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Results 1501 to 1530 of 1601:

A new genus and new species of Staphylinidae (Coleoptera) from Baltic amber

Grzegorz PA¦NIK, Daniel KUBISZ

Eur. J. Entomol. 99 (3): 353-361, 2002 | DOI: 10.14411/eje.2002.045

One new genus and nine new species of Staphylinidae are described from Baltic amber, namely Palaeosepedophilus gen.n. and the species P. succinicus sp.n., Lathrobium balticum sp.n., Lathrobium succini sp.n., Lathrobium ambricum sp.n., Lathrobium jantaricum sp.n., Sepedophilus balticus sp.n., Dictyon antiquus sp.n., Phymatura electrica sp.n., Aleochara baltica sp.n. Their affinity with related species is discussed.

BOOK REVIEW: Erzinçioðlu Z.: Maggots, Murder and Men. (Memories and Reflections of a Forensic Entomologist).

J. CHALUPSKÝ

Eur. J. Entomol. 99 (1): 28, 2002 | DOI: 10.14411/eje.2002.007

Colchester, Essex, UK, 2000, 256 pp.

Superparasitism by Torymus cyanimus (Hymenoptera: Torymidae) in the Volga-Kama region

Vladimir M. BASOV

Eur. J. Entomol. 99 (3): 277-284, 2002 | DOI: 10.14411/eje.2002.038

On the basis of a twenty-year investigation, the life-cycle of Torymus cyanimus Boheman (Hymenoptera: Torymidae), a hyperparasitoid of a gall-forming fly in the Volga-Kama region is described. This parasitoid is the top-consumer in a food chain on Cirsium setosum (Willdenow) Iljin, in which the herbivore is Urophora cardui L. (Diptera: Tephritidae) and the primary parasitoids belong to the genus Eurytoma (Hymenoptera: Eurytomidae). Mating and oviposition behaviour were studied, and the superparasitism and larval cannibalism investigated in the second parasitoid generation. The superparasitism in T. cyanimus evolved in connection with the ovipositor elongation, leading to eggs being laid later when the fly host has already been completely consumed by larvae of Eurytoma serratulae F. Hyperparasitism and larval cannibalism in the second generation of T. cyanimus might account for the evolution of hyperparasitism in this species.

Description of the first-instar larva of Geocharidius (Coleoptera: Carabidae: Trechitae) with a discussion of the phylogeny of the subtribe Anillina

Vasily V. GREBENNIKOV

Eur. J. Entomol. 99 (4): 523-527, 2002 | DOI: 10.14411/eje.2002.068

This paper describes the first-instar larva of Geocharidius Jeannel, a species from Mexico, which is the second record of an Anillina (Coleoptera: Carabidae: Trechitae) larva; previously described was a species of the European genus Typhlocharis. Larvae of these two genera share ten synapomorphic characters, which support the monophyletic origin of Anillina. Sister-group relationships of Anillina with Tachyina + Xystosomina are proposed on the basis of three shared larval synapomorphies: seta LA5 of ligula absent; coronal suture in first-instar larvae very short or absent; second- third-instar larvae have none or one secondary seta on lateral sides of stipes and labium and none on mandibles.

Controversial aspects of diapause development

Ivo HODEK

Eur. J. Entomol. 99 (2): 163-173, 2002 | DOI: 10.14411/eje.2002.024

Although some parts of diapause development have been clarified up by endocrinologists, knowledge of the underlying processes remains insufficient. The survey of ecophysiological aspects of diapause development has thus to be limited to inputs and outputs from the blackbox. The terms diapause development, diapause intensity, post-diapause quiescence, horotelic processes of diapause, and tachytelic processes of diapause (reactivation) are defined. Andrewartha's term diapause development has been accepted because it shows diapause as a dynamic event.
In about the last 20 years, some views on diapause development have been updated, while others have fossilised. The assumption that chilling is a general prerequisite for completion of diapause development in all insects still survives in part of the scientific community, in spite of much contradictory evidence and often due to inadequate interpretation of experiments (examples given in figures and tables). On the contrary, it has been generally recognised that in temperate climates overwintering diapause is usually already completed in early/mid winter and the dormancy is then temperature quiescence. The conception of multiple pathways of diapause completion postulates that diapause can be completed either by the normal (slow) progress of diapause development (horotelic processes), or by a faster activation (tachytelic processes). There are important differences between the mechanisms regulating activation and the horotelic processes. Thus, e.g., the photoperiodic response is lost during horotelic completion, while after photoperiodic activation it persists. In addition to photoperiodic activation other kinds of activation are being studied, particularly activation by high temperature.
Some conclusions can be made from modern studies on diapause development. In every individual, several (at least two) possible pathways exist that are evidently interlinked and mutually complementary. Thus the time of diapause passed at any condition has to be considered, as well as the exposure to very low temperatures. In temperature studies the experimental range ought to be adequately wide and less affected by a priori assumptions. Stimulation by temperature increase or improvement in food or other conditions has to be considered.
The success of diapause completion should be measured by at least four parameters: (1) incidence (%) of developmental steps; (2) duration of delay; (3) synchronization; (4) vigour of post-diapause insects (shown by long-term survival or fecundity). The last two parameters have usually been neglected.

Choice of perching sites by East Asian robber flies (Diptera: Asilidae)

Joachim HAUPT

Eur. J. Entomol. 99 (1): 35-42, 2002 | DOI: 10.14411/eje.2002.009

Field observations in different habitats on the island of Iriomote (Yaeyama, Ryukyu, Japan) were carried out concerning their importance as perching sites of robber flies (Diptera, Asilidae), including the specialization of different species to varying microhabitats. Factors of mutual exclusion for the different species include spatial (horizontal and vertical), seasonal and behavioural factors. Some geographically widespread species prefer open areas, commonly used for agriculture, but endemic species are localized in the tropical forests of the lowlands, and afford that area the need for special protection.

Patterns of attack by herbivores on the tropical shrub Bauhinia brevipes (Leguminosae): Vigour or chance?

Tatiana Garabini CORNELISSEN, G. Wilson FERNANDES

Eur. J. Entomol. 98 (1): 37-40, 2001 | DOI: 10.14411/eje.2001.006

The plant vigour hypothesis (PVH) predicts that females of galling insects preferentially oviposit on the most vigorous plants or plant modules, where their offspring's performance is highest. In the years 1995 to 1998, we evaluated the responses of species of two different guilds, two chewing species, Pantomorus sp. and Naupactus lar (Coleoptera: Curculionidae) and one galling species, Contarinia sp. (Diptera: Cecidomyiidae), to the length of shoots that were assumed to show the vigour of the tropical shrub Bauhinia brevipes (Leguminosae). The abundance of the chewing herbivores was not influenced by shoot length, since attack rates were randomly distributed among shoot length classes. The abundance of Contarinia galls increased with increasing shoot length, as proposed by the PVH. However, when we related the attack rate to unit length of shoot (cm), which denotes the resource availability per unit length, there was no effect of shoot length on Contarinia sp. These data corroborate the idea of a continuum of responses to plant quality, even when different herbivores feed on the same host plant.

Effect of innate preferences, conditioning and adult experience on the attraction of Aphidius ervi (Hymenoptera: Braconidae) toward plant volatiles

Luis C. RODRÍGUEZ, Eduardo FUENTES-CONTRERAS, Hermann M. NIEMEYER

Eur. J. Entomol. 99 (3): 285-288, 2002 | DOI: 10.14411/eje.2002.039

The aphid parasitoid Aphidius ervi was collected and subsequently reared on Sitobion avenae on wheat or Acyrthosiphon pisum on alfalfa. Parasitoids from both origins were exposed in an olfactometer to alfalfa or wheat volatiles after plant experience (wheat or alfalfa) or after oviposition experience (S. avenae on wheat or A. pisum on alfalfa). The results showed the importance of adult experience, conditioning and innate preferences on the responses of A. ervi toward volatiles and provided a mechanistic explanation to the high prevalence of A. ervi on aphids on cereals and legumes in central Chile.

Interactions of water, ice nucleators and desiccation in invertebrate cold survival

William BLOCK

Eur. J. Entomol. 99 (2): 259-266, 2002 | DOI: 10.14411/eje.2002.035

Four case studies are used to examine the relationships of water, ice nucleators and desiccation in the cold survival of invertebrates and the viability of frozen plant material: the freeze intolerant Antarctic springtail Cryptopygus antarcticus (Willem) (Collembola, Isotomidae), the freeze tolerant larvae of the fly Heleomyza borealis Boh. (Diptera: Heleomyzidae), the freeze intolerant Arctic springtail Onychiurus arcticus (Tullberg) (Collembola, Onychiuridae) and meristems of the currant Ribes ciliatum Humb. & Bonpl.(Grossulariaceae) from Mexico. Prevention of ice nucleation, lowering the water content by removal of osmotically active (freezable) water are critical features of the different cold survival strategies of the three species of invertebrates. In C. antarcticus, which desiccates rapidly by losing water via the cuticle to the atmosphere, the number of ice nucleators (and their activity) increases with lowered ambient temperature. During prolonged cold exposure ice nucleators are masked, but re-activated rapidly by water uptake in this species. Larval H. borealis do not readily desiccate and conserve their body water, 20-25% of it being bound (osmotically inactive). Experiments showed that a high proportion (c. 80%) of slowly cooled larvae survived exposure to -60°C. By comparison O. arcticus is able to sustain up to 40% loss of its body water and desiccation lowers its supercooling point to promote over winter survival. Dehydration leading to partial vitrification of currant (R. ciliatum) meristems improves their viability after cryopreservation in liquid nitrogen. From this comparison of four biological systems, it is concluded that the role of water and its activity at sub-zero temperatures are fundamental to the survival of freezing conditions by all the species studied. Although similar features exist in the four systems, no common basic mechanism was found.

Insect cold tolerance: How many kinds of frozen?

SINCLAIR B.J.

Eur. J. Entomol. 96 (2): 157-164, 1999

Insect cold tolerance mechanisms are often divided into freezing tolerance and freeze intolerance. This division has been criticised in recent years; Bale (1996) established five categories of cold tolerance. In Bale's view, freezing tolerance is at the extreme end of the spectrum of cold tolerance, and represents insects which are most able to survive low temperatures. Data in the literature from 53 species of freezing tolerant insects suggest that the freezing tolerance strategies of these species are divisible into four groups according to supercooling point (SCP) and lower lethal temperature (LLT): (1) Partially Freezing Tolerant-species that survive a small proportion of their body water converted into ice, (2) Moderately Freezing Tolerant-species die less than ten degrees below their SCP, (3) Strongly Freezing Tolerant-insects with LLTs 20 degrees or more below their SCP, and (4) Freezing Tolerant Species with Low Supercooling Points which freeze at very low temperatures, and can survive a few degrees below their SCP. The last 3 groups can survive the conversion of body water into ice to an equilibrium at sub-lethal environmental temperatures. Statistical analyses of these groups are presented in this paper. However, the data set is small and biased, and there are many other aspects of freezing tolerance, for example proportion of body water frozen, and site of ice nucleation, so these categories may have to be revised in the future. It is concluded that freezing tolerance is not part of Bale's (1996) continuum, but rather a parallel, alternative strategy of cold tolerance.

Effect of photoperiod on flight activity in Graphosoma lineatum (Heteroptera: Pentatomidae)

NAKAMURA K., HODKOVA M., HODEK I.

Eur. J. Entomol. 95 (2): 297-300, 1998

Flight activity in a pentatomid bug, Graphosoma lineatum, was measured under different photoperiodic conditions. Insects started flying 3 days after adult ecdysis and the percentage of flying adults became highest about 1 week after the ecdysis, regardless of the photoperiod. Under long day (18L : 6D), high flight activity was continued, whereas under short day (12L : 12D), most adults stopped flying when diapause was induced. In both photoperiods, a small number of adults showed flight of a long duration, longer than 30 minutes. Thus, no evidence was found relating the long flight to diapause. It is suggested that diapause adults of G. lineatum do not overwinter far from their breeding sites and thus there is no migration to hibernation sites. Also, the long flight is probably only a foraging flight, enabling the bugs to find their dispersed host plants.

Environmental variables influencing the distribution of Hydraenidae and Elmidae assemblages (Coleoptera) in a moderately-polluted river basin in north-western Spain

GARCIA-CRIADO F., FERNANDEZ-ALAEZ C., FERNANDEZ-ALAEZ M.

Eur. J. Entomol. 96 (1): 37-44, 1999

The Hydraenidae and Elmidae assemblages living in the Órbigo River Basin (NW Spain) were studied during one year. The aim of the research was to determine which factors were best related to species composition. This knowledge is the first step towards the definition of indicator species or assemblages.

Canonical Correspondence Analysis (CCA) showed that altitudinal gradient was the factor most correlated with beetle distribution. However, some other variables, such as water mineralization and eutrophication, were also important.
Using TWINSPAN program, groups of sites were defined and, afterwards, represented on the CCA diagram. Several species assemblages were defined on the basis of their frequencies of occurrence in these site groups. The environmental features of site groups and beetle assemblages were assessed with the aid of CCA. In this way, assemblages typical of high reaches could be separated from those of low stretches of the rivers. Similarly, communities from non-polluted waters could also be defined. Although several species are present in polluted sites, no assemblage exclusive to these sites has been found.

Immunolocalization of two types of allatostatins in the central nervous system of the cricket Gryllus bimaculatus (Ensifera: Gryllidae)

WITEK G., VERHAERT P., LORENZ M.W., HOFFMANN K.H.

Eur. J. Entomol. 96 (3): 279-285, 1999

Two anti-peptide antisera (anti-A and anti-B) raised against Gryllus bimaculatus allatostatin A1 (Grb-AST A1) and B1 (Grb-AST B1), respectively, were applied in the peroxidase-antiperoxidase (PAP) immunohistochemical technique on complete series of sections from the brain, suboesophageal ganglion, corpora cardiaca (CC), and corpora allata (CA) of G. bimaculatus. Both antisera yielded intense staining of numerous cells and nerve fibres. Serial sections, alternately stained with anti-A and anti-B confirmed that the anti-B generally stained more cells and nerves. Extensive immunoreactivity in the retrocerebral complex suggests that the CC and CA may represent a storage and/or release site for both allatostatin types or allatostatin-like molecules produced in the brain.

Autosomal univalents as a common meiotic feature in Jadera haematoloma (Herrich-Schaeffer, 1847) and Jadera sanguinolenta (Fabricius, 1775) (Heteroptera: Rhopalidae: Serinethinae)

María José BRESSA, Alba G. PAPESCHI, Liliana MOLA, Marcelo L. LARRAMENDY

Eur. J. Entomol. 98 (2): 151-157, 2001 | DOI: 10.14411/eje.2001.026

So far, available cytogenetic data on 24 species of Rhopalidae reveal a male diploid chromosome number of 13, with a pair of m chromosomes and an X0/XX (male/female) sex chromosome determining system. As a rule Heteroptera have holokinetic chromosomes and a pre-reductional type of meiosis: the autosomal bivalents and the m pseudobivalent segregate reductionally at first meiotic division, while the X chromosome segregates equationally. In the present study, the meiotic chromosome behaviour was analyzed in males from different Argentinean populations of Jadera haematoloma and J. sanguinolenta. Our results corroborate the diploid chromosome number and general patterns of male meiosis previously reported by other authors in samples from Brazil and Texas (USA). Among bivalents, one is remarkably larger and may present one or two terminal chiasmata. Comparison of mean chiasma frequency between Jadera haematoloma (5.63) and J. sanguinolenta (5.14) revealed that differences are significant. In most individuals of both species the largest pair appears as univalents in a variable number of cells and shows a regular meiotic segregation. Autosomal univalents orientate axially at metaphase I (with their long axis parallel to the spindle axis) and segregate equationally at anaphase I. At metaphase II they associate end-to-end forming a pseudobivalent that segregates reductionally at anaphase II. An hypothesis is suggested to explain the appearance of the largest pair, either as a ring/rod bivalent or as univalents within the same individual, although an asynaptic or desynaptic origin of the univalents cannot be ascertained. The highly regular meiotic behaviour of this autosomal pair could ensure a high fertility of the individuals, and could be considered a selectively neutral condition or, at least, not detrimental.

Scuttle flies (Diptera: Phoridae) whose larvae develop in flowers of Aristolochia (Aristolochiaceae) in Panama

R. Henry L. DISNEY, Shoko SAKAI

Eur. J. Entomol. 98 (3): 367-373, 2001 | DOI: 10.14411/eje.2001.057

Megaselia metropolitanoensis Disney, sp. n., M. sakaiae Disney, sp. n. and Puliciphora pygmaea (Borgmeier, 1960) comb. n. are reported developing in the flowers of Aristolochia inflata H. B. K. and A. maxima Jacq. in Panama. The new species are described, as is the hitherto unknown male of Puliciphora pygmaea. The latter is transferred to the the genus Puliciphora Dahl, 1897 from the genus Myrmomyia Silvestri, 1911 which is formally synonymised with Puliciphora, along with P. brachymyrmecis (Silvestri, 1911) comb. n. and P. nigroflava (Borgmeier, 1958) comb. n.

Reproduction and immature development of Hyssopus pallidus (Hymenoptera: Eulophidae), an ectoparasitoid of the codling moth

Kathrin TSCHUDI-REIN, Silvia DORN

Eur. J. Entomol. 98 (1): 41-45, 2001 | DOI: 10.14411/eje.2001.007

Hyssopus pallidus (Askew) (Hymenoptera: Eulophidae) is a gregarious ectoparasitoid of late larvae of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). In the present work reproduction and the development and morphology of the immature stages were studied. Five larval instars were differentiated by the shape and size of the mandibles. The larvae are hymenopteriform with a weakly sclerotized head and 13 segments. The first instar has four pairs of spiracles, while the other four instars have nine pairs. Under laboratory conditions of 22-24°C and 60-80% RH the egg stage lasted 1.5 days, the larval instars 6.3 days, and the pupal stage 7.9 days in females and 7.2 days in males. The duration of each of the five larval instars (L1-L5) is approximately 1, 0.5, 0.75, 0.75 and 3.5 days, respectively. Male and female development time does not differ significantly in the egg and larval stages, but differences are highly significant in the pupal stage. Male and female pupae can be differentiated by their sexual rudiments. Copulation takes place immediately upon emergence of the females between siblings, adult males appearing before the females. Females in culture with access to an energy source can survive for more than 60 days. They are synovigenic: they emerge with no mature eggs in their ovaries and take the first two days after emergence to mature the full set of around 24-30 eggs. They continue paralyzing hosts, ovipositing and maturing eggs for as long as they live. After an oviposition a female needs two to three days to mature a new full set of eggs. Age and feeding influence egg load. Oösorption is significant in starved females, but also occurs in older fed females with no host contact.

Revision of the genus Wakarumbia (Coleoptera: Lycidae)

Ladislav BOCÁK

Eur. J. Entomol. 97 (2): 271-278, 2000 | DOI: 10.14411/eje.2000.043

A revision of the genus Wakarumbia Bocák, 1999 from Sulawesi is presented. Altogether 10 species are included in the genus Wakarumbia: the type species W. gracilis Bocák, 1999 is redescribed, a new combination of Wakarumbia celebensis (Kleine, 1933) is proposed (originally placed in Protaphes Kleine, 1926) and the following new species are described: Wakarumbia brendelli sp. n., W. brunnescens sp. n., W. flavohumeralis sp. n., W. grandis sp. n., W. nigra sp. n., W. oculata sp. n., W. pallescens sp. n. and W. similis sp. n. The important diagnostic characters are illustrated and all species are keyed. Relationship between species and ecological data are briefly discussed.

Fitness of two phenotypes of Harmonia axyridis (Coleoptera: Coccinellidae)

Antonio O. SOARES, Daniel CODERRE, Henrique SCHANDERL

Eur. J. Entomol. 98 (3): 287-293, 2001 | DOI: 10.14411/eje.2001.048

The coccinellid H. axyridis shows considerable intraspecific variability of elytral patterns. In this paper, we suggest that a genotype that confers a specific pattern of elytra could also confer other specific autecological attributes. The aim of this paper is to compare fitness parameters of two phenotypes (aulica and nigra). Aulica is a common morph characterized by two light red areas that nearly cover the whole elytra, leaving a narrow black border, whereas nigra is completely black; the latter is a rare morph that was naturally obtained from mass cultures. Intraspecific differences occur between H. axyridis phenotypes. The aulica phenotype is more voracious than nigra. Consumption rate of males is higher in aulica than in nigra, but there is no difference for females. Larval biomass of aulica is generally higher than that of nigra. The maximum body-weights reached by larval instars and adults are significantly higher for aulica. Aulica also has greater longevity and reproductive capacity. Only life stage duration of eggs and pre-pupae differ between the two phenotypes. Nigra shows lower fecundity and fertility. Our study showed that the strong differences in phenotype traits of the coccinellid H. axyridis could affect its fitness.

Identification of PBAN-like immunoreactivity in the neuroendocrine system and midgut of Dysdercus cingulatus (Heteroptera: Pyrrhocoridae)

Viswanathan Sarada AJITHA, Damodaran MURALEEDHARAN

Eur. J. Entomol. 98 (2): 159-165, 2001 | DOI: 10.14411/eje.2001.028

Polyclonal antibodies against PBAN were used to map the distribution of PBAN-like antigenic sites in the brain-suboesophageal ganglion (Br-SOG) complex, associated neurohaemal structures, ventral nerve cord ganglia and in the alimentary canal. A pair of lateral neurosecretory cells immunopositive to the antiserum were found in each half of the deutocerebrum. PBAN-like immunoreactivity (PLI) was also noticed in the tritocerebral region of the brain and in the aorta. Two groups of immunopositive cells of four and two cells respectively, were found in the SOG. Small and weakly immunoreactive neurons were identified in the prothoracic ganglion, whereas in the pterothoracic ganglion a pair of cells reacted positively to the antibody. Immunoreactive cells were also identified in the corpora cardiaca. Some of the epithelial endocrine cells of the midgut also showed immunoreactivity to PBAN antiserum.

BOOK REVIEW: Boucias D.G. & Pendland J.C.: Principles of Insect Pathology.

J. WEISER

Eur. J. Entomol. 98 (1): 116, 2001 | DOI: 10.14411/eje.2001.018

Kluwer Academic Publisher, Dordrecht, The Netherlands, 1998, 537 pp + 12 pp, 151 ill., 39 tab.

Measuring and reporting life-cycle duration in insects and arachnids

Hugh V. DANKS

Eur. J. Entomol. 97 (3): 285-303, 2000 | DOI: 10.14411/eje.2000.046

Some previous work on arthropod development is insufficiently detailed or incompletely reported. Much of the published information in this area is of limited use for the general analysis of life cycles. These difficulties arise primarily because many experiments do not control fully for the strain of the material (and even its specific identity) nor for rearing conditions, do not adequately take account of the complexity of life cycles and their stages, or are restricted to only part of the life cycle. For example, 285such factors as variable numbers of instars, sexual differences, abbreviated or hidden stages and dormancies may mean that the "average durations" reported apply to an unknown mixture of developmental types. Nor are experiments always designed or results reported and analysed in a logical and transparent manner. Undefined terms may obscure what actual developmental intervals were measured. Highly derived developmental or demographic measures may obscure core data. Statistical information may be inadequate. Such pitfalls are reviewed here, suggesting ways to ensure that results on the duration of development are both valid for specific studies and more widely useful. General experimental difficulties, recommended background information that should be provided, recommended life-cycle intervals and their terminology, and recommended ways to report numerical and statistical information are briefly summarized in tabular form.

Immature stages, morphology and feeding behaviour of the saprophytic syrphids Copestylum tamaulipanum and Copestylum lentum (Diptera: Syrphidae)

Ma. Angeles MARCOS-GARCÍA, Celeste PÉREZ-BAÑÓN

Eur. J. Entomol. 98 (3): 375-385, 2001 | DOI: 10.14411/eje.2001.058

Adults of Copestylum tamaulipanum and C. lentum were reared from larvae collected from decaying platyclades of the cactus Opuntia in the state of Veracruz (Mexico). The larvae and puparia of both species, as well as preliminary data about their life cycles are described. The feeding behaviour of the larva in relation to the morphology of the cephalopharyngeal skeleton is analysed.

Differences in the searching behaviour of two strains of the egg parasitoid Telenomus busseolae (Hymenoptera: Scelionidae)

Stefano COLAZZA, M. Cristiana ROSI

Eur. J. Entomol. 98 (1): 47-52, 2001 | DOI: 10.14411/eje.2001.009

Telenomus busseolae Gahan (Hymenoptera: Scelionidae) is an egg parasitoid, which is under evaluation for possible introduction into Italy as a biological control agent of the Corn Stalk Borer, Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Two strains are being considered, one from Africa and the other from Turkey. In a series of laboratory experiments we compared their reproductive capacities, walking behaviour, and host selection behaviour mediated by the sex pheromone and body scales of the host. As reciprocal crosses between the two strains yielded female offspring, they are not reproductively isolated. The two strains were similar in both their reproductive capacity and female longevity. Females of both produced 75-90 eggs and lived on average for 6-7 days. There were differences between the two strains in walking behaviour, searching pattern and in the host location behaviour. The African strain walked faster then the Turkish strain, and showed a slower angular speed and lower turning rate. The African strain showed a significant increase in its speed of movement in response to the host's sex pheromone and a more intense local search after encountering host body scales. These results on intraspecific variability could help choosing an appropriate strain of T. busseolae for corn borer management in Italy.

Measuring and modelling the dispersal of Coccinella septempunctata (Coleoptera: Coccinellidae) in alfalfa fields

Wopke VAN DER WERF, Edward W. EVANS, James POWELL

Eur. J. Entomol. 97 (4): 487-493, 2000 | DOI: 10.14411/eje.2000.075

Dispersal of the sevenspotted lady beetle, Coccinella septempunctata, was measured in a series of mark-release-recapture experiments in Utah alfalfa. In three experiments, samples were taken in a radial pattern around the release point. Released beetles for the most part left the 0.36 ha (68 m diameter) sample area within 24 hours, and their average residence time in the sample area was calculated as 12, 6 and 1.6 h in the three experiments, respectively. The spatial distribution of beetles around the point of release could be described with normal distributions whose variance increased linearly in time with 3.8, 1.1 and 0.34 m2 per hour. In three additional field experiments the departure of marked beetles was compared between sugar-sprayed plots and control plots. Residence time was 20-30% longer in sugar-sprayed plots than in control plots, with mean residences of 5.3, 3.6, and 2.9 h in the sugar-sprayed plots in the three experiments, respectively, and means of 4.4, 2.7, and 2.4 h in the control plots. The density of unmarked beetles rose by a factor of 10-20 in the sugar sprayed plots during the first 4 to 6 hours following early morning spraying of sugar. This rapid and substantial increase in density cannot be explained by the slightly longer residence time in sugar-sprayed plots. We hypothesize that the aggregation in sugar-sprayed plots is mostly due to greatly increased immigration into those plots, in response to volatiles produced by the plant-pest-predator assembly.

Assessing spider community structure in a beech forest: Effects of sampling method

Klaus HÖVEMEYER, Gabriele STIPPICH

Eur. J. Entomol. 97 (3): 369-375, 2000 | DOI: 10.14411/eje.2000.056

The spider community of a beech forest on limestone was studied for one year using four sampling techniques: emergence traps, pitfall traps, soil samples, and arboreal eclectors. 87 spider species were recorded. Emergence traps and arboreal eclectors were particularly efficient in detecting spider species. Dominance identity (percentage similarity) was highest for catches from emergence traps and pitfall traps. Species recorded were assigned to various ecological groups. In terms of proportional abundance, representation of the ecological groups varied and appeared related to the sampling method used. Stratum type and type of prey capture strategy accounted for >60% of the variance in the catch results (canonical correspondence analysis). Proportional abundance of funnel-web spiders was much higher in pitfall trap catches (31.7%) than in any other method (1.0-11.6%).

A review of the species of the reduviid genus Tiarodes (Heteroptera: Reduviidae: Reduviinae) from China

Wanzhi CAI, Lu SUN, Masaaki TOMOKUNI

Eur. J. Entomol. 98 (4): 533-542, 2001 | DOI: 10.14411/eje.2001.067

The species of the genus Tiarodes Burmeister from China are reviewed. Three species are recognized, described or redescribed, illustrated and keyed. T. venenatus Cai et Sun and T. pictus Cai et Tomokuni are described as new species. The T. versicolor (Laporte) previously reported from China by Hua is in fact T. salvazai Miller.

BOOK REVIEW: Lawrance J.F., Hastings A.M., Dallwitz M.J., Paine T.A. & Zurcher E.J.: Beetles of the World: A Key and Information System for Families and Subfamilies. CD-ROM.

J. KOLIBÁÈ

Eur. J. Entomol. 98 (2): 165-166, 2001 | DOI: 10.14411/eje.2001.029

Version 1.0 for MS-Windows, CSIRO Publishing, Melbourne, 1999.

BOOK REVIEW: Lacey L.: Manual of Techniques in Insect Pathology.

J. WEISER

Eur. J. Entomol. 98 (1): 120, 2001 | DOI: 10.14411/eje.2001.020

Academic Press, London, 1997, 409 pp., 102 ill., 4 tab.

Life history correlates and reproductive biology of Laelius pedatus (Hymenoptera: Bethylidae) in The Netherlands

Peter J. MAYHEW, Wijnand R.B. HEITMANS

Eur. J. Entomol. 97 (3): 313-322, 2000 | DOI: 10.14411/eje.2000.048

Bethylid wasps are a medium sized family of parasitic Hymenoptera, with biological control potential, which have recently proved excellent model systems for testing evolutionary and life history theory. We report observations on a species of Laelius from The Netherlands. The species is morphologically indistinguishable from Laelius pedatus, previously reported only from the New World. Reciprocal crosses between the Dutch wasps and L. pedatus from Madison, Wisconsin, USA confirmed that the Dutch population belongs to L. pedatus. We compared the life history of the Dutch wasps with those from Madison by rearing them on Trogoderma glabrum, but found no significant differences. The Dutch wasps successfully parasitize Trogoderma angustum, an invasive museum and domestic pest found in situ, but suffer high developmental mortality on T. glabrum. Wasp egg size was positively correlated with the size of ovipositing female, which was also negatively correlated with the developmental mortality of offspring. Larger wasps also carried more mature eggs. Time taken to lay the clutch increased with the size of the eventual clutch laid and was longer in unmated than mated females. When some wasps died before completing development, surviving members of the brood grew to a larger size and took longer to complete development. The number of males per brood increased with previous oviposition experience, an indication of sperm depletion through life. We discuss the implications of these trends for parasitoid life history theory.

Vindobonella leopoldina gen. n., sp. n. from Austria (Protura: Acerentomidae s. l.)

Andrzej SZEPTYCKI, Erhard CHRISTIAN

Eur. J. Entomol. 98 (2): 249-255, 2001 | DOI: 10.14411/eje.2001.041

A new genus, Vindobonella gen. n. (Acerentomidae s. l.), and a new species, Vindobonella leopoldina sp. n., are described from Vienna. The new genus belongs to a group characterized by a reduced labial palp and a non-modified striate band on abdominal segment VIII.

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