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Results 781 to 810 of 1110:

Isolation of antibacterial response genes from the dung beetle Copris tripartitus (Coleoptera: Scarabaeidae) immunized with Escherichia coli

Jae-Sam HWANG, Yeon-Ju KIM, Hea-Son BANG, Eun-Young YUN, Young-Tae KIM, Seong-Ryul KIM, Kwan-Ho PARK, Nam-Soon KIM, Iksoo KIM, Seok-Jo HWANG, Jae-Pil JEON

Eur. J. Entomol. 105 (2): 355-359, 2008 | DOI: 10.14411/eje.2008.042

Dot blot hybridization of total RNA from normal and bacteria-injected larvae of the dung beetle Copris tripartitus identified 13 cDNA clones that seem to be associated with the immune response. A cDNA encoding a dung beetle homolog of the heat shock protein HSP70 (CTHSP70) was characterized by full-length sequencing and expression pattern analysis. CTHSP70 was upregulated 4 h after bacterial injection, reached maximum level after 8 h, and declined gradually after 16 h. Our data suggest that CTHSP70 and another 12 genes are involved in the anti-microbial defense that is particularly important for dung beetle larvae living in pathogen-rich conditions.

Male territorial behaviour of the endemic large carpenter bee, Xylocopa (Koptortosoma) ogasawarensis (Hymenoptera: Apidae), on the oceanic Ogasawara Islands

Shinji SUGIURA

Eur. J. Entomol. 105 (1): 153-157, 2008 | DOI: 10.14411/eje.2008.021

The endemic large carpenter bee, Xylocopa (Koptortosoma) ogasawarensis Matsumura (Hymenoptera: Apidae), on the oceanic Ogasawara (Bonin) Islands, located in the northwestern Pacific Ocean, approximately 1000 km south of the Japanese mainland, is a generalist flower visitor. Although the flower-visiting behaviour of X. ogasawarensis females has been frequently recorded, the behaviour of the males in this species has rarely been studied. I observed the territorial behaviour of males on flowers of the native plant species Scaevola sericea Vahl (Campanulales: Goodeniaceae) in a coastal area of Hahajima in early July 2007. Each male chose a particular inflorescence, hovered near it (mean distance, 239 mm from the inflorescence) and patrolled around it for several minutes (mean time, 331 s). Therefore, X. ogasawarensis males exhibit resource-based (i.e., flowers) territoriality. Males frequently attacked other males when defending their territories. However, males did not defend their territories against flower visitors of other species (i.e., introduced honeybees). Therefore, male territorial behaviour in X. ogasawarensis may be related to intrasexual competition for sites visited by females. This is the first report describing the male territorial behaviour of X. ogasawarensis.

Influence of host plant on susceptibility of the aphid Acyrthosiphon pisum (Hemiptera: Aphididae) to the fungal pathogen Pandora neoaphidis (Zygomycetes: Entomophthorales)

Cezary TKACZUK, Paresh A. SHAH, Suzanne J. CLARK, Judith K. PELL

Eur. J. Entomol. 104 (2): 205-210, 2007 | DOI: 10.14411/eje.2007.032

The performance of the aphid-specific fungal pathogen Pandora neoaphidis was studied in relation to changes in herbivore resources for the pea aphid, Acyrthosiphon pisum, on different host plant species. Dose-response bioassays were conducted with A. pisum which had been reared on dwarf bean then inoculated with P. neoaphidis and returned to dwarf bean or inoculated and transferred to field bean, pea or lucerne. The smallest estimated median lethal concentration (LC50) was 7.7 conidia mm-2 (95% confidence interval 5.4-11.2) for aphids returned to dwarf bean, with LC50s of 13.0 (9.2-19.1) and 14.6 (10.2-21.5) conidia mm-2 for aphids transferred to field bean or pea, respectively. The LC50 when aphids were transferred to lucerne [2941.0 conidia mm-2 (237.3-2.1x109)] was greater than for the other three plants. In a subsequent experiment, A. pisum were reared on pea as well as dwarf bean for four generations before bioassays. The LC50 was 7.3 conidia mm-2 (4.4-12.4) for aphids reared and incubated on dwarf bean, compared to 13.3 (8.0-23.9) and 15.3 (8.8-29.9) conidia mm-2 when aphids were transferred between dwarf bean and pea, and vice versa, respectively. The LC50 for aphids reared then incubated on pea plants was 27.9 (15.8-57.3) conidia mm-2. Hence, the virulence of P. neoaphidis, measured by LC50, was greatest when A. pisum was reared and maintained on dwarf bean, the plant used for long-term routine culturing of the aphid in our facilities. In conclusion, virulence of P. neoaphidis was greater on plant species to which A. pisum had become adapted during long-term laboratory rearing. Plant resources may affect infection by P. neoaphidis and the fungal entomopathogen will have a greater impact on aphid herbivores which are not suffering physiological stress related to a change in host plant.

Limited variation in mitochondrial DNA of maize-associated Ostrinia nubilalis (Lepidoptera: Crambidae) in Russia, Turkey and Slovenia

Sugihiko HOSHIZAKI, Ryôta WASHIMORI, Shun-Ichi KUBOTA, Andrei N. FROLOV, Daisuke KAGEYAMA, Stanislav GOMBOC, Suguru OHNO, Sadahiro TATSUKI, Yukio ISHIKAWA

Eur. J. Entomol. 105 (4): 545-552, 2008

A sequence analysis of the mitochondrial cytochrome oxidase subunit II (COII) gene in Russian and Turkish maize-associated populations of Ostrinia nubilalis and a Slovenian population of O. nubilalis probably infesting maize revealed little diversity. This lack of diversity may have resulted from bottleneck event(s) when the maize-associated population of O. nubilalis expanded from small population(s) in association with the cultivation of maize in Europe ca. 500 years ago. In the genealogy of COII genes obtained in the present and previous studies, Eurasian samples were substantially differentiated from North American samples. Since the North American population of O. nubilalis came from Europe, our finding suggests that there is geographical differentiation in European maize-associated O. nubilalis, and that maize-associated populations of O. nubilalis expanded multiple times in Europe. Finally, a phylogenetic analysis of the COII gene did not support that O. nubilalis and O. furnacalis are the closest relatives within the O. furnacalis species group.

A modified method for clearing, staining and mounting plant-inhabiting mites

Farid FARAJI, Frank BAKKER

Eur. J. Entomol. 105 (4): 793-795, 2008

A modified method for clearing, staining and mounting plant-inhabiting mites is proposed. With this method, all mites can be cleared with a single agent and mounted in a single medium. The stain added to the mounting medium enhances the clarity of the fine structures of soft-bodied mites under phase contrast and more significantly under bright field microscopy.

Factors terminating ovarian arrest in long-winged females of a flightless bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Radomír SOCHA

Eur. J. Entomol. 104 (1): 15-22, 2007 | DOI: 10.14411/eje.2007.003

The aim of the present study was to determine the factors that are involved in termination of a non-diapause type of ovarian arrest in the adult macropterous females of a flightless bug, Pyrrhocoris apterus (L.), reared under a long-day (18L : 6D) photoperiod. Application of an active analogue of juvenile hormone, methoprene, to adult macropterous females kept under the above conditions induced precocious termination of ovarian arrest and shortened the length of the pre-oviposition period. The results indicate that a temporary ovarian arrest in spontaneously fasting long-day macropterous females results from a deficiency of juvenile hormone. The length of the pre-oviposition period was shortened and ovarian arrest terminated also by de-alation, high temperature and by a prolonged period of starvation. Mating of long-day macropterous females with reproductively active males had no effect on the length of the pre-oviposition period. There was a relationship between the length of the starvation period and the post-feeding pre-oviposition period. The longer the starvation period, the shorter the period from when food was supplied to first oviposition. The results indicate that depletion of the fat body reserves resulting from prolonged fasting, followed by resumption of food intake are pre-requisites for full activation of the corpus allatum and egg development, and play a role in completion and termination of non-diapause ovarian arrest in long-day macropterous females. This phenomenon was never observed in short-day brachypterous females in reproductive diapause.

Taxonomy of the genera Scaeva, Simosyrphus and Ischiodon (Diptera: Syrphidae): Descriptions of immature stages and status of taxa

Pavel LÁSKA, Celeste PÉREZ-BAÑÓN, Libor MAZÁNEK, Santos ROJO, Gunilla STÅHLS, M. Angeles MARCOS-GARCÍA, Vítìzslav BIÈÍK, Jindra DU©EK

Eur. J. Entomol. 103 (3): 637-655, 2006 | DOI: 10.14411/eje.2006.085

A review of all known descriptions of immature stages of the species of the genera Scaeva Fabricius, 1805, Ischiodon Sack, 1913 and Simosyrphus Bigot, 1882 is presented using SEM illustrations. The third instar larval and/or pupal morphology of Scaeva dignota (Rondani, 1857), Scaeva mecogramma (Bigot, 1860) and Simosyrphus grandicornis (Macquart, 1842) are newly described. All species of the genera studied in this paper are very similar for all the studied characters of their immature stages, including the chaetotaxy. Molecular characters of the mitochondrial cox1 gene (1128bp) were used for inferring relationships of the studied taxa. The nuclear internal transcribed spacer 2 (ITS2) was additionally applied for species delimitation of the closely related species Scaeva selenitica and S. dignota. The Palaearctic Scaeva species could be split into two groups based on the analysis of morphology of posterior respiratory process. These groups were previously diagnosed as S. selenitica-group [i.e., S. selenitica (Meigen, 1822), S. dignota (Rondani, 1857), S. mecogramma (Bigot, 1860)] and S. pyrastri-group [i.e., S. pyrastri (Linnaeus, 1758), S. albomaculata (Macquart, 1842), S. latimaculata (Brunetti, 1923)]. Semiscaeva Kuznetzov, 1985 and Scaeva Fabricius, 1805 are the available names for these two natural groups that should be classified as subgenera; the former name is proposed for S. selenitica-group and the latter for S. pyrastri-group. Mecoscaeva Kuznetzov, 1985 syn. n. is transferred as a junior synonym of the subgenus Semiscaeva Kuznetzov, 1985 according to the principle of the first reviser. Based on the analysis of immature stages, the generic name Ischiodon Sack, 1913 syn. n. is proposed as a junior synonym of the genus Simosyrphus Bigot, 1882. The similarity of immature stages between Scaeva s. str. and Simosyrphus grandicornis Macquart, 1842, Simosyrphus aegyptius (Wiedemann, 1830) comb. n. and Simosyrphus scutellaris (Fabricius, 1805) comb. n. is discussed. All the proposed subgeneric and generic taxa based on morphological studies received high support employing molecular characters.

Orthopteran communities in the conifer-broadleaved woodland zone of the Russian Far East

Thomas FARTMANN, Martin BEHRENS, Holger LORITZ

Eur. J. Entomol. 105 (4): 673-680, 2008

We investigate orthopteran communities in the natural landscape of the Russian Far East and compare the habitat requirements of the species with those of the same or closely related species found in the largely agricultural landscape of central Europe. The study area is the 1,200 km2 Lazovsky State Nature Reserve (Primorsky region, southern Russian Far East) 200 km east of Vladivostok in the southern spurs of the Sikhote-Alin Mountains (134°E/43°N). The abundance of Orthoptera was recorded in August and September 2001 based on the number present in 20 randomly placed 1 m2 quadrates per site. For each plot (i) the number of species of Orthoptera, (ii) absolute species abundance and (iii) fifteen environmental parameters characterising habitat structure and microclimate were recorded. Canonical correspondence analysis (CCA) was used first to determine whether the Orthoptera occur in ecologically coherent groups, and second, to assess their association with habitat characteristics. In addition, the number of species and individuals in natural and semi-natural habitats were compared using a t test. A total of 899 individuals of 31 different species were captured, with numbers ranging between 2 and 13 species per plot. Species diversity was higher in semi-natural habitats than natural habitats. There was a similar but non-significant pattern in species density. Ordination analysis indicated four orthopteran communities, which were clearly separable along a moisture and vegetation density gradient. The natural sites in the woodland area of the Lazovsky Zapovednik are characterized by species-poor and low-density orthopteran assemblages compared to the semi-natural sites. But, the natural sites have a higher diversity of habitat specialists. Our findings corroborate the hypothesis that intermediate habitat disturbance levels support particularly species-rich animal communities at high densities. Under such regimes, orthopterans presumably mostly profit from the high diversity in plant species, which generates great structural and microclimatic heterogeneity.

The importance of termites (Isoptera) for the recycling of herbivore dung in tropical ecosystems: a review

Bernd P. FREYMANN, Robert BUITENWERF, Og DESOUZA, Han OLFF

Eur. J. Entomol. 105 (2): 165-173, 2008 | DOI: 10.14411/eje.2008.025

While the key role of termites in the decomposition of litter in the tropics has been acknowledged for a long time, much less information exists on their importance in the recycling of dung of primary consumers, especially herbivores. A review of published studies shows that a diverse group of termites (at least 126 species) has been reported to feed on a wide range of mammalian dung (18 species). Predominantly, wood-feeding and polyphagous wood-litter feeding species were found to feed also frequently on dung. Moreover, we found that termites can quickly remove large amounts of mammalian dung, especially in the dry season, when on average about 1/3 of the dung deposited in a given habitat is removed by termites within one month (with the highest rates observed in savannas). No distinctive preference for mammalian dung over other organic food sources was observed for fungus-growing termites (Macrotermitinae), whereas the majority of the non-fungus growing taxa studied prefer dung over other food. As termites bring large quantities of dung below the soil surface, disturb and enrich soils with nutrients, dung feeding by termites appears to be a previously underestimated process important in the functioning of tropical ecosystems.

Chromosome number, karyotype morphology, heterochromatin distribution and nuclear DNA content of some talitroidean amphipods (Crustacea: Gammaridea)

Angelo LIBERTINI, Renata TRISOLINI, Massimiliano RAMPIN

Eur. J. Entomol. 105 (1): 53-58, 2008 | DOI: 10.14411/eje.2008.007

Chromosome number, karyotype formula, C-banding pattern, genome size and DNA base composition were studied in three species of Hyalidae and seven species of Talitridae. A karyotype of 25 chromosome pairs, with median centromeres (FN = 100), was found in all the species of Talitridae analysed and Apohyale prevostii. Genome size (C-value) varies among Talitrida from 0.94 pg in Apohyale crassipes to 2.81 pg in Orchestia gammarellus, and the percentage of AT-DNA in the whole genome ranges from 56.12% in A. crassipes to 68.17% in Sardorchestia pelecaniformis. In comparison with Hyalidae, Talitridae show more uniformity in chromosome number and karyotype formula, and have larger genomes. There is a direct correlation between total DNA content and the amount of C-heterochromatic DNA. The cytogenetical data on Talitrida were compared from a phylogenetic and an evolutional point of view. The increase in genome size during the evolution of the Talitrida possibly had a role in their adaptation to supralittoral life and extreme subaerial conditions.

Dispersal dynamics: Distribution of lady beetles (Coleoptera: Coccinellidae)

Vlastimil KØIVAN

Eur. J. Entomol. 105 (3): 405-409, 2008 | DOI: 10.14411/eje.2008.051

This article studies coccinellid dispersal in heterogeneous environments using some hypotheses on dispersal rates that correspond to empirical observations. It is assumed that emigration rates increase with decreasing patch payoff that is measured either as the number of aphids per a lady beetle, or as the number of aphids only. Three scenarios for immigration are considered: individuals choose patches unconditionally, immigration is proportional to patch quality, and immigration is proportional to patch payoff. Coccinellid spatial distributions corresponding to these assumptions are given by a power law. Using some data from the literature on distribution of Coccinella septempunctata it is shown that the model with emigration proportional to the ratio of the number of conspecifics to aphid density and unconditional immigration rates provides the best fit when compared with the other models. This model predicts undermatching where better patches get lower consumer density when compared with the ideal free distribution.

Polymorphic microsatellite loci in the endangered butterfly Lycaena helle (Lepidoptera: Lycaenidae)

Jan Christian HABEL, Aline FINGER, Marc MEYER, Thomas SCHMITT, Thorsten ASSMANN

Eur. J. Entomol. 105 (2): 361-362, 2008 | DOI: 10.14411/eje.2008.043

Six polymorphic microsatellite loci were isolated in the endangered butterfly Lycaena helle. Five of them provided interpretable results. We detected four to 34 alleles per locus in a total of 235 samples (males and females) collected from meadows in the Ardennes-Eifel (Germany, Luxemburg and Belgium) and the Westerwald (Germany). We collected one leg for DNA-extraction as a non-lethal method. The expected heterozygosities ranged from 48.6% to 83.1%, depending on the locus analysed. These markers are currently being used in our studies of the species´ phylogeography over its western Palearctic distribution area and for the analysis of the conservation status of the fragmented populations in Central Europe.

Odour-mediated sexual attraction in nabids (Heteroptera: Nabidae)

Steffen ROTH, Arne JANSSEN, Maurice W. SABELIS

Eur. J. Entomol. 105 (1): 159-162, 2008 | DOI: 10.14411/eje.2008.022

In many insects, mate finding is mediated by volatile sex pheromones, but evidence in nabids is still fragmentary. The role of odour-mediated sexual attraction in two nabid species, Nabis pseudoferus and N. rugosus, was studied in a Y-tube olfactometer. Females of the two species were significantly attracted by odours of conspecifics males, and males of N. rugosus, but not of N. pseudoferus, were attracted by odours of conspecific females. Odours of conspecifics of the same gender were unattractive. These results suggest the existence of male pheromones in both species and a different female pheromone in N. rugosus.

Cold tolerance and trehalose accumulation in overwintering larvae of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)

Abbas KHANI, Saeid MOHARRAMIPOUR, Mohsen BARZEGAR

Eur. J. Entomol. 104 (3): 385-392, 2007 | DOI: 10.14411/eje.2007.057

Seasonal variations in the supercooling point, survival at low temperatures and sugar content were studied in field-collected codling moth larvae. The supercooling point of field-collected larvae decreased significantly from a mean value of -13.4°C in August 2004 (feeding larvae) to -22.0°C in December 2004 (overwintering larvae). Survival at -20°C/24 h was 0% during early autumn, whereas it increased to approximately 60% during winter. The survival at low temperature was well correlated with the supercooling point. The supercooling point of the diapause destined larvae decreased from -16.9 to -19.7°C between September and October as the larvae left the food source and spun a cocoon. For early-diapause larvae, exposure to 5°C/30 days has an additional effect and decreased the supercooling point from -19.7 to -21.3°C. One-month exposure of overwintering larvae to 5°C led to a mortality of 23% in early diapause larvae, while only 4% of diapause larvae died after acclimation. Overwintering larvae accumulated trehalose during winter. There was approximately a threefold increase in trehalose content between larvae at the onset of diapause (5.1 mg/g fresh weight) and larvae in a fully developed diapause (18.4 mg/g fresh weight) collected in January. Trehalose content was correlated with supercooling capacity, survival at low temperatures and chilling tolerance, suggesting that trehalose may play some role in the development of cold tolerance in this species.

Diversity of ground beetles (Coleoptera: Carabidae) and spiders (Araneae) in roadside verges with grey hair-grass vegetation

Jinze NOORDIJK, André P. SCHAFFERS, Karlè V. SÝKORA

Eur. J. Entomol. 105 (2): 257-265, 2008 | DOI: 10.14411/eje.2008.036

Roadside verges in densely populated areas are often a significant addition to the total semi-natural area and as such may contribute to the conservation of biodiversity. Furthermore, they can enhance the ecological cohesion of a region, especially when the existing nature reserves are small and/or highly fragmented. We investigated the occurrence of ground beetles and spiders in six highway verges with grey hair-grass vegetation in the Veluwe region, The Netherlands. Total species number in the verges was similar to the values found in nearby nature reserves with comparable vegetation, but the ground beetles tended to be more abundant in the reserves. Many stenotopic species were present in the verges, confirming the significant conservation value of this habitat. However, compared with the nature reserves, there were fewer species of stenotopic ground beetles and the stenotopic spiders were less abundant in the verges. From our knowledge of the biology and ecology of the species captured it seems likely that this is attributable to differences in "habitat quality". In the verges, species preferring bare sand are scarcer, and the weighted mean body length of ground beetles is shorter than in nature reserves. This suggests that the sward in the road verges is too dense and the suitable vegetation too patchy to sustain some of the stenotopic species. Habitat analyses support this contention: Compared with the nature reserves, the verges had proportionally less bare sand, more herb and tree cover and the vegetation patches were smaller. The strategy suggested to promote stenotopic species entails removing encroaching trees and shrubs from the verges in order to expand the nutrient-poor zone and (re-)create pioneer conditions. Subsequent management should aim at further improving the road verges as extensions of nutrient-poor habitat.

First demonstration of the influence of photoperiod on the thermal requirements for development in insects and in particular the linden-bug, Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Elena B. LOPATINA, Sergei V. BALASHOV, Vladilen E. KIPYATKOV

Eur. J. Entomol. 104 (1): 23-31, 2007 | DOI: 10.14411/eje.2007.004

The influence of photoperiod on the thermal requirements for development was discovered for the first time in insects during experiments on the linden-bug, Pyrrhocoris apterus. The effect of photoperiod on the duration of linden-bug development at five constant temperatures (20, 22, 24, 26 and 28°C) was measured and the thermal requirements for development at three photoperiods (14, 17 and 20 h light per day) were calculated. Bugs from four geographic populations were used in these experiments: Pyatigorsk (44°02´N, 43°04´E), Borisovka (50°36´N, 36°01´E), Mikhailov (54°15´N, 39°0´E) and Ryazan (54°36´N, 39°42´E). From the values of individual development times at different temperatures the coefficient of linear regression of development rate (the inverse of the duration) on temperature and the thermal threshold for development were calculated. Both these parameters were found to decrease significantly with decrease in day-length for all four populations studied. It means that at shorter day-lengths nymphal development is less dependent on temperature compared to the development at longer day-lengths. These effects seem to be adaptive. The development times of nymphs at relatively high temperatures (above 24-25°C) are shorter under long-days than under short days which should be advantageous at the height of summer when the days are long and the weather is warm. In the contrast, at relatively low temperatures (below 24-25°C) the nymphs develop significantly faster under short-days than under long days, which is advantageous at the end of summer as it allows the nymphs to reach the adult stage, the only stage capable of overwintering. The influence of photoperiod on the thermal reaction norm appeared to be more or less gradual, i.e. the shorter the day-length the shallower the slope of the regression line of development rate on temperature and the lower the thermal threshold for development. An analysis of the literature shows that this effect of photoperiod on the thermal requirements for development is widespread among insects but has been overlooked by previous authors. The authors conclude that the variation in the development time observed in insects at different seasons, photoperiods or food regimes, or from different populations, etc., are generally due to some modification of the thermal reaction norms and more specifically to differences in the thermal requirements for development.

Bladder grasshoppers (Caelifera: Pneumoridae) contain three adipokinetic peptides

Gerd GÄDE

Eur. J. Entomol. 105 (2): 211-217, 2008 | DOI: 10.14411/eje.2008.030

The corpora cardiaca (CC) of the pneumorid grasshopper species Bullacris discolor contain at least one substance that causes hyperlipaemia in the migratory locust. Isolation of neuropeptides belonging to the adipokinetic hormone (AKH) family was achieved by single-step reversed-phase high performance liquid chromatography (RP-HPLC) of CC extracts and monitoring tryptophan fluorescence. The material of the bladder grasshopper showed three distinct fluorescence peaks with adipokinetic activity in the migratory locust. The peptide sequences were identified by Edman degradation after the N-terminal pyroglutamate residue had been cleaved off enzymatically, and the exact peptide masses were determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Moreover, the assigned peptides were synthesised and natural and synthetic peptides were compared in their behaviour in RP-HPLC. B. discolor stores three AKH peptides in its CC: two of those are octapeptides, Schgr-AKH-II (pELNFSTGWamide) and Peram-CAH-II (pELTFTPNWamide), whereas the third peptide is a decapeptide, Phyle-CC (pELTFTPNWGSamide. The concentration of carbohydrates in the haemolymph of B. discolor is about 3 times higher than the lipid concentration. Upon injection with synthetic Schgr-AKH-II no adipokinetic or hypertrehalosaemic effect was measurable. A literature survey appears to indicate that an active role of these AKH peptides in substrate mobilisation is only overtly displayed in those caeliferan species that undertake well-defined flight periods.

Oviposition, flight and walking capacity at low temperatures of four aphid parasitoid species (Hymenoptera: Aphidiinae)

Alain LANGER, Guy BOIVIN, Thierry HANCE

Eur. J. Entomol. 101 (3): 473-479, 2004 | DOI: 10.14411/eje.2004.067

Precocious activity of parasitoids is a key factor for cereal aphid control. We investigated the oviposition, flight and walking capacities at low temperature of four aphid parasitoids (Aphidius rhopalosiphi, A. ervi, Praon volucre, P. gallicum) on one of their aphid hosts (Sitobion avenae). Oviposition behaviour was tested at 2, 4, 6, 8, 10, 15 and 20°C, under a photoperiod of 12 h light. Some females of A. rhopalosiphi oviposited at 6°C while the percentage of parasitization below 10°C remained low for the other species. The proportion of males decreased with temperature for A. ervi, P. volucre and P. gallicum but not for A. rhopalosiphi. For all species, flight and walking activities increased with temperature, Aphidius species being active at lower temperature than Praon species. Field captures showed that the activity threshold for A. rhopalosiphi is 12°C, 15°C for A. ervi and P. volucre, and 19.5°C for P. gallicum. These results are discussed regarding the potential of these four species for aphid control.

The effect of heat stress on the survival of the rose grain aphid, Metopolophium dirhodum (Hemiptera: Aphididae)

Chun-Sen MA, Bernhard HAU, Hans-Michael POEHLING

Eur. J. Entomol. 101 (2): 327-331, 2004

The rose grain aphid, Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) is one of the three most important cereal aphid species in Europe. High temperature is detrimental for the survival of this species. Detailed experiments were conducted on the effect of high temperature (27, 28, 29, 30, 31, 31.5, 32.5, 33 and 34°C), period of exposure (2, 3, 4, 6 and 8 h per day for 1, 2, 4, 6 days) and developmental stage (2nd, 3rd, 4th instar nymph and adult) on the survival of the aphid. The results show that all three factors significantly affect survival. Temperatures over 29°C for 8 h significantly reduced survival, which decreased generally as the temperature increased. The survival was inversely related to the period of exposure. Exposing aphids to 32.5°C for 4 h or longer significantly reduced survival. Mature aphids had a lower tolerance of high temperatures than nymphs. Periods of high temperature experienced by 4th instar and adult aphids can greatly affect their survival. The value of these results for forecasting and determining control thresholds, the effect of global warming on cereal aphid abundance and the dropping off behaviour of the aphids are discussed.

Instar preference and parasitization of Aphis gossypii and Myzus persicae (Hemiptera: Aphididae) by the parasitoid Aphidius colemani (Hymenoptera: Aphidiidae)

Dionyssios C. PERDIKIS, Dionyssios P. LYKOURESSIS, Nikolaos G. GARANTONAKIS, Stylianh A. IATROU

Eur. J. Entomol. 101 (2): 333-336, 2004

The instar preference and parasitization (expressed as mummification rate) of Aphis gossypii Glover and Myzus persicae (Sulzer) (Hemiptera: Aphididae) by the parasitoid Aphidius colemani Viereck (Hymenoptera: Aphidiidae) were studied at 25±0.5°C, 65±5% r.h. and a 16L : 8D photoperiod. The female parasitoids were 24-36 h old and were left to forage for 1 h on an eggplant leaf on which 10 nymphs of each instar of A. gossypii or M. persicae were placed. The percentage of A. gossypii nymphs mummified was higher than that of M. persicae (43.2 and 25.2%, respectively). The parasitoid parasitized nymphs of all instars of both aphid species, but it showed a preference for 1st and 2nd instars of A. gossypii and 1st instar of M. persicae. Nymphs of both aphid species parasitized in the 1st and 2nd instars were mummified when reached the 4th instar or adult stage, whereas those parasitized in the 3rd and 4th instars were mummified in the adult stage. The importance of these results in the effectiveness of A. colemani in biological control of A. gossypii and M. persicae is discussed.

Phylogeography of the Eurasian pine shoot beetle Tomicus piniperda (Coleoptera: Scolytidae)

Sarah RITZEROW, Heino KONRAD, Christian STAUFFER

Eur. J. Entomol. 101 (1): 13-19, 2004 | DOI: 10.14411/eje.2004.003

Tomicus piniperda is a pest in pine stands in Eurasia and is also found in the USA, where it has caused a decline in the abundance of pine since 1992. Knowledge of the genetic structure of pine shoot beetle populations is important for understanding their phylogeographic history and for quarantine control. In this study, European, Asian and American T. piniperda populations were analyzed by sequencing a region of the mitochondrial COI gene. Twenty-five haplotypes (HT) were detected and over 70% of these HT were found in individual areas, e.g. 5 HT in China, 5 HT in France and 3 HT in Spain. Nested clade analysis revealed that most European and the American population was in a clade containing 9 HT connected by one to two mutational steps. A second clade contained HT from France (2 HT), Spain (2 HT), Sweden (1 HT), Russia (1 HT) and China (5 HT). In this clade, one to 13 mutational steps and 13 missing or theoretical HT were detected. The third clade had 5 HT from France, Russia, Poland, Finland and Switzerland; 1 to 7 mutational steps and 5 missing or theoretical HT were detected. Although only a few significant relationships were found in the nested clade analysis, the following conclusions can be drawn: (1) T. piniperda is a polymorphic species with numerous HT throughout Europe, and HT are likely to exist regarding the missing or theoretical HT; (2) It is likely there were refugial areas in Southern Europe and Western Russia; (3) The Pyrenees formed a barrier to migration after the last ice age; (4) Chinese and European populations have been separated for at least 0.6 MYA.

Monoclonal antibody against Rab8 from Bombyx mori (Lepidoptera: Bombycidae)

Tomohide UNO, Takuya NAKADA, Yuichi UNO, Kengo KANAMARU, Hiroshi YAMAGATA, Masahiko NAKAMURA, Michihiro TAKAGI

Eur. J. Entomol. 104 (4): 641-645, 2007 | DOI: 10.14411/eje.2007.080

Small GTPases of the Rab family are key regulators of membrane trafficking. Monoclonal antibodies are useful tools for identifying proteins that interact with other proteins and for examining their tissue distribution. We selected a monoclonal antibody against Rab8 of Bombyx mori L. It specifically recognized amino acid residues 30-109, which are conserved among Rab8 proteins, and did not recognize any other Rab proteins. Western blotting using the antibody revealed one band in the brains of B. mori and rat. Far-Western blotting analysis detected three proteins interacting with Rab8. These results indicate that this antibody is useful for clarifying the physiological function of Rab8 of B. mori and other species. This is a report of a study on a monoclonal antibody against insect Rab protein.

Temporal effects of multiple mating on components of fitness in the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)

Penelope R. HADDRILL, David M. SHUKER, Sean MAYES, Michael E.N. MAJERUS

Eur. J. Entomol. 104 (3): 393-398, 2007 | DOI: 10.14411/eje.2007.058

Insects have provided much of the best evidence to date concerning possible costs and benefits of multiple mating, and here we investigate the benefits of polyandry in the two-spot ladybird, Adalia bipunctata, by attempting to replicate the highly promiscuous mating system in this species. We compared the temporal pattern of reproductive success of females mated multiple times to one male with that of females mated an equal number of times to multiple males, and found transient differences in offspring production and hatch rate over time. Our data suggest that polyandrous females benefit from multiple mating in some circumstances, but the patterns are complex. Following how both the costs and benefits to mating accrue over time will be necessary if we are to fully understand why polyandry evolves.

An Erratum has been published for this article: https://doi.org/10.14411/eje.2010.054

Morphological separation of host adapted taxa within the Hyalopterus pruni complex (Hemiptera: Aphididae)

Konstantinos D. POULIOS, John T. MARGARITOPOULOS, John A. TSITSIPIS

Eur. J. Entomol. 104 (2): 235-242, 2007 | DOI: 10.14411/eje.2007.037

Morphometric variation of individuals in field collected samples of the Hyalopterus pruni complex from various Prunus species and regions of Greece was examined, to determine whether this variation is correlated with the host-trees from which the aphids originated. Morphometric data for 13 parameters of aphids from 74 field samples (760 adult apterae) were analysed by canonical variates analysis (CVA). Each sample was collected from a different tree and consisted of individuals from 2-3 neighbouring leaves from the same branch. Each field sample was used as a grouping factor in the CVA. The analysis produced three clusters corresponding to the taxa indicated by previous studies using allozyme markers (i.e., Hyalopterus pruni on apricot, blackthorn, plum and cherry, H. amygdali A on almond and H. amygdali B on peach). The separation was independent on the geographical origin of the samples. However, host associations within the complex were not absolute, and in particular the samples from apricot appeared to include both H. pruni and H. amygdali A. In contrast to previous views, the present study showed that the taxa have their own distinct morphology. Lastly, discriminant functions for separating the adult apterae of the taxa are given.

Energy budget of wood-feeding larvae of Corymbia rubra (Coleoptera: Cerambycidae)

Aleksandra WALCZYNSKA

Eur. J. Entomol. 104 (2): 181-185, 2007 | DOI: 10.14411/eje.2007.027

The energy budget of xylem-feeding Corymbia rubra (Coleoptera: Cerambycidae) larvae was estimated by determining bioenergetic parameters. The values of several of the life history and bioenergetic parameters of this wood-feeding insect are exceptional and associated with specific adaptations to living in and feeding on wood. The energy budget of C. rubra sheds light on the life strategy of a xylem-feeder. Its slow growth (0.012 mg × mg-1 × d-1) is associated with a low consumption rate (0.097 mg × mg-1 × d-1) and the low nutritional value of its food (the assimilation efficiency is 34%). The gross growth and net growth efficiency are 15% and 43%, respectively.

Current knowledge on genes and genomes of phytophagous beetles (Coleoptera: Chrysomeloidea, Curculionoidea): a review

Jesús GÓMEZ-ZURITA, José GALIÁN

Eur. J. Entomol. 102 (4): 577-597, 2005

Fifteen years after the publication of the first genomic sequence of a phytophagous beetle, we review here the wealth of genetic and genomic information generated so far for the species-rich beetle superfamilies Chrysomeloidea (longhorn, seed and leaf beetles) and Curculionoidea (weevils and bark beetles). In this review we briefly describe the most common methods used to investigate the beetle genomes and also compile the nucleotide sequence information stored in public gene databases until December 2004. The motivations and relevance of these research initiatives are described in certain detail, distinguishing among structural and population studies, phylogenetic research, the study of genes involved in development and diapause, energetic metabolism, vegetal tissue digestion, and genes for insect resistance and defence.

Cicadas "dig wells" that are used by ants, wasps and beetles

Kazuo YAMAZAKI

Eur. J. Entomol. 104 (2): 347-349, 2007 | DOI: 10.14411/eje.2007.050

There is a high density of the cicada Cryptotympana facialis (Walker) (Hemiptera: Cicadidae) in urban parks in central Japan during summer. This cicada uses its stylet to pierce holes in the trunks of keyaki trees, Zelkova serrata and then feeds on the exuding xylem sap. Three ant species, Formica japonica Motschulsky, Lasius japonicus Santschi and Crematogaster matsumurai Forel (Hymenoptera: Formicidae) were observed aggregatively feeding on these exudates. In addition, two wasp species, Polistes jokohamae Radoszkowski (Hymenoptera: Vespidae), and Ampulex dissector (Thunberg) (Hymenoptera: Sphecidae) fed on the sap. These ants and wasps can therefore be classified as commensals. Two flower chafers, Protaetia brevitarsis (Lewis) and P. orientalis submarumorea (Burmeister) (Coleoptera: Scarabaeidae) were also observed displacing cicadas from their feeding sites and feeding on the exuding sap. Thus, these chafers can be classified as both commensals and kleptoparasites.

Effects of polymorphic Robertsonian rearrangements on the frequency and distribution of chiasmata in the water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae)

Pablo C. COLOMBO

Eur. J. Entomol. 104 (4): 653-659, 2007 | DOI: 10.14411/eje.2007.082

The New World grasshopper Cornops aquaticum (Leptysminae: Acrididae) shows a geographical pattern for three Robertsonian polymorphisms in its southernmost area of distribution in Argentina and Uruguay. The frequency and distribution of chiasmata were analysed in five Argentinian populations. This study reveals a strong redistribution of chiasmata in fusion carriers, with a reduction in proximal and increase of distal chiasma frequency in fusion bivalents and trivalents, when all three karyotypes were compared. However, when only fusion bivalents and trivalents were compared, chiasma frequency was significantly higher in the former than in the latter. This higher chiasma frequency in fusion bivalents is due to an increase in proximal chiasma frequency. It is argued that the reduction in proximal chiasma frequency (relative to unfused bivalents) in fusion bivalents may be due to interference across the centromere. Proximal chiasma reduction in trivalents may be attributed either to a physical effect of structural heterozygosity or to an adaptation to the polymorphic condition. Therefore the differences in the distribution of chiasmata in trivalents and Robertsonian bivalents have different causes.

Environmental determination of the male morph in the ant Cardiocondyla obscurior (Hymenoptera: Formicidae)

Yanyang DU, Alexandra SCHREMPF, Jürgen HEINZE

Eur. J. Entomol. 104 (2): 243-246, 2007 | DOI: 10.14411/eje.2007.038


Cardiocondyla
is one of the few ant genera in which winged dispersing males coexist with wingless fighter males, which predominantly mate inside their maternal nests. Male polymorphism is not genetically determined but induced by environmental conditions (e.g., a decrease in temperature). The factors leading to the production of winged males were studied in more detail by exposing colonies of C. obscurior to a specific set of rearing conditions. A "stressful" environmental condition (rearing temperature lowered on average by 5°C) experienced for at least two days, the decrease of temperature by a minimum of 3°C, and the addition of protein-rich food triggered the development of winged males. In contrast, a smaller decrease in temperature, starvation, encounters with workers from other species, and encounters with alien, conspecific winged males did not induce the production of winged males. Colonies differed strongly in their reaction to changing environmental conditions, which might indicate a difference in their threshold sensitivity. The results are discussed and compared with data from other dimorphic insect species.

Review of Ceranisus (Hymenoptera: Eulophidae) of Turkey, with description of a new species

Miktat DOĞANLAR, Serguei V. TRIAPITSYN

Eur. J. Entomol. 104 (1): 105-110, 2007 | DOI: 10.14411/eje.2007.016

Three species of Ceranisus Walker, 1841 (Hymenoptera: Eulophidae: Entedoninae) were collected recently in Turkey, including C. menes (Walker, 1839) and C. pacuvius (Walker, 1841) in southeastern Anatolia. A new species, C. hirsutus Doğanlar & S. Triapitsyn, is described from ªanliurfa Province. The genus Urfacus Doğanlar, 2003 is synonymized under Ceranisus and its type species, U. bozovaensis Doğanlar, 2003 is transferred to Ceranisus as C. bozovaensis (Doğanlar, 2003) comb. n., and the species is redescribed from the new material. An identification key to both sexes of Ceranisus from Turkey and Europe is provided.

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