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Heteroptera
Selected AbstractsSensillary morphology on the rostral apex and their possible role in prey location behaviour of the carnivorous stinkbug, Eocanthecona furcellata (Wolff) (Heteroptera: Pentatomidae)ACTA ZOOLOGICA, Issue 3 2009Pathipati Usha Rani Abstract Eocanthecona furcellata (Wolff), the carnivorous heteropteran, demonstrates interesting feeding mechanisms that suggest the involvement of the antennal and labial tip sensilla. This study was conducted to identify the morphology of various sensilla present on the labial tip of this insect using scanning electron microscopy. Four morphologically different types of trichoid sensilla comprise the largest and most numerous sensilla and occur throughout the surface of the labial tip. Three new and unique types of sensilla were discovered. Long hairs with profusely branched shafts are present at the entrance of the rostral groove. An oval-shaped peg surrounded by sensory hairs with branched shafts and a short, stout peg encircled by a group of long hair-like sensilla was found among the sensilla population of two lobes. The morphology of the new sensilla is given and possible functions of individual receptors are suggested on morphological grounds. [source] Morphology and chemical composition of metathoracic scent glands in Dolycoris baccarum (Linnaeus, 1758) (Heteroptera: Pentatomidae)ACTA ZOOLOGICA, Issue 3 2008Dilek Durak Abstract One of the general defining characters of the Heteroptera is the presence of metathoracic scent glands (MTG). Using scanning electron microscopy, the morphology of the MTG of Dolycoris baccarum (Linnaeus 1758) (Heteroptera: Pentatomidae) was studied. The MTG belong to the diastomian type. The two glandular pores located between the mesothoracic and metathoracic coxae are associated with ,mushroom-like' structures. The MTG are composed of a reservoir and a pair of lateral glands is connected to the reservoir by a duct. A groove-like structure extends downwards from the ostiole. While this structure is long and wide, its ostiole is oval. Extracts of the volatile fractions from male and female MTG secretions were analysed by capillary gas chromatography,mass spectrometry (GC-MS) and exhibited a typical pentatomid composition. Seventeen chemical compounds were detected in female secretions, whereas 13 chemical compounds were detected in the male secretions. Most chemical compounds were similar between the sexes but were different in their quantities. In this regard, the compounds identified were investigated and the biological functions of the glandular secretions were discussed. In the analyses of the MTG of females of D. baccarum, tridecane (50.97%) was a major odour component and (Z,Z)-4,16-octadecadien-1-ol acetate (0.02%) was a minor odour component. In males, tridecane (50.80%) was a major odour component and 1,2-benzenedicarboxylic acid (0.02%) was a minor odour component. [source] Pretarsal structures in Reduviidae (Heteroptera, Ins ecta)ACTA ZOOLOGICA, Issue 2 2005Christiane Weirauch Abstract A survey of pretarsal structures in Reduviidae of 22 higher-level taxa and several outgroup representatives is conducted using scanning electron microscopy (SEM) and light microscopy. Based on histology and SEM, pretarsal structures are described in detail for Rhodnius prolixus. Structures of the distal tarsomer, which appear to be functionally correlated with the pretarsus, are documented for the first time in Heteroptera. These comprise lateral oval sclerites, two campaniform sensilla and two marginal setae, observed in Reduviidae and other heteropteran taxa. The presence of a peg-like dorsomedian sensillum medially between the claws in Reduviidae and Nabidae is demonstrated. As a result of its structure and position, homology of this sensillum with the ,dorsal arolium' in other heteropteran groups is proposed. Within Reduviidae, the transformation of the peg-like dorsomedian sensillum to a campaniform sensillum, as seen in most representatives of the harpactoroid complex, is hypothesized. The first record of parempodia other than setiform within Reduviidae is noted in nymphs of Harpactorinae, which may possess lamellate parempodia. Several characters that are possibly useful for clarifying relationships among the harpactoroid groups are described and discussed. The pretarsal structures, including the unguitractor plate and the tarsal marginal setae among reduviid groups are discussed in a phylogenetic context. [source] Body size and host range in European HeteropteraECOGRAPHY, Issue 1 2000Martin Brändle We used data on body size and host range of phytophagous Heteroptera in central Europe, an inverse measure of specialisation, to analyse the relationship of body size vs specialisation: 1) we found a clear positive relationship between body size and host range using species as independent data points. 2) However, a nested analysis of variance shows that most of the variance in body size occurred at higher taxonomic levels whereas most of the variance in host specialisation occurred between species. This suggests different phylogenetic inertia of body size and specialisation. Nevertheless, using means of different higher taxonomic levels there is still a significant positive correlation between body size and host range. 3) With more sophisticated methods of correcting for the phylogenetic relatedness between species, the positive correlation between body size and host range still holds, despite the different assumptions of each method. Thus, the relationship between body size and host range is a very robust pattern in true bugs. [source] Health food versus fast food: the effects of prey quality and mobility on prey selection by a generalist predator and indirect interactions among prey speciesECOLOGICAL ENTOMOLOGY, Issue 2 2000Micky D. Eubanks Summary 1. In order to understand the relative importance of prey quality and mobility in indirect interactions among alternative prey that are mediated by a shared natural enemy, the nutritional quality of two common prey for a generalist insect predator along with the predator's relative preference for these prey was determined. 2. Eggs of the corn earworm Helicoverpa zea (Lepidoptera: Noctuidae) were nutritionally superior to pea aphids Acyrthosiphum pisum (Homoptera: Aphididae) as prey for big-eyed bugs Geocoris punctipes (Heteroptera: Geocoridae). Big-eyed bugs survived four times as long when fed corn earworm eggs than when fed pea aphids. Furthermore, only big-eyed bugs fed corn earworm eggs completed development and reached adulthood. 3. In two separate choice experiments, however, big-eyed bugs consistently attacked the nutritionally inferior prey, pea aphids, more frequently than the nutritionally superior prey, corn earworm eggs. 4. Prey mobility, not prey nutritional quality, seems to be the most important criterion used by big-eyed bugs to select prey. Big-eyed bugs attacked mobile aphids preferentially when given a choice between mobile and immobilised aphids. 5. Prey behaviour also mediated indirect interactions between these two prey species. The presence of mobile pea aphids as alternative prey benefited corn earworms indirectly by reducing the consumption of corn earworm eggs by big-eyed bugs. The presence of immobilised pea aphids, however, did not benefit corn earworms indirectly because the consumption of corn earworm eggs by big-eyed bugs was not reduced when they were present. 6. These results suggest that the prey preferences of generalist insect predators mediate indirect interactions among prey species and ultimately affect the population dynamics of the predator and prey species. Understanding the prey preferences of generalist insect predators is essential to predict accurately the efficacy of these insects as biological control agents. [source] Development of a biological control-based Integrated Pest Management method for Bemisia tabaci for protected sweet pepper cropsENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2009F. J. Calvo Abstract The tobacco whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), is a key pest in commercial sweet pepper crops in southeast Spain. Its biological control is currently based on augmentative introductions of the parasitic wasp Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae), which need to be occasionally supplemented with pesticide applications. These pesticides can be harmful for the biological control agents. Therefore, it is important to improve the current strategy by reducing dependency on pesticides. Two potential solutions are conceivable: addition of another effective biocontrol agent or application of pesticide prior to the release of biocontrol agents. The mirid bug Nesidiocoris tenuis Reuter (Heteroptera: Miridae) and the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) are promising candidates as additional biocontrol agents. The aim of the present study was to test these possible solutions in two subsequent trials, i.e., a ,selection' and an ,improvement' experiment. In the selection experiment, four treatments were compared: E. mundus, N. tenuis + E. mundus, A. swirskii + E. mundus, and A. swirskii + N. tenuis + E. mundus. Amblyseius swirskii appeared able to significantly increase effectiveness against the pest, in contrast to N. tenuis, which did not contribute to whitefly control. The best strategy was the combination of E. mundus and A. swirskii. In the improvement experiment, three treatments were compared: E. mundus, A. swirskii + E. mundus, and A. swirskii + E. mundus + pesticides. Amblyseius swirskii again proved capable of significantly reducing whitefly populations, and the implementation of pesticides before the release of the biocontrol agents was shown to increase the effectiveness against the pest even more. [source] Sexual conflicts, loss of flight, and fitness gains in locomotion of polymorphic water stridersENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2007Pablo Perez Goodwyn Abstract In insect wing polymorphism, morphs with fully developed, intermediate, and without wings are recognized. The morphs are interpreted as a trade-off between flight and flightlessness; the benefits of flight are counterbalanced by the costs of development and the maintenance of wings and flight muscles. Such a trade-off has been widely shown for reproductive and developmental parameters, and wing reduction is associated with species of stable habitats. However, in this context, the role of water locomotion performance has not been well explored. We chose seven water striders (Heteroptera: Gerridae) as a model to study this trade-off and its relation to sexual conflicts, namely, Aquarius elongatus (Uhler), Aquarius paludum (Fabr.), Gerris insularis (Motschulsky), Gerris nepalensis Distant, Gerris latiabdominis Miyamoto, Metrocoris histrio (White), and Rhagadotarsus kraepelini Breddin. We estimated the locomotion performance as the legs' stroke force, measured on tethered specimens placed on water with a force transducer attached to their backs. By dividing force by body weight, we made performance comparisons. We found a positive relationship between weight and force, and a negative one between weight and the force-to-weight ratio among species. The trade-off between water and flight locomotion was manifested as differences in performance in terms of the force/weight ratio. However, the bias toward winged or wing-reduced morphs was species dependent, and presumably related to habitat preference. Water strider species favouring a permanent habitat (G. nepalensis) showed higher performance in the apterous morph, but in those favouring temporary habitats (A. paludum and R. kraepelini) morphs' performance did not differ significantly. Males had higher performance than females in all but three species studied (namely, A. elongatus, G. nepalensis, and R. kraepelini); these three have a type II mating strategy with minimized mating struggle. We hypothesized that in type I mating system, in which males must struggle strongly to subdue the female, males should outperform females to copulate successfully. This was not necessarily true among males of species with type II mating. [source] Nutrigenomics: a case study in the measurement of insect response to nutritional qualityENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2006Thomas A. Coudron Abstract Recent developments in the area of nutrigenomics hold the promise of providing valuable information about the impact of nutrition on a wide range of biochemical parameters by investigating how nutrition alters global gene expression patterns. Our goal is to use a nutrigenomics approach to identify insect molecular markers that could be used as early indicators of insect responses to different nutritional sources. Such molecular markers could be chosen for degree of expression and evaluated for suitability as nutritional biomarkers by examining developmental and generational expression. Ideal markers would be highly expressed, manifested in the first generation within one developmental stage, and consistent over many generations. Our objective for the current study was to illustrate the potential discovery of molecular markers using Perillus bioculatus (F.) (Heteroptera: Pentatomidae), when reared on an optimal vs. suboptimal diet, and analyze the presence of differentially expressed genes resulting from those treatments. In this paper we present preliminary results of microarray and subtractive hybridization experiments that represent the feasibility of using nutrigenomics to assist in analyzing insect responses to nutritional changes and dietary quality with the intent of stimulating further studies in this area. [source] Plant preference in relation to life history traits in the zoophytophagous predator Dicyphus hesperusENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2004Juan Antonio Sanchez Abstract Dicyphus hesperus Knight (Heteroptera: Miridae) is an omnivorous predator used to control pests of greenhouse vegetables. Plant preferences and life history traits were studied using nine plant species: Lycopersicon esculentum Mill. (Solanaceae), Capsicum annuum L. (Solanaceae), Verbascum thapsus L. (Scrophulariaceae), Nepeta cataria L. (Lamiaceae), Stachys albotomentosa (Lamiaceae), Nicotiana tabacum L. (Solanaceae), Vicia sativa L. (Fabaceae), Zea mays L. (Gramineae), and Chrysanthemum coronarium L. (Asteraceae). Plants were selected from among potential target crops, natural hosts, plants used for mass rearing, and plants on which D. hesperus has not been reported. Plant preference was measured by multi-choice host plant selection and oviposition assays. Development and reproduction were measured on each of the plant species on both a plant diet alone and on a plant diet supplemented with Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs. Dicyphus hesperus females and nymphs expressed a preference for some plants over others. Plant preference ranged from low preference plants, such as Z. mays, V. sativa, C. coronarium, and C. annuum, to high preference plants such as V. thapsus, N. tabacum, and S. albotomentosa. When E. kuehniella eggs were supplied, there were few differences in the development time and fecundity of D. hesperus among plants, with the exception of corn and broad bean, where fecundity was lower. On a plant diet alone, nymphs were able to complete their development on V. thapsus, C. annuum, and N. cataria. However, mortality and development time were much lower on V. thapsus than on C. annuum and N. cataria. On most of the plant species D. hesperus did not lay any eggs when fed on a plant diet alone. On V. thapsus, females laid a few eggs and lived longer than when fed on prey. Dicyphus hesperus females tended to prefer host plants on which nymph survival without prey was greatest. [source] Temperature and Ca2+ ion as modulators in cellular immunity of the Sunn pest Eurygaster integriceps Puton (Heteroptera: Scutelleridae)ENTOMOLOGICAL RESEARCH, Issue 6 2009Arash ZIBAEE Abstract Environmental conditions in addition to divalent cations may affect the interactions between pathogens and insects. Elucidation of factors which modulate insect immune responses could be a significant part of investigations in this area. In this study, adults of Eurygaster integriceps, as the destructive pest of wheat, were kept at different temperatures in addition to injection with different concentrations of Ca2+ to find the effect on cellular immune reactions against Beauveria bassiana. Results showed that total and differentiate hemocyte numbers, nodule formation and phenoloxidase activity increased with elevation of temperature so that the higher values were obtained at 30 and 40°C at various intervals. Higher concentrations of Ca2+ ion (5 mM) caused an increase in plasmatocyte length and width especially after 60 min. Similar results were observed for nodule formation and phenoloxidase activity of E. integriceps adults after injection by B. bassiana spores and phenoloxidase activity. It is clear from the current study that thermoregulation and Ca2+ ion can positively affect the hemocyte numbers especially plasmatocytes and granulocytes, nodule formation and phenoloxidase activity in E. integriceps. The understanding of modulators of the insect immune response may directly influence novel approaches to obtain safe and effective biological control agents. [source] Comparison of the life history strategies of three Dysdercus true bugs (Heteroptera: Pyrrhocoridae), with special reference to their seasonal host plant useENTOMOLOGICAL SCIENCE, Issue 4 2005Katsuyuki KOHNO Abstract The life history strategy and seasonal host plant use of three Dysdercus bugs (D. cingulatus, D. poecilus and D. decussatus) were compared based on 2 years of twice monthly observations on Ishigaki-jima Island (24°N, 124°E) in the southernmost part of Japan. Dysdercus poecilus reproduced almost year round, exclusively on Sida rhombifolia, which bears fruit and/or seeds almost year round. Dysdercus cingulatus reproduced successively on various malvaceous and bombacaceous plant species, according to their seasonal fruiting cycles. Its robust reproduction was observed on Hibiscus makinoi during winter months and on Chorisia speciosa and Bombax ceiba in early summer, whereas small-scale reproduction was observed on various malvaceous plant species during the summer and autumn months. Dysdercus decussatus reproduced on Hibiscus tiliaceus and Thespesia populnea during the summer months, when these host plants bear abundant fruit and/or seeds, and its adults formed conspicuous aggregations without copulation on the underside of the leaves of those plants from November to the subsequent May. Each Dysdercus species showed a species-specific life history strategy according to the differences in the phenology of their host plants. [source] Patapius spinosus: First record of Leptopodidae (Heteroptera) from JapanENTOMOLOGICAL SCIENCE, Issue 4 2004Kazuo YAMAZAKI Abstract Patapius spinosus, a remarkable leptopodid bug whose body is covered with spines, was collected for the first time in Japan. This species was found in the supralittoral zone of a sandy beach in Osaka Prefecture, central Japan, in autumn 2002 and in spring 2004. Patapius spinosus is known to be distributed in the Mediterranean and North African regions, and has been introduced into North America and Chile. Its occurrence in Japan could signify either an eastern limit of its native distribution or an exotic origin. [source] First record of the emesine assassin bug genus Emesopsis (Heteroptera: Reduviidae) from Vietnam, with descriptions of two new speciesENTOMOLOGICAL SCIENCE, Issue 2 2004Tadashi ISHIKAWA Abstract The emesine assassin bug genus Emesopsis is reported from Vietnam for the first time and is briefly diagnosed, and two new species of the genus, E. longipilosa and E. albispinosa, are described. They were collected by beating dead, drooping leaves of the banana, Musa acuminata (Musaceae). [source] Seasonal changes in wing dimorphism of the lygaeid bug Dimorphopterus japonicus (Heteroptera: Lygaeidae) in relation to environmental factorsENTOMOLOGICAL SCIENCE, Issue 2 2003Rikiya SASAKI Abstract The lygaeid bug Dimorphopterus japonicus Hidaka, which mainly feeds on a eulalia, Miscanthus sinensis, shows marked wing dimorphism of brachyptery and macroptery. Its production of macropters is stimulated in rearing conditions such as high temperature, long photoperiod and crowding during the nymphal stage. In this study, we investigated the seasonal prevalence in occurrence and the seasonal change in incidence of macroptery in D. japonicus for field populations in Okayama, western Japan. The results demonstrated that nymphal density was a key factor in determining the proportion of macropters, indicating an escape strategy from crowded populations. The field surveys also revealed that this bug has a univoltine life cycle in Okayama. There was a seasonal change in the incidence of macroptery in the new generation. The combined effects of temperature and photoperiod on wing-form determination explained this seasonality trait. [source] Relative sensitivity distribution of aquatic invertebrates to organic and metal compoundsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2004Peter Carsten von der Ohe Abstract In the field, a multitude of species can be exposed to numerous toxicants; thus, the sensitivity of individual species to particular toxicants must be known to predict effects and to analyze changes in species composition. For most species, no information about their toxicant sensitivity is available. To address this limitation, we have grouped the available information to assign sensitivities to aquatic invertebrate taxa relative to Daphnia magna. With respect to organic compounds, most taxa of the orders Anisoptera, Basommatophora, Coleoptera, Decapoda, Diptera, Ephemeroptera, Eulamellibranchiata, Heteroptera, Hirudinea, Isopoda, Oligochaeta, Prosobranchia, Trichoptera, Tricladida, and Zygoptera are less sensitive than D. magna. Some taxa of the Amphipoda, Plecoptera, and Cladocera (other than D. magna) are significantly more sensitive. For organic compounds, approximately 22% of the investigated taxa were more sensitive than D. magna. Most taxa of the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera, Eulamellibranchiata, Heteroptera, Isopoda, Oligochaeta, and Tricladida are significantly less sensitive than D. magna to metal compounds. The taxa belonging to the Crustacea, with the exception of the order Isopoda, are much more sensitive. For metal compounds, approximately 30% of the investigated taxa were more sensitive than D. magna. Hence, D. magna is among the most sensitive taxa regarding both groups of toxicants. The sensitivities for several taxa are listed, and use of the relative sensitivity distribution to link toxicant effects in mesocosm studies and field investigations is discussed. [source] Trophic Egg Production in a Subsocial Shield Bug, Parastrachia japonensis Scott (Heteroptera: Parastrachiidae), and its Functional ValueETHOLOGY, Issue 12 2005Mantaro Hironaka Females of the gregarious shield bug, Parastrachia japonensis Scott (Heteroptera: Parastrachiidae) engage in extensive parental care behaviors that include egg and nymph guarding and progressive provisioning of drupes of the solitary host tree, Schoepfia jasminodora (Olacaceae: Rosidae: Santales). We noted that some eggs in every egg mass failed to turn pink and develop eye-spots indicative of developing embryos, suggesting that they are infertile, and therefore non-viable. We also observed newly hatched nymphs probing, and presumably feeding, on the egg mass remains. In the present report, through field observations and experiments involving removal of these non-viable eggs in the laboratory, we demonstrate that their presence is correlated with significant increases in nymphal weight, developmental rate and survival in the absence of other food. Thus, we conclude that an additional manifestation of the parental care behaviors that P. japonensis females use to increase their reproductive success is the production of trophic eggs. Some physical traits of the trophic eggs and their functional role in this system are discussed in the context of our current theoretical understanding of extended parental care. [source] A ,polarisation sun-dial' dictates the optimal time of day for dispersal by flying aquatic insectsFRESHWATER BIOLOGY, Issue 7 2006ZOLTÁN CSABAI Summary 1. Daily changes in the flight activity of aquatic insects have been investigated in only a few water beetles and bugs. The diel flight periodicity of aquatic insects and the environmental factors governing it are poorly understood. 2. We found that primary aquatic insects belonging to 99 taxa (78 Coleoptera, 21 Heteroptera) fly predominantly in mid-morning, and/or around noon and/or at nightfall. There appears to be at least four different types of diurnal flight activity rhythm in aquatic insects, characterised by peak(s): (i) in mid-morning; (ii) in the evening; (iii) both in mid-morning and the evening; (iv) around noon and again in the evening. These activity maxima are quite general and cannot be explained exclusively by daily fluctuations of air temperature, humidity, wind speed and risks of predation, which are all somewhat stochastic. 3. We found experimental evidence that the proportion (%) P(,) of reflecting surfaces detectable polarotactically as ,water' is always maximal at the lowest (dawn and dusk) and highest (noon) angles of solar elevation (,) for dark reflectors while P(,) is maximal at dawn and dusk (low solar elevations) for bright reflectors under clear or partly cloudy skies. 4. From the temporal coincidence between peaks in the diel flight activity of primary aquatic insects and the polarotactic detectability P(,) of water surfaces we conclude that the optimal times of day for aquatic insects to disperse are the periods of low and high solar elevations ,. The , -dependent reflection,polarisation patterns, combined with an appropriate air temperature, clearly explain why polarotactic aquatic insects disperse to new habitats in mid-morning, and/or around noon and/or at dusk. We call this phenomenon the ,polarisation sun-dial' of dispersing aquatic insects. [source] Insects in a warmer world: ecological, physiological and life-history responses of true bugs (Heteroptera) to climate changeGLOBAL CHANGE BIOLOGY, Issue 8 2007DMITRY L. MUSOLIN Abstract Focusing on the southern green stink bug, Nezara viridula (Pentatomidae), in central Japan the effects of climate change on true bugs (Insecta: Heteroptera) are reviewed. In the early 1960s, the northern edge of the species's distribution was in Wakayama Prefecture (34.1°N) and distribution was limited by the +5°C coldest month (January) mean temperature isothermal line. By 2000, N. viridula was recorded 70 km further north (in Osaka, 34.7°N). Historical climate data were used to reveal possible causes of the northward range expansion. The increase of mean and lowest winter month temperatures by 1,2°C in Osaka from the 1950s to the 1990s improved potential overwintering conditions for N. viridula. This promoted northward range expansion of the species. In Osaka, adult diapause in N. viridula is induced after mid-September, much later than in other local seed-feeding heteropterans. This late diapause induction results in late-season ineffective reproduction: some females start oviposition in autumn when the progeny have no chance of attaining adulthood and surviving winter. Both reproductive adults and the progeny die. A period from mid-September to early November represents a phenological mismatch: diapause is not yet induced in all adults, but it is already too late to start reproduction. Females that do not start reproduction but enter diapause in September have reduced postdiapause reproductive performance: they live for a shorter period, have a shorter period of oviposition and produce fewer eggs in smaller egg masses compared with females that emerge and enter diapause later in autumn. To some extent, N. viridula remains maladapted to Osaka environmental conditions. Ecological perspectives on establishment in recently colonized areas are discussed. A review of available data suggests that terrestrial and aquatic Heteroptera species respond to climate change by shifting their distribution ranges, changing abundance, phenology, voltinism, physiology, behaviour, and community structure. Expected responses of Heteroptera to further climate warming are discussed under scenarios of slight (<2°C) and substantial (>2°C) temperature increase. [source] The fatty acid compositions of predator Piocoris luridus (Heteroptera: Lygaeidae) and its host Monosteria unicostata (Heteroptera: Tingidae) reared on almondINSECT SCIENCE, Issue 6 2007OZLEM CAKMAK Abstract The changes in fatty acid compositions during nutritional interaction among almond Amygdalus communis Linnaeus (Rosales: Rosaceae) (host plant), lacebug Monosteria unicostata (Mulsant and Rey) (Heteroptera: Tingidae) and its predator Piocoris luridus Fieber (Heteroptera: Lygaeidae) were determined by gas chromatography and gas chromatography-mass spectrometry analyses. The fatty acid profiles of phospholipids and triacylglycerols were substantially different. Unlike the general observations for virtually most terrestrial insects, arachidonic and eicosapentaenoic acids were detected in high proportions of phospholipid fractions in both insects, especially in P. luridus. Also the almond tissues provide very little oleic acid to the herbivore diet, yet both insect species developed high proportions of this component. Our data reveals instances of specific accumulation of fatty acid biosynthesis, elongation/desaturation, and not incorporating selected fatty acids into cellular lipids. [source] Single host trees in a closed forest canopy matrix: a highly fragmented landscape?JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2007J. Müller Abstract:, Whether trees represent habitat islands and therefore are influenced by similar biogeographic processes as ,real' islands is controversial. For trees in highly fragmented landscapes the impacts of spatial isolation on arthropod communities have already been demonstrated. However, we have almost no evidence that in large forests the arthropod communities on single trees in a closed canopy matrix are influenced by similar processes. In the present study the influence of spatial isolation on the specialized oak crown fauna was analysed in a large broadleaved forest area in northern Bavaria, Germany. The dependence of specialists on the proportion of oaks in the surrounding forest was investigated by using flight interception traps (67 on oak, 19 on beech). As target species, saproxylic and herbivorous Coleoptera and Heteroptera were sampled. The following two hypotheses were tested: (1) The proportion of oak specialists differs for oaks in beech forests and oaks in oak forests. (2) The proportion of oak specialists increases with the proportion of oaks in the surrounding forest. For all species groups, the proportion of oak specialists was higher in oak crowns than in beech crowns. Herbivorous beetles and true bugs showed a higher proportion of specialists in oak forests than on single oaks in beech forests. The proportion of herbivorous oak specialists increased significantly with increasing numbers of adjacent oak trees, while saproxylic Coleoptera showed no relationship to oak density. For herbivorous Coleoptera a threshold of higher proportion occurred where >30% oak was present, and for Heteroptera a first threshold was identified at values >70% and a second at >30%. This indicates that larger habitat patches within a closed forest canopy matrix support larger populations of herbivorous oak specialists. Hence, similar effects of spatial isolation might occur in a closed forest as have already been shown for highly fragmented open landscapes. [source] Effect of day length on development and reproductive diapause in Nysius huttoni White (Heteroptera, Lygaeidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2004X. Z. He Abstract:,Nysius huttoni White is endemic to New Zealand and an important pest of wheat and brassica crops. To provide critical information for pest forecast, management and quarantine inspection, we investigated the effect of day length on the growth, development and reproductive diapause of this pest under a series of photoperiodic regimes: 16 : 8, 14 : 10, 12 : 12 and 10 : 14 h [light : dark (L : D)]. Long day lengths [16 : 8 and 14 : 10 h (L : D)] promote a continuous lifecycle while short day lengths [12 : 12 and 10 : 14 h (L : D)] slow up the growth and development, prolong the pre-mating period, and induce the reproductive diapause. The absence of oviposition for approximately 30 days is recognized as the criterion for N. huttoni reproductive diapause definition. When all life stages are kept under the short day length conditions, only 60,73% of females enter reproductive diapause; if the exposure to short day lengths starts in late instar nymphs, 100% of females enter reproductive diapause. If only adults experience short day lengths, does diapause incidence fall in between, with up to 26% of females laying a few eggs before entering diapause. The critical photoperiod for the induction of reproductive diapause falls between 13.3 : 10.7 and 13.5 : 10.5 h. [source] Chemical ecology of triatomine bugs: vectors of Chagas diseaseMEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2001L. Cruz-López Abstract. Knowledge of chemical ecology of haematophagous triatomine bugs (Hemiptera: Heteroptera: Reduviidae) could be of practical value because this polyphyletic subfamily includes species of medical importance, such as vectors of Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae), the aetiological agent of Chagas disease. For particular species of Dipetalogaster, Panstrongylus, Rhodnius and Triatoma, therefore, we review information on exocrine glands and products, interpreting their apparent roles as semiochemicals in the aggregation, alarm, defence, host-finding and sexual behaviour of these Triatominae. [source] A new species of the family Hypsipterygidae from Vietnam, with notes on the hypsipterygid fore wing venation (Heteroptera, Dipsocoromorpha)MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2007Dávid Rédei Abstract Hypsipteryx vasarhelyii sp. n., belonging to the small dipsocoromorphan family Hypsipterygidae previously containing only three recent and one fossil species, is described from the southern part of Vietnam. The new species was extracted from Berlese samples collected in a mixed forest of pines and broad-leaf trees. It seems to be more closely related to the two African species, H. machadoi Drake, 1961 and H. ugandensis ,tys, 1970 than to the Oriental H. ecpaglus Drake, 1961. An identification key to all known species of Hypsipterygidae is provided. The homologies of the wing venation of recent and fossil Hypsipteryx are discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Stalireduvius, a new harpactorine genus (Heteroptera, Reduviidae) from VietnamMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2004Masaaki Tomokuni Abstract A new harpactorine reduviid, Stalireduvius nodipes Tomokuni & Cai, gen. et sp. nov., from Vietnam is described. A key to related genera is provided. [source] A review of the genus Henricohahnia Breddin (Heteroptera, Reduviidae, Harpactorinae) from ChinaMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 2 2003Wanzhi Cai Abstract The species of the genus Henricohahnia Breddin from China are reviewed. Six species are recognized, described or redescribed, illustrated and keyed. H. obscara Cai et Li is described as new species. [source] Egg performance on an egg-carrying bug.OIKOS, Issue 2 2001Experiments in the field Selection of oviposition sites has direct influence on female fitness. Differences in offspring survival among sites should favour females to select oviposition sites with the highest survival. Golden egg bug females (Phyllomorpha laciniata; Coreidae, Heteroptera) use conspecifics as oviposition substrates. Most eggs are laid on the back of the bug but they can be found on all body parts. Females never carry their own eggs, and males commonly carry eggs received without copulation with the donor. We examined differences in egg survival relative to paternity to the egg, host sex and body size and attachment of an egg on a host's body in the field. We also studied which bugs received eggs. Egg loss was surprisingly common: 30,80% of recaptured individuals lost eggs during a six-day period. Unexpectedly, host's paternity to the eggs did not affect egg survival. Also, egg loss did not differ among hosts in respect to other parameters studied. Males received more eggs than females, but survival of the eggs was not better on a male's back than on a female's back. Since egg loss is common in the golden egg bug, we suggest that female oviposition strategy to lay eggs on conspecifics is not perfect. This is due to active behaviour of potential hosts (for example, rejected oviposition attempts) or lack of suitable oviposition substrates (conspecifics) in the field. Since eggs do not survive unless carried, females may be acting opportunistically, doing the best job possible by laying eggs on available conspecifics. [source] Intraclutch egg-size variation in acanthosomatid bugs: adaptive allocation of maternal investment?OIKOS, Issue 2 2001Shin-ichi Kudo If there are differences in predation risk among the offspring within a clutch, parents may allocate less resources to the offspring facing higher risk. I examined parental investment in terms of egg size within clutches in five species of stink bugs (Heteroptera, Acanthosomatidae). In subsocial Elasmucha and Sastragala species, the female guards her eggs and first-instar nymphs against invertebrate predators by covering her clutch with her body. Large differences in survival from predation between offspring at the centre and offspring at the periphery of the clutch have been reported in such subsocial insects. I found that Elasmucha and Sastragala females laid significantly smaller eggs in the peripheral (and thus more vulnerable) part of the clutch. Phenotypic trade-offs between egg size and clutch size were detected in these subsocial species. Egg size was positively correlated with hatched first-instar nymph size: smaller nymphs hatched from smaller peripheral eggs. In asocial Elasmostethus humeralis, however, no significant difference in size was detected between the eggs at the centre of and those at the periphery of the clutch. Thus, in subsocial acanthosomatid bugs, females seem to allocate their resources according to the different predation risks faced by the offspring within the clutch. [source] The adipokinetic hormones of Heteroptera: a comparative studyPHYSIOLOGICAL ENTOMOLOGY, Issue 2 2010DALIBOR KODRÍK The adipokinetic hormones (AKHs) from 15 species of heteropteran Hemiptera (encompassing eight families, six superfamilies and three infraorders) have been isolated and structurally identified using liquid chromatography coupled with mass spectrometry. None of the structures are novel and all are octapeptides. These peptide sequence data are used, together with the previously available AKH sequence data on Heteroptera, to create a larger dataset for comparative analyses. This results, in total, in AKH sequences from 30 species (spanning 13 families), which are used in a matrix confronted with the current hypotheses on the phylogeny of Heteroptera. The expanded dataset shows that all heteropterans have octapeptide AKHs; three species have two AKHs, whereas the overwhelming majority have only one AKH. From a total of 11 different AKH peptides known from Heteroptera to date, three AKHs occur frequently: Panbo-red pigment-concentrating hormone (RPCH) (×10), Schgr-AKH-II (×6) and Anaim-AKH (×4). The heteropteran database also suggests that particular AKH variants are family-specific. The AKHs of Heteroptera: Pentatomomorpha (all terrestrial) are not present in Nepomorpha (aquatic) and Gerromorpha: Gerridae (semiaquatic); AKHs with a Val in position 2 are absent in the Pentatomomorpha (only AKHs with Leu2 are present), whereas Val2 predominates in the nonterrestrial species. An unexpected diversity of AKH sequences is found in Nepomorpha, Nepoidea, Nepidae and Nepinae, whereas Panbo-RPCH (which has been identified in all infraorders of decapod crustaceans) is present in all analysed species of Pentatomidae and also in the only species of Tessaratomidae investigated. The molecular evolution of Heteroptera with respect to other insect groups and to crustaceans is discussed [source] Photoperiodic and temperature control of nymphal development and induction of reproductive diapause in two predatory Orius bugs: interspecific and geographic differencesPHYSIOLOGICAL ENTOMOLOGY, Issue 4 2008DMITRY L. MUSOLIN Abstract The effects of day-length and temperature on pre-adult growth and induction of reproductive diapause are studied in Orius sauteri and Orius minutus (Heteroptera: Anthocoridae) from northern (43.0°N, 141.4°E) and central (36.1°N, 140.1°E) Japan. In the north, at 20 °C, pre-adult growth is slower under an LD 14 : 10 h photoperiod than under shorter or longer photophases. At 24 and 28 °C, the longer photophases result in shorter pre-adult periods. Acceleration of nymphal growth by short days in autumn appears to be adaptive. In the central region, this response is less pronounced, suggesting that timing of adult emergence is less critical than in the north. Day length also influences the thermal requirements for pre-adult development. The slope of the regression line representing temperature dependence of pre-adult development is significantly smaller and the lower development threshold (LDT) is significantly lower under an LD 12 : 12 h photoperiod than under long-day conditions. The weaker dependence of nymphal growth on temperature and the lower LDT in autumn might be adaptive. In the north, increased temperature shifts the critical day length of diapause induction and suppresses the photoperiodic response in O. sauteri but not in O. minutus. Further south, the incidence of diapause in both species is low even under short-day conditions but the same interspecific difference is observed (i.e. increase of temperature affects the response in O. sauteri but not in O. minutus). This suggests seasonally earlier diapause induction with weaker temperature dependence in O. minutus than in O. sauteri. [source] Oviposition habitat selection by mosquitoes in response to predator (Notonecta maculata) densityPHYSIOLOGICAL ENTOMOLOGY, Issue 2 2004Avi Eitam Abstract., Some species of mosquitoes can detect the presence of predatory notonectid bugs and avoid oviposition in predator pools. The oviposition response of two mosquito species, Culiseta longiareolata Macquart and Culex laticinctus Edwards (Diptera: Culicidae), to a range of densities of the predator, Notonecta maculata Fabricius (Heteroptera: Notonectidae), was tested here. Densities of 0, 1, 2 or 4 Notonecta were established in 30-L artificial pools. Both mosquito species oviposited less in predator pools, but the response was unrelated to predator density, whereas vulnerability of Culiseta immatures to predation was density-dependent. Thus, although mosquitoes can detect Notonecta at any density within the range tested, they may be unable to discriminate among predator densities. The avoidance of predator pools by Culiseta, as well as its vulnerability to predation, occurred to a lesser degree than in earlier studies. This may have been due to the mitigating effects of components of the biotic community. [source] | |||||||||||||||||||||||||