traps, baited with Biolure, were used to trap C. rosa in different climatic regions of South Africa over a two-year period. A CLIMEX niche model of the potential global distribution of C. rosa was fitted using the collected trapping data and other distribution records from South Africa. Independent distribution records for elsewhere in Africa were reserved for model validation. The CLIMEX model results conformed well to the South African trapping data, including information on relative abundance and seasonal phenology, as well as to the pattern of presence records of the species elsewhere in Africa. The model suggests that under recent historical conditions a large part of South America, Central America, Mexico and southern USA may be climatically suitable for establishment of C. rosa. In Europe, climatically suitable habitat is restricted to coastal regions of the Mediterranean, in Asia, mostly to the southern and south eastern countries, and in Australia mostly to the wetter south and east. The independent cross-validation provided by South African relative abundance and seasonal phenology data, central African distribution data and relevant species specific biological information provides greater confidence in the modelled potential distribution of C. rosa.

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.

The sterile insect technique (SIT) has been proposed as an area-wide method to control the South American fruit fly, Anastrepha fraterculus (Wiedemann). This technique requires sterilization, a procedure that affects, along with other factors, the ability of males to modulate female sexual receptivity after copulation. Numerous pre-release treatments have been proposed to counteract the detrimental effects of irradiation, rearing and handling and increase SIT effectiveness. These include treating newly emerged males with a juvenile hormone mimic (methoprene) or supplying protein to the male's diet to accelerate sexual maturation prior to release. Here, we examine how male irradiation, methoprene treatment and protein intake affect remating behavior and the amount of sperm stored in inseminated females. In field cage experiments, we found that irradiated laboratory males were equally able to modulate female remating behavior as fertile wild males. However, females mated with 6-day-old, methoprene-treated males remated more and sooner than females mated with naturally matured males, either sterile or wild. Protein intake by males was not sufficient to overcome reduced ability of methoprene-treated males to induce refractory periods in females as lengthy as those induced by wild and naturally matured males. The amount of sperm stored by females was not affected by male irradiation, methoprene treatment or protein intake. This finding revealed that factors in addition to sperm volume intervene in regulating female receptivity after copulation. Implications for SIT are discussed.

Invasive organisms can have major impacts on the environment. Some invasive organisms are parthenogenetic in their invasive range and, therefore, exist as a number of asexual lineages (=clones). Determining the reproductive mode of invasive species has important implications for understanding the evolutionary genetics of such species, more especially, for management-relevant traits. The willow sawfly Nematus oligospilus Förster (Hymenoptera: Tenthredinidae) has been introduced unintentionally into several countries in the Southern Hemisphere where it has subsequently become invasive. To assess the population expansion, reproductive mode and host-plant relationships of this insect, microsatellite markers were developed and applied to natural populations sampled from the native and expanded range, along with sequencing of the cytochrome-oxidase I mitochondrial DNA (mtDNA) region. Other tenthredinids across a spectrum of taxonomic similarity to N. oligospilus and having a range of life strategies were also tested. Strict parthenogenesis was apparent within invasive N. oligospilus populations throughout the Southern Hemisphere, which comprised only a small number of genotypes. Sequences of mtDNA were identical for all individuals tested in the invasive range. The microsatellite markers were used successfully in several sawfly species, especially Nematus spp. and other genera of the Nematini tribe, with the degree of success inversely related to genetic divergence as estimated from COI sequences. The confirmation of parthenogenetic reproduction in N. oligospilus and the fact that it has a very limited pool of genotypes have important implications for understanding and managing this species and its biology, including in terms of phenotypic diversity, host relationships, implications for spread and future adaptive change. It would appear to be an excellent model study system for understanding evolution of invasive parthenogens that diverge without sexual reproduction and genetic recombination.

Two Macrolophus species, M. melanotoma (=M. caliginosus) and M. pygmaeus, have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants (Dittrichia viscosa and tomato) through crossing experiments. Then, using multivariate morphometric analysis, we proposed a linear discriminant function that combines head measurements separating males from the two species without error. Finally, we designed specific primers for a mitochondrial DNA region that were able to distinguish field-collected Macrolophus individuals through conventional PCR. In conclusion, the tools developed in the present study will allow reliable identification of the Macrolophus species present in crops and in the native flora that are the source of populations that colonise them. They will also allow correct identification of mass reared Macrolophus to be introduced in greenhouse crops in inoculative releases.

In pest management programmes that incorporate the sterile insect technique (SIT), the ability of mass-reared insects to tolerate dry conditions may influence their survival after release in the field. In the present study, desiccation resistance of adult mass-reared Queensland fruit flies, Bactrocera tryoni (Frogatt) (Diptera: Tephritidae), that are routinely released in SIT programmes was compared with that of wild flies at 1, 10 and 20 days after adult eclosion. Under dry conditions without access to food or water, longevity of mass-reared B. tryoni was significantly less than that of their wild counterparts. Desiccation resistance of mass-reared flies declined monotonically with age, but this was not the case for wild flies. The sharp decline in desiccation resistance of mass-reared flies as they aged was likely explained by decreased dehydration tolerance. As in an earlier study, desiccation resistance of females was significantly lower than that of males but this was particularly pronounced in mass-reared females. Female susceptibility to dry conditions corresponded with declining dehydration tolerance with age and associated patterns of reproductive development, which suggests that water content of their oocyte load is not available for survival during periods of water stress.

Megaplatypus mutatus (=Platypus sulcatus Chapuis) is an Ambrosia beetle native to South America, which was recently introduced in Italy and its presence there is causing severe damage to the local poplar plantations. The male M. mutatus pheromone is composed of (S)-(+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone) and 3-pentanol. A series of field trials testing dose, blend and enantiomer composition performed in Argentina and Italy evaluated attraction and found that the optimal release rate of pheromone components as baits in cross vane baited traps (CIPEIN-CV) was 6, 6 and 30 mg day−1 of sulcatone, (+)-sulcatol and 3-pentanol, respectively. It was also determined that racemic sulcatol is as effective as the pure (+)-isomer for the purpose of beetle catch, due to the inert nature of the (−)-isomer allowing the usage of low cost racemic sulcatol instead of highly expensive (+)-sulcatol. The results of our work contribute to the development of pheromone-based local technologies with low environmental impact and low cost for control or monitoring of an important pest.

Transgenic maize, Zea maize L., expressing the Cry1F protein from Bacillus thuringiensis has been registered for Spodoptera frugiperda (J. E. Smith) control since 2003. Unexpected damage to Cry1F maize was reported in 2006 in Puerto Rico and Cry1F resistance in S. frugiperda was documented. The inheritance of Cry1F resistance was characterized in a S. frugiperda resistant strain originating from Puerto Rico, which displayed >289-fold resistance to purified Cry1F. Concentration–response bioassays of reciprocal crosses of resistant and susceptible parental populations indicated that resistance is recessive and autosomal. Bioassays of the backcross of the F1 generation crossed with the resistant parental strain suggest that a single locus is responsible for resistance. In addition, cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba, Cry2Aa and Vip3Aa was assessed in the Cry1F-resistant strain. There was no significant cross-resistance to Cry1Aa, Cry1Ba and Cry2Aa, although only limited effects were observed in the susceptible strain. Vip3Aa was highly effective against susceptible and resistant insects indicating no cross-resistance with Cry1F. In contrast, low levels of cross-resistance were observed for both Cry1Ab and Cry1Ac. Because the resistance is recessive and conferred by a single locus, an F1 screening assay was used to measure the frequency of Cry1F-resistant alleles from populations of Florida and Texas in 2010 and 2011. A total frequency of resistant alleles of 0.13 and 0.02 was found for Florida and Texas populations, respectively, indicating resistant alleles could be found in US populations, although there have been no reports of reduced efficacy of Cry1F-expressing plants.

Fopius arisanus is a solitary egg–pupal endoparasitoid that attacks several species of tephritid fruit flies, particularly Bactrocera spp. This species, indigenous from the Indo-Australian region, was introduced into Mexico for biological control purposes. From the standpoint of the ‘new associations’ concept this parasitoid has been evaluated against fruit flies in the Anastrepha complex. We investigated the specificity of F. arisanus responses to fruits infested with two species of Anastrepha. We examined whether fruit volatiles attractive to this parasitoid are induced as a result of fruit fly oviposition. We also investigated whether F. arisanus females are able to discriminate between the oviposition-induced volatiles from host eggs parasitised by conspecifics and volatiles from unparasitised eggs. All experiments were performed in a wind tunnel. Results showed that mango fruits infested with A. ludens eggs (2–3 days after egg deposition) were significantly more attractive to naïve F. arisanus females compared with non-infested fruits or fruits infested with larvae. In addition, guava fruits harbouring A. striata eggs were significantly more attractive to the parasitoid than non-infested fruits or fruits infested with larvae. Thus, the parasitoid was attracted to fruits with eggs, but fruit and fly species did not influence the parasitoid attraction. We also found that F. arisanus females were more attracted to fruits exposed to fertile A. ludens females (i.e. fruits with eggs inside) compared with fruits exposed to sterile females (i.e. fruits with no eggs inside) or fruits with mechanical damage. Parasitoid females were not attracted to A. ludens eggs. The results suggest that the presence of eggs induces volatiles that attract parasitoids. Finally, we found that F. arisanus was able to discriminate between fruits with unparasitised eggs vs. eggs parasitised by conspecifics, indicating that host discrimination could be mediated by olfactory cues.

Host specificity of Neotropical hard ticks (Acari: Ixodidae) was analyzed by using the number of hosts species for each tick species and the index of host specificity STD*, which integrates phylogenetic and ecological information. The analyses were based on 4172 records of hard ticks collected from wild and domestic tetrapods. Most tick species included in this study were associated with three to 20 host species. No tick species has been associated either with a single species or with a single genus of host. It was found that the number of host species is sensitive to sampling effort, but not the STD*. The most frequent values of STD* were between 2.5 and 3.5, which shows that the host species more frequently used by Neotropical hard tick species belong to different families or different orders. Immature stages tend to use a broader taxonomic range of hosts than adults, and the interpretation of both measures of host specificity used in this study led to the conclusion that the impact of non-endemic hosts does not alter the patterns of host specificity in Neotropical hard ticks. The index STD* showed that a high proportion of tick species has phylogenetically unrelated species as principal hosts. The conclusion reached in this work indicates that strict host specificity is not common among Neotropical hard ticks and suggests that the influence of tick ecology and evolution of habitat specificity, tick generation time, phenology, time spent off the host and the type of life-cycle could be more important than hosts species.

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.

Male contributions, both chemical and behavioural, can influence female sperm usage and reproductive success. To determine whether such male factors are subject to depletion in Coccinella septempunctata and Coccinella transversalis, we tested the effects of male mating history on male virility, as estimated by measures of mating behaviour, female reproductive success and progeny fitness, with parental age held constant. Overt measures of male mating effort (wriggling duration, number of shaking bouts and total copula duration) all diminished from virgin to 5 × mated males and were mirrored by concurrent declines in female fecundity and fertility (measured over 20 days). Paternal effects were also observed which diminished as a function of mating history, suggesting that transgenerational signals of male origin are also subject to depletion. Progeny of virgin fathers had higher rates of survival (C. transversalis) and faster development (both species) than progeny of 5 × mated fathers. Seminal fluid proteins are known to have allohormonal properties and can stimulate female fecundity and fertility in a number of insects, making them strong candidates for depletion as a function of mating activity. However, it is also possible that sperm limitation and/or reduced tactile stimulation of females by multiple-mated males may have contributed to some of the observed effects.

Telchin licus, the giant sugarcane borer, is an important pest species of sugarcane in northeast Brazil. Four subspecies of Telchin licus are recognized in Brazil based on their geographic distribution and subtle differences in wing colour pattern. Some taxa are morphologically indistinguishable, and their accurate identification is key to their efficient control. Mitochondrial genes sequences (cytochrome oxidase I and subunit 6 of the nicotinamide adenine dinucleotide dehydrogenase) were applied to delimit taxonomic entities of T. licus, and to infer the origin of a newly established population in the state of São Paulo. The molecular data indicated that specimens sampled at different regions in Brazil are morphologically cryptic but genetically isolated entities, and at least three subspecies were assigned to the sampled localities. These data also suggested that the population collected from the state of São Paulo must have a common origin with populations from northeast Brazil, which corroborate the hypothesis that ornamental plants infested with larvae of T. licus might have been transported from the northeast to the southeast regions.

The muscid Synthesiomyia nudiseta (van der Wulp, 1883) is a species with forensic importance in tropical and subtropical regions of the world. This fly has recently been introduced into southern Europe and, until now, had not been recorded in forensic cases in this region. Here, morphology of all larval instars of S. nudiseta is documented in detail by using a combination of light and scanning electron microscopy. Literature data concerning larval morphology are revised and characters allowing identification from other forensically important Muscidae are listed. The life cycle of this species was studied at four constant temperatures: 15, 20, 25 and 30 °C. Total development varied between 46.50 ± 0.97 days at 15 °C and 15.39 ± 0.32 days at 30 °C. Moreover, we report this species breeding in human corpses, for the first time in Europe, in forensic cases from autopsies at the Anatomical Forensic Institute of Madrid and the Institute of Legal Medicine of Alicante, Spain.

We tested the enemy hypothesis for gall morphology on a model system comprising two Diplolepis rose gall wasp species and their associated parasitoids. The enemy hypothesis predicts both that gall traits will influence parasitoid attack rates within species, and that galls with contrasting morphologies will support different parasitoid communities. This hypothesis is supported by studies at both intraspecific and broader taxonomic levels (i.e. between genera), but patterns remain to be explored in closely related species. Our aims were to explore the relationships between aspects of gall morphology (number of larval chambers, overall gall size and thickness of the gall wall) in each of Diplolepis mayri and D. rosae, and to explore correlations between these traits and both the presence/absence (=incidence) and attack rates imposed by parasitoids. We found in both galls that chamber number is positively correlated with gall size. In galls of D. mayri, parasitoid incidence was negatively correlated with thickness of the wall of the larval chamber, but there was no significant correlation between parasitoid attack rates and overall gall size. In D. rosae galls, parasitoid incidence was positively correlated with chamber wall thickness, but parasitoid attack rates were negatively correlated with gall size, suggesting that selection may favour the induction of galls containing more larval chambers. These results confirm that gall extended phenotypes can significantly influence enemy attack rates, consistent with the ‘enemy hypothesis’. Further, differences in gall morphology between the two Diplolepis species may underlie differences in their associated parasitoid communities – further research is required to test this hypothesis.

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.

Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an invasive citrus pest in southern California, which secretes honeydew and has the potential to spread a lethal bacterial disease, huanglongbing, of citrus. In urban citrus, Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), also an invasive pest, tends honeydew-producing hemipterans. We used field data to determine whether the mutualistic relationship between L. humile and six established species of honeydew producers may hinder or favor the establishment of D. citri and its biological control with Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in citrus via competition or mutualism for ants, respectively. In the field, L. humile and D. citri are engaged in a mutualistic relationship. Ants harvest solid honeydew secreted by psyllid nymphs and tended more than 55% of observed D. citri colonies. Linepithema humile displayed a preference hierarchy when tending honeydew producers infesting citrus. It responded equally or less intensively to D. citri than to other honeydew-producing species. Consequently, the mutualism between L. humile and D. citri was affected by the presence of other honeydew-producing species, and the percentage of D. citri colonies tended by L. humile. The number of ants per D. citri colony also decreased as the number of other honeydew producers increased. Diaphorina citri density was also affected by the presence of other honeydew producers. Both colony size and the number of D. citri nymphs counted per tree decreased as the number of other honeydew producers increased. Our results indicate that competition between honeydew producers for the mutualist ant L. humile may hinder the establishment of D. citri by possibly facilitating increased biological control.

The interplay between the host plant of an insect herbivore and an insect predator (here two-spot ladybird beetles; Adalia bipunctata (L).; Coleoptera: Coccinellidae), feeding upon such a herbivore was examined in the laboratory as factors possibly determining the differential abundance and success of green and red host races of pea aphid, Acyrthosiphon pisum Harris. The experiment comprised three treatments: two host plants (bean and clover), two treatment levels (control and predation) and three colour morph levels (green alone, red alone and green and red in mixture). Green morphs had higher fitness on the general host plant, bean Vicia faba, than on the derived host, clover (Trifolium pratense), in the absence of predation. Although green morph fitness was reduced by predation when infesting bean together with reds, there was no observable net fitness loss due to predation on clover in mixed colonies with red morphs. Red morphs exhibited fitness loss alone on both bean and clover, while clover plants seemingly prevented fitness loss in the presence of predation when red morphs were mixed with green ones. According to this scenario, when colour morphs existed as a mixed colony, the net fitness of either pea aphid morph was not influenced by predation on clover. Predators had significant effects only on red morphs on broad bean either when alone or were mixed together with green morphs. Thus, only red morphs experienced the benefits of switching from the general to the derived host red clover in the presence of predation. For green morphs, there was no apparent cost of switching host plants when they faced predation. Hence, the co-existence of green-red colour polymorphism of pea aphids on single host plants appears to be maintained by the morph gaining fitness on the derived host due to a host plant– and predation–reduction effect. These findings have important implications for understanding the ecology and evolution of host switching by different colour-plant host adapted races of pea aphids.

Arion vulgaris Moquin-Tandon 1855 is one of the most important invasive species in Europe, affecting both biodiversity and agriculture. The species is spreading in many parts of Europe, inflicting severe damage to horticultural plants and cultivated crops partly due to a lack of satisfactory and effective management solutions. Molluscicides have traditionally been used to manage slug densities, although the effects are variable and some have severe side-effects on other biota. Thus, there is a need to explore potential alternatives such as biological control. The nematode Phasmarhabditis hermaphrodita is the only biological agent that has been applied commercially so far. However, other biological control agents such as carabid beetles have also been found to be promising. In addition, some carabid species have been shown to feed on A. vulgaris in the field as well as in the laboratory. Two species in particular have been found to be important predators of A. vulgaris, and these species are also common in agricultural environments: Pterostichus melanarius and Carabus nemoralis. This study is the first to use semi-field experiments in a strawberry field, manipulating densities, to investigate how P. melanarius and C. nemoralis affect densities of A. vulgaris eggs and juveniles, respectively. Gut contents of C. nemoralis were analysed using multiplex PCR methods to detect DNA of juvenile slugs. Results show that both P. melanarius and C. nemoralis significantly affect densities of slug eggs and juvenile slugs under semi-field conditions and that C. nemoralis seems to prefer slugs smaller than one gram. Carabus nemoralis seems to be especially promising in reducing densities of A. vulgaris, and future studies should investigate the potential of using this species as a biological control agent.