Fulltext search in archive



« advanced mode »

 previous    ...   12   13   14   15   16  17   18   19   20   21   ...    next 

Results 451 to 480 of 1601:

A synthesis of feeding habits and reproduction rhythm in Italian seed-feeding ground beetles (Coleoptera: Carabidae)Review

Federica TALARICO, Anita GIGLIO, Roberto PIZZOLOTTO, Pietro BRANDMAYR

Eur. J. Entomol. 113: 325-336, 2016 | DOI: 10.14411/eje.2016.042

Many species of carabid beetles are important pre- and post-dispersal seed feeders of herbaceous plants. Here we summarise data from dissections, field observations, rearing and "cafeteria" experiments on 55 granivorous and 188 omnivorous species that occur in Italy. We tested the hypothesis that seed feeding carabids are restricted to taxa with pronounced morphological adaptations for manipulating and crushing seeds in both the larval and adult stages. The feeding guilds of carabids were rearranged into the following groups: (i) strict predators with long mandibles and predaceous larvae, often depending also on non-prey food; (ii) omnivorous species with stout mandibles and larvae of a seed-eating morphotype; (iii) granivorous species, feeding only on seeds with larvae sometimes of the scarabeoid c-form type. The seed feeding carabids in the Italian fauna belong to the tribe Zabrini (Amara and Zabrus genera) and to all the Harpalinae (sub)tribes, from Anisodactylini to Ditomina. The time of reproduction seems to be associated with habitat preference; wetland or dry open land, rather than true granivorous versus omnivorous habits, but in stenophagous seed feeders, a phenological coincidence with particular plants is sometimes recorded.

Niche partitioning in tenebrionid species (Coleoptera: Tenebrionidae) inhabiting Mediterranean coastal dunesOriginal article

Simone FATTORINI, Davide BERGAMASCHI, Cristina MANTONI, Alicia T.R. ACOSTA, Andrea DI GIULIO

Eur. J. Entomol. 113: 462-468, 2016 | DOI: 10.14411/eje.2016.060

We analyzed the abundance, distribution and niche overlap of species (Pianka's Ojk index) in tenebrionid beetle communities inhabiting different biotopes in Tyrrhenian and Adriatic sand dunes. The rank abundance distribution of the different species has the form of a geometric series in both communities as predicted by the niche preemption hypothesis for communities in harsh environments. Mean niche overlap values did not deviate significantly from null expectations, which indicates random interspecific interactions. These results, coupled with evidence of species habitat preferences, led us to conclude that the community organization of tenebrionid species inhabiting coastal dunes is determined more by habitat preferences than interspecific competition.

Depilation increases while hairiness decreases the risk of drowning: A hitherto unappreciated survival role of setae in woolly bear caterpillars of the moth Lemyra imparilis (Lepidoptera: Noctuoidea: Erebidae)Note

V. Benno MEYER-ROCHOW

Eur. J. Entomol. 113: 130-134, 2016 | DOI: 10.14411/eje.2016.016

This note aims to put on record a hitherto unreported function of caterpillar setae supplementary to those already known. When woolly bear caterpillars of the moth Lemyra imparilis (Butler) have their body hairs removed and are dropped into a bucket of water from a height of 30 cm, they sink immediately. Caterpillars, however, with an intact coat of hairs usually float. This hitherto unreported role of caterpillar setae as life-rafts should depend on a high contact angle θe, and thus on the position, density and dimensions of the hairs. An SEM examination of the surface structure of the setae revealed a system of fine grooves and small distally pointing barbs on the hair shaft, which can trap air to support the weight of the insect. Insect setae generally and body hairs of caterpillars in particular are known to possess many functions, but a role as life-rafts for caterpillars in danger of drowning can now be added to the list of possible uses of body hairs.

Molecular evidence resolving the confusion of two species of Spilopteron (Hymenoptera: Ichneumonidae) caused by marked geographical colour variation

Masato ITO, Kyohei WATANABE, Kaoru MAETO

Eur. J. Entomol. 112 (3): 543-556, 2015 | DOI: 10.14411/eje.2015.068

The delimitation of two ichneumonid species, Spilopteron apicale (Matsumura) and S. tosaense (Uchida), was investigated using DNA sequences of the mitochondrial COI and nuclear 28S rRNA genes, as well as adult morphology. The two species have long been confused and were until recently speculated to be the same species with continuous colour variation. Our molecular and morphological studies reveal that there are two distinct species: a dark species confined to northern or high latitude localities (S. apicale) and a widely distributed species with a marked geographical gradient in body colour (S. tosaense) across the Japanese Archipelago. In the latter species, female body colour became significantly darker with latitude and altitude. A lectotype of Chorischizus apicalis Matsumura, 1912 is designated.

Electrophysiological and behavioural responses of female Isoceras sibirica (Lepidoptera: Cossidae) to volatiles produced by the plant, Asparagus officinalisOriginal article

Hongxia LIU, Zhixiong LIU, Haixia ZHENG, Zerong JIN, Jintong ZHANG

Eur. J. Entomol. 114: 101-105, 2017 | DOI: 10.14411/eje.2017.014

In herbivorous insects plant volatiles have an important role in locating mates and oviposition sites. The aim of this study was to test the antennal and behavioural responses of females of Isoceras sibirica Alpheraky (Lepidoptera: Cossidae) to the volatiles produced by Asparagus officinalis L. Electroantennographs (EAG) revealed that the antennae of I. sibirica respond in a dose dependent way to hexanal, limonene, 2-ethyl-2-hexenal, linalool and α-terpineol. In flight tunnel experiments, 2-ethyl-2-hexenal, α-terpineol, hexanal, ρ-cymene and geraniol were significantly more attractive to females of I. sibirica than other chemicals. These findings indicate that host volatiles are important for host recognition in I. sibirica.

Protogyny after hibernation and aestivation in Cheilomenes sexmaculata (Coleoptera: Coccinellidae) in central JapanNote

Yasuko KAWAKAMI, Kazuo YAMAZAKI, Kazunori OHASHI

Eur. J. Entomol. 114: 275-278, 2017 | DOI: 10.14411/eje.2017.033

Differences in the time of occurrence of both sexes of adult ladybirds, which reflect differences in the longevity and reproductive strategies of the sexes, is important from the perspective of applied entomology, including biological control, as well as basic entomology. Nevertheless, there is little field census data on this topic. We investigated the seasonal occurrence of both sexes of Cheilomenes sexmaculata (Fabricius) in Osaka City, central Japan, from 2003 to 2011. Female adults tended to appear earlier than males after hibernation or aestivation. That males never appeared earlier than females during the nine year period of this study indicate that protogyny occurs after hibernation and aestivation in this species.

Benign neglect enhances urban habitat heterogeneity: Responses of vegetation and carabid beetles (Coleoptera: Carabidae) to the cessation of mowing of park lawns

Stephen VENN, D. Johan KOTZE

Eur. J. Entomol. 111 (5): 703-714, 2014 | DOI: 10.14411/eje.2014.089

In this study, we investigate the changes in both vascular plant and carabid beetle assemblages in response to reducing the intensity of management of park lawns in the city of Helsinki. Three levels of mowing were applied to patches of previously managed park lawns: (1) intensively mown, (2) mown until the previous season and unmanaged since, and (3) unmanaged for ten years (benign neglect). The lawns were dominated by plants that disperse vegetatively. This treatment gradient had little or no effect on the flight capability, feeding type or body-size of carabid beetles. However, there was an increase in species richness and the numbers of stenotopic species in the benign neglect treatment. We conclude that benign neglect of open grassland vegetation will result in higher levels of biodiversity than in more intensely managed vegetation. However, we consider it likely that the optimal strategy for maintaining urban biodiversity would be to apply a meadow management regime of mowing once or twice per year and leaving some areas of unmanaged grassland to maintain habitat heterogeneity.

New species of Cicadocoris (Hemiptera: Coleorrhyncha: Progonocimicidae) from mid-Jurassic deposits in northeastern ChinaOriginal article

Jia-Qian JIANG, Di-Ying HUANG

Eur. J. Entomol. 114: 355-364, 2017 | DOI: 10.14411/eje.2017.045

A new progonocimicid bug named Cicadocoris parvus sp. n. is described from the mid-Jurassic Haifanggou Formation at Daohugou, Ningcheng County, Inner Mongolia, northeastern China. It differs from other species by being distinctly smaller, veins dSc, R1 and Rs run parallel to one another and are nearly evenly spaced on left tegmen, widest length of apical half/basal half of left tegmen is 1.1 and that of right tegmen is 1.0. Thus, there are at least three species of Cicadocoris (Progonocimicidae) described from Daohugou. All these species are relatively abundant in the Haifanggou Formation and are remarkable representatives of the early Yanliao biota.

Pharmacological analysis of the feeding response of codling moth (Cydia pomonella; Lepidoptera: Tortricidae) neonates to bitter compoundsOriginal article

Maciej A. PSZCZOLKOWSKI

Eur. J. Entomol. 114: 500-506, 2017 | DOI: 10.14411/eje.2017.063

Feeding in codling moth neonate caterpillars was inhibited by 0.67 mM and 2.24 mM concentrations of denatonium benzoate. This inhibitory effect was abolished by phospholipase C inhibitor, U-73122 and the phosphodiesterase inhibitor, Rolipram. Quinine and quinidine did not have inhibitory effects at concentrations as high as 1.64 mM and 0.43 mM, respectively. The inhibitory effect of denatonium was partially reversed in the presence of the calcium ion chelator, EGTA, at concentrations ranging from 2.5 µM to 250 µM. These results indicate that transduction of the taste of denatonium in codling moth neonates relies on signalling pathways that involve phospholipase C, phosphodiesterase and calcium ion influx into cells.

Benthic communities in inland salinized waters with different salinities and nutrient concentrations and the ecology of Chironomus aprilinus (Diptera: Chironomidae) in the Czech RepublicOriginal article

Josef MATĚNA, Iva ŠÍMOVÁ, Jakub BROM, Kateřina NOVOTNÁ

Eur. J. Entomol. 113: 122-129, 2016 | DOI: 10.14411/eje.2016.015

The macrozoobenthos in saline pools at dumps in a former coal mining area was studied over a period of two years. Due to specific environmental conditions these pools are unique in the Czech Republic. Extremely high values of salinity (up to 11‰) along with a low concentration of dissolved phosphorus (0.01-0.1 mg.l-1) are typical of some of the water in this area. The pools were grouped into three categories based on their conductivity values and treated using cow dung, municipal wastewater treatment sludge and inorganic NPK (nitrogen-phosphorus-potassium) fertilizer at doses recommended for carp ponds. The application of fertilizer had a positive effect on the density and biomass of all the groups in the macrozoobenthos. The highest and the lowest increases in macrozoobenthos biomass were recorded after the application of NPK and cow dung, respectively. However, the application of fertilizer had no effect on the diversity of macrozoobenthos. Chironomus aprilinus, recorded in the Czech Republic for the first time, inhabited all pools with conductivity ranges of between 5,000-16,000 µS.cm-1. The density of C. aprilinus larvae increased with increasing salinity reaching a maximum of about 17,083 ind.m-2 (biomass - 82 g.m-2). Analysis of C. aprilinus phenology revealed a bivoltine pattern with the summer generation of larvae reaching a maximum in June-July and the overwintering generation in October to November.

Northern geometrid forest pests (Lepidoptera: Geometridae) hatch at lower temperatures than their southern conspecifics: Implications of climate changeOriginal article

Julia FÄLT-NARDMANN, Tero KLEMOLA, Mechthild ROTH, Kai RUOHOMÄKI, Kari SAIKKONEN

Eur. J. Entomol. 113: 337-343, 2016 | DOI: 10.14411/eje.2016.043

Climate change may facilitate shifts in the ranges and the spread of insect pests, but a warming climate may also affect herbivorous insects adversely if it disrupts the locally adapted synchrony between the phenology of insects and that of their host plant. The ability of a pest species to colonize new areas depends on its ability to adjust the timing of phenological events in its life cycle, particularly at high latitudes where there is marked seasonality in temperature and day length. Here we incubated eggs of three species of geometrid moth, Epirrita autumnata, Operophtera brumata and Erannis defoliaria from different geographical populations (E. autumnata and O. brumata from Northern Finland, E. autumnata and E. defoliaria from Southern Finland and all three species from Germany) in a climate chamber at a constant temperature to determine the relative importance of geographic origin in the timing of egg hatch measured in terms of cumulative temperature sums (degree days above 5°C, DD5); i.e. the relative importance of local adaptation versus phenotypic plasticity in the timing of egg hatch. In all three species, eggs from northern populations required a significantly lower temperature sum for hatching than eggs from southern populations, but the differences between them in temperature sum requirements varied considerably among species, with the differences being largest for the earliest hatching and northernmost species, E. autumnata, and smallest for the southern, late-hatching E. defoliaria. In addition, the difference in hatch timing between the E. autumnata eggs from Southern Finland and Germany was many times greater than the difference between the two Finnish populations of E. autumnata, despite the fact that the geographical distances between these populations is similar. We discuss how these differences in hatching time may be explained by the differences in hatch-budburst synchrony and its importance for different moth species and populations. We also briefly reflect on the significance of photoperiod, which is not affected by climate change. It is a controller that works parallel or in addition to temperature sum both for egg hatch in moths and bud burst of their host plants.

Trophic induction of diapause in native and invasive populations of Harmonia axyridis (Coleoptera: Coccinellidae)Original article

Antonina A. OVCHINNIKOVA, Andrey N. OVCHINNIKOV, Margarita Yu. DOLGOVSKAYA, Sergey Ya. REZNIK, Natalia A. BELYAKOVA

Eur. J. Entomol. 113: 469-475, 2016 | DOI: 10.14411/eje.2016.061

Ovipositing females from invasive (Krasnodar Territory of Russia) and native (Far East of Russia) populations of Harmonia axyridis were fed one of a set of diets ranging from 50 Myzus persicae aphids every day to 1 aphid every 10 days and all were also provided with a 10% sugar solution. The experiment was conducted at 20°C under short (12 h) and long (18 h) day conditions. Most of the females from the native population that consumed 50 or 10 aphids per day continued to oviposit under both long and short day conditions. Females that consumed 1 aphid per day or every 2 days practically stopped laying eggs but under long day conditions their ovaries were still active, whereas under short day conditions ca 50% of them were reproductively inactive (only germaria present) and had a well-developed fat body. Further reduction in diet resulted in an increase in the proportion of reproductively inactive females. However, about half of the females that terminated oogenesis under long day conditions had poorly developed fat bodies, which indicates that diapause was not induced. For the females from the invasive population, both photoperiodic and trophic effects were weak: under short day conditions, some females entered diapause when prey was abundant, whereas about 50% (independent of photoperiod) did not enter diapause when starved. This risk-spreading strategy, possibly, facilitates the adaptation of this invasive ladybird to unpredictable environmental conditions.

Temporal variations in the life-cycles of aphids (Sternorrhyncha: Aphididae) and their coccinellid predators

Mohamed El Fodhil AROUN, Bahia DOUMANDJI-MITICHE, Daniel PETIT, Zahr-Eddine DJAZOULI

Eur. J. Entomol. 112 (3): 432-439, 2015 | DOI: 10.14411/eje.2015.060

Aphids are either monoecious living either on trees or herbaceous plants, or heteroecious, which involves host alternating between a tree (primary host) and a herbaceous plant (secondary host). We described the temporal variations in abundance and richness of aphids in an Algerian orchard, over a 6 month period. We recorded the choice of basin colour, the relative height of traps, and monthly Barycenter of winged populations. We also recorded temporal variations in the structure of ladybird communities. Tree-living species of aphids are the last to be caught with most caught by the yellow traps, possibly because of the predominant greenness of the vegetation in April. Most were also caught by high traps. Their phenology coincides with that of the second peak of ladybirds. In contrast, the phenology of species of aphids living on herbaceous plants differs greatly, which reflects their host plant diversity. In March relatively more of these aphids were caught by the green traps, possibly because at that time the ground was not yet covered by vegetation. Early and late species of aphids are at greater risk of being attacked by ladybirds as they are also most active early and late in the season. The highest catches of the heteroecious species of aphids were recorded in the middle of the trapping period and between those of the two groups of monoecious species of aphids. The adaptive significance of the differences in the behaviour and ecology of the aphids in the three groups is discussed.

Has the currently warming climate affected populations of the mountain ringlet butterfly, Erebia epiphron (Lepidoptera: Nymphalidae), in low-elevation mountains?Original article

Martin KONVIČKA, Jiří BENEŠ, Oldřich ČÍŽEK, Tomáš KURAS, Irena KLEČKOVÁ

Eur. J. Entomol. 113: 295-301, 2016 | DOI: 10.14411/eje.2016.036

Climate change scenarios predict losses of cold-adapted species from insular locations, such as middle high mountains at temperate latitudes, where alpine habitats extend for a few hundred meters above the timberline. However, there are very few studies following the fates of such species in the currently warming climate. We compared transect monitoring data on an alpine butterfly, Erebia epiphron (Nymphalidae: Satyrinae) from summit elevations of two such alpine islands (above 1300 m) in the Jeseník Mts and Krkonoše Mts, Czech Republic. We asked if population density, relative total population abundance and phenology recorded in the late 1990s (past) differs that recorded early in 2010s (present) and if the patterns are consistent in the two areas, which are separated by 150 km. We found that butterfly numbers recorded per transect walk decreased between the past and the present, but relative population abundances remained unchanged. This contradictory observation is due to an extension in the adult flight period, which currently begins ca 10 days earlier and lasts for longer, resulting in the same total abundances with less prominent peaks in abundance. We interpret this development as desynchronization of annual cohort development, which might be caused by milder winters with less predictable snow cover and more variable timing of larval diapause termination. Although both the Jeseník and Krkonoše populations of E. epiphron are abundant enough to withstand such desynchronization, decreased synchronicity of annual cohort development may be detrimental for innumerable small populations of relic species in mountains across the globe.

New set of microsatellite markers for the spotted-wing Drosophila suzukii (Diptera: Drosophilidae): A promising molecular tool for inferring the invasion history of this major insect pest

Antoine FRAIMOUT, Anne LOISEAU, Donald K. PRICE, Anne XUÉREB, Jean-François MARTIN, Renaud VITALIS, Simon FELLOUS, Vincent DEBAT, Arnaud ESTOUP

Eur. J. Entomol. 112 (4): 855-859, 2015 | DOI: 10.14411/eje.2015.079

Historical and observational data for invasive species are often sparse and incomplete, so molecular genetic markers are increasingly used and have proved to be efficient tools to make inferences about invasion histories. Here, we report the development of 28 polymorphic microsatellite markers in the invasive spotted-wing drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) designed from recent genomics resources, and their cross-amplification in closely related Drosophila species of the suzukii subgroup. The markers, located on autosomal chromosomes, were characterized in two distinct invasive populations from France and Hawaii (USA), and in four sister species of the suzukii subgroup. They all showed substantial polymorphism as well as revealing strong genetic differentiation between the two genotyped populations. These markers represent a promising molecular tool for population genetic studies on D. suzukii, more especially in order to reconstruct the pathways and demographic processes of the world-wide invasion in this major insect pest.

Tri-trophic interaction involving host plants, black legume aphid, Aphis craccivora (Hemiptera: Aphididae) and the predator, Cheilomenes sexmaculata (Coleoptera: Coccinellidae)Original article

Snehasish ROUTRAY, Karnam V. HARI PRASAD

Eur. J. Entomol. 113: 551-557, 2016 | DOI: 10.14411/eje.2016.075

Interactions involving host plants (cowpea, groundnut, cotton, sunflower, greengram, blackgram) an insect herbivore, black legume aphid Aphis craccivora Koch (Hemiptera: Aphididae) and a predator, the zigzag beetle Cheilomenes sexmaculata (Fabricius) (Coleoptera: Coccinellidae) were investigated during 2014-2015. The preference of the aphid A. craccivora for host plants measured in terms of growth and multiplication was cowpea > groundnut > greengram > blackgram > sunflower > cotton (most preferred to least preferred). Cowpea was the most preferred host plant for growth and multiplication of A. craccivora. Aphid's oviposition period was longest, fecundity greatest; adult longevity longest (188.40 ± 28.87 h; 52.00 ± 10.92; 231.60 ± 40.41 h), and nymphal mortality was lowest (0%) when reared on cowpea followed by groundnut, greengram and blackgram. Aphids had highest nymphal mortality (100%), with very few or no live adults produced, when reared on sunflower and cotton, the least preferred host of A. craccivora in this study. At the third trophic level, both the larvae and the adults of the coccinellid, Cheilomenes sexmaculata, consumed more of the aphids reared on groundnut than of those reared on blackgram, greengram, cowpea, sunflower and cotton. The biochemical constituents (phenols) present in cotton and sunflower, which contributed to the aphid's nymphal mortality, also affected the feeding behaviour of the coccinellid.

Effect of ant attendance on aphid population growth and above ground biomass of the aphid's host plantOriginal article

Afsane HOSSEINI, Mojtaba HOSSEINI, Noboru KATAYAMA, Mohsen MEHRPARVAR

Eur. J. Entomol. 114: 106-112, 2017 | DOI: 10.14411/eje.2017.015

Ant-aphid mutualism is considered to be a beneficial association for the individuals concerned. The population and fitness of aphids affected by ant attendance and the outcome of this relationship affects the host plant of the aphid. The main hypothesis of the current study is that ant tending decreases aphid developmental time and/or increases reproduction per capita, which seriously reduces host plant fitness. The effect of attendance by the ant Tapinoma erraticum (Latreille, 1798) (Hymenoptera: Formicidae) on population growth and duration of different developmental stages of Aphis gossypii Glover (Hemiptera: Aphididae) were determined along with the consequences for the fitness of the host plant of the aphid, Vicia faba L., in greenhouse conditions. The initial aphid density was manipulated in order to study aphid performance due to density-dependent changes in ant attendance. The population growth rate of ant attended aphids was more than that of unattended aphids. However, the ratio of 1st-2nd nymphs to adults in aphid populations attended by ants was lower. The yields of bean plants on which the aphids were attended by ants were significantly greater than those of unattended plants. This study indicates that ants not only increase aphid fitness in terms of their population growth rate, but also benefit the host plant.

Modelling the effects of global warming on the ground beetle (Coleoptera: Carabidae) fauna of beech forests in Bavaria, Germany

Stefan MÜLLER-KROEHLING, Matthias C. JANTSCH, Hagen S. FISCHER, Anton FISCHER

Eur. J. Entomol. 111 (1): 35-49, 2014 | DOI: 10.14411/eje.2014.005

We studied the effects of global warming and rising temperatures on the ground beetle fauna of Bavarian beech forests using the space for time approach at two geographical scales. The first was a Bavarian-wide gradient of 50 plots in beech forests and the second a regional gradient in the Bavarian Forest in the mountains in eastern Bavaria consisting of 48 plots, which also included subalpine spruce forests. For purposes of validation, we used backdrop data from 413 additional plots all across Bavaria from a wide range of forest habitats. We found five species that would be favoured and six species that would be disadvantaged by rising temperatures in beech forests. For another five species the conditions within the gradient studied reach both their minimum and their maximum temperatures. As a consequence of increasing temperatures there will be winners and losers in these forests and the species composition of ground beetle communities will change. Approximately the same number of species is likely to profit as will be affected negatively. However, when considering the "global responsibility species" for Germany, the balance is negative. Species may react differently in different habitats and at different regional scales, which must be taken into consideration when applying the results.

Effects of ultraviolet-C and microwave irradiation on the expression of heat shock protein genes in the maize weevil (Coleoptera: Curculionidae)Original article

Jatuporn TUNGJITWITAYAKUL, Nujira TATUN, Boongeua VAJARASATHIRA, Sho SAKURAI

Eur. J. Entomol. 113: 135-142, 2016 | DOI: 10.14411/eje.2016.017

The maize weevil, Sitophilus zeamais (Motschulsky), is a major pest of stored grain kernels. Irradiation is an established technique for controlling insects in stored grain and is a major stress factor affecting these insects. Since heat shock protein (hsp) genes respond to this stress, we proposed that hsps may be associated with irradiated stress tolerance in S. zeamais. The responses of the maize weevil to exposure to ultraviolet-C (UV-C) and microwave irradiation were assessed at four developmental stages: egg, larva, pupa and adult. The results revealed that exposure to UV-C (254 nm, < 8 h) did not affect the survival of the maize weevils; however, Szhsp70, Szhsc70 and Szhsp90 mRNA levels significantly increased during the first 1 h of UV-C exposure. The median lethal time (LT50) of exposure to microwave irradiation indicated that the adult stage was more tolerant of microwave irradiation than the other developmental stages. Microwave irradiation enhanced the expression of the three hsps, but the intensity of up-regulation differed among the three genes, with Szhsp70 the most highly up-regulated. Our experiments revealed that UV-C and microwave irradiation influenced the expression profile of hsp genes in S. zeamais. At the tissue level, the gene responses to UV-C and microwave irradiation varied greatly in different tissues.

Preference of antlion and wormlion larvae (Neuroptera: Myrmeleontidae; Diptera: Vermileonidae) for substrates according to substrate particle sizes

Dušan DEVETAK, Amy E. ARNETT

Eur. J. Entomol. 112 (3): 500-509, 2015 | DOI: 10.14411/eje.2015.052

Sand-dwelling wormlion and antlion larvae are predators with a highly specialized hunting strategy, which either construct efficient pitfall traps or bury themselves in the sand ambushing prey on the surface. We studied the role substrate particle size plays in these specialized predators. Working with thirteen species of antlions and one species of wormlion, we quantified the substrate particle size in which the species were naturally found. Based on these particle sizes, four substrate types were established: fine substrates, fine to medium substrates, medium substrates, and coarse substrates. Larvae preferring the fine substrates were the wormlion Lampromyia and the antlion Myrmeleon hyalinus originating from desert habitats. Larvae preferring fine to medium and medium substrates belonged to antlion genera Cueta, Euroleon, Myrmeleon, Nophis and Synclisis and antlion larvae preferring coarse substrates were in the genera Distoleon and Neuroleon. In addition to analyzing naturally-occurring substrate, we hypothesized that these insect larvae will prefer the substrate type that they are found in. Specifically, we tested substrate preference in a choice experiment for four species of antlions. This was then compared to the substrate that the larvae were naturally found in. Larvae of the four antlion species were allowed to choose among eight substrates differing according to their particle size. Our findings show that the majority of M. hyalinus larvae built pits in the finest sand fraction, and the majority of N. microstenus larvae were found in a coarser fraction. The other two species, M. immaculatus and E. nostras, constructed majority of their pits in a medium sand fraction. These results support the hypothesis that neuropteran larvae prefer specific substrates for pitbuilding or ambushing prey, and that this - in combination with other abiotic and biotic factors - may drive selection of appropriate habitats.

Infestation of the mycoheterotrophic orchid Yoania japonica by the two-winged fly, Chyliza vittata (Diptera: Psilidae)Note

Kenji SUETSUGU

Eur. J. Entomol. 113: 393-396, 2016 | DOI: 10.14411/eje.2016.050

Chyliza vittata is known to utilize leaves, stems and underground parts of several leafy and leafless orchids. Compared to the well-recorded feeding habits of C. vittata in Europe, its feeding habits in Japan are poorly studied. Thus, further records of its host plants and the habits of its larvae in Japan are likely to reveal the similarities and differences in its feeding habits in Europe and Japan. The current study reports C. vittata feeding on the stems of the mycoheterotrophic orchid Yoania japonica in central Japan. This study also showed that in spite of the small size of Yoania its reproductive success is not severely reduced when infested with C. vittata, whereas the robust stems of Gastrodia elata, which is its main host plant in Japan, are thought to be a defence against infestation by C. vittata.

Seasonal polyphenism in body size and juvenile development of the swallowtail butterfly Papilio xuthus (Lepidoptera: Papilionidae)Original article

Shinya KOMATA, Teiji SOTA

Eur. J. Entomol. 114: 365-371, 2017 | DOI: 10.14411/eje.2017.046

Seasonal polyphenism in adults may be a season-specific adaptation of the adult stage and/or a by-product of adaptive plasticity of the juvenile stages. The swallowtail butterfly Papilio xuthus L. exhibits seasonal polyphenism controlled by photoperiod. Adults emerging in spring from pupae that spend winter in diapause have smaller bodies than adults emerging in summer from pupae that do not undergo diapause. Pupal diapause is induced by short-day conditions typical of autumn. To explore the interactive effects of temperature and developmental pathways on the variation in adult body size in P. xuthus, we reared larvae at two temperatures (20°C, 25°C) under two photoperiods (12L : 12D and 16L : 8D). Pupal weight and adult forewing length were greater in the generation that did not undergo diapause and were greater at 25°C than at 20°C. Thus, body size differences were greatest between the individuals that were reared at the longer day length and higher temperature and did not undergo diapause and those that were reared at the shorter day length and lower temperature and did undergo diapause. Unlike in other Lepidoptera, larvae of individuals that undergo diapause had shorter developmental times and higher growth rates than those that did not undergo diapause. This developmental plasticity may enable this butterfly to cope with the unpredictable length of the growing season prior to the onset of winter. Our results indicate that there are unexplored variations in the life history strategy of multivoltine Lepidoptera.

A case study of Heleomyzidae (Diptera) recorded on snow in Poland with a review of their winter activity in EuropeOriginal article

Agnieszka SOSZYŃSKA-MAJ, Andrzej J. WOŹNICA

Eur. J. Entomol. 113: 279-294, 2016 | DOI: 10.14411/eje.2016.035

Twenty eight species of winter-active Heleomyzidae were collected during a long-term study in Poland. More than 130 samples of insects, including Heleomyzidae, were collected from the surface of snow in lowland and mountain areas using a semi-quantitative method. Lowland and mountain assemblages of Heleomyzidae recorded on snow were quite different. Heleomyza modesta (Meigen, 1835) and Scoliocentra (Leriola) brachypterna (Loew, 1873) dominated in the mountains, Tephrochlamys rufiventris (Meigen, 1830) mainly in the lowlands and Heteromyza rotundicornis (Zetterstedt, 1846) was common in both habitats. Heleomyzidae were found on snow during the whole period of snow cover, but the catches peaked from late November to the beginning of February. In late winter and early spring the occurrence of heleomyzids on snow decreased. Most individuals were active on snow at air temperatures between -2 and +2.5°C. A checklist of 78 winter active European Heleomyzidae is presented. Helomyza nivalis Wahlgren, 1918 is herein considered as a new junior synonym of Helomyza caesia Meigen, 1830, syn. n.

Partial consumption of different species of aphid prey by the predator Macrolophus pygmaeus (Hemiptera: Miridae)Original article

Dionyssios LYKOURESSIS, Dionyssios PERDIKIS, Ioannis MANDARAKAS

Eur. J. Entomol. 113: 345-351, 2016 | DOI: 10.14411/eje.2016.045

The partial consumption of prey refers to when a predator does not consume all the digestible biomass of an animal it has killed. The frequency of partial consumption of prey by the polyphagous predator Macrolophus pygmaeus (Hemiptera: Miridae) was recorded for different species of prey and prey population structures, in single and mixed prey species patches. All the instars of the aphid, Aphis gossypii, were provided as prey alone or together with Myzus persicae or Macrosiphum euphorbiae. Numbers killed were determined when equal (10 nymphs of each instar, 40 in total) or unequal numbers (higher numbers of young nymphs but again 40 in total) of nymphs were placed on an eggplant leaf in a plastic Petri dish. In each dish a single 5th instar nymph of the predator was introduced and the numbers killed and numbers of partially consumed aphids were recorded after 24h, at 25 ± 1°C. The numbers of A. gossypii killed were higher than those of the other species of prey used. The frequency of partially consumed prey was highest when A. gossypii was offered alone in equal numbers of each instar, followed by when A. gossypii was provided together with M. persicae in unequal numbers of instars (23.6% and 11.2%, of the total mortality, respectively). Killed but not consumed prey was also recorded, at frequencies that reached 10.7% of the total mortality when A. gossypii was provided alone in equal numbers of each instar. For M. persicae and M. euphorbiae, these percentages were significantly lower. The higher frequency of this behaviour when A. gossypii was the prey may be related to its lower nutritional quality for the predator. The effect of prey instar was not significant. These results indicate that in determining the numbers killed by a predator, partially consumed prey may make up a significant part of the total kill and thus should be taken into consideration.

Temperature-dependent functional response of Nesidiocoris tenuis (Hemiptera: Miridae) to different densities of pupae of cotton whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)Original article

Mohammad Ali ZIAEI MADBOUNI, Mohammad Amin SAMIH, Peyman NAMVAR, Antonio BIONDI

Eur. J. Entomol. 114: 325-331, 2017 | DOI: 10.14411/eje.2017.040

The effect of temperature on the functional response of female adults of Nesidiocoris tenuis Reuter to different densities of Bemisia tabaci (Gennadius) pupae was assessed. Three constant temperatures (15, 25, and 35°C) and six prey densities (5, 10, 20, 35, 50, and 70) were tested over a 24-h period. Nesidiocoris tenuis exhibited a type II functional response at 15 and 25°C, and a type III response at 35°C. The number of prey consumed by the predator increased with increase in the prey density at all temperatures. Temperature influenced attack rates and handling times. The highest attack rate occurred at 35°C at high densities (35, 50, and 70 prey) and the lowest handling time was recorded at 35°C. The maximum attack rates (T/Th) were 17.13, 42.12, and 45.07 whitefly pupae per day at 15, 25 and 35°C, respectively. As a result, the value of a/Th indicates that N. tenuis was relatively more efficient in attacking B. tabaci at 35°C than at lower temperatures. Results suggest that the ability of N. tenuis to detect and consume B. tabaci over a broad range of temperatures, especially high temperatures (25-35°C), makes this mirid a good candidate for the biological control of whiteflies in warm environments, such as greenhouses.

Condensella and Endogena, two new genera of the Alebroides genus group (Hemiptera: Cicadellidae: Typhlocybinae) from the Oriental Region with notes on the phylogeny of EmpoasciniOriginal article

Ye XU, Christopher H. DIETRICH, Wenhui ZHAO, Daozheng QIN

Eur. J. Entomol. 114: 462-469, 2017 | DOI: 10.14411/eje.2017.059

Two new microleafhopper genera of Empoascini within the subfamily Typhlocybinae (Hemiptera: Cicadellidae), Condensella Xu, Dietrich & Qin gen. n., based on the type species C. filamenta Xu, Dietrich & Qin sp. n., and Endogena Xu, Dietrich & Qin gen. n., based on the type species E. flava Xu, Dietrich & Qin sp. n., are described from southern China and Thailand. Male habitus photos and illustrations of male genitalia of the two new species are provided. Comparative notes on related genera are provided. Phylogenetic relationships and the status of genus groups within the tribe are also discussed.

Phenological responses of Pseudomallada (Neuroptera: Chrysopidae): Comparative data from three Nearctic species and interspecific hybrids

Maurice J. TAUBER, Catherine A. TAUBER

Eur. J. Entomol. 112 (1): 49-62, 2015 | DOI: 10.14411/eje.2015.015

Three Nearctic species - Pseudomallada macleodi (Adams & Garland), P. perfectus (Banks), and P. sierra (Banks) - share a suite of phenological characteristics with their Western Palearctic congeners. They overwinter as free-living larvae (primarily third instars) in a photoperiodically induced diapause. For these three species, the critical photoperiods for diapause induction fell between LD 16:8 and LD 14:10. In the laboratory, larvae remained responsive to daylength throughout diapause - short daylengths maintained diapause until diapause terminated spontaneously or death occurred. Transfer of diapausing larvae from short to intermediate or longer days accelerated diapause development, apparently in a quantitative response to daylength. A period of chilling appeared to delay, rather than hasten, diapause development. In general, the expression of diapause in F1 hybrids (P. perfectus × P. sierra) resembled that of the parents; there were minor differences in some features. Among populations of the three species under non-diapause conditions, the times for complete development (egg hatch to adult emergence) ranged between 40 and 50 days (23.9°C). Under long-day conditions, developmental rates of the P. perfectus egg and prepupal-pupal stages were linearly related to temperature; we provide thermal thresholds and heat-degree days for these stages. In contrast, developmental rates of free-living larvae did not have a linear relationship with temperature; photoperiod may interact with temperature to affect non-diapause development in these stages.

Inheritance of diapause regulation in the multicoloured Asian ladybird Harmonia axyridis (Coleoptera: Coccinellidae)Original article

Sergey Ya. REZNIK, Antonina A. OVCHINNIKOVA, Andrey N. OVCHINNIKOV, Larisa V. BARABANOVA, Natalia A. BELYAKOVA

Eur. J. Entomol. 114: 416-421, 2017 | DOI: 10.14411/eje.2017.053

It is known that females from native populations of the multicoloured Asian ladybird, Harmonia axyridis, have a strong photoperiodic response (enter reproductive diapause under short photoperiods), whereas the proportion of diapausing females from invasive populations is less dependent on day length. The aim of the present study was to determine the mode of inheritance of these differences. The experiments were conducted with two laboratory populations of H. axyridis, the High Diapause (HD) population originated from Irkutsk (Southern Siberia, ca 52.3°N, 104.3°E) and the Low Diapause (LD) population originated from Sochi (North Caucasus, ca 43.6°N, 39.6°E). Reciprocal first generation hybrids and reciprocal backcrosses were investigated. Under a strong diapause-inducing photoperiod (12 h) 100% of the females from the HD population and about 70% of those from the LD population entered diapause. First generation hybrids, as well as their backcrosses with individuals from the HD population, showed almost 100% diapause. Among the backcrosses with the LD population the percentage of diapausing females was widely variable (70-100%) but close to the average between the two populations. The comparison of reciprocal crosses did not reveal any significant difference. We conclude that photoperiodic induction of diapause in the populations of H. axyridis studied is most probably determined by several genes (although one of them evidently plays a leading role with diapause being dominant over non-diapause) and that male and female genotypes are equally important in the determination of female reproductive diapause.

Diversity and abundance of arboreal psocids (Psocoptera) along latitudinal gradients in northern Europe

Jussi KANERVO, Mikhail V. KOZLOV

Eur. J. Entomol. 111 (1): 51-58, 2014 | DOI: 10.14411/eje.2014.006

Psocids are small insects that feed primarily on fungi, algae, lichens and organic detritus. Although they are relatively common in forest ecosystems, the general patterns in their abundance and diversity in boreal forests are still poorly known. We report records of 20 species of psocids quantitatively collected from four species of woody plants (Pinus sylvestris, Picea abies, Betula pubescens and B. pendula) at 50 sites in northern Europe, located between 59° and 70°N and between 10° and 60°E. Seven species were found only on conifers, seven other species only on birches and six species inhabited both birches and conifers. The overall density of psocids was 18.9 ± 2.9 exx/kg (d.w. of plant material). Densities varied among the studied species of trees, being highest on P. abies and lowest on B. pendula. The species diversity was highest on B. pendula and lowest on B. pubescens. Both diversity and abundance of arboreal psocids in northern Europe decreased with latitude. However, due to the relatively low number of specimens collected, the conclusions about the diversity of psocids should be seen as tentative.

Development, reproduction, host range and geographical distribution of the variegated caper bug Stenozygum coloratum (Hemiptera: Heteroptera: Pentatomidae)

Shahar SAMRA, Murad GHANIM, Alex PROTASOV, Zvi MENDEL

Eur. J. Entomol. 112 (2): 362-372, 2015 | DOI: 10.14411/eje.2015.041

The variegated caper bug (CB) Stenozygum coloratum (Klug, 1845) is common in the Eastern Mediterranean region and a minor agricultural pest. CB eggs were recently shown to serve as alternative hosts for Ooencyrtus pityocampae Mercet, 1921, an important natural enemy of the pine processionary moth (PPM) Thaumetopoea wilkinsoni Tams, 1924 (Lepidoptera: Notodontidae). In this study various aspects of the life history of CB were studied, including its distribution, host range, development, reproduction and ability to develop on various cultivated species of plants. CB occurs in almost all areas and habitats in Israel, except in the coldest regions, attacking several caper species (Capparis spp.). When reared on Capparis zoharyi at 25°C, one generation lasted 6 weeks and females laid a single 12-egg cluster every 3 days. Decreases in temperature, but not changes in day length, terminated reproductive activity. CB nymphs survived for up to three months, or even completed their development, on some agricultural plants. However, reproductive activity was initiated only if adults were fed capers. These findings emphasize the importance of capers in the CB life cycle and account for why other plants are rarely attacked. These plants may serve as a temporary refuge for CB when capers are scarce or unsuitable, mainly late in the season. Morphology of developmental stages, egg deposition, cannibalistic behaviour, sex ratio and effects of temperature on egg production were also studied. The possibility of using CB for enhancing the biological control of PPM is discussed.

 previous    ...   12   13   14   15   16  17   18   19   20   21   ...    next