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A new genus and species of Homoiopteridae from the Upper Carboniferous of the Intra-Sudetic Basin, Czech Republic (Insecta: Palaeodictyoptera)Jakub PROKOP, André NELEur. J. Entomol. 101 (4): 583-589, 2004 | DOI: 10.14411/eje.2004.082 New palaeodictyopterid Paraostrava stanislavi gen. n., sp. n. is described from the Upper Carboniferous (Duckmantian) deposits of the Jan ©verma Mine in northern Bohemia (Czech Republic). The new taxon based on hindwing venation is attributed to Homoiopteridae and compared with the other homoiopterid and heolid genera within Homoiopteroidea. Due to the poor state preservation of Boltopruvostia robusta, we consider this taxon as Palaeodictyoptera: Homoiopteridae of uncertain position and restore the well defined genus Ostrava Kukalová, 1960 (type species Ostrava nigra Kukalová, 1960). Some uncertainties in the current state of knowledge on the taxonomy and phylogeny of the Homoiopteridae are pointed out. The characters matrix used to separate the genera of Homoiopteroidea is included. |
BOOK REVIEW: Ryan M.F.: Insect Chemoreception - Fundamental and Applied.J. ®ĎÁREKEur. J. Entomol. 101 (3): 378, 2004 | DOI: 10.14411/eje.2004.053 Kluwer Academic Publishers, Dordrecht, The Netherlands, 2002, 330 pp. |
Environmental regulation of the purine synthesis enzyme purH transcript during adult diapause in Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)George D. YOCUMEur. J. Entomol. 101 (2): 199-203, 2004 A 1962 bp cDNA clone of 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (purH) was isolated from diapausing adults of Leptinotarsa decemlineata using RT-PCR and 3' and 5'-RACE. The probe generated from this clone hybridized to a transcript approximately 1960 bp in length on northern blots. The clone encodes for a deduced protein 594 amino acids in length with 73% identity, 83% similarity to purH from Drosophila melanogaster. Northern blot (total RNA) analysis determined that L. decemlineata purH (LdpurH) was downregulated in diapausing beetles stored at 10°C. Developmental studies revealed that LdpurH is expressed at nearly constant high levels in both nondiapausing and prediapause adults. LdpurH expression during the first 20 days of diapause is equivalent to that seen in nondiapausing beetles, after which expression decreases. Exposing 70 day old diapausing beetles to 20°C for 24 h induced an increase in expression of purH indicating that purH is regulated by temperature in diapausing/overwintering beetles. |
Number and position of wounds on honey bee (Apis mellifera) pupae infested with a single Varroa miteGhazwan KANBAR, Wolf ENGELSEur. J. Entomol. 101 (2): 323-326, 2004 The wounds inflicted on pupae in capped brood cells of the honey bee, Apis mellifera, infested with a single female of the ectoparasitic mite, Varroa destructor, were investigated after visualisation by vital staining with trypan blue. On average the mites made two integumental perforations for feeding on prepupae and one on pupae. Most of the punctures were on particular ventral sites on the abdomen. Possible reasons for this pronounced preference and the evolutionary aspects of this highly specialised parasite-host relationship are discussed. |
The guarding posture of females in the subsocial bug Elasmucha dorsalis (Heteroptera: Acanthosomatidae)Shin-Ichi KUDOEur. J. Entomol. 97 (1): 137-139, 2000 | DOI: 10.14411/eje.2000.023 The subsocial bug Elasmucha dorsalis lays egg masses on the underside of the leaves of female plants of Aruncus dioicus. Each bug straddles her eggs and shields her offspring with her body, until they moult to the 2nd instar. Females that: attended aggregations of 2nd and later instar nymphs feeding on fruit of inflorescences often settled close to the basal part of or just below the aggregation, and faced towards the base of the inflorescence. The nymphal aggregations often Seemed to be too large for females to guard effectively. The position and orientation of females attending 2nd or later instar nymphs probably enabled them to detect predators walking towards the nymphs. |
Decreased mating propensity of macropterous morph in a flightless wing-polymorphic insect, Pyrrhocoris apterus (Heteroptera)Radomír SOCHAEur. J. Entomol. 101 (4): 539-545, 2004 | DOI: 10.14411/eje.2004.077 The effect of wing length (brachyptery and macroptery) on mating activity was investigated in adult males and females of a flightless wing-polymorphic insect, Pyrrhocoris apterus (L.). Mating activity of the brachypterous and macropterous adult bugs was assessed according to 14 different parameters. The competition tests revealed higher numbers of copulations and greater duration of mating activity in brachypterous than in macropterous males. Brachypterous males are between two to four times more successful in competition for females than their macropterous counterparts, depending on the wing morph and physiological status of the females. Decreased mating success of macropterous males is associated with the smaller size of their accessory glands. Lowered competitive ability for mates is a likely penalty associated with macroptery. Receptivity tests showed the highest tendency to mate in reproductive brachypterous females, lower in macropterous females and the least in diapausing brachypterous females. This is the first report of decreased mating propensity of macropterous morphs in insects with non-functional wing polymorphism. The association of lowered mating success with the higher dispersal activity of the macropterous morph in this bug and a trade-off between the ability to reproduce and to disperse in the flightless wing-polymorphic insects is discussed. |
Polyploid spermatozoa in Pityogenes chalcographus and Ips typographus (Coleoptera: Scolytidae)Erwin FÜHREREur. J. Entomol. 101 (1): 21-27, 2004 | DOI: 10.14411/eje.2004.005 Abnormal spermatogenesis in Pityogenes chalcographus (L.) and Ips typographus (L.) results in oversized spermatozoa in all the populations investigated. They can be identified by light microscopy and classified as 2n up to 16n polyploid. The percentage of polyploid sperm increases when allopatric parents are crossed: Parental populations with less than 1% polyploid, result in male F1 with more than 20% polyploid. Wild populations of P. chalcographus and I. typographus have very different percentages of polyploid sperm. Populations from allochthonous sites for the host tree, Picea abies (Karst.), are distinguished by higher rates of sperm polyploidy than those from autochthonous areas. Thus, it is assumed that polyploid sperm indicates populations originating from the mixing of partially incompatible beetles. |
Test of the correlation between body size and DNA content in Pimelia (Coleoptera: Tenebrionidae) from the Canary IslandsMiquel PALMER, Eduard PETITPIERRE, Joan PONSEur. J. Entomol. 100 (1): 123-129, 2003 | DOI: 10.14411/eje.2003.022 Comparative analyses of interspecific data in evolutionary biology usually require specific methods to remove the effects of phylogenetic inertia. When phylogenetic inertia is not considered, the Canarian Pimelia species show a positive, and almost significant (Prob. = 0.066) correlation between nuclear genome size and body size. However, after controlling for phylogenetic inertia there was a negative and significant correlation (Prob. = 0.007 to 0.017, depending on the DNA fraction considered). Such a change in the relationship after controlling for phylogenetic inertia is rarely reported. Moreover, the relationship usually reported is positive and thought be a consequence of species having a similar number of cells at the same stage of development. The aim of the present study is to report a case of a negative correlation, but not to explain the causal mechanism involved in genome size variations or propose a formal hypothesis on the specific links between DNA content and body size. However, a common explanation of the change in the relationship, i.e., positive to negative, is suggested. Moreover, the data available on the highly repetitive, non-coding satellite DNA allows us to analyse the specific pattern exhibited by this fraction. |
Effect of temperature on the biology of Noctua atlantica (Lepidoptera: Noctuidae), a species endemic to the AzoresMaria Luísa Melo OLIVEIRA, Virgílio VIEIRA, Patrícia Ventura GARCIAEur. J. Entomol. 101 (3): 423-426, 2004 | DOI: 10.14411/eje.2004.059 The effect of constant temperatures (5, 10, 15, 20, 25 and 30°C) on several biological parameters of Noctua atlantica (Warren), a noctuid endemic to the Azores, was studied using an artificial diet as food. At 5 and 30°C no eggs hatched. Developmental time (egg, larval, pupal and egg-to-adult) differed significantly at each temperature. Pupal weight (males and females) was significantly higher at 10°C and lower at 25°C. Adult longevity and the pre-oviposition period were longer at 10 and 15°C and differed significantly from those observed at higher temperatures. The mean number of eggs laid per female (fecundity) was significantly higher at 15°C, and lower at 25°C. Pupal weight (males and females) was positively correlated with larval, pupal, egg-to-adult developmental times and with adult longevity. Female pupal weight was also positively correlated with the pre-oviposition period and with fecundity. Temperatures ranging from 10 to 20°C are the most suitable for the development of N. atlantica, suggesting that this species is well adapted to the climatic conditions found in their natural habitat. The number of day-degrees required for the development from egg to adult emergence was 1428.57 D°, and 117.79 D° for the pre-oviposition period. Thus, N. atlantica can have two generations per year at high altitudes (550 or 800 m) in the Azores. |
BOOK REVIEW: Wheater C.P. and Cook P.A. 2003: Studying Invertebrates.O. NEDVĚDEur. J. Entomol. 101 (2): 346, 2004 Naturalists' Handbooks 28. The Richmond Publishing, Slough, 120 pp. |
New cytogenetic data on Nabidae (Heteroptera: Cimicomorpha), with a discussion of karyotype variation and meiotic patterns, and their taxonomic significanceValentina G. KUZNETSOVA, Snejana GROZEVA, Seppo NOKKALAEur. J. Entomol. 101 (2): 205-210, 2004 As a part of ongoing cytogenetic studies on the bug family Nabidae (Heteroptera), the karyotypes and meiotic patterns of male Nabis (Aspilaspis) viridulus Spinola, 1837, N. (A.) indicus (Stål, 1873) (subfamily Nabinae) and Prostemma guttula (Fabricius, 1787) (subfamily Prostemmatinae) are described. |
Revision of European species of the genus Rhabdomastix (Diptera: Limoniidae). Part 1: Introduction and subgenus Lurdia subgen. n.Jaroslav STARÝEur. J. Entomol. 100 (4): 587-608, 2003 | DOI: 10.14411/eje.2003.089 The first part of a revision of the European species of the genus Rhabdomastix Skuse, 1890 is presented. The history of taxonomic research on Rhabdomastix is reviewed, relationships of the genus are discussed, and the subgeneric classification outlined and re-assessed. A new subgenus, Lurdia subgen. n., is established for species centred around R. lurida (Loew, 1873), and Palaeogonomyia Meunier, 1899 and Sacandaga Alexander, 1911, previously considered subgenera, are synonymized with Rhabdomastix. A revision of the European species of Lurdia subgen. n. is presented. Two species are redescribed, Rhabdomastix (Lurdia) lurida (Loew, 1873) and R. (L.) inclinata Edwards, 1938, and the lectotype of the former is designated. Descriptions are provided of seven species, viz. R. (L.) mendli sp. n. (Switzerland, Germany, Italy), R. (L.) sublurida sp. n. (Czech Republic, Slovakia), R. (L.) furva sp. n. (Slovakia), R. (L.) loewi sp. n. (Switzerland, Germany, Austria, Italy), R. (L.) robusta sp. n. (Czech Republic, Slovakia), R. (L.) falcata sp. n. (Switzerland, Germany, Bulgaria) and R. (L.) tatrica sp. n. (Slovakia). Male and female terminalia are illustrated for all the species (except female falcata), and a key to species is appended. |
Trophobiotic relationships between ants (Hymenoptera: Formicidae) and Tettigometridae (Hemiptera: Fulgoromorpha) in the grey dunes of BelgiumValérie S. LEHOUCK, Dries B. BONTE, Wouter DEKONINCK, Jean-Pierre E. MAELFAITEur. J. Entomol. 101 (4): 547-553, 2004 | DOI: 10.14411/eje.2004.078 We recorded the association between the planthopper Tettigometra laetus Herrich-Schäffer, 1835 (Hemiptera: Fulgoromorpha: Tettigometridae) and three ant species belonging to the subfamilies Myrmicinae and Formicinae in a coastal dune area of Flanders (Belgium). Lasius psammophilus Seifert, Tetramorium caespitum L. and Formica cunicularia Latreille were observed attending and palpating the dorsal glandular area of this planthopper, taking honeydew directly from its anus, herding them and carrying them into their nests when disturbed. The planthopper was rarely found in the absence of ants and probably develops within ant nests, which may provide protection against predation and adverse weather conditions. The natural history of temperate ant-hemipteran relationships is discussed. |
Diapause development in Aquarius paludum (Heteroptera: Gerridae)Tetsuo HARADA, Ken ITO, Magdalena HODKOVA, Ivo HODEKEur. J. Entomol. 101 (3): 427-430, 2004 | DOI: 10.14411/eje.2004.060 Diapause fixation and development were studied in females of a Czech population of Aquarius paludum by monitoring changes in oxygen uptake, weight and reproduction potential in field adults between August and February. The fall in oxygen uptake related to fresh weight (from > 1000 µl O2 per g per h to around 500 µl O2 per g per h) in field adults during early diapause was similar in two age cohorts, although the time of adult ecdysis differed by 50 days and thus occurred at markedly different temperatures and photoperiods of late August vs. early October. The different conditions affected the weight of females and thus also the absolute value of oxygen consumption: both parameters were much lower in the October females. The seasonal time of diapause termination in A. paludum did not differ from findings in other cold temperate insects: diapause and the photoperiodic response ended in the winter, as was shown by the possibility of insects' reactivation by 26°C in spite of a diapause promoting daylength of 12L : 12D. In most females (78.6%) ovaries matured after transfer to these conditions in mid-February, while ovarian maturation occurred in only 16.7% of females transferred in early January and no ovarian maturation was observed in females transferred in early December. Ovarian maturation was preceded by a transient increase in oxygen consumption from 600 µl O2 per g per h to 1400 µl O2 per g per h. |
Intraguild predation between the aphidophagous ladybird beetles Harmonia axyridis and Coccinella undecimpunctata (Coleoptera: Coccinellidae): the role of body weightSandra FÉLIX, António Onofre SOARESEur. J. Entomol. 101 (2): 237-242, 2004 The magnitude, direction and symmetry of intraguild predation (IGP) between the developmental stages of the aphidophagous Harmonia axyridis Pallas and Coccinella undecimpunctata L. were characterized and compared. Mobility and body weight were the main factors affecting the magnitude of IGP. |
Identification key to Central European species of Trachytes (Acari: Uropodina) with redescriptions, ecology and distribution of Slovak speciesPeter MA©ÁNEur. J. Entomol. 100 (3): 435-448, 2003 | DOI: 10.14411/eje.2003.066 A total of 23 uropodine species of the genus Trachytes (Acari, Mesostigmata) are reliably recorded to occur in Central Europe and included in identification keys for adults (23 spp.) and deutonymphal stages (9 spp.), respectively. For the first time, the diagnostic characters of deutonymphs of the species T. baloghi, T. minima, T. minimasimilis, T. mystacinus and T. splendida are figured. Ten species found in Slovakia are redescribed (T. aegrota, T. baloghi, T. hirschmanni, T. irenae, T. lamda, T. minima, T. minimasimilis, T. mystacinus, T. pauperior and T. splendida) and characterised by their external morphology, geographic distribution and ecological requirements in terms of habitat preference, affinity to merocoenoses and vertical distribution. The zoogeographic origin of Trachytes is analysed. Most species are found only in woodlands and have not been recorded in the distribution area of the Pannonian flora in Central Europe (except for T. aegrota and T. baloghi). Short taxonomic remarks are given for the species of dubious taxonomic status or whose occurrence is not reliably known. |
BOOK REVIEW: Chapman R.F. 1998: The Insects. Structure and Function.P. ©VÁCHAEur. J. Entomol. 97 (1): 32, 2000 | DOI: 10.14411/eje.2000.008 Chapman R.F.: The Insects. Structure and Function. 4th ed. Cambridge University Press, Cambridge, UK, 1998, xviii + 770 pp. |
Cytogenetic studies on Mepraia gajardoi (Heteroptera: Reduviidae). Chromosome behaviour in a spontaneous translocation mutantRuben PÉREZ, Lucia CALLEROS, Virginia ROSE, Myriam LORCA, Francisco PANZERAEur. J. Entomol. 101 (2): 211-218, 2004 We analysed the chromosome complement and male meiosis in a natural population of Mepraia gajardoi (Hemiptera: Reduviidae: Triatominae). The normal karyotype of this species is 20 autosomes plus X1X2Y in males and X1X1X2X2 in females. We confirmed that M. gajardoi is cytogenetically strikingly different from M. spinolai (with which it was previously included), which supports the taxonomic separation of these two species. For the first time in the holocentric chromosomes of the subfamily Triatominae, a structural rearrangement was detected. Observations made during meiosis and mitosis indicated that one of eleven individuals had undergone a fusion between two non-homologous chromosomes, probably before germinal cell development. This autosomal translocation resulted in chromosomal irregularities such as an autosomal trivalent, autosomal univalents and chromosomal fragments, which altered the normal segregation of both autosomes and sex chromosomes. The chromosomal fragments resemble supernumerary or B chromosomes, which supports the idea that these chromosomes are remnants of structural rearrangements. The genetic consequences of translocations in holokinetic chromosomes and their role in the evolution of chromosomes in triatomines are also discussed. |
BOOK REVIEW: Jongjean F. & Kaufman W.R. (Eds): Ticks and Tick-Borne Pathogens.F. DUSBÁBEKEur. J. Entomol. 101 (2): 332, 2004 Kluwer Academic Publishers, Dordrecht, The Netherlands, 2003, 309 pp. |
A taxonomic review of Japanese Asteia (Diptera: Acalyptrata: Asteiidae)Masahiro SUEYOSHIEur. J. Entomol. 100 (4): 609-623, 2003 | DOI: 10.14411/eje.2003.090 The Japanese species of Asteiidae are revised. Six species of Asteia Meigen, 1830, are recorded here in addition to Astiosoma okinawae Sabrosky, 1957, hitherto recorded from Japan. Among them, Asteia gemina, A. longistylus, A. lunaris, and A. nigrigena are described as new to science. Asteia angustipennis Duda, 1934, and A. megalophthalma Duda, 1927, are recorded from Japan for the first time. There are conspicuous morphological differences in the male and female genitalia of the seven species of Asteia. It is suggested that Asteia angustipennis, A. concinna, and A. gemina are very closely related and may be reproductively isolated because of their body markings and male genitalia. These species are assigned to the concinna group of Asteia, newly designated in this study. A key to Japanese species and distribution maps are provided. |
Influence of slug defence mechanisms on the prey preferences of the carabid predator Pterostichus melanarius (Coleoptera: Carabidae)Pavel FOLTANEur. J. Entomol. 101 (3): 359-364, 2004 | DOI: 10.14411/eje.2004.050 Two-choice experiments on prey preferences of a generalist predator Pterostichus melanarius, and five species of slug prey, were conducted in the laboratory. Different preferences of P. melanarius for each of the slug species are described. They are interpreted as the outcome of differing slug species-specific defence mechanisms. The influence of hunger level, temperature, day/light period, condition of slugs and beetles, weight of slugs and beetles, and the sex of beetles were controlled experimentally or statistically. The order of slug species preference for predation by P. melanarius was: Deroceras reticulatum (Agriolimacidae), Malacolimax tenellus, Lehmania marginata (Limacidae), Arion distinctus and A. subfuscus (Arionidae). Efficiency of slugs' species-specific defence mechanisms reflected their phylogeny. Defence mechanisms of slugs from the superfamily Arionoidea were significantly more effective at deterring an attack of non-specialised ground beetles than the defence mechanisms of slugs from Limacoidea superfamily. P. melanarius significantly preferred Agriolimacidae to Limacidae, and Limacidae to Arionidae. Slug species was the strongest factor influencing prey preferences of P. melanarius amongst slug prey. Surprisingly, this preference was much more significant than the slug weight. Weight and sex of P. melanarius had no impact on its prey preference. |
Oviposition, flight and walking capacity at low temperatures of four aphid parasitoid species (Hymenoptera: Aphidiinae)Alain LANGER, Guy BOIVIN, Thierry HANCEEur. 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. |
Poor control of the horse chestnut leafminer, Cameraria ohridella (Lepidoptera: Gracillariidae), by native European parasitoids: a synchronisation problemGiselher GRABENWEGEREur. J. Entomol. 101 (1): 189-192, 2004 | DOI: 10.14411/eje.2004.023 Horse chestnut trees in many regions of Europe have suffered from epidemic infestations of C. ohridella for more than ten years. There has been no obvious decrease in the infestation level anywhere on the continent. One reason is, that the native natural enemies have not been able to control mass outbreaks of the leafminer. Parasitoid Hymenoptera have very little impact on the first generation of the moth in early summer, regardless of the number of parasitoids that overwintered in horse chestnut leaves. This study revealed that there is a considerable time lag between the emergence of the parasitoids from the leaflitter in spring and the appearance of suitable host instars in early summer. The poor control of C. ohridella by natural enemies may partly be due to the poor synchronisation between the life cycles of the introduced host and native parasitoid wasps. |
Relationships among coleopteran suborders and major endoneopteran lineages: Evidence from hind wing charactersJarmila KUKALOVÁ-PECK, John F. LAWRENCEEur. J. Entomol. 101 (1): 95-144, 2004 | DOI: 10.14411/eje.2004.018 A phylogenetic analysis of the four coleopteran suborders (Polyphaga, Archostemata, Myxophaga and Adephaga), four other endoneopteran taxa (Strepsiptera, Neuropterida, Mecopterida and Hymenoptera) and three neopteran outgroups (Orthoneoptera, Blattoneoptera and Hemineoptera) is performed based on 63 characters of hind wing venation, articulation and folding patterns, with character states coded for the groundplan of each taxon (not for exemplar genera or species). The shortest tree found using Winclada with Nona exhibits the following topology: Orthoneoptera + (Blattoneoptera + (Hemineoptera + Endoneoptera: (Hymenoptera + ((Neuropterida + Mecopterida) + (Coleoptera + Strepsiptera))))). Homologization of the hind wing venation in Coleoptera is reviewed and updated, and comments are made concerning recent works on wing folding. Recent phylogenetic schemes proposed for the orders of Endoneoptera and suborders of Coleoptera are reviewed and their supporting evidence critically examined. The special role and influence of the hind wing anojugal lobe on the diversification of Neoptera and Endoneoptera is discussed. A scenario is proposed for the origin and evolution of the insect hind wing. |
Revision and hypothetical phylogenetic analysis of the species of the New World genus Ataeniopsis (Coleoptera: Aphodiinae: Eupariini)Zdzisława T. STEBNICKAEur. J. Entomol. 100 (1): 101-113, 2003 | DOI: 10.14411/eje.2003.019 The New World genus Ataeniopsis Petrovitz, 1973 is revised. Fifteen species are recognized including three new species: Ataeniopsis carupanoi sp. n. from Venezuela, A. jaltipani sp. n. from Mexico and A. vinacoensis sp. n. from Argentina. Lectotype of A. haroldi (Steinheil, 1872) is designated, the name of type species A. notabilis Petrovitz, 1973 is reestablished, five species are given in a new combination. The taxa are diagnosed, keyed and illustrated, and biological information and distribution data summarized following the species descriptions. A hypothetical phylogenetic analysis of Ataeniopsis based on cladistic analysis is presented. |
Grub-like larvae of Neuroptera (Insecta): a morphological review of the families Ithonidae and Polystoechotidae and a description of Oliarces claraVasily V. GREBENNIKOVEur. J. Entomol. 101 (3): 409-417, 2004 | DOI: 10.14411/eje.2004.056 First instar larvae of Polystoechotidae sp., and first and older instar larvae of Ithone fusca Newman and Oliarces clara Banks are described; those of the latter species for the first time. The family Ithonidae is unique in Neuroptera in having grub-like C-shaped older instar larvae. Potential morphological synapomorphies of mature larvae of Ithonidae and Polystoechotidae are the mandibles with exceptionally broad base and markedly thickened apical part; antennal curvature is fixed and rather characteristic in shape; ocular area reduced or absent; cardo and stipes are markedly enlarged with stipes much larger than the cardo; presence of gula (Polystoechotes) or some traces of gular sclerotisation (Ithone, Oliarces). Larvae of Ithone have numerous larval autapomorphies such as C-shaped first instar larva with reduced abdominal segments IX and X; fused tibia and tarsus on all legs and dorsally directed maxillae. Larvae of Ithonidae and Polystoechotidae have some similarities with those of the family Dilaridae, such as no or one pair of stemmata; body not flattened dorso-laterally; mesothoracic spiracle located on fold between prothorax and mesothorax; short and stout mandibles widened at base and tapered apically; robust and elongated fore legs; tarsi on all legs markedly shortened; more than three larval instars. Older instar larvae of Ithonidae are markedly similar to those of the beetle superfamily Scarabaeoidea in having a C-shaped body, at least in older instars; body round in cross-section; sclerites on thorax and abdomen reduced and body surface membranous; each thoracic and abdominal segment subdivided dorsally into two or three fleshy lobes; ventral surface of abdominal apex bears a field of short and stout setae. Chaetotaxy pattern in first instar Ithonidae and Polystoechotidae larvae suggests that it is possible to homologise the sensilla in different genera and provide a system of sensilla designation for Neuroptera larvae. This study is illustrated with 36 morphological drawings. |
Patterns in abdominal pumping, miniature inspirations and heartbeats simultaneously recorded during cyclical gas exchange in adult Hylobius abietis (Coleoptera: Curculionidae) using a respirometer and IR actographsIvar SIBUL, Aare KUUSIK, Kaljo VOOLMAEur. J. Entomol. 101 (2): 219-225, 2004 Rhythms in abdominal pumping, heartbeats and discontinuous gas exchange cycles (DGCs) of CFV subtype (closed, flutter and ventilation periods) in adults of pine weevil Hylobius abietis were simultaneously recorded using an electrolytic microrespirometer and an infrared (IR) cardiograph or IR actograph (IRA). The cyclic release of carbon dioxide was associated with active ventilation (V phase) provided by vigorous abdominal pumping movements due to contractions of tonic longitudinal and transversal abdominal muscles, which are visible to the naked eye. On the IRA-recordings, the abdominal pumping signals are superimposed on the heartbeat spikes. The relative amplitude of the abdominal pumping signals on these recordings is more than 10 times greater than that of the heart beats. Visual observations showed that the subelytral cavity appeared to be closed during the release of carbon dioxide and open at other times. The flutter (F) of the CFV cycle is characterised by active miniature inspirations or ventilations before the V period. The miniature ventilation movements were imperceptible to the naked eye, but were recorded on the respirometer-actigraph as clear spikes. In addition, movements of the tip of the abdomen, of between 10-20 mm were seen under a stereomicroscope at a magnification of 40×. Some cycles were categorized as (C)FV cycles, when the C period disappears into the end of the V period. Abdominal pumping and miniature inspirations were clearly synchronized with the CFV cycles. Abdominal pumping movements, miniature inspirations or ventilations and heartbeats in adult H. abietis were distinguishable when recordings of the electrolytic microrespirometer-actograph and IRA were made in parallel. These three events were recognized by their different amplitudes and frequencies. It is presumed that abdominal pumping and miniature inspirations in adult H. abietis are obligatory rhythmic movements of different function and origin. |
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. IATROUEur. 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. |
Sexual size and development time dimorphism in a parasitoid wasp: an exception to the rule?Jeffrey A. HARVEY, Michael R. STRANDEur. J. Entomol. 100 (4): 485-492, 2003 | DOI: 10.14411/eje.2003.074 Sexual dimorphisms in adult size (SSD) and development time (SDTD) occur in many groups of organisms. In insects, some of the best examples occur in parasitoid wasps where most studies report that females are larger than males but take longer to develop. Sex-specific differences in the effects of size on reproductive success is generally regarded as the main factor responsible for SSD in parasitoids. Most studies also assume that development time must be extended in order to achieve larger size. Here, SSD and SDTD were compared in the solitary endoparasitoid, Microplitis mediator that develops in larvae of the moth Pseudoplusia includens. The relationship between male and female body size and development time were isometric in M. mediator, but contradict most predictions of parasitoid development models. Across first to fourth instars at parasitism, male wasps were consistently larger than females but completed their development significantly faster. The longer development time in female wasps was due primarily to an extended pupal phase, whereas the duration of larval development did not vary significantly with offspring sex. Secondary sex ratios (percentage male) also did not vary with host instar. We conclude that SSD in M. mediator is not only a function of extended development time, but also because of several possible factors: (i) selection favours an increase in male size (relative to female size); (ii) female size is constrained because of predation risk, (iii) as a cost of reducing the cost of inbreeding or (iv) constraints on egg maturation rate. We argue that failure to look carefully at how parasitoids grow can lead to incorrect conclusions about the basis or significance of SSD. |
A review of Palaearctic Gymnophora Macquart (Diptera: Phoridae), with description of new speciesMikhail B. MOSTOVSKI, Marina V. MIKHAILOVSKAYAEur. J. Entomol. 100 (1): 153-165, 2003 | DOI: 10.14411/eje.2003.025 Palaearctic species of the genus Gymnophora are reviewed. Four new species, G. amurensis sp. n., G. gornostaevi sp. n., G. perpropinqua sp. n., and G. victoria sp. n., are described from the European Russia, Middle Asia, and Russian Far East. Females of two other species from the Far East are described under code letters. G. laciniata Michailovskaya, 1997 is synonymised under G. prescherweberae Disney, 1997. Lectotypes of G. arcuata (Meigen, 1839) and G. verrucata (Schmitz, 1929) are designated. The latter species is redescribed. Palaearctic females of G. nigripennis demonstrate wide variation of taxonomically important features and may, in fact, represent a group of closely related species. One female of G. nigripennis, which has been caught alive, is recorded to be infected with fungi. |