We have investigated the relative importance of bark roughness and host tree species in determining the diversity and make-up of coleopteran assemblages on the trunks of trees in sub-tropical rainforest in south-east Queensland, Australia. There are clear, statistically significant, patterns in the composition of the assemblages which reflect bark roughness. Rougher bark had associated greater species and family richness, a higher proportion of "rare" species, a higher value for Shannon diversity and lower values for the Simpson and Berger-Parker Index (measures of dominance within the sample). The data support strongly the idea that there is a bark-specific beetle assemblage. The rougher bark was associated with significantly greater numbers of an anobiid species, Dorcatoma sp., and of the latridiid species Aridius australicus. Rougher bark also harboured significantly larger species. The most likely explanation for this seems to be related to the physical heterogeneity and biological complexity of the habitat, presenting, as it does, greater opportunities for shelter, feeding specialisation and intra-species aggregation. Rougher bark contained a higher proportion of both predatory and xylophagous groups than did smoother categories. No clear influence of tree species could be detected although some trends were evident.

Mating success is linked to reproductive success in males, but parameters influencing it are poorly known. The relationships between lifetime mating success (LMS), fluctuating asymmetry (FA), body size (SIZE), reproductive period (RP) and emergence date (MD) of males of Cercion lindeni were investigated. Males were marked and photographed in their pre-reproductive period, and their matings monitored. RP was assumed to be the period between the MD and the last sighting of each individual. Three different FA measures and the size of each individual were determined. The results showed that the individuals not present at the pond during the reproductive period had a higher FA (but not for meristic characters) than those present. For those individuals actually involved in reproductive activity, LMS was only positively correlated with RP, which was negatively related with MD, and this with SIZE.

Investigations of the interactions between aphids and ants in multispecies ant communities and an experimental investigation of some ethological aspects of ant-aphid interactions were carried out in mixed forests at Novosibirsk Academic Centre, from 1998-2002. The eight species of ants investigated were characterized by different levels of territorial organization and interaction with aphids, which were associated with different degrees of specialization of the worker ants. The most myrmecophilous species of aphids (24 out of 33 species identified) were associated with the red wood ants. By placing Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) in aphid colonies it was shown that only ants with large protected territories attacked the adults and larvae of the predator. Other species of ants either protected aphids only from adult ladybirds or did not guard them at all. Moreover, only individuals of Formica s. str., which has specialized workers, did not switch to collecting protein food. However, aphids make up a considerable part of the prey of ants, in which non-myrmecophilous aphids predominate (about 60-100% of the aphid prey). Moreover, ants only killed unattended or damaged myrmecophilous aphids. Formica s. str., which has the highest level of social and territorial organization, provides aphids with the most services and is the dominant species forming symbiotic relationships with aphids in the communities studied.

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.

The complete nucleotide sequence and the exon-intron structure of the luciferase gene of the firefly, Luciola lateralis (Coleoptera: Lampyridae) is described. The luciferase gene of the L. lateralis firefly spans 1,971 bp and consists of six introns and seven exons coding for 548 amino acid residues. From samples collected at Boun and Muju, Korea, three isoforms, with identical exon-intron structure, named BU, MJ1 and MJ2, respectively, were obtained. Although the amino acid sequences of MJ1 and MJ2 were identical to those of known luciferase genes of Korean origin, the BU type was novel, differing from each of the MJ1 and MJ2 types by one amino acid. The luciferase sequences of the Korean samples, including those previously revealed, differed only by one - two amino acid residues, but differed by five - six amino acid residues from that of the luciferase gene recorded from specimens from Japan, which suggest genetic divergence has occurred in this species. Phylogenetic analyses using both amino acid and nucleotide sequences further showed that the luciferase gene of the Japanese L. lateralis firefly is genetically distinguishable from that of Korean L. lateralis, suggesting the presence of a genetic subdivision between the L. lateralis dwelling in the Korean Peninsula and Japanese Islands.

The uzifly, Exorista sorbillans (Diptera: Tachinidae), a parasite of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), causes heavy losses to the silk industry. This parasitoid harbours a Wolbachia endosymbiont, which controls the fly's reproduction. In the present study a method for curtailing this notorious pest by administering Wolbachia-targeted tetracycline via its silkworm host's diet is investigated. Tetracycline not only influenced the larval growth of the silkworms' by decreasing larval duration, increased silk production and fecundity, without affecting hatchability, it also decreased the reproductive fitness of the uzifly endoparasite by killing the Wolbachia. The antibiotic exerts a beneficial influence by affecting the intestinal flora of silkworm larvae. On the other hand the reproductive fitness of uzifly was greatly reduced in terms of different reproductive abnormalities. When male and female flies that emerged from treated host silkworms were crossed and males from untreated hosts and females from treated hosts were crossed, approximately 72% and 97% of the eggs failed to hatch, respectively. However, of the eggs from crosses between male and female flies that emerged from untreated hosts and between males from treated hosts with females from untreated hosts, an average of 30% failed to hatch and the Wolbachia infection enhanced the fecundity of uziflies. These results demonstrate that the Wolbachia may be essential for uzifly reproduction and that Wolbachia-targeted antibiotics have a beneficial influence on silkworm growth while decreasing the reproductive fitness of the uzifly, E. sorbillans.

The suitability of Liriomyza sativae Blanchard, L. trifolii (Burgess) and L. bryoniae (Kaltenbach) as hosts of the solitary larval-pupal parasitoid Dacnusa sibirica Telenga was studied. This parasitoid is used as a biological control agent against L. trifolii and L. bryoniae. The parasitoid laid eggs in L. sativae, but no adult parasitoids emerged from the puparia. In contrast, D. sibirica adults emerged from the puparia of L. trifolii and L. bryoniae, and there was no significant difference in emergence rate, female developmental time, or sex ratio when parasitizing these two host species. The parasitoid adults that emerged from the L. bryoniae puparia were significantly larger than those from L. trifolii puparia. In conclusion, D. sibirica, a useful biological control agent of L. trifolii and L. bryoniae, cannot control L. sativae.

Bemisia tabaci (Gennadius) is a worldwide pest of vegetable, ornamental and field crops. Biotype B of B. tabaci, which is economically most important of the biotypes, is distinct from all other biotypes (non-B biotypes). Fourteen populations of B. tabaci were collected from different localities and host plants in the Chinese mainland and Taiwan, namely TWYDH (tassel flower, Taiwan), HNYC (tobacco, Hainan), GXNG (pumpkin, Guangxi), GDYPH (poinsettia, Guangdong), GDBSM (croton, Guangdong), GDFS (Chinese hibiscus, Guangdong), SHYPH (poinsettia, Shanghai), FJGS (sweet potato, Fujian), SDFQ (tomato, Shandong), BJXHL (squash, Beijing), XJQZ (eggplant, Xinjiang), XJYPH (poinsettia, Xinjiang), XJJM (abutilon, Xinjiang) and XJMH (cotton, Xinjiang). The internally transcribed spacer 1 sequences (ITS1) of ribosomal DNA of B biotype and other biotypes were sequenced and analyzed. The B biotype-specific primers were then designed for rapid identification of B biotype of B. tabaci. The results show that the diagnostic primer only gave a positive result with the B biotype. This is the first report of a rapid means of identifying B. tabaci B biotype using a diagnostic primer based on ribosomal DNA. This protocol is especially useful for identifying the B biotype in Bemisia populations consisting of several biotypes.

Concordant differences in morphology, phenology and RAMS markers, as well as in sequenced mtDNA (COI, COII, cytb) and nuclear DNA (ITS2) fragments, indicate that Dolerus asper Zaddach, 1859 and Dolerus brevicornis Zaddach, 1859 are valid species. On the basis of morphology, molecular markers, and distributional records, both species are distinct from Dolerus gibbosus Hartig, 1837 (= Dolerus planatus Hartig, 1837). Taxonomy of the species is clarified and the neotypes of Dolerus asper Zaddach, 1859 and Dolerus brevicornis Zaddach, 1859 are designated. The synonymies of Dolerus asper Zaddach, 1859, to Dolerus planatus Hartig, 1837 and Dolerus derzavini Malaise, 1931, spec. rev. to D. asper Zaddach, 1859 are abandoned. Dolerus carbonarius Zaddach, 1859 and Dolerus fumosus Zaddach, 1859 are considered to be species inquirendae. Phylogenetic analyses of the ITS2 fragment and fragments of ITS2 + COI and ITS2 + COII yielded the topology [D. asper, (D. brevicornis, D. gibbosus)], while those of all other markers and their combinations resulted in the topology [D. brevicornis, (D. asper, D. gibbosus)]. In the latter hypothesis the clade asper + gibbosus is also supported by structural synapomorphies.

The rose grain aphid, Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) is one of the three most important cereal aphid species in Europe. High temperature is detrimental for the survival of this species. Detailed experiments were conducted on the effect of high temperature (27, 28, 29, 30, 31, 31.5, 32.5, 33 and 34°C), period of exposure (2, 3, 4, 6 and 8 h per day for 1, 2, 4, 6 days) and developmental stage (2nd, 3rd, 4th instar nymph and adult) on the survival of the aphid. The results show that all three factors significantly affect survival. Temperatures over 29°C for 8 h significantly reduced survival, which decreased generally as the temperature increased. The survival was inversely related to the period of exposure. Exposing aphids to 32.5°C for 4 h or longer significantly reduced survival. Mature aphids had a lower tolerance of high temperatures than nymphs. Periods of high temperature experienced by 4th instar and adult aphids can greatly affect their survival. The value of these results for forecasting and determining control thresholds, the effect of global warming on cereal aphid abundance and the dropping off behaviour of the aphids are discussed.

The comparative biology of the solitary endoparasitoid Meteorus gyrator (Thun.) was investigated in five noctuid pest species. Meteorus gyrator parasitized all larval stages of the noctuid pests Lacanobia oleracea, Mamestra brassicae, Spodoptera exigua, Spodoptera littoralis and Chrysodeixis chalcites. When female parasitoids were offered host larvae of all developmental stages, host larvae in their third stadium were parasitized most frequently in all species. When the parasitoid was offered a choice of third stadium larvae from each of the five lepidopteran host species, L. oleracea was the most frequently parasitized, followed by M. brassicae. The growth of L. oleracea and M. brassicae was markedly reduced when larvae were parasitized by M. gyrator, with the effect of parasitism on the remaining species being much less pronounced. In excess of 94% of parasitized hosts gave rise to live wasps in L. oleracea, whilst in M. brassicae only 52% of parasitized hosts gave rise to a live wasp, the remainder dying (44.6%) or pupating (3.1%).
The larval development of the parasitoid was also strongly influenced by the host species. Thus, the development (egg to cocoon) of female wasps was most rapid in C. chalcites (9.7 ± 0.09 days), and longest in M. brassicae (17.2 ± 1.08 days). The cocoon weight of wasps was also significantly affected by host species, with the heaviest female cocoons being derived from C. chalcites (10.4 ± 0.16 mg) and the lightest female cocoons being derived from M. brassicae (7.0 ± 0.14 mg). In all cases, the development times and cocoon weights of male parasitoids were less than those of female wasps.

Beetle luciferase, a mono-oxygenase within the AMP-binding superfamily, is synthesized by bioluminescent beetles in concentrated levels within specialised cells clustering in the abdominal light organs. In vivo expression of luciferase has been rarely investigated and little is known about the role of enhancers and promoters in the expression of this gene. In order to investigate the gene structure and potential control of gene expression the luciferase gene along with 6 kb of upstream genomic sequence was characterised from the European glow-worm Lampyris noctiluca. Three TATA box motifs and a CAAT repeat were identified, two of these were found to be conserved in two other species of bioluminescent beetle. Although no enhancer regions were identified in the upstream sequence a region coding for a putative transposase DDE domain was identified 686 bp from the start codon of the luciferase gene. Although disrupted, the open reading frame also shared extensive identity to an mRNA transcript from the mosquito Anopheles gambiae. The remnants of an ancient transposase provide support for an ancestral luciferase transposition/insertion event that may have occurred within the genome of bioluminescent beetles.

For polyphagous predators, the link between food consumption and reproduction is not always straightforward, and instead may reflect that even predators with very broad diets may have reproductive tactics that are tied to consumption of a restricted range of prey. We studied the consumption and use of two prey species for reproduction by the ladybird, Harmonia axyridis Pallas. This polyphagous predator feeds on both pea aphids [Acyrthosiphon pisum (Harris)] and larvae of the alfalfa weevil [Hypera postica (Gyllenhal)] that it encounters when foraging in alfalfa fields. When provided a diet of pea aphids or of alfalfa weevils and/or sugar water, females of H. axyridis laid eggs in large numbers only on the diet of aphids. Females laid no eggs on diets of weevils or sugar alone, and laid only small numbers of eggs when the two foods were provided together. When placed on a diet of aphids, females began laying eggs earlier, and laid more eggs altogether, when they had previously fed on weevils versus sugar water. The predators' consumption rates of aphids were greater than their consumption rates of weevils, and they produced less frass per mg of prey consumed on an aphid versus weevil diet. The predators searched more actively when maintained on a weevil versus aphid diet. Hence, lower rates of food intake and assimilation, and greater allocation of nutrients and energy to searching, appear to contribute to the reduced egg production of H. axyridis females that feed on weevils versus aphids. Alfalfa weevils are also less suitable prey than pea aphids for larval survival and development of H. axyridis. Thus, the differing responses of H. axyridis adults to these two prey types may reflect that these predators are well adapted in the linking of their feeding and reproductive behavior.

Meaningful ecological studies on insect communities require sampling protocols that take into consideration temporal fluctuations in abundance and species composition. Bees with their specific requirements for nutrition and nesting are good indicators of landscape structure and overall biodiversity, provided the ecological and seasonal patterns they show are taken into consideration. The present two year study traced the ecological and seasonal patterns on 2 km² of a southern slope in the Swiss Alps, ranging from 1150 to 1550 m above sea level. The study area consisted mainly of grassland under different regimes, mostly hay meadows and pastures. By direct netting at five monthly intervals in each year a total of 247 bee species were recorded. This comprehensive sampling scheme identified one of the most diverse bee faunas in Central and Northern Europe, consisting of a statistically estimated 280 species. Most species were rare with 14.6% represented by a single individual. Ecological analysis of the bee community showed that the primitively eusocial species were over represented among the abundant species and the parasitic species among the rarest.
Both abundance and species richness were subject to marked seasonal variations. A substantial turnover in species composition as well as changes in ecological patterns were observed. More than 25% of all species were recorded in only one of the two years, in particular many of the parasitic species. Singletons accounted for a higher proportion when individual years rather than the pooled data were analysed. All these findings underline the importance of season-long sampling and sampling over more than one year if bees are to be used as indicators in ecological and studies on bee communities.

Second to fifth instars of nine New Caledonian species of Tingidae are described. A key to fifth instars is provided. The comparison of immature stages among the known larvae shows that translocation of marginal tubercles in larvae, considered as the general rule, is absent in New Caledonian larvae. Also, external morphology of larvae becomes more complex through development, by the addition and ramification of tubercles, as it does also through evolution. Such a tendency is reminiscent of a heterochronous phenomenon, like peramorphosis. Translocation phenomenon could be an intermediate stage of evolution in terms of aquiring more tubercles.

The role of relatedness and diet in kin recognition was investigated in the aphidophagous ladybirds Propylea dissecta and Coccinella transversalis. Third instar larvae of both species exhibited kin recognition, as they were reluctant to consume related first instar larvae. They spent significantly more time prior to cannibalism when interacting with genetically related victims; this indicates the presence of a kin recognition system. Kin recognition, however, was not evident in fourth instar larvae as they ate both related and unrelated victims. This result reveals that the need of fourth instar larvae to attain a critical weight for pupation might subdue kin recognition. The diet of cannibals did not affect cannibalism, number of encounters or time that elapsed prior to cannibalism. This indicates that kin recognition is not dependent on exogenous cues derived from the diets of the cannibal and victim.

The inhibitory potential of primary and secondary reproductives was studied using half-orphaned colonies of Kalotermes flavicollis. Both primary and secondary reproductives (neotenics) were equally effective in inhibiting the development of replacement reproductives. Single females totally inhibited the development of female secondary reproductives but did not affect the development of male secondary reproductives. Single males had neither a stimulatory nor inhibitory effect on the development of secondary reproductives. The inhibitory ability of pairs of primary reproductives shortly after dealation and at the stage of incipient colony formation (couple with the first batch of eggs) was also examined. While pairs of freshly dealated reproductives were not able to inhibit the development of neotenics, pairs of primary reproductives that had their first batch of eggs, fully inhibited the development of neotenics.

The hypothesis that small body size is correlated with preference for young leaves was tested in a community of leaf-chewing insect herbivores feeding on Ficus wassa in a humid tropical forest in Papua New Guinea. Feeding experiments on 48 species of herbivorous insects revealed a negative correlation between body size and a preference for feeding on young leaves. While small species preferred young leaves, large species showed no preferences, or preferred young leaves only slightly. This relationship was found for the entire leaf-chewing community, as well as for many of the constituent taxa on several taxonomic levels, from orders to genera. Taxonomic position of a species played little role in determining its preferences. It is proposed that higher toughness and lower nutrient content may act as complementary defences, which prevent small insects from feeding on mature foliage. While the low nutrient content of mature leaves may affect smaller herbivores due to their relatively higher metabolic rate and lower digestion efficiency, their toughness complicates feeding mechanically and may prevent the compensatory feeding necessary to offset the low nutritive value of mature leaves.

Data on nesting densities of Bembix rostrata, a digger wasp inhabiting dynamic coastal dunes, were used to document the detrimental effects of trampling by cattle and vacationers. Both types of disturbance resulted in similar sand displacement and prey availability. Nesting densities of Europe's largest digger wasp declined dramatically with increasing trampling, probably below the critical population size. Hence, additional human disturbance, although resulting in similar environmental conditions compared to natural disturbance, significantly affected local population sizes. As a result, anthropogenic has to be avoided disturbance in order to restore or conserve natural dynamics and efforts to restore natural dynamics in a more natural way should be promoted. Although this is here only documented for one, large specialised invertebrate, the application of traditional management techniques, such as grazing by large herbivores, within newly evolved landscapes may introduce new pressures that affect pre-adapted species to natural disturbances negatively within short time spans.

Halobates spp. are the only insects inhabiting the open sea. One sea skater species, Halobates sericeus, was collected at 18 locations in the East China Sea area (27°10´N- 33°24´N, 124°57´E-129°30´E), and H. micans and/or H. germanus at only 8 locations in the area south of 29°47´N, where water temperatures were more than 25°C. At three locations, where the water temperature was less than 23°C, neither H. micans nor H. germanus were caught. The effect of photoperiod on the aggregation and mating behaviour of the sea skater, H. sericeus, was studied under laboratory conditions during a one-month cruise. Adults and 5^th instar larvae of H. sericeus, collected between 29°02´N and 30°29´N, were kept under long (14.5L : 9.5D) or short-day (10.5L : 13.5D) conditions at 23 ± 2°C for 20 days. Aggregation and mating behaviour of these sea skaters were recorded over a period of 150 min during the daytime. To analyze the data, the observation period of 150 min was divided into 50 intervals of 3 min. Aggregation was observed more under short than long-days. Duration of a group was much longer under the short (mean ± SD : 43.0 ± 108.1 sec) than long-days (7.6 ± 3.1 sec).

A new genus of parathalassiine-like flies, Eothalassius gen. n., and two new species, Eothalassius platypalpus sp. n. (type species), E. gracilis sp. n., are described from the coasts of Southeast Asia and Papua New Guinea. The phylogenetic relationships of the new genus with other genera assigned to Parathalassiinae and Dolichopodidae are discussed.

Survival under dry conditions was examined in males and females of Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), a beetle of tropical origin. The range of individual responses and the effect of gender on water loss were also evaluated. Females exhibit significantly longer survival (Lt₅₀ and Lt₉₀) than males under desiccating conditions. Larger females beetles have a greater initial water mass and hence can tolerate greater water losses. Such beetles have longer survival under dry conditions. Males and females loose an average of 54.8 and 58.9% of their body water prior to death. The insects were inactive most of the time, when kept under dry conditions; the rate of decrease in body water was thus reduced. Beetles of both gender display a negative correlation between the rates of water loss under desiccating conditions and the duration of survival. We conclude that the difference in survival period between males and females is due to a combination of greater female tolerance to desiccation and larger body size.

Life-history parameters (juvenile development time, adult longevity, host instar preference and rate of parasitism) of four parasitoids of Bemisia argentifolii (two strains of Encarsia formosa (D and B), Eretmocerus eremicus and Eretmocerus mundus) were studied in the laboratory. At 15°C juvenile development time was the shortest for E. formosa B (48 days), longest for E. eremicus (79.3 days) and intermediate for E. formosa D (62.8 days) and E. mundus (64 days) at 15°C. With increase in temperature, development time decreased to around 14 days for all species/strains at 32°C. The lower developmental threshold for development was 11.5, 8.1, 13.0 and 11.5°C for E. formosa D, E. formosa B, E. eremicus and E. mundus, respectively. E. formosa D and B, and E. mundus all appeared to prefer to parasitize 3^rd instar nymphs. The presence of hosts shortened adult longevity in most of the parasitoids, with the exception of E. formosa B, which lived longer than other species/strains irrespective of the presence of hosts. At 15°C daily parasitism was very low by all parasitoids. The two Encarsia strains had a constant, but low rate of reproduction during adult life, while the two Eretmocerus species had a very high rate of reproduction when one-day old, which then decreased very quickly. Lifetime fecundity, estimated using a non-linear model, indicated that it was higher for the two Encarsia strains than for the Eretmocerus species. Life history parameters reported in the literature for the four parasitoids are reviewed and compared with our results. Finally, the potential value for the biological control of whiteflies on greenhouse crops of parasitoids having either a high reproductive rate over a short period (Eretmocerus spp.) or a low rate of reproduction over a long period (Encarsia spp.) is discussed.

Euzophera pingüis (Lepidoptera: Pyralidae) is a secondary olive pest, which has increased in importance during recent years. In this study, more than 1300 predatory arthropods were collected from a Spanish olive orchard over two years and assayed using a pest-specific ELISA. Abundance and the percentage of positive responses to E. pingüis obtained using ELISA showed spiders to be the main predator, especially in 1998, when they accounted for 18% of the predation, followed by Scymnus suturalis (Coleoptera: Coccinellidae) and Brachinotocoris ferreri (Heteroptera: Miridae). Neuroptera and ants were less important as predators of E. pingüis.

The foraging behaviour of beneficials such as aphidophagous predators depend largely on volatile compounds emitted by potential preys. Even if polyphagous predatory species are considered, all the potential preys are not systematically localised and accepted. In this work, chemical cues from different aphids and plants, each alone or in association, were studied to elucidate their role in prey location. Using a four-arm olfactometer, attraction of combinations of three aphid (Megoura viciae, Acyrthosiphon pisum and Aphis fabae) and one plant (Vicia faba) species for Episyrphus balteatus larvae was observed. Predatory hoverfly larvae were attracted by all tested stimuli in the presence of aphids, whatever the species. Whole or crushed aphids and also aphids on bean plant parts were attractive to syrphid larvae, but the host plant alone did not present any infochemical role for E. balteatus. Identification and quantification of the volatile releases from aphid and plant species, alone or in association, were performed using SPME and GC-MS methods. Aphid alarm pheromone, (E)-β-farnesene, was found in the volatile pattern of each aphid and was tested for its role as an effective kairomone for the hoverfly.

Winglessness in the two-spot ladybird beetle Adalia bipunctata (L.) is determined by a single locus with the wingless allele recessive to the winged wildtype allele. The expression of the wingless trait is highly variable, with individuals missing a variable part of elytra and flight wings; the elytra and wings appear to be truncated rather than miniature in form. The degree of winglessness is partly determined genetically. Here we report on the phenotypic plasticity of the degree of winglessness. The environmental effect on elytron length relative to maximal elytron length in wingless phenotypes was studied by rearing offspring of single pair crosses of this form at a low (19°C) or high (29°C) temperature. Offspring reared at 19°C showed relatively longer elytra than those reared at 29°C.

This paper presents a synthesis of morphological information on larvae of the beetle suborder Archostemata. Larvae of the following families and species were studied: Ommatidae: Omma sp.; Micromalthidae: Micromalthus debilis LeConte, 1878; Cupedidae: Priacma serrata LeConte, 1861, Distocupes varians (Lea, 1902), Rhipsideigma raffrayi (Fairmaire, 1884), Tenomerga cinerea (Say, 1831) and Tenomerga mucida (Chevrolat, 1829). Morphological characters of the suborder and three families are described. Monophyly of the suborder is strongly supported by more than 10 larval autapomorphies. A close relationship between Micromalthidae and Cupedidae is confirmed. New larval characters are introduced, including chaetotaxy of first instar larvae of Micromalthus LeConte, 1878, Priacma LeConte, 1874 and Distocupes Neboiss, 1984. An identification key to families and subfamilies of Archostematan larvae is provided, along with a checklist of extant Archostemata taxa. The work is illustrated with 120 morphological drawings.

SPB Academic Publishing bv, The Hague, 2004, 804 pp., 793 figs, 80 tables. ISBN 90-5103-142-4. Price EUR 290.00, USD 345.00.

The paper reviews existing data on the food quality of cereal aphids for generalist predators. Data are presented for spiders, harvestmen, carabid and staphylinid beetles, cockroaches, ants and one species of bird. All results agree that cereal aphids are low-quality food compared to alternative prey types (in most studies fruit flies). This is associated both with a low consumption capacity for aphids and a low utilization efficiency of the aphid food. A pure aphid diet allows full juvenile development in only a few species. Aphids as part of mixed diets can have negative, neutral or positive effects, which depends on the quality of the remaining diet. The low consumption capacity for aphids is due to the development of a specific feeding aversion. Genetic variation in the ability to tolerate aphids has been documented, indicating that predators may be able to adapt to a higher proportion of aphids in the diet in areas where outbreaks are frequent. A consequence of these findings is that predator populations rely on alternative prey (e.g. Collembola and Diptera) for maintenance and reproduction, and are probably unable to benefit nutritionally from an aphid outbreak. The low food quality of aphids to generalist predators explains why generalist and specialist predators have widely different roles in aphid biocontrol, but does not rule out that under some conditions the generalists may be able to inhibit aphid population growth sufficiently to prevent an outbreak, as field experiments have indicated. Simulation modelling shows that a low consumption capacity for aphids has little influence on the ability to prevent aphid population increase at low aphid immigration rates, but a great influence at high aphid immigration rates. Modelling also indicates that there may be an optimal availability of high-quality alternative prey that maximizes the impact of generalist predators on aphid population growth.

The relative occurrence and seasonal abundance of aphidophagous predators (Insecta and Arachnida) were determined in alfalfa fields at two locations in the northeast Iberian Peninsula, using D-Vac and sweep-net sampling techniques. Among the insects, Heteroptera, Dermaptera, Neuroptera, Coleoptera and Diptera were found. The relative abundance of predators was similar at the two locations. Polyphagous predators were much more abundant than aphid specific species. Heteroptera were the most abundant order of insect predators: members of the Nabidae, Anthocoridae and Miridae were very common. Coleoptera were also abundant, represented mainly by the family Staphylinidae. Coccinellidae were less abundant and their occurrence coincided with maximum aphid presence. There was a low occurrence of other aphid-specific predators, i.e. Diptera: Syrphidae and Neuroptera: Chrysopidae. Arachnida varied between localities (from 35% to 65%). Over a five-year period, numerical responses by Orius spp., Nabis provencalis and Coccinellidae to aphids were found using polynomial regression models; however the abundance of predators was weakly explained by aphid abundance. Alfalfa, maize and winter cereals share similar aphid predator groups and these crops partially coincide in time, enabling the movement of predators among crops. The persistence of several predatory groups (Anthocoridae, Nabidae, Staphylinidae, Araneae) during most of the season suggests that alfalfa plays a major role as a reservoir of aphid predators.