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Berchmansus elegans (Neuroptera: Chrysopidae): Larval and adult characteristics and new tribal affiliationCatherine A. TAUBER, Maurice J. TAUBER, Gilberto S. ALBUQUERQUEEur. J. Entomol. 103 (1): 221-231, 2006 | DOI: 10.14411/eje.2006.024 The genus Berchmansus Navás, which was previously assigned to the tribe Leucochrysini, consists of three very rare species, all described from the Neotropics and all poorly known. Our report (1) provides the first description of a Berchmansus larva, the first instar of Berchmansus elegans (Guérin Méneville), (2) illustrates and redescribes the B. elegans adult, with emphasis on male and female genitalia, and (3) examines the larval and adult characters vis-à-vis the tribal affiliation of the genus. Given that the B. elegans adult and first instar share many apomorphies with other belonopterygine genera, this species belongs in the cosmopolitan tribe Belonopterygini, rather than the New World tribe Leucochrysini. Although Berchmansus larvae have not been collected in the field, we suspect that, like other belonopterygines, they are associated with ant nests. B. elegans exhibits a number of highly modified and unusual structures, some of which (#1 to #5) are not reported for any other chrysopids. Specifically: Males have (1) a unique, quadrate, dome-like hood above the gonarcus and (2) large, coiled parameres on the gonosaccus. First instars have (3) a greatly enlarged subapical seta on the flagellum, (4) a transverse row of long, hooked setae along the dorso-anterior margin of the pronotum, and (5) setose laterodorsal tubercles on the meso- and metathorax, with (6) multi-pronged, hooked setae. |
BOOK REVIEW: Gadau J. & Fewell J. (eds): ORGANIZATION OF INSECT SOCIETIES, FROM GENOM TO SOCIOCOMPLEXITY.J. ®ĎÁREKEur. J. Entomol. 106 (3): 361-362, 2009 | DOI: 10.14411/eje.2009.045 Harvard University Press, Cambridge, MA, and London, UK, 2009, 617 pp., hard cover. ISBN 978-0-674-03125-8. Price USD 79.95. |
Life tables and demographic statistics of Russian wheat aphid (Hemiptera: Aphididae) reared at different temperatures and on different host plant growth stagesZhanshan (Sam) MA, Edward J. BECHINSKIEur. J. Entomol. 106 (2): 205-210, 2009 | DOI: 10.14411/eje.2009.026 Laboratory experiments were used to investigate the influences of 25 combinations of temperature and barley plant growth stage (5 × 5 factorial combination of temperature and barley plant growth stage) on the development, survival and reproduction of the Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko). For each of the 25 treatments, the developmental time and nymphal production of 72 RWA individuals were recorded (1800 RWA in total) throughout their entire lifetimes. The collected data were used for analyzing demography, modelling phenology, and simulating population growth of RWA. In this paper, the results of demographic analyses are reported. Specifically, for each treatment, cohort life tables, reproductive heterogeneity tables (parity and birth intervals), and reproductive schedule tables were constructed, and demographic parameters such as intrinsic rate of increase, life-span, fecundity, life table entropy, etc. calculated. Based on these analyses, the most important summary demographic statistics are reported. Using the intrinsic rate of increase (rm) as an example, a procedure is demonstrated that builds a dynamic rm model by applying the Best Subset Regression approach. A more comprehensive (considering reproductive heterogeneity and schedule tables) yet concise (comprising dynamic rm models) demographic model than that based on standard life table analysis alone is presented. |
Responses of life-history traits of brackish- and freshwater populations of the water strider to NaCl Aquarius paludum (Hemiptera: Gerridae)Manabu KISHI, Tetsuo HARADA, Kenji FUJISAKIEur. J. Entomol. 106 (1): 43-48, 2009 | DOI: 10.14411/eje.2009.006 The water strider Aquarius paludum inhabits the surfaces of a wide variety of freshwater habitats both temporary and permanent. It can also live on the surface brackish-water around river mouths. Exposure to a brackish rather than freshwater environment may affect a range of adult and offspring life-history traits. In a two-stage experiment A. paludum offspring from fresh- (F) and brackish-water (B) populations were obtained and their offspring reared in either a fresh- or brackish-water (0.45% NaCl) environments. The four offspring treatment groups (F-F, F-B, B-F, B-B) varied in terms of the parental and offspring rearing environments. The effect of parental and offspring rearing environment on longevity, fecundity and flight was assessed. Offspring reared in a brackish environment throughout their larval and adult stages had a reduced longevity and egg production. The flight activity of the offspring originated from the brackish-water population was maintained when they were reared in a brackish environment, but inhibited when they were exposed to freshwater. Our results suggest that the life-history strategies depend critically on the degree of salinity in both the current environment and that of their parents. |
Experimental hybridization between X0 and XY chromosome races in the grasshopper Podisma sapporensis (Orthoptera: Acrididae). II. Cytological analysis of embryos and adults of F1 and F2 generationsElżbieta WARCHAŁOWSKA-¦LIWA, Alexander G. BUGROV, Yoshikazu SUGANO, Anna MARYAŃSKA-NADACHOWSKA, Shin-Ichi AKIMOTOEur. J. Entomol. 105 (1): 45-52, 2008 | DOI: 10.14411/eje.2008.006 Experimental hybridization of X0 and XY chromosome races of the brachypterous grasshopper P. sapporensis did not reveal pre-zygotic reproductive isolation. However, a partial zygotic barrier was found between the X0-standard race from Shimokawa and XY-standard chromosome race from Akan. Approximately 40% of embryos from females crossed with males from other chromosome races developed parthenogenetically, the remaining embryos were normal heterozygotes. Adult F1 males and females from crosses of this type had properly developed testes and ovaries. Non-sister associations and other irregularities in meiosis were not observed in male meiosis. Crossing experiments demonstrated that hybrids between X0 and XY races occur to some extent. The absence of a hybrid zone between the X0 and XY chromosome races may be the result of selection against heterozygotes. Crosses between the XY-Tanno and X0-standard (Teine) subraces resulted in F1 and F2 generations in spite of the many chromosome differences between them such as a X-A translocation and fixed pericentric inversions in four pairs of autosomes. These results do not support the hypothesis that chromosomal differences play a key role in restricting gene flow between the X0 and XY races of P. sapporensis. |
Cockroach tergal glands producing female sex attractant pheromones and male aphrodisiacs in particular in the subfamily Blaberinae (Blattaria: Blaberidae)Leam SRENGEur. J. Entomol. 103 (4): 817-829, 2006 | DOI: 10.14411/eje.2006.112 Two principal pheromones are essential in all cockroach sexual behavioral sequences: the volatile sex attractant pheromone released by one partner for long distance attraction and an aphrodisiac sex pheromone produced exclusively by male tergal glands for female mounting and feeding behavior. In the Blaberinae subfamily, the female produces volatile sex attractant pheromones and the male, aphrodisiacs. A close relationship is known to exist between the release of these pheromonal signals from specific glands and the corresponding behaviors (female calling posture and male wing raising). However, in this cockroach group, no data on the glands secreting sex attractant pheromones and aphrodisiacs have been available until now. In seven species of the Blaberinae subfamily: Blaberus colosseus, B. craniifer, B. discoidalis, Blaptica interior, Byrsotria fumigata, Eublaberus distanti and E. posticus; one species of the Zetoborinae subfamily: Schultesia lampyridiformis; one species of the Epilamprinae subfamily: Epilampra maya and one species of the Panesthiinae subfamily, Panesthia sp., the females possess all pygidial glands on the 10 th tergite and the males have tergal glands situated anteriorly, generally on tergites T1 and T2. These glands are formed of type 3 glandular units with two cells, i.e. glandular and canal cells. The uniform presence of female pygidial glands and male tergal glands explains their relationship with their corresponding sexual behaviors. |
Isolation and characterization of polymorphic microsatellite loci in the bamboo locust Rammeacris kiangsu (Orthoptera: Acrididae)Wen-Juan XUAN, Yan-Yan ZHANG, Na-Na LIU, Jin-Liang ZHAO, Guo-Fang JIANGEur. J. Entomol. 106 (4): 663-665, 2009 | DOI: 10.14411/eje.2009.082 Twelve polymorphic microsatellite loci were developed and characterized from the bamboo locust, Rammeacris kiangsu, based on enriched genomic libraries. Analysis of 30 individuals showed that the number of alleles ranged from seven to 25 with the observed heterozygosity ranging from 0.333 to 0.767 and expected heterozygosity from 0.784 to 0.963. Test of cross-species amplification showed that some of these microsatellite markers could be used for studying other species such as Ceracris nigricornis, C. fasciata, and Chorthippus brunneus. |
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. |
BOOK REVIEW: Van Driesche R., Hoddle M. & Center T.: Control of Pests and Weeds by Natural Enemies. An Introduction to Biological Control.I. HODEKEur. J. Entomol. 106 (2): 323, 2009 | DOI: 10.14411/eje.2009.038 Blackwell, Malden, MA & Oxford, 2008, 473 pp. ISBN 978-1-4051-4571-8. Price: USD 69.95. |
Life table parameters of the aphid predators Coccinella septempunctata, Ceratomegilla undecimnotata and Propylea quatuordecimpunctata (Coleoptera: Coccinellidae)Dimitrios C. KONTODIMAS, Panagiotis G. MILONAS, George J. STATHAS, Nickolaos E. PAPANIKOLAOU, Anna SKOURTI, Yiannis G. MATSINOSEur. J. Entomol. 105 (3): 427-430, 2008 | DOI: 10.14411/eje.2008.054 The life tables of the aphid predators Coccinella septempunctata L., Ceratomegilla undecimnotata (Schneider) and Propylea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae), fed on Aphis fabae Scopoli (Hemiptera: Aphididae), were constructed at constant conditions (25 ± 1°C, 65 ± 2% RH; 16L : 8D). The average total fecundities of C. septempunctata, C. undecimnotata and P. quatuordecimpunctata were 1996.8, 1160.5, and 724.6 eggs / female, and the average longevities were 94.9, 88.3, and 68.9 days, respectively. The net reproductive rates (Ro) were 1004.1, 544.3, and 375.1 females/female, and the intrinsic rates of increase (rm) 0.118, 0.142 and 0.166 females/female/day, respectively. |
Geographical patterns of chromosomal differentiation in the brachypterous grasshopper Podisma sapporensis (Orthoptera: Acrididae)Elżbieta WARCHAŁOWSKA-¦LIWA, Haruki TATSUTA, Shin-Ichi AKIMOTO, Anna MARYAŃSKA-NADACHOWSKA, Marek KOWALCZYK, Alexander BUGROVEur. J. Entomol. 105 (2): 185-196, 2008 | DOI: 10.14411/eje.2008.027 The distribution patterns of the X0/XX and neo-XY/neo-XX chromosome races, subraces, and "hybrids" between subraces of the grasshopper P. sapporensis were analyzed. The origin of the observed variation is Robertsonian translocations between a sex chromosome and an autosome, and chromosome rearrangements. The fixation levels of inversions varied depending on geographic regions. No hybrid population is known implying that a strong reproductive isolation system exists in hybrids between the different chromosomal races. The probable reasons for the purity of X0 and neo-XY chromosome races and high chromosome polymorphism in contact zones between chromosomal subraces are discussed. The presence of isolating barriers between chromosome races indicates a review of the taxonomic structure of P. sapporensis is required. It is proposed to divide P. sapporensis into two sibling species, which differ in the chromosome mechanisms of the sex determination system.The analysis of the distribution of chromosomal races and subraces of P. sapporensis allows a reconstruction of the history of this species in the Okhotsk sea region. |
Patch size and connectivity influence the population turnover of the threatened chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae)Atte KOMONEN, Tuuli TIKKAMÄKI, Niina MATTILA, Janne S. KOTIAHOEur. J. Entomol. 105 (1): 131-136, 2008 | DOI: 10.14411/eje.2008.018 Chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae) has severely declined in many parts of Europe and is currently red-listed in many countries. We studied the population structure and turnover of the species in a lake-island system in a National Park in eastern Finland over a three-year period. The incidence of the chequered blue on the suitable islands (n = 41) and habitat patches (n = 123) was high: an average of 82% of the islands and patches were occupied over the three year period. At the island scale, the annual population turnover rate was 17%, with an extinction and colonization rate of 7% and 10%, respectively. At the patch scale, the annual population turnover was 16%, with 7% extinction and 9% colonization rate. Islands that were occupied over the three year period had a larger area of suitable habitat than islands in which turnover events were observed. At the patch scale, turnover events were observed in small and poorly connected patches. Patchy occurrence of the host plant and observed extinction-colonization dynamics suggest that the chequered blue population confirms a metapopulation structure. Although the local populations are small, the observed high patch occupancy and balanced population turnover indicates that the metapopulation is not in immediate risk of extinction. |
Female copulatory tubes and the subdivision of the genus Anthocoris (Heteroptera: Anthocoridae: Anthocorini)Yunling KE, Wenjun BUEur. J. Entomol. 104 (1): 89-98, 2007 | DOI: 10.14411/eje.2007.014 We report a systematic study of the female copulatory tubes of forty species in the genus Anthocoris, most of which are from the Northern Hemisphere. Our results indicate that female copulatory tubes can be used as a reliable character to identify females and analyze phylogenetic relationships in this genus. We propose thirteen species groups based on the copulatory tubes of females, other morphological characters of both sexes, and the previous species groups adopted in the continental faunas. |
Comparative study of larval head structures of Megaloptera (Hexapoda)Rolf G. BEUTEL, Frank FRIEDRICHEur. J. Entomol. 105 (5): 917-938, 2008 | DOI: 10.14411/eje.2008.119 External and internal head structures of the larva of Neohermes are described in detail. The results are compared to conditions found in other representatives of Corydalidae, in Sialidae, and in Raphidioptera and Neuroptera. Corydalidae and Sialidae are mainly characterised by plesiomorphic features such as distinct frontal and coronal sutures, six stemmata, a movable labrum with a full set of muscles, a thin tentoriomandibular muscle, a distinct maxillary groove, 4-segmented maxillary palps, an oblique arrangement of the extrinsic maxillary muscles, a labium with all components except for the glossae and paraglossae, 3-segmented labial palps, and a largely complete muscle system. The partly reduced maxillary groove, the strongly elongated stipes, the apical membranous stipital collar, the close connection of the palp and galea, the subdivision of the galea, the strongly shortened palp, the bipartite tentoriocardinal and tentoriostipital muscles, the anterolateral submental notch, the lateral tentoriopharyngeal muscle, and the postgular plate are autapomorphies of Corydalidae. An additional antennomere is present in large corydalid species. The monophyly of the subfamilies Corydalinae and Chauliodinae is not supported by features of the larval head. The reduced condition of the anterior and dorsal tentorial arms and the antennal muscles, the transverse labial muscle, the loss of muscles of the salivary duct, and possibly the lateral origin of M. frontopharyngalis posterior are autapomorphies of Sialidae. The monophyly of Megaloptera is suggested by the insertion of a peg-like or spine-shaped sensillum on the antepenultimate antennomere, the vestigial salivary duct, and a verticopharyngeal muscle composed of several bundles. The distinct neck region, the parietal ridge, and the anterior position of the posterior tentorial grooves are features shared by Corydalidae and Raphidioptera. Arguments in favour of a clade comprising Megaloptera and Raphidioptera are the presence of a circular ridge anterad of the neck region, an increased number of Semper cells and retinula cells in the stemmata, the presence of a gula in adults, a similar cleaning behaviour, and molecular data. Potential autapomorphies of Neuropterida are the prognathism of the larvae and the absence of a mandibular mola. However, the polarity of these characters is unclear. A derived condition found in most groups of Endopterygota, but not in Hymenoptera, is the presence of one or two sensorial appendages on one of the intermediate antennomeres, usually the penultimate. Larval autapomorphies of Endopterygota suggested in earlier studies are confirmed for Corydalidae. |
Multitrophic interactions among plants, aphids, alternate prey and shared natural enemies - a reviewEdward W. EVANSEur. J. Entomol. 105 (3): 369-380, 2008 | DOI: 10.14411/eje.2008.047 Given the generalist tendencies of most predatory arthropods, it is widely thought that their impact on a particular prey species in a given habitat (e.g., an insect pest in a crop) will depend frequently on the local availability of other prey (which for omnivorous predators, can include plant resources, such as fruit and pollen). Thus, from a slightly different perspective, aphids, other herbivorous insects, and plants often may interact indirectly by sharing natural enemies. Such interactions may be either negative or positive, as in the concepts of apparent competition and apparent mutualism, and may therefore have variable impact on the herbivores' host plants as well. I examine the different mechanisms for such indirect effects among herbivores as explored in the experimental literature. An impressive collective effort by numerous researchers recently has expanded considerably our empirical base of support for a variety of hypothesized mechanisms; aphids stand out as the most commonly studied subjects in research on these mechanisms. I therefore focus especially on the recent literature of cases involving aphids interacting indirectly with other prey for generalist predators. My remarks are organized by considering how the availability of alternate prey may alter functional and numerical (aggregative and reproductive) responses of predators to focal prey density. Although the distinctions among these different classes of predator responses and the associated indirect effects are often blurred and scale-dependent, this classification remains useful for organizing the diverse ways in which aphids have been found to participate in indirect interactions among prey as mediated by predators. Collectively, the results of the numerous studies reviewed here suggest that many such indirect interactions likely occur frequently in natural settings, with consequences ultimately for host plant performance. |
Apple aphid, Aphis spp. (Hemiptera: Aphididae), and predator populations in an apple orchard at the non-bearing stage: The impact of ground cover and cultivarBruno FRÉCHETTE, Daniel CORMIER, Gérald CHOUINARD, Franz VANOOSTHUYSE, Éric LUCASEur. J. Entomol. 105 (3): 521-529, 2008 | DOI: 10.14411/eje.2008.069 A two-year field experiment was conducted to determine whether a conservation biological control strategy could be applied to enhance the biological control of green apple aphids, Aphis spp., in a high-density and scab-resistant apple orchard at the non-bearing stage. The natural occurrence of aphid predators and their impact on aphid populations were evaluated in 2005. The impact of predation on aphid densities was evaluated by comparing a predator exclusion treatment with a control. In 2006, the possibility to enhance predator abundance/performance and aphid biological control with a flowering ground cover was tested: trees were grown either with a flowering ground cover of phacelia, Phacelia tanacetifolia Bentham, and buckwheat, Fagopyrum esculentum Moench, or with a conventional ground cover of mixed Poaceae species. In 2006, it was also determined whether aphid densities differ between Liberty and Topaz, 2 scab-resistant cultivars. Results indicate that the predatory arthropod community was dominated by Coccinellidae, Cecidomyiidae, and various spider species. The ladybird community was dominated by the exotic species Harmonia axyridis Pallas, and the abundance of this species was correlated with aphid density. Naturally occurring predators had little impact on aphid abundance, although the proportion of trees with aphid colonies was greater in the predator exclusion treatment on two consecutive dates in 2005. Ground cover types had no impact on aphid densities. The oviposition response of Cecidomyiidae to aphid density was greater in Liberty trees with flowering ground cover than with the conventional ground cover. Conversely, the response of ladybird adults to aphid density was more important in Topaz trees with the conventional ground cover than with the flowering ground cover. Finally, no difference occurred in aphid abundance between Liberty and Topaz trees. Those results are discussed from a biological control and ecological point of view. |
Egg-dumping behaviour in the seed beetle Acanthoscelides obtectus (Coleoptera: Chrysomelidae: Bruchinae) selected for early and late reproductionDarka ©E©LIJA, Biljana STOJKOVIĆ, Branka TUCIĆ, Nikola TUCIĆEur. J. Entomol. 106 (4): 557-563, 2009 | DOI: 10.14411/eje.2009.070 In the present study the egg dumping behaviour in short (E)- and long (L)-lived lines of the seed beetle Acanthoscelides obtectus was analyzed. Females of the short-lived E line exhibited substantially higher egg dumping than long-lived L line females. We hypothesize that, since cessation of egg dumping enhances longevity, non-dumping females were selectively favoured in the L regime. Our study also produced evidence that the selection regime affected the male's ability to influence female egg-dumping behaviour. The females mated to males from the lines that were selected for extended longevity and of which the females exhibited little egg-dumping dumped fewer eggs. We suggest that in the L selection regime, where offspring produced at the end of the females' reproductive period were recruited to the next generation, selection operated against those males that stimulated female oviposition in the absence of seeds. This is the first study to provide evidence that selection for long-lived insects results in the reduced potency of male seminal products to stimulate female oviposition. |
Effect of female size on host selection by a koinobiont insect parasitoid (Hymenoptera: Braconidae: Aphidiinae)Dionyssios LYKOURESSIS, Nikolaos GARANTONAKIS, Dionyssios PERDIKIS, Argyro FANTINOU, Andronikos MAUROMOUSTAKOSEur. J. Entomol. 106 (3): 363-367, 2009 | DOI: 10.14411/eje.2009.046 Body size is a main fitness component of insect parasitoids. We assessed the potential influence of maternal size of the parasitoid wasp Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae) on its ability to parasitize the different instars of Aphis gossypii Glover (Hemiptera: Aphididae) on eggplant and cucumber. In the experiments "small" vs "large" parasitoid females were used. Females oviposited in all instars but more of the smaller hosts were parasitized. Host selection was affected by female size and the larger hosts were more frequently mummified by the large than the small females. Thus, parasitoid female size influenced host selection. This could affect the potential of the parasitoid to exploit populations of aphids that differ in their size structure. The importance of these results in terms of the ecological adaptations of the parasitoid and their implication for biological control are discussed. |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splittingJean-François DAVIDEur. J. Entomol. 106 (2): 211-216, 2009 | DOI: 10.14411/eje.2009.027 First-stadium juveniles of Polydesmus angustus born each month from May to September were reared throughout their life cycle under controlled seasonal conditions. At maturity, the reproductive patterns of 62 females were studied individually. It was confirmed that females born from May to August have a 1-year life cycle and those born from late August onwards a 2-year life cycle (cohort-splitting). A third type of life cycle - interseasonal iteroparity - was observed in a few females born late in the season. On average, annual females started to reproduce when 11.4 months old and produced 3.6 broods per female over 1.8 months; the later they were born from May to August, the later they reproduced the following year. Biennial females started to reproduce when 19.9 months old and produced 3.8 broods per female over 2.2 months; all reproduced early in the breeding season. These results indicate that only annual females can produce an appreciable proportion of biennial offspring from late August onwards, which rules out direct genetic determination of life-cycle duration. The reproductive characteristics of P. angustus suggest a non-genetic mechanism that can drive cohort-splitting. Because individual females reproduce for about 2 months on average, this automatically results in cyclic variation in life-cycle duration (annual/biennial/annual) in the long-term progeny of any female. |
BOOK REVIEW: H.F. van Emden & R. Harrington (eds): Aphids as Crop Pests.J. HAVELKAEur. J. Entomol. 106 (1): 56, 2009 | DOI: 10.14411/eje.2009.008 CABI Publishing, London, 2007, 717 pp. ISBN 978 0 85199 819 0. Price USD 290.00 / EUR 230.00 / GBP 147.00. |
Chromosome number, karyotype morphology, heterochromatin distribution and nuclear DNA content of some talitroidean amphipods (Crustacea: Gammaridea)Angelo LIBERTINI, Renata TRISOLINI, Massimiliano RAMPINEur. 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. |
Revision of the genus Teratolytta (Coleoptera: Meloidae)Marco A. BOLOGNA, Andrea DI GIULIOEur. J. Entomol. 103 (1): 137-161, 2006 | DOI: 10.14411/eje.2006.019 The blister beetle genus Teratolytta, belonging to the tribe Lyttini, is revised and a classification is proposed. Two main sections of the genus - one including five groups of species and the other three groups - are tentatively defined. Four new species from Eastern and Southern Anatolia are described (T. carlae sp. n., T. dvoraki sp. n., T. monticola sp. n., T. taurica sp. n.), and a key to the 17 recognized species is proposed. A diagnosis of the species as well as taxonomic remarks are proposed, and a catalogue of localities is presented. In particular, Teratolytta tricolor (Haag-Rutenberg, 1880) comb. n. is re-established as a distinct species, T. cooensis G. Müller, 1936 is confirmed as a synonym of T. gentilis (Frivaldszky, 1877), T. bytinskii Kaszab, 1957 as a synonym of T. senilis (Abeille de Perrin, 1895), and T. holzschuhi Dvořák, 1983 is proposed as a synonym of T. eylandti Semenow, 1894; some infraspecific forms are referred to the variability of T. gentilis and T. flavipes (Mulsant & Rey, 1858). The first instar larva of T. gentilis is described and figured, and the sexual behaviour of this species is also briefly studied. |
Rhythmic oscillations of α-amylase protein and its enzymatic activity levels in Drosophila melanogaster (Diptera: Drosophilidae)Marcin A. CIUK, Piotr BEBAS, Bronislaw CYMBOROWSKIEur. J. Entomol. 106 (4): 519-528, 2009 | DOI: 10.14411/eje.2009.065 In this report, we show that α-amylase activity is rhythmic in the wild-type fruit fly Drosophila melanogaster, and that this rhythm exhibits the properties of a clock output. Moreover, the rhythm of amylase activity is accompanied by fluctuations in the Amy protein level under 12L : 12D conditions. A strong sexual dimorphism is evident in the oscillations of Amy protein and enzymatic activity. Under light : dark (LD) conditions on the control diet, CantonS wild-type Drosophila melanogaster exhibit a bimodal rhythm of amylase activity, particularly of the AmyD3 (Amy3) isoform, with morning and evening peaks. Under these conditions, Amy protein levels also oscillate significantly, again more strongly for the Amy3 isoform than Amy1 (Amy1). A robust oscillation of Amy3 and Amy1 activity is also observed under DD conditions for both sexes. In constant light (LL) the rhythms dampen out, particularly in the males. A high level of dietary glucose causes an overall decrease in the amplitudes of the rhythmic oscillations of amylase activity, but the processes are nevertheless rhythmic, with peak activities at Zt8 for the females, and at Zt0 for the males in LD. In constant darkness (DD) the rhythms are maintained. Mutants lacking a functioning oscillator, per01, exhibit a slight photoperiodicity in LD, with a decrease in amylase activity in both males and females during the late night in LD, but no rhythmic oscillations in DD. |
Population structure and speciation in the dragonfly Sympetrum striolatum/nigrescens (Odonata: Libellulidae): An analysis using AFLP markersKatharine A. PARKES, William AMOS, Norman W. MOORE, Joseph I. HOFFMAN, Janet MOOREEur. J. Entomol. 106 (2): 179-184, 2009 | DOI: 10.14411/eje.2009.021 There has been a long-standing debate as to whether Sympetrum striolatum (Charpentier, 1840) and the darker northern form, S. nigrescens (Lucas, 1912) should be recognised as separate species of dragonfly. Here we address this question using genetic analysis based on AFLP markers and samples collected from sites across the species' United Kingdom range. The program STRUCTURE finds no support for specific status. Instead, it reveals strong patterns of divergence between populations sampled from Scottish islands and those on the mainland, suggesting that salt water is a major barrier to gene flow. Thus, the dark form is quite likely to reflect a beneficial polymorphism that allows individuals to take advantage of short periods of warmer weather. Our AFLP markers appear to be very rapidly evolving, showing little or no overlap between congeneric species, and hence are ideally suited to answering questions relating to the levels of gene flow among populations within species. |
Chromosomal differentiation among bisexual European species of Saga (Orthoptera: Tettigoniidae: Saginae) detected by both classical and molecular methodsElżbieta WARCHAŁOWSKA-¦LIWA, Beata GRZYWACZ, Anna MARYAŃSKA-NADACHOWSKA, Tatjana V. KARAMYSHEVA, Nikolai B. RUBTSOV, Dragan P. CHOBANOVEur. J. Entomol. 106 (1): 1-9, 2009 | DOI: 10.14411/eje.2009.001 We report the karyotype characteristics including chromosome numbers of Saga campbelli campbelli, S. c. gracilis, and S. rammei using the following classical cytogenetic methods: C-banding, silver staining, and fluorochrome staining DAPI and CMA3. We also present FISH data showing the distribution of telomeric repeats and 18S rDNA on the chromosomes of these species and the results of similar studies cited in the literature on S. hellenica, S. natoliae, and S. rhodiensis. The five European Saga species exhibit a high rate of karyotype evolution. In addition to changes in chromosome number and morphology (by chromosomal inversion and/or chromosome fusion), interspecific autosomal differentiation involved changes in the distribution and quantity of constitutive heterochromatin and GC-rich regions, as well as the number and location of NORs. In the present study we focused on testing a hypothetical model of karyotype evolution in Saga, with particular reference to the cytogenetic mapping of rDNA and telomeric sequences. Variation in the distribution of rDNA and location of Ag-NORs are novel phylogenetic markers for the genus Saga. |
Lepidosina, a new genus of New World Limosininae (Diptera: Sphaeroceridae)Stephen A. MARSHALL, Matthias BUCK, Owen LONSDALEEur. J. Entomol. 104 (3): 573-599, 2007 | DOI: 10.14411/eje.2007.074 The New World genus Lepidosina Marshall & Buck gen. n. is described including nine new and two previously described species: L. angusticercus Marshall & Buck sp. n. (Caribbean, Central and South America), L. argentinensis Marshall & Buck sp. n. (Argentina), L. cubensis Marshall & Buck sp. n. (Cuba), L. evanescens Marshall & Buck sp. n. (Central and South America), L. gibba (Spuler) comb. n. (Florida, Caribbean), L. inaequalis (Malloch) comb. n. (southern U.S.A., Central America, Venezuela), L. multispinulosa Marshall & Buck sp. n. (Ecuador, Peru), L. platessa Marshall & Buck sp. n. (Bolivia), L. proxineura Marshall & Buck sp. n. (Brazil), L. quadrisquamosa Marshall & Buck sp. n. (Venezuela), and L. rutricauda Marshall & Buck sp. n. (Colombia to Peru). Keys to males and females are provided, and the species level phylogeny is analyzed based on a matrix of 24 morphological characters. The sister group of this well-defined, highly apomorphic genus remains unknown. Most species are restricted to lowland habitats. Larvae and puparia of Lepidosina remain unknown. |
Afroaltica subaptera, new genus and new species of flea beetles from the southern Africa (Coleoptera: Chrysomelidae: Alticinae)Maurizio BIONDI, Paola D'ALESSANDROEur. J. Entomol. 104 (1): 99-103, 2007 | DOI: 10.14411/eje.2007.015
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The eye of the parthenogenetic and minute moth Ectoedemia argyropeza (Lepidoptera: Nepticulidae)Anna HONKANEN, Victor Benno MEYER-ROCHOWEur. J. Entomol. 106 (4): 619-629, 2009 | DOI: 10.14411/eje.2009.078 Ectoedemia argyropeza (Zeller, 1839) possesses a compound eye that exhibits features of both apposition and superposition type eyes. Like apposition eyes, the eye of E. argyropeza lacks a clear-zone, which in superposition eyes separates the distal dioptric from the proximal light-perceiving structures. On the other hand, a tracheal layer around the proximal ends of the rhabdom as well as a well-developed corneal nipple array on the corneal surfaces are features that E. argyropeza shares with the larger moths. Unique, and so far only seen to this extreme degree in any insect, is the hourglass-shape of E. argyropeza's rhabdom, in which two almost equally voluminous regions (one distal, one proximal and formed in both cases by seven rhabdomeres) are connected by a narrow waist-like region of the retinula. An eighth retinula cell, not participating in rhabdom formation, is developed as a basal cell, just above the basement membrane. The eye responds with photomechanical changes to dark/light adaptation, but while the proximal rhabdom moiety slightly expands (as expected) in the dark, the distal rhabdom increases its diameter only upon light-adaptation. Owing to the tandem position of the two rhabdom moities, it is in the light-adapted state that the distally-placed rhabdom is favoured, while the proximal rhabdom plays a more important role at low ambient light levels. With screening pigments withdrawn, tracheal tapetum exposed, and distal rhabdom diameters reduced, the proximal and in the dark enlarged rhabdom is then in a position to capture photons that have entered the eye through not only the ommatidial window above, but other facets as well even in the absence of a clear-zone and superposition optics. |
Resources for British butterflies (Lepidoptera: Hesperioidea, Papilionoidea). The alien consumer component and its significance for butterfly habitatsPeter B. HARDY, Roger L.H. DENNISEur. J. Entomol. 105 (4): 649-657, 2008 With climatic warming there is an expectation that phytophagous insects will increasingly use alien (non native) plants as nectar sources and larval host plants. Alien plant use is investigated in British butterflies. Butterflies are considered to be larval host plant specialists relative to their use of nectar plants. Supporting this view, use of alien plants as nectar sources (50.1%, 27 novel plant families) is almost twice that of their use as larval host plants (21.6%; three novel plant families). Some 80% of the variation in percent alien nectar plant use is accounted against 30% of that for percent alien host plant use. The key variable accounting for alien plant use is butterfly mobility. Other prominent variables that facilitate access to alien nectar plants are southern distributions, longer adult life span, host plants in garden biotopes. A different set of variables additionally account for alien host plant exploitation (% alien host plant use: woody host plants; number of alien host plants: polyphagy; greater abundance of native host plants in gardens). Although threatened butterfly species do not depend on alien plants, this may well reflect on specialisation in resource use accompanying habitat fragmentation and an inability to use novel resources that are becoming increasingly available. Detailed study of alien resources is advocated to assess the importance of alien plant resources for phytophagous insects. |
How small you can go: Factors limiting body miniaturization in winged insects with a review of the pantropical genus Discheramocephalus and description of six new species of the smallest beetles (Pterygota: Coleoptera: Ptiliidae)Vasily V. GREBENNIKOVEur. J. Entomol. 105 (2): 313-328, 2008 | DOI: 10.14411/eje.2008.039 The recently described and originally monotypic genus Discheramocephalus Johnson, 2007 from the Solomon Islands is revised. Six new species are described, illustrated and keyed: Discheramocephalus brucei sp. n. (Cameroon), D. elisabethae sp. n. (Cameroon), D. mikaeli sp. n. (Tanzania), D. stewarti sp. n. (Bolivia), D. jarmilae sp. n. (Bolivia), D. minutissimus sp. n. (Indonesia). Adults of D. minutissimus have a body length of about 400-426 µm, which is at the lower limit among non-egg-parasitoid insects. Evidence is provided that an egg size large enough to produce a viable larva is the main factor limiting miniaturisation of female insects. Females and males of egg-parasitoids are able to overcome the 400 µm threshold and reach limits of 180 µm and 130 µm, respectively. Brain size is likely the second most important factor limiting miniaturisation in insects. |



