Dactylopius coccus is a sessile scale insect living on cladodes of Opuntia ficus indica which has commercial importance as a source of carminic acid. We herein present behavioural evidence of the existence of a sex pheromone in D. coccus, based on olfactometric experiments using both biological sources of odours and collected chemical extracts.

In the High Plains of western Kansas, USA, the convergent lady beetle Hippodamia convergens Guérin completes a spring generation feeding on cereal aphids in winter wheat before leaving fields in large numbers around the time of harvest. In late May, large aggregations of coccinellids form on wild sunflowers, Helianthus annuus, and certain other weeds, that appear to serve as important sources of water absorption for the beetles, and other beneficial insects, during the dry prairie summer. Adult beetles were collected from sunflower plants and held in four treatments: (1) access to water only, (2) access to sunflower stalks only, (3) eggs of Ephestia kuehniella provided ad libitum + water and, (4) greenbug, Schizaphis graminum Rondani provided ad libitum. Most females fed greenbug matured eggs in less than a week and only a few entered reproductive diapause. In contrast, more than half of the females fed Ephestia eggs, an inferior diet, entered reproductive diapause, and those that matured eggs required an average of almost three weeks to do so. Time to 50% mortality was 7 days for beetles receiving only water, and 12 days for those receiving only sunflower stalks, whereupon all survivors were fed greenbug. Even after feeding on greenbugs for a month, less than half of the surviving females in these two treatments produced eggs. We conclude that reproductive diapause is an important adaptation for improving H. convergens survival during summer when aphids are scarce, although females will forgo diapause if they have continuous access to high quality prey.

Populations of the specialist gall-forming fly, Urophora cardui (Diptera: Tephritidae), were studied at the western and eastern margins of its distribution. In western Europe U. cardui attacks the creeping thistle Cirsium arvense, whereas in eastern Europe, in the Ural mountains, it attacks Cirsium setosum, a taxon closely related to C. arvense. Gall densities are high in the Ural mountains and can be predicted by environmental variables. Compared to galls on C. arvense, those on C. setosum are on average larger. This indicates better performance of U. cardui on C. setosum in terms of cell numbers per gall. Despite the wide distribution of U. cardui, the dominant parasitoids are the same at the western and eastern ends of its distribution and the interactions between parasitoids and the host are similar. In general, we suggest that the synchronisation between the host plant species, the phytophage and the parasitoids is an important factor in the spatial ecology and evolution of this food web.

Kluwer Academic Publishers, Dordrecht, 2001, 305 pp. ISBN 0-7923-7153-4. Price USD 179.00.

Many gregarious insects aggregate in naturally occurring refuges on their host plants. However, when refuges are filled, they may be forced to aggregate on exposed areas of the plant. This study examines the effects of refuge saturation on group size and defence against parasitism in larvae of Ammalo helops Cramer (Lepidoptera: Arctiidae) that form day-resting groups on the trunks of weeping laurel, Ficus benjamina L., in El Salvador. Population densities, group sizes and parasitism were recorded on eight trees for each of four generations in 1995 and 1996. When population densities were low, all larvae were located in small groups in naturally occurring structural refuges (rotted out holes, spaces between crossing branches and under aerial roots) on the host plant. In contrast, when population densities were high and structural refuges were full, many larvae formed significantly larger groups (density refuges) on the open trunk. Between 20 and 24% of late-instar larvae were parasitized and this was inversely dependent on the size of within tree populations, in spite of populations being fragmented among structural refuges. Similarly, in a study carried out at a different location on young trees without structural refuges, parasitism of larvae was inversely related to group size. Although parasitism rates decreased with increasing group size, most larvae preferentially selected the small naturally occurring refuges, where groups were restricted to low densities. If this behaviour is an adaptive trait, I speculate that parasitism (or some other unmeasured mortality factor) is lower in naturally occurring refuges than in large open groups.

Fenoxycarb is an insecticide with a juvenile hormone mimicking effect, which disturbs metamorphosis in several insect species, including the neuropteran Chrysoperla carnea. Administration of different doses of fenoxycarb to third instar larvae causes a dose dependent inhibition of metamorphosis and cocoon spinning. When treated within 48 h of the last larval ecdysis, this insect shows a temporary inhibition of metamorphosis and cocoon spinning, which leads to a prolongation of the third larval instar. When treated after 60 h into the last instar, most of larvae were unable to metamorphose and spin a cocoon. Thus, C. carnea is most sensitive to this juvenoid in the period after 60 h into the last larval instar.

This paper presents data on the activity rhythms of the Brazilian cave cricket, Strinatia brevipennis. Recordings were made in the laboratory in a sound-proof constant environment. Recordings were made either under constant darkness or LD cycles, with food provided ad libitum or not, and with crickets isolated or with a conspecific near the cage. Some crickets were tested with pulses of sound. Raw data are presented in the form of single plot actograms and analyzed using the phase weighted stack (PWS) method. These cave crickets showed a somewhat erratic patterns of activity, although a circadian component could be detected. All the environmental variants tested (food availability, presence of conspecific and sound pulses) seemed to mask any activity rhythm indicating they are possibly important in determining the temporal organization of these crickets. Their activity patterns are discussed in terms of the plasticity of a cave animal's circadian system.

Kluwer Academic Publishers, Dordrecht/Boston/London, 2003, viii + 329 pp. ISBN 1-4020-1520-8. Price USD 197.00.

Sherwood 95, Suppl. 2, Compagnia delle Foreste, Arezzo (Italy), 100 pp.

Great progress has recently been made in cryobiology. One field, however, has been neglected: the temporal sequence of the effects of photoperiod and temperature, and their relative importance in cold hardening. This is relevant to the question of importance of diapause in cold-hardiness. Denlinger (1991) outlined the categories of such relations and stressed a great need for further detailed research. A survey of studies done over the past decade revealed many gaps in the evidence and the ambiguous nature of the data on the photoperiodic regulation of cold-hardiness. We hope that this review will stimulate further research in this field. Among several directions where research is most needed we have stressed (1) simultaneous recording of changes in survival and dynamics of suspected cryoprotectants (stressed also by Danks, 1996), (2) checking the regulation of different phases of cold hardening, and (3) discrimination between direct and indirect (mediated via neuroendocrine system) effects of environmental cues on cold hardening.

When investigating sexual strategies of aphids, it is necessary to set up multiple replicates to compensate for the small number of eggs laid per female. Genetic variation among replicates can be minimised if members of the same clone are used, but problems can arise unless the participants are also physiologically equivalent. A series of experiments on Myzus persicae (Sulzer) was performed to investigate aspects of male maturation and semen transfer that should be considered in planning or interpreting experiments on aphid sexual strategies.

Kluwer Academic Publishers, Dordrecht/Boston/London, 2002, viii + 419 pp. ISBN 1-4020-0775-2. Price USD 197.00.

Empirical protocols for assessing the suitability of prey for aphidophagous coccinellids are examined and a modified scheme of categorization is presented. It is argued that prey suitability should be assessed independently for larval development and adult reproduction because of potentially divergent nutritional requirements between these life stages. A scheme is proposed for assessing prey suitability for larval development using conspecific eggs as a reference diet against which diets of various prey types can be compared both within and among coccinellid species. Among suitable prey (those that support ca. 100% survival of larvae to the adult stage), those that promote faster development and yield larger adults relative to a conspecific egg diet are considered "optimal" for larvae. Prey that yield viable adults with similar or reduced adult weight after a similar or extended period of development relative to a diet of conspecific eggs are classified as "adequate". Prey are "marginal" if they support the survival of some larvae, but significantly less than 100%. Supplementary water should be provided with any non-aphid diet (e.g. pollen and alternative sources of animal protein) given the potential for food-specific diet-drought stress interactions. For adults, suitable prey are classified as "adequate" if they support the production of viable eggs when fed as a monotypic diet, or "marginal" if they merely prolong adult life relative to a water source. Prey that comprise an optimal or adequate diet for both larval development and adult reproduction are termed "complete" and these can be indexed for relative suitability according to derived estimates of r_m. Potential sources of error in diet evaluation studies are identified and discussed.

Hall J.C. & Evenhuis N.L.: Homeodactyla and Asilomorpha. In Griffiths G.C.D. (ed.): Flies of the Nearctic Region. Vol. V, Part 13, No. 7, Bombyliidae. pp. 657-713. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, 2004, 60 pp., 46 Figs. ISBN 3-510-70027-9.

Density dependent host mortality in the interaction between the solitary endoparasitoid Aphidius colemani (Aphidiidae), and its host, the green peach aphid Myzus persicae, was examined on greenhouse peppers. The experimental approach attempted to eliminate spatial interdependence in the relationship between host density and host mortality by using different plants to measure parasitism at different spatial scales. Increasing host density at the plant scale caused a significant increase in the proportion of host mortality. However, at the shoot and leaf scale, increasing host density caused a significant decrease in host mortality. This may be one of the first experimental demonstrations of a switch from inverse to direct density dependence. The pattern is assumed to be a result of searching parasitoids using different cues at different spatial scales.

The univoltine leaf miner Chromatomyia fuscula Zetterstedt is a Scandinavian cereal pest. We wanted to compare the phenology of C. fuscula in southern Norway with that of its most important natural enemies: 15 parasitoids of the families Eulophidae and Pteromalidae (Hymenoptera: Chalcidoidea). The use of two Malaise traps in an organically-grown spring barley field and its boundary through 6 seasons (1992-1997) also allowed us to compare these two habitats and to observe the effect of harvesting on the parasitoid activity without interference from pesticides. C. fuscula overwinters as an adult and oviposits in May/June. Few specimens of the next generation, emerging in the crop, were caught in the boundary traps, suggesting the fly hibernates elsewhere. In contrast, the F₁ generation of the parasitoids was caught in considerable amounts both in the crop and boundary. The abundance of parasitoids was highest in July/August; in the crop it usually started decreasing well before harvesting; in the boundary it peaked two weeks or more after harvesting. The results suggest that many parasitoids (especially females) move from the crop to the boundary (or beyond) before harvesting. In both habitats parasitoid species richness usually increased until harvesting, and thereafter decreased. The pooled parasitoid female proportion was 0.36; in crop and boundary it was 0.30 and 0.66, respectively, and the majority of species had a higher proportion of females in the boundary than in the crop. The phenology of two of the most common parasitoids is presented: The pupal parasitoid Cyrtogaster vulgaris Walker (Pteromalidae) had a high activity in the boundary, also very early (females only) and late (both sexes) in the season. The larval parasitoid Diglyphus begini (Ashmead) (Eulophidae) was less active early and late in the season, and had a much smaller boundary activity than C. vulgaris. Both sexes were present throughout the season. The annual sex ratio of D. begini was density dependent, being highly male biased in the two years with highest catches. In C. vulgaris neither density nor habitat explained the sex ratio. D. begini probably overwinters inside the mine as a preadult, having one generation on C. fuscula in the crop and another one in an alternate host away from the habitats sampled here. C. vulgaris overwinters as fertilized females in the border habitat.

Brodsky A.K.: The Evolution of Insect Flight. Oxford University Press, Oxford, New York, Tokyo, 1994, xiv + 229 pp.

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.

This report describes 7 new species of Drosophila found in the Eastern Arc mountains and on Mount Kilimanjaro in Tanzania: D. baucipyga, D. gata, D. kilimanjarica, D. neogata, D. paragata, D. pilocornuta and D. usambarensis spp.n. Two new species complexes, the megapyga species complex (Sophophora subgenus, melanogaster group, montium subgroup) and the gata species complex (Drosophila subgenus) are introduced. Only one species, D. baucipyga of the montium subgroup, has a geographical range matching the whole Eastern Arc, from the Usambara Mts. in the north-east of Tanzania to Mt. Uzungwa in the south-south west of the country. Five others, including one representative of the dentissima group of the Sophophora subgenus, D. usambarensis, and four representatives of the Drosophila subgenus, D. gata, D. neogata, D. paragata and D. pilocornuta, were found only in the Usambara Mts. Two of these five, D. usambarensis and D. pilocornuta were found only in West-Usambara, while two other related species, D. gata and D. paragata, were found only in East-Usambara. Only the distribution of D. neogata covers the whole of the Usambara mountains. Outside the Eastern Arc, another representative of the dentissima group, D. kilimanjarica, was found only on Mount Kilimanjaro. This new, highly specific, montane fauna of Drosophila further contributes to the unique biological diversity of the Eastern Arc Mts. The biogeographic affinities of the new taxa suggest past connections with the Virunga and Ruwenzori ranges and further west with the Cameroon Volcanic Line. It indicates, in particular, that the Eastern Arc forests have passed through a succession of coalescence and fragmentation events.

As part of a search for natural enemies of the gypsy moth (Lymantria dispar), virus-infected samples were collected near Toulouse, France. Light and electron microscope studies confirmed that the French strain is a multinucleocapsid nuclear polyhedrosis virus (MNPV). In vivo bioassays using the New Jersey strain of L. dispar, and comparing L. dispar MNPV (LdMNPV) strains from France, North America and Korea, showed that the French strain was the least active, whereas the North American strain had the highest activity. The viral efficacy of all strains was enhanced 200 to 1300-fold in the presence of 1% fluorescent brightener. The enhancement was highest in the American strain and lowest in the French strain. French LdMNPV (LdMNPVF) DNA cut with four restriction enzymes (BamHI, EcoRI, HindIII, and NotI) revealed minor fragment size differences, but many similarities when compared to the North American and the Korean strain. PCR amplification of a LdMNPV early gene (G22) was detected in the North American and the Korean strain, but not in the French strain.

The Oriental helotrephid genus Idiotrephes Lundblad, 1933, is taxonomically revised. Species discrimination is based on male genitalia and female terminalia. Three species groups are recognized. The I. chinai group contains I. chinai Lundblad, 1933 (type species; from Sumatra, Borneo, and West Malaysia) and three newly described species; I. asiaticus sp. n. (from Vietnam, Thailand, and west Malaysia); I. yupae sp. n., and I. polhemusi sp. n. (both from Thailand). The I. maior group contains I. maior Papáček, 1994; I. meszarosi Papáček, 1995 (both from Vietnam), and I. hainanensis sp. n. (from Hainan, China). The I. thai group consists of two newly described species from north and northeast Thailand, I. thai sp. n. and I. shepardi sp. n. In addition, some features of biology and morphology of the ovipositor are also included.

In this study, aspects of the reproductive performance and behaviour of male Myzus persicae (Sulzer) (Hemiptera: Aphididae) were investigated. We report that males of clones possessing an autosomal 1,3 translocation conferring insecticide resistance show a weak trend for a reduction in reproductive potential. Clones with the translocation that can produce males but no mating females (androcyclic clones) did not have an additional disadvantage. The age of virgin males and females affected mating success. Young males and females, 0-5 days old, were the most successful with respect to the number of females mated and number of eggs produced. There was a decline in reproductive potential after 9-10 days into adult life for males and after 4-5 days for females. Mating behaviour was observed in the laboratory and described. Some pre-copulatory stroking behaviour by the fore and hind legs of the male was observed. Females occasionally walked in copula sometimes resulting in the disengagement of the male before the termination of mating. Average mating duration in the experimental conditions was 10.5 ± 4.0 minutes and both males and females readily mated more than once.

The aim of this study was to determine if there is a latitudinal gradient in the photoperiodic regulation of wing dimorphism in the flightless bug, Pyrrhocoris apterus (L.). For this purpose individuals from three geographical populations (Israel, Spain and Czech Republic) were reared under different photoperiods and the wing length of the adults analyzed. The highest percentage of long-winged (macropterous) specimens was found in the population from Israel (35.3%), whereas percentages of macroptery were lower in the cultures from Spain (9.5%) and Czech Republic (8.6%). A higher proportion of macropterous specimens was recorded in the northern population of P. apterus kept under long daylengths (Czech Republic, 16 h) than in the southern populations (Spain, 14-15 h; Israel, 12 h). The results indicate that there is a latitudinal gradient in the critical photoperiod determining wing length in P. apterus.

The genus Vanniusoides Carvalho & Lorenzato is revised and redescribed, a new species V. clypeatus is described from the Solomon Islands. Redescription of the species V. brevis (Poppius) and a key to the species of the genus are given. Illustrations of dorsal habitus, tarsi and male genitalia of the new species are provided.

Eggs of thirteen synanthrophic psocids of the families Trogiidae, Psyllipsocidae, Liposcelididae and Lachesillidae, commonly occurring in stored products in Europe, are described. Descriptions are based on overall appearance during embryogenesis, size and surface sculpturing. Morphological details are illustrated using scanning electron micrographs. A key for distinguishing eggs at both the generic and species level is provided. The presence or absence of a micropyle and aeropyle is discussed.

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.

The reservoirs of dorso-abdominal scent glands and the occurrence of the metapleural scent gland evaporatoria in the adults of nine central European and one North American species in the family Rhopalidae (Hemiptera) were studied. All published data about the persistence of the dorso-abdominal scent glands in rhopalid adults are reviewed, and systematic and phylogenetic implications are derived from the patterns of variation.

 The genus Curriea Ashmead is recorded from Europe. Endovipio Turner is downgraded to a subgenus of Curriea. Curriea (Endovipio) jacobsoni (Tobias) comb. n. is redescribed in order to draw at tention to previously overlooked characters, and a new combination is designated. The species is recorded for the first time from Spain, France, Morocco, Senegal and the Canary Islands.

In 1992-1994, the activity of ground surface arthropods was investigated on a fallow field divided into small plots with different regimes of weed management. Daily operated pitfall traps were placed in a transect across the field. The aim of the study was to investigate the effect of temperature on the magnitude of total arthropod catches. The pooled catches of all arthropod species were poorly correlated with temperature since its effects were damped by differences in timing of peak abundance of the species. To compensate for the effect of this variation groups of species with similar patterns of annual variation of abundance were selected. The regressions of pooled catch on average daily temperature were then calculated for periods of their peak occurrence when changes of their abundance and/or behaviour were minimum. Seven abundant carabid species were selected and regressions calculated for periods of April 20-May 13 (Bembidion lampros, Harpalus tardus, Poecilus cupreus), June 25-July 25 (H. tardus, P. cupreus), and August 8-September 9 (Amara convexiuscula, H. affinis, H. distinguendus, Pseudoophonus rufipes). By this procedure a significant effect of temperature on carabid activity was shown, similar for different species groups and periods. The catch size increased in the average by 6.3 percentage points per 1°C increase of average temperature. Using this temperature/catch size relationship daily catches of several species were recalculated on a standard temperature of 20°C. This procedure decreased the variation of daily catches by 5-31%. The decrease was proportional to the variation of daily temperatures during the period of sampling.

The persistence of oviposition-deterring effects of coccinellid and chrysopid larval tracks on females of three aphidophagous coccinellid species was compared. One month old tracks of first instars of the coccinellid Cycloneda limbifer Casey deterred conspecific females from oviposition in choice tests with clean and contaminated substrates. Intraspecific effect of larval tracks in Semiadalia undecimnotata Schneider was statistically significant after 10 days. Although fresh tracks of conspecific first instars effectively deterred females in both tested populations of Coccinella septempunctata L., deterrent effects disappeared when tracks of larvae were only one day old. However, females of C. septempunctata laid fewer eggs on sites with 10 days old tracks of Chrysopa oculata Say or sites with one month old tracks of Chrysopa perla (L.) first instars than on clean sites. In contrast to females of C. septempunctata and S. undecimnotata, C. limbifer females left significantly more faecal spots on clean sites than on sites with 5-30 days old tracks of conspecific first instars. This indicates that sites with tracks of larvae can also effectively repel conspecific females of some coccinellid species from searching.