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A fossil head of an enicocephalomorphan (Hemiptera: Heteroptera) from England revisited: Identity of the first fossil species of Enicocephalidae from EuropePavel ŠTYSEur. J. Entomol. 107 (3): 455-460, 2010 | DOI: 10.14411/eje.2010.052 † Pyrenicocephalus jarzembowskii, gen. et sp. n. (Hemiptera: Heteroptera: Enicocephalomorpha: Enicocephalidae: Enicocephalinae) from Early Eocene, London Clay, England, Isle of Sheppey, is described and illustrated according to the unique pyritized adult head reported as a larval enicocephalid head by Jarzembowski (1986). The head anatomy of similar and related genera of Enicocephalinae is compared and the close relationship of the new genus to a clade including the extant genera Oncylocotis, Embolorrhinus and Hoplitocoris is suggested, most probably as the sister genus to Hoplitocoris (presently with Afrotropical, East Palaearctic and Oriental range). |
Effect of temperature on the reproduction and development of Trichogramma buesi (Hymenoptera: Trichogrammatidae)Sergey Ya. REZNIK, Natalia D. VOINOVICH, Nina P. VAGHINAEur. J. Entomol. 106 (4): 535-544, 2009 | DOI: 10.14411/eje.2009.067 At emergence females of Trichogramma had a lot of mature eggs in their ovaries, but some delayed parasitization or refused to parasitize a laboratory host. The effect of constant and alternating temperatures on the percentage of Trichogramma buesi females parasitizing Sitotroga cerealella eggs and the duration of the pre-parasitization period were investigated. The temperature dependencies of the rate of preimaginal development, pre-emergence survival, number of eggs laid daily, and total lifetime fecundity were also determined. As the temperature was increased from 12 to 35°C, the median pre-oviposition period decreased from 5 days to 3 h, with maximum values of 24 and 1.5 days, respectively. The rate of induction of parasitization (reciprocal of duration of the pre-parasitization period of the females that parasitized) increased with temperature like the rate of preimaginal development and average number of eggs laid daily by a parasitizing female. Total cumulative percentage of parasitizing females reached a maximum (ca 60%) at temperatures of 25-30°C, while at 12 and 35°C, respectively, 25 and 50% of females parasitized the S. cerealella eggs. Average lifetime fecundity and pre-emergence survival showed a similar dependence on temperature. The influence of the thermorhythm (25°C for 4 h and 15°C for 20 h) was strongly dependent on its position within the photoperiod. When thermophase coincided with photophase, the percentage of females that parasitized was close to that recorded at a constant temperature of 25°C. But when the high temperature pulse coincided with the dark period, the percentage of parasitizing females was the same as at 15°C. Thus, the temperature dependence of ethogenesis (supposedly, an increase in motivation to parasitize or search for a host) in Trichogramma females was similar to that of morphogenesis, although the reaction to alternating temperatures may have been complicated by interaction with the light : dark regime. |
Does climate influence phenological trends in social wasps (Hymenoptera: Vespinae) in Poland?Piotr TRYJANOWSKI, Tadeusz PAWLIKOWSKI, Krzysztof PAWLIKOWSKI, Weronika BANASZAK-CIBICKA, Tim H. SPARKSEur. J. Entomol. 107 (2): 203-208, 2010 | DOI: 10.14411/eje.2010.027 Responses of insects to recent climate change have been well documented in a number of taxa, but not in wasps. This study examined shifts in phenology of the two most important wasp species (Vespa crabro and Vespula germanica) in Poland over the last three decades. Both species showed similar temporal trends, advancing their phenology after the early 1980s, but this pattern was detected only for workers not for the appearance of queens. The appearance times for V. germanica were negatively related to mean April temperature, appearing earlier in years with warmer springs, and positively related to precipitation in April. The studied species advanced aspects of their phenology, but linking this to temperature was not achieved for V. crabro suggesting that we have to pay more attention to the life history traits of the study organisms. |
Studies on the identity of the parasitoids Aphidius colemani and Aphidius transcaspicus (Hymenoptera: Braconidae)Nikolaos GARANTONAKIS, Dionyssios PERDIKIS, Dionyssios LYKOURESSIS, Anna KOURTI, Theodoros GKOUVITSASEur. J. Entomol. 106 (4): 491-498, 2009 | DOI: 10.14411/eje.2009.062 The taxonomic status of the aphid parasitoid Aphidius colemani Viereck has been questioned, especially in regard to Aphidius transcaspicus Telenga (Hymenoptera: Braconidae). The genetic association between A. colemani and A. transcaspicus was studied by cross mating individuals of A. colemani and A. transcaspicus (A.c.& × A.t.% and A.c.% × A.t.&) and applying appropriate molecular methods. The cross mating resulted in offspring (female and males) that were fertile. Therefore, the cross mating assays performed in an artificial environment showed that these two populations are potentially compatible. The mean number of mummies that developed and the sex ratio of the offspring of each cross were similar. Most of the male and female offspring from each cross were assigned to A. transcaspicus. Furthermore, the genetic divergence between the ribosomal internal transcribed spacers (ITS2) of the A. colemani and A. transcaspicus studied was 16%. These results indicate that A. colemani might be a complex of species with different morphological and biological characters attacking different host aphids. |
Loss of genetic diversity through spontaneous colonization in the bog fritillary butterfly, Proclossiana eunomia (Lepidoptera: Nymphalidae) in the Czech RepublicGabriel NÈVE, Alois PAVLÍČKO, Martin KONVIČKAEur. J. Entomol. 106 (1): 11-19, 2009 | DOI: 10.14411/eje.2009.002 The butterfly Proclossiana eunomia (Lepidoptera: Nymphalidae) was discovered at a single locality in the Czech Republic in 1963. Until the 1980s, it was known from a restricted area, from which it spontaneously expanded during the 1980s to other localities up to 23 km from the source population. Samples were collected in 2002 from the source and ten other populations, totalling 274 specimens. All samples were analysed by electrophoresis for four polymorphic loci. Mean heterozygosity decreased with distance from the source population; this suggested a process of stepping stone colonization, involving the loss of rare alleles along the way. The populations close to the source population (less then ca. 15 km) retain a similar heterozygosity, whereas populations further away have a much reduced heterozygosity. Such a pattern of genetic differentiation and founder effect within a region is typical of specialized species with relatively low dispersal ability. The high level of genetic polymorphism found in the Šumava populations suggests that populations of this northern species in temperate-zone mountains are not just outposts of otherwise huge northern distribution, but represent genuine phylogeographic refugia. Survival of such species depends on the survival of the source population and of a sufficiently dense network of habitat patches. |
BOOK REVIEW: Adler P.H., Currie D.C. & Wood D.M.: The Black Flies (Simuliidae) of North America.J. OLEJNÍČEKEur. J. Entomol. 102 (2): 154, 2005 | DOI: 10.14411/eje.2005.024 Adler P.H., Currie D.C. & Wood D.M.: The Black Flies (Simuliidae) of North America. With a foreword by D.H. Jansen and illustrations by R.M. Idema & L.W. Zettler. Comstock Publishing Press, Ithaca & London in association with the Royal Ontario Museum. ROM publication in science, 2004, xv + 1999 pp., 255 distribution maps, 888 line drawings, 97 black-and-white photos and 24 page color folio. ISBN 0-8014-2498-4. |
The composition of the arthropod fauna of the canopies of some species of oak (Quercus)T. Richard E. SOUTHWOOD, G.R. William WINT, Catherine E.J. KENNEDY, Steve R. GREENWOODEur. J. Entomol. 102 (1): 65-72, 2005 | DOI: 10.14411/eje.2005.009 1. A study was made by knockdown sampling and branch clipping of the arthropod fauna of the canopy of two native oak species (Quercus robur and Q. petraea) and of two introduced species (Q. cerris and Q. ilex ) in woods near Oxford, UK, and of two native species (Q. pubescens and Q. ilex) in southern France. Sampling was undertaken for five years in the UK and for four years in France. All the specimens from the UK, except Acarina, Collembola and Nematocera were identified to species or, occasionally, to morphotype. |
Germ cell cluster formation and ovariole structure in Puto albicans and Crypticerya morrilli (Hemiptera: Coccinea). Phylogenetic implicationsTeresa SZKLARZEWICZ, Anna MICHALIK, Anna CZAJA, Sylwia SZYDLOWSKAEur. J. Entomol. 107 (4): 589-595, 2010 | DOI: 10.14411/eje.2010.068 The organization and development of ovaries in representatives of two families (Putoidae and Monophlebidae) of scale insects are described. Developing ovaries of Puto albicans McKenzie, 1967 and Crypticerya morrilli (Cockerell, 1914) consist of numerous clusters of cystocytes that are arranged in the form of rosettes. At the end of the last nymphal instar these clusters start to protrude from the interior of the ovary into the body cavity and the ovarioles begin to be formed. The ovary of a young female is composed of about 200 spherical telotrophic ovarioles devoid of terminal filaments. The ovarioles of C. morrilli contain 8 germ cells (7 trophocytes and a single oocyte). From 25 to 45 germ cells (23-43 trophocytes and 2 or 3 oocytes) occur in the ovarioles of P. albicans. An ovariole of an adult female is subdivided into a trophic chamber (tropharium), vitellarium and ovariolar stalk (pedicel). At each stage of development, the ovaries are accompanied by large cells (termed bacteriocytes) that contain endosymbiotic microorganisms. The organization of the ovary in P. albicans is more similar to that in archaeococcoid scale insects than in neococcoid taxa. In contrast, the number of germ cells per ovariole in C. morrilli is not typical of other archaeococcoids, but resembles the derived condition seen in other iceryine taxa. The classification and phylogeny of scale insects are discussed in the light of these results. |
Relationship between the natural duration of diapause and post-diapause reproduction in the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)Xiao-Tang WEI, Yu-Chen ZHOU, Hai-Jun XIAO, Xiao-Ping WANG, Zhen-Min BAO, Fang-Sen XUEEur. J. Entomol. 107 (3): 337-340, 2010 | DOI: 10.14411/eje.2010.042 The cabbage beetle, Colaphellus bowringi Baly undergoes an imaginal summer and winter diapause in the soil; adult emergence is spread over several months to more than 2 years, with prolonged diapause occurring in certain adults under natural conditions. The relationship between natural duration of diapause and postdiapause reproduction was investigated at 25°C under 12L: 12D photoperiod. The mean body weight of postdiapause adults with the long diapause duration of 21 months was significantly greater than with the shorter diapause duration of 5, 11 and 17 months. The longevity and mean total egg production of the postdiapause adult females with the long diapause duration of 21 months was significantly greater than that of postdiapause females with shorter diapause duration of 5, 11 and 17 months. All results demonstrate that extended diapause is associated with a high level of postdiapause reproductive performance. There is no negative trade off between diapause duration and the post-diapause reproductive traits that we measured in C. bowringi. |
Bottom-up effects of host plant nutritional quality on Plutella xylostella (Lepidoptera: Plutellidae) and top-down effects of herbivore attack on plant compensatory abilityRana M. SARFRAZ, Lloyd M. DOSDALL, Andrew B. KEDDIEEur. J. Entomol. 106 (4): 583-594, 2009 | DOI: 10.14411/eje.2009.073 The plant stress and plant vigour hypotheses are competing paradigms pertaining to the preference and performance of herbivorous insects on their host plants. Tests of these hypotheses ideally require detailed information on aspects of soil nutrition, foliar nutrient levels and parameters of herbivore fitness, but such studies are uncommon. These hypotheses were tested using the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), reared on its host plant, Brassica napus (L.), grown in an experimental system of five nutrient regimes. Different levels of fertilizer treatments significantly affected the nutrient content of B. napus foliage and this in turn affected the preference and performance of P. xylostella. Ovipositing females discriminated among host plants grown in soils subjected to different fertilizer treatments and selected plants on which pre-imaginal survival was highest, development fastest and longevity of the next generation of adults the longest, even when food was scarce. Plants subjected to herbivory by P. xylostella responded by producing elevated levels of some nutrients (e.g., sulphur), but other nutrient levels declined in infested leaves (e.g., nitrogen). Regardless of the rate of fertilizer application, plants compensated for herbivory by increasing root mass compared to un-infested control plants; plants grown in soils receiving the optimum quantity of fertilizer developed the most robust root systems when infested. The plant stress and the plant vigour hypotheses are likely to be at the opposite ends of a continuum of responses between insects and their host plants. Our investigations indicate a complex set of interactions involving both bottom-up and top-down effects, which interact to affect host plant quality, oviposition site selection by female herbivores and the fitness of their offspring. |
Genetic and physiological variation among sexual and parthenogenetic populations of Asobara japonica (Hymenoptera: Braconidae), a larval parasitoid of drosophilid fliesYusuke MURATA, Shinsuke IDEO, Masayoshi WATADA, Hideyuki MITSUI, Masahito T. KIMURAEur. J. Entomol. 106 (2): 171-178, 2009 | DOI: 10.14411/eje.2009.020 We studied variations in genetic, physiological, and ecological traits, and the phylogenetic relationship among sexual and parthenogenetic populations of Asobara japonica, a larval parasitoid of drosophilid flies, in order to understand how they adapt to local environments and have differentiated. The strain from Iriomote-jima (IR) differed from other Japanese strains in the nucleotide sequences of its cytochrome oxidase subunit I (COI) and in not undergoing diapause and having a shorter preimaginal period and a higher adult tolerance of cold. The strains other than IR showed a low level of nucleotide variation in COI but varied in their mode of reproduction; the strains from the Ryukyu Islands were sexual, whereas those from the main islands of Japan and Ogasawara were parthenogenetic. In addition, strains from higher latitudes generally showed a high incidence of diapause, although there were some exceptions. On the other hand, preimaginal period and adult cold tolerance varied little among the strains excluding IR, and pupal cold tolerance, oviposition preference and incidence of parasitism varied little among the strains including IR. Evolution and environmental adaptations in this species are discussed, particularly focusing on parthenogenetic populations. |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspectsSvend KAABER, Niels P. KRISTENSEN, Thomas J. SIMONSENEur. J. Entomol. 106 (2): 303-313, 2009 | DOI: 10.14411/eje.2009.036 Throughout most of its range the Palaearctic moth Hepialus humuli shows a striking sexual dimorphism correlated with a dimorphism in wing scale ultrastructure. Male uppersides are uniformly silvery white, due to light reflection from unpigmented scales with an elaborate internal cuticular meshwork; the conspicuous wings are visual cues for females when lekking males swarm at dusk. Female uppersides have a yellow-and-orange pigment pattern, and commonplace scale morphology. Male specimens from the Shetland and Faroe Islands populations are polymorphic, with wing uppersides ranging from the typical uniform white to being patterned much as in females, or even more melanic; forewing length is slightly greater in the darker and patterned male morphs. Male wing-scale polymorphism is only modest: even the superficially most female-like specimens are overall similar to typical males with respect to important details of scale structure. The polymorphic N. Atlantic forms are likely derived from dimorphic ancestors of the continental type. The principal selective force favouring male darkening in these insular populations is most probably a locally strong predation by visual hunters (primarily gulls and terns) on the lekking moths, combined with a lessened importance of the colour-related conspicuousness of males for female mate-searching at the high ambient light level at the swarming time at these high latitudes. This assumption is supported by the finding of a higher abundance of cryptic males (and perhaps by the smaller average size of the non-cryptic male morphs) in sites with intense bird predation. |
Seasonal occurrence and local coexistence within scarabaeid dung beetle guilds (Coleoptera: Scarabaeoidea) in Tunisian pastureFaïek ERROUISSI, Imen LABIDI, Saïd NOUIRAEur. J. Entomol. 106 (1): 85-94, 2009 | DOI: 10.14411/eje.2009.013 Dung beetle assemblages were monitored using baited pitfall traps from January to December 2006 in Northern Tunisia. 4,965 beetles belonging to 37 species were trapped. Aphodius lineolatus and Onthophagus taurus dominated the assemblages. Results showed a significant seasonal variation in assemblage composition, and diversity. There were four periods of activity during the course of the year. Temporal turnover was highest in October and in February. Temporal distribution of species shows seasonal segregation and opposite patterns in the two dominant guilds (Aphodiinae-dwellers and Scarabaeidae-tunnelers). Aphodiidae-dwellers were active from autumn to spring, although they were affected by summer drought. The Aphodius-dweller showed high temporal plasticity and phenological segregation. In contrast, Scarabaeidae-tunnelers were active all year round but mainly in the spring-summer period and less so in winter. Species in this guild showed a high degree of phenological overlap and a short ecological length. Our results suggest that coexistence in dung beetle guilds is facilitated by their phenological patterns, which reflect distinct ecological requirements and biogeographical origin of species. Geotrupidae-tunnelers and Scarabaeidae-rollers were rare and occurred mainly in the summer-autumn period, when individuals of the two other guilds were rare. |
Predatory behaviour of some Central European pselaphine beetles (Coleoptera: Staphylinidae: Pselaphinae) with descriptions of relevant morphological features of their headsAndrea SCHOMANN, Kerstin AFFLERBACH, Oliver BETZEur. J. Entomol. 105 (5): 889-907, 2008 | DOI: 10.14411/eje.2008.117 The Pselaphinae is a large subfamily of staphylinid beetles with a characteristic habitus and small body size. Detailed morphological and behavioural studies on these beetles are scarce. In this study, specimens of Bryaxis puncticollis (Denny, 1825), Bryaxis bulbifer (Reichenbach, 1816), Bythinus burrelli (Denny, 1825), Brachygluta fossulata (Reichenbach, 1816), Rybaxis longicornis (Leach, 1817), Pselaphus heisei (Herbst, 1792) and Tyrus mucronatus (Panzer, 1803), all collected in Northern Germany, have been examined with regard to their sensory organs (eyes and antennae), mouthparts and method of capturing prey. Scanning electron microscope studies revealed sex-specific differences in the numbers of ommatidia in Bryaxis puncticollis. A multitude of different sensilla on the antennae and great differences in the shape of the mouthparts were observed and peculiarities of the antennae and maxillary palps (e.g., the segment-like appendage) were examined using scanning and transmission electron microscopy. The prey-capture behaviour of these species is described in detail for the first time based on laboratory experiments using Heteromurus nitidus (Templeton, 1835) (Collembola) as prey. This behaviour seems to be tribe specific, ranging from simple seizure with the mandibles (e.g., Rybaxis longicornis, tribe Brachyglutini) to the employment of raptorial legs (Tyrus mucronatus, tribe Tyrini). The two Bryaxis species (tribe Bythinini) even employ their apparently sticky maxillary palps to capture prey. The assumption that a viscous secretion is used by these species is supported by the finding of glandular structures in the interior of their maxillary palps. Prey-capture is preceded by a complicated preparation phase in most of the species and followed by a sequence of prey-handling movements that seem to be adapted to restrain prey such as Collembola. In simple prey-choice experiments the beetles of several species preferred small prey, irrespective of their own body size. In these experiments, Bryaxis bulbifer and Brachygluta fossulata were more successful in capturing prey than Bryaxis puncticollis and Pselaphus heisei. This might be related to their different sensory equipment and different methods of capturing prey. |
The effects of six species of aphids on some life history parameters of the ladybird Propylea quatuordecimpunctata (Coleoptera: Coccinellidae)Plamen KALUSHKOV, Ivo HODEKEur. J. Entomol. 102 (3): 449-452, 2005 | DOI: 10.14411/eje.2005.064 One of the factors affecting the effectiveness of predatory coccinellids in an aphid infested crop is the food specificity of the predator. The response towards six species of aphids (Sternorrhyncha: Aphididae) was therefore tested in one of the most abundant aphidophagous coccinellids in Bulgaria - Propylea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae). All aphid species studied (Acyrthosiphon pisum Harris, Aphis craccivora Koch, Eucallipterus tiliae (L.), Euceraphis betulae (L.), Phorodon humuli (Schrank) and Myzus persicae (Sulzer) cultured on transgenic Bt and conventional (non-Bt) potatoes were suitable food according to the rate of larval development, larval mortality and adult fresh weight. Females of P. quatuordecimpunctata fed with M. persicae cultured on Bt potato, or on non-Bt potato or on a mixture of M. persicae from Bt potatoes and A. craccivora, laid a little more eggs than those fed only with A. craccivora. |
A comparison of the amino acid profiles of the pea aphid, Acyrthosiphon pisum, and the social aphid species, Pemphigus spyrothecae (Hemiptera: Aphididae)Nathan PIKEEur. J. Entomol. 107 (3): 461-463, 2010 | DOI: 10.14411/eje.2010.053 The relative proportions of free amino acids as well as the amino acid compositions of hydrolysed unprecipitated peptides and hydrolysed whole carcasses were quantified for two aphid species: the gall-dwelling social aphid Pemphigus spyrothecae and the pea aphid Acyrthosiphon pisum. The whole-tissue amino acid profiles of the two taxonomically distant species had a surprisingly high level of correspondence. In contrast, when comparing the A. pisum profiles obtained in the current study to those obtained in an earlier study, major differences were identified. It is concluded that there are good prospects for developing an artificial diet for P. spyrothecae. There may also exist considerable scope for tailoring the existing diets of A. pisum to suit specialised populations which develop poorly on the standard diet. The amino acid profile of P. spyrothecae is the first such profile that has been reported for a gall-forming aphid. |
Mesostigmatid mites associated with the dung beetle Copris lunaris (Coleoptera: Scarabaeidae)Peter MAŠÁN, Bruce HALLIDAYEur. J. Entomol. 106 (4): 545-550, 2009 | DOI: 10.14411/eje.2009.068 We examined the mesostigmatid mites found in four nest chambers of the dung beetle Copris lunaris (Scarabaeidae) in Slovakia. A total of 763 mites was found, belonging to ten species. The most frequent and abundant species were Pelethiphis opacus, Macrocheles copridis, Parasitus copridis, Uropoda copridis, Copriphis pterophilus, and Onchodellus hispani. The nests contained 19 dung balls, each enclosing a beetle pupa. Altogether 472 mites were found in these brood balls. A further 291 mites were found on the parental beetles in the nests. Three mite species were clearly more abundant in brood balls than on parental beetles, and these belonged to the life cycle stage that disperses by phoresy. The mites found in brood balls apparently disperse on the young adult beetles when they emerge. Only Parasitus copridis was more abundant on parental beetles than in brood balls. Different species of mites have developed different strategies for dispersal, as shown by their preferential attachment to either the parental or progeny generations of beetles. |
On top of a Mediterranean Massif: Climate change and conservation of orophilous moths at the southern boundary of their range (Lepidoptera: Macroheterocera)Stefano SCALERCIOEur. J. Entomol. 106 (2): 231-239, 2009 | DOI: 10.14411/eje.2009.031 During the last few decades the tree line has shifted upward on Mediterranean mountains. This has resulted in a decrease in the area of the sub-alpine prairie habitat and an increase in the threat to strictly orophilous moths that occur there. This also occurred on the Pollino Massif due to the increase in temperature and decrease in rainfall in Southern Italy. We found that a number of moths present in the alpine prairie at 2000 m appear to be absent from similar habitats at 1500-1700 m. Some of these species are thought to be at the lower latitude margin of their range. Among them, Pareulype berberata and Entephria flavicinctata are estimated to be the most threatened because their populations are isolated and seem to be small in size. The tops of these mountains are inhabited by specialized moth communities, which are strikingly different from those at lower altitudes on the same massif further south. The majority of the species recorded in the sub-alpine prairies studied occur most frequently and abundantly in the core area of the Pollino Massif. Species and, as a consequence, communities found at high altitudes are highly vulnerable to climate warming, and need further monitoring. |
Weighty matters: Body size, diet and specialization in aphidophagous ladybird beetles (Coleoptera: Coccinellidae)John J. SLOGGETTEur. J. Entomol. 105 (3): 381-389, 2008 | DOI: 10.14411/eje.2008.048 Aphidophagous ladybirds exhibit a broad range of body sizes. Until now this has been thought to be a function of the different prey densities that they feed at, with smaller ladybirds feeding at lower prey densities. The size of the prey species they feed on has been considered to have no relationship with ladybird body size. However, these arguments possess a limited capacity to explain observed data from the field. I here demonstrate a more realistic, complex approach incorporating both prey density and the size of prey species. Small ladybirds can feed on small aphids at both low and high densities. However when the aphid species is large they cannot catch the older, bigger, more energy-rich aphid instars due to their small size. They are thus unable to feed on large aphid prey at low densities, although at higher densities numbers of the smaller instars may be sufficient to sustain them. By contrast large ladybirds can feed on large aphids at both low and high densities due to their superior ability to catch the bigger, more energy-rich older aphids; however they cannot be sustained by low densities of small aphids due to food limitation consequent on their large size. This more complex association between ladybird size, prey size and prey density possesses a better explanatory power for earlier field data. Because of this relationship, ladybird body size also provides an important trade-off determining dietary breadth and specialization in the aphidophagous Coccinellidae. Dietary specialists more closely match the size of their limited prey species, have higher overall capture efficiencies and can thus continue to reproduce at lower aphid densities for longer. By contrast dietary generalists adopt a one-size-fits-all strategy, are medium-sized and have lower capture efficiencies of individual prey species, thus requiring higher aphid densities. The role of body-size in dietary specialization is supported by data from the British fauna. Rather than trade-offs related to prey chemistry, which have hitherto been the centre of attention, body size trade-offs are the likely most important universal factor underlying dietary specialization in aphidophagous coccinellids. |
Characterization of polymorphic microsatellite loci in the neotropical plant-ant Allomerus decemarticulatus (Formicidae: Myrmicinae) and multiplexing with other microsatellites from the ant subfamily MyrmicinaePierre-Jean G. MALÉ, Anne LOISEAU, Arnaud ESTOUP, Angélique QUILICHINI, Jérôme ORIVELEur. J. Entomol. 107 (4): 673-675, 2010 | DOI: 10.14411/eje.2010.074 Five polymorphic microsatellite loci of the arboreal ant Allomerus decemarticulatus (Myrmicinae) were isolated and characterized. The amplification and polymorphism of seven additional microsatellite loci, previously developed for the ant species A. octoarticulatus and Wasmannia auropunctata, were also tested and the amplification conditions necessary for genotyping the complete set of 12 multiplexed markers in A. decemarticulatus determined. The number of alleles per locus ranged from three to 15 and observed heterozygosity varied from 0.09 to 0.95. Cross-species amplification of these loci was also successfully achieved in additional species of the same ant subfamily, Myrmicinae. This set of microsatellite markers will be used in studies on the mating system and population genetic structure of Myrmicinae in general and A. decemarticulatus in particular. |
Phosphorylation of small GTPase Rab proteins from Bombyx mori (Lepidoptera: Bombycidae)Tomohide UNO, Keisuke HATA, Dieu Trang LE THI, Susumu HIRAGAKI, Takuya NAKADA, Masahiko NAKAMURA, Yuichi UNO, Hiroshi YAMAGATA, Kengo KANAMARU, Makio TAKEDA, Mamoru MATSUBARAEur. J. Entomol. 106 (4): 499-506, 2009 | DOI: 10.14411/eje.2009.063 Small GTPases of the Rab family act as essential regulators of vesicle transport pathways. Five Rab cDNA clones (BRab1, 7, 8, 11 and 14) from Bombyx mori were expressed in Escherichia coli as a thioredxin or glutathione sulfotransferase fusion protein. After purification, the fusion protein was tested for phosphorylation using protein kinase C (PKC). Results indicate that all of them were phosphorylated in vitro. The phosphorylation site of BRab1 was determined by mass-spectrometric analysis, which identified that Ser-17 of BRab1 was phosphorylated by PKC. Deletion and site-directed mutagenesis indicated that Ser-111of BRab8, in addition to Ser-17, was newly phosphorylated. Further immunohistochemical analysis using antibodies against Rab8 indicated that there are some Rab8 immunoreactive cells close to the neuropeptide secreting cells. This result suggests that in insects Rab proteins are regulated by phosphorylation and at least some of them are involved in neuropeptide secretion. |
Systematic revision of Macrotingis and phylogenetic analysis of the genera Macrotingis and Ceratotingis (Heteroptera: Tingidae)Sara Itzel MONTEMAYOR, Luiz Antônio Alves COSTAEur. J. Entomol. 106 (4): 631-642, 2009 | DOI: 10.14411/eje.2009.079 The Central American genus Macrotingis Champion, 1897 was revised and the morphological characters of the species of Macrotingis and those of its sister group Ceratotingis Montemayor, 2008 were subjected to a phylogenetic analysis. A species previously placed in the genus Tigava is now Ceratotingis spatula (Monte, 1945), new combination. Cladistic analysis indicates that both genera are monophyletic and defined the relationships between species. Keys to the species in these genera are provided together with illustrations of their main morphological characters and a map of their distribution in Central America. |
Host specificity or habitat structure? - The epicortical beetle assemblages in an Australian subtropical rainforestFlorian MENZEL, Roger L. KITCHING, Sarah L. BOULTEREur. J. Entomol. 101 (2): 251-259, 2004 We have investigated the relative importance of bark roughness and host tree species in determining the diversity and make-up of coleopteran assemblages on the trunks of trees in sub-tropical rainforest in south-east Queensland, Australia. There are clear, statistically significant, patterns in the composition of the assemblages which reflect bark roughness. Rougher bark had associated greater species and family richness, a higher proportion of "rare" species, a higher value for Shannon diversity and lower values for the Simpson and Berger-Parker Index (measures of dominance within the sample). The data support strongly the idea that there is a bark-specific beetle assemblage. The rougher bark was associated with significantly greater numbers of an anobiid species, Dorcatoma sp., and of the latridiid species Aridius australicus. Rougher bark also harboured significantly larger species. The most likely explanation for this seems to be related to the physical heterogeneity and biological complexity of the habitat, presenting, as it does, greater opportunities for shelter, feeding specialisation and intra-species aggregation. Rougher bark contained a higher proportion of both predatory and xylophagous groups than did smoother categories. No clear influence of tree species could be detected although some trends were evident. |
Multiple matings affect the reproductive performance of the aphidophagous ladybird beetle, Coelophora saucia (Coleoptera: Coccinellidae)OMKAR, Satyendra K. SINGH, Geetanjali MISHRAEur. J. Entomol. 107 (2): 177-182, 2010 | DOI: 10.14411/eje.2010.023 The effect of multiple matings on the readiness with which mating occurred, fecundity, egg viability and adult longevity in the aphidophagous ladybird beetle, Coelophora saucia (Mulsant) (Coleoptera: Coccinellidae), was investigated under laboratory conditions. The time to onset of mating after previous pairing was found to decrease with increase in the number of matings. Multiply mated females had a higher fecundity and egg viability than single mated females. The trends in the results were analyzed using both binomial regression and the Gompertz equation. The best fitting curve was that based on the binomial equation, which indicates that 95% of the maximum theoretical fecundity was attained after mating 11 times and 95% of the maximum theoretical egg viability after mating 3 times. Unlike previous studies on ladybirds, a slight but statistically significant increase in female longevity was observed with increase in number of matings indicating that the male ejaculate might provide a supply of nutrients. |
Afromontane Coelocorynus (Coleoptera: Scarabaeidae: Cetoniinae): Larval descriptions, biological notes and phylogenetic placementPetr ŠÍPEK, Bruce D. GILL, Vasily V. GREBENNIKOVEur. J. Entomol. 106 (1): 95-106, 2009 | DOI: 10.14411/eje.2009.014 This paper reports the collecting of adult beetles and third-instar larvae of Coelocorynus desfontainei Antoine, 1999 in Cameroon and provides new data on the biology of this high-altitude Afromontane genus. It also presents the first diagnosis of this genus based on larval characters and examination of its systematic position in a phylogenetic context using 78 parsimony informative larval and adult characters. Based on the results of our analysis we (1) support the hypothesis that the tribe Trichiini is paraphyletic with respect to both Valgini and the rest of the Cetoniinae, and (2) propose that the Trichiini subtribe Cryptodontina, represented by Coelocorynus, is a sister group of the Valgini: Valgina, represented by Valgus. The larvae-only analyses were about twofold better than the adults-only analyses in providing a phylogenetic resolution consistent with the larvae + adults analyses. Only one of the ten clades was consistently supported by the analyses of both the larval and adult datasets, while the remaining nine were invariably strongly supported by one but not the other analysis, thus highlighting the importance of employing different data sources. |
BOOK REVIEW: Jolivet P., Santiago-Blay J.A. & Schmitt M. (eds): NEW DEVELOPMENTS IN THE BIOLOGY OF CHRYSOMELIDAE.J. BEZDĚK, A. BEZDĚKEur. J. Entomol. 102 (4): 606, 2005 SPB Academic Publishing bv, The Hague, 2004, 804 pp., 793 figs, 80 tables. ISBN 90-5103-142-4. Price EUR 290.00, USD 345.00. |
Influence of linear versus network corridors on the movement and dispersal of the bush-cricket Metrioptera roeseli (Orthoptera: Tettigoniidae) in an experimental landscapeAnders ERIKSSON, Matthew LOW, Åsa BERGGRENEur. J. Entomol. 110 (1): 81-86, 2013 | DOI: 10.14411/eje.2013.010 Linear landscape elements are generally considered beneficial for promoting the movements of species between isolated habitats. However, relatively little consideration has been given to the effect of interconnections (nodes) between these elements: e.g. a simple linear element offers limited options for movement, whereas a network of such structures provides an exponential increase in potential pathways. In this pilot study we compared two experimental landscapes (single versus a lattice of four interconnected linear elements) in terms of their effect on the movement of males of Roesel's bush-cricket (Metrioptera roeseli) (Orthoptera: Tettigoniidae). Emigration of released bush-crickets from experimental landscapes was greater if there was a single rather than a lattice of linear elements (corridors). In the landscape with a lattice of corridors, 50% of the bush-crickets changed their direction of movement at nodes at least once. There was also evidence that nodes were attractive to bush-crickets; a higher proportion of individuals were found in and around nodes than in adjoining corridors, with the strength of this effect (i.e. aggregation at nodes) increasing with time. Thus nodes may not only affect the direction of movement but may also act as a local attractant. These effects may have an important role in the movement of species and their success in colonizing fragmented landscapes. These results indicate that in future landscape planning more consideration should be given to the connectivity between linear landscape elements as it is likely to be important in determining the movement and distribution of species. |
Seasonal cues mediate host behaviour modification and cocoon polymorphism in Microplitis mediator (Hymenoptera: Braconidae)Shu-Ping LUO, J.P. MICHAUD, Jian-Cheng LI, Jing ZHANG, Xiao-Xia LIU, Qing-Wen ZHANGEur. J. Entomol. 110 (2): 271-276, 2013 | DOI: 10.14411/eje.2013.040 Laboratory experiments were conducted to examine the effects of photoperiod and temperature on the pupation behaviour of the parasitoid, Microplitis mediator (Haliday) (Hymenoptera: Braconidae), parasitizing larvae of Mythimna separata Walker (Lepidoptera: Noctuidae). A combination of long photoperiod (14 + h L) and warm temperatures (20-24°C) caused parasitized caterpillars to climb to upper plant parts where the parasitoid produced a green, non-diapausing cocoon on a green leaf, initially retaining the dying caterpillar host as a protective covering. In contrast, short photoperiod (8-10 h L) and low temperature (16-18°C) induced host caterpillars to descend the plant where the parasitoid produced a brown, diapausing cocoon either hanging by silk from a senescing leaf or simply lying on the soil, but without any continued association with the host. These findings illustrate the potential for seasonal environmental cues to simultaneously mediate diapause induction, cocoon polymorphism, and alternate forms of host behaviour modification in a hymenopterous parasitoid. |
Molehills as important larval habitats for the grizzled skipper, Pyrgus malvae (Lepidoptera: Hesperiidae), in calcareous grasslandsMerle STREITBERGER, Thomas FARTMANNEur. J. Entomol. 110 (4): 643-648, 2013 | DOI: 10.14411/eje.2013.087 Small-scale soil disturbance, such as animal mounds created by subterraneous ecosystem engineers are important microhabitats for species of conservation concern. There are many studies on the effects of ecosystem engineers on plant species diversity and soil properties, but the influence of such organisms on other taxa, such as insects, are rarely analyzed. In this paper, we demonstrate for the first time the role of molehills produced by the European Mole (Talpa europaea) (Linnaeus, 1758) as a larval habitat for a threatened butterfly species within central European calcareous grasslands. We selected the grizzled skipper (Pyrgus malvae) (Linnaeus, 1758) as a study species as previous studies revealed that it prefers warm and open microhabitats for oviposition. Our study clearly showed that host plants occurring on or in the close vicinity of molehills were regularly occupied by immature stages of P. malvae. Occupied host plants at these disturbed sites were characterized by a more open vegetation structure with a higher proportion of bare ground or stones and a lower cover of the herb layer compared with available host plants (control samples). Among molehills those were preferred that had the highest cover of host plants, especially Agrimonia eupatoria. Molehills are important larval habitats for P. malvae in calcareous grasslands on deeper soils. At these sites succession occurs rapidly and the amount of bare ground is usually low, even when they are managed. In contrast to other known breeding sites in calcareous grasslands, molehills with a high cover of host plants provide ideal conditions for the successful larval development of P. malvae: (i) sufficient food during the larval period and (ii) warm microclimatic conditions. |
Abundance and host associations of parasitoids attacking frugivorous drosophilids on Iriomote-jima, a subtropical island of JapanBiljana NOVKOVIĆ, Ayako OIKAWA, Yusuke MURATA, Hideyuki MITSUI, Masahito T. KIMURAEur. J. Entomol. 109 (4): 517-526, 2012 | DOI: 10.14411/eje.2012.065 To understand the factors governing the diversity, abundance and host associations of parasitoids attacking frugivorous drosophilid flies on Iriomote-jima, a subtropical island of Japan, we monitored parasitism on several occasions over the period 2003-2009. Fifteen drosophilid and 12 parasitoid species were recorded. Three species of Drosophila, D. bipectinata, D. albomicans and D. takahashii, bred abundantly in banana baits, though their abundance varied between years and seasons. Frequent parasitoid species were Asobara japonica, A. pleuralis (Braconidae), Leptopilina ryukyuensis and L. pacifica (Figitidae). L. victoriae was recorded only in December 2003. In addition, host acceptance and host suitability of the four most frequently recorded parasitoid species were studied in the laboratory. Most parasitoid and drosophilid species showed species-specific associations with more than one antagonist species, suggesting that they have been subjected to complex coevolutionary interactions. In addition, host range of most of the parasitoid species included one of the three major Drosophila species, suggesting that the abundance of potential hosts is one of the factors determining the evolution of parasitoid host use. |