The diamondback moth, Plutella xylostella (L.), is a notorious insect pest of cruciferous plants. To examine the pattern and magnitude of genetic variation in this species in China a portion of the mitochondrial (mt) COI gene of P. xylostella, collected at six Chinese and two Korean localities, which cover ~2,151,600 km², was sequenced. Sequence analysis of the 681-bp mt COI gene from 80 individuals resulted in 16 haplotypes, ranging in sequence divergence from 0.1% (one nucleotide) to 0.9% (six nucleotides). One nucleotide position among 16 variable sites was a transversional substitution and the remaining positions were transitional substitutions. No position resulted in amino acid substitution. Phylogenetic analysis showed that all haplotypes were highly interrelated and no discernable haplotype group was found. From a geographical perspective, most haplotypes were found singly at one or two localities, with three haplotypes widely distributed. Little genetic differentiation (F_ST = -0.038-0.309) and a high rate of female migration (Nm = 1.117 - infinite) between Chinese populations suggests that dispersal over long distances is a major factor in the demography of this species.

Field studies were conducted, in order to assess the seasonal occurrence and the spatial distribution of Aphidius colemani Viereck, Aphidius matricariae Haliday, Diaeretiella rapae (M'Intosh), Praon staryi Kavallieratos & Lykouressis and Praon volucre (Haliday), all parasitoids of Myzus persicae (Sulzer) on tobacco. The experiments took place in western Greece (Agrinion, Aitoloakarnania), during the 1996 and 1997 growing seasons, in an area of approximately 2.5 ha, where tobacco was the main crop. The experimental field was insecticide-free and tobacco leaf samples (from the upper and lower half of plants) were taken from June until September, in both years. The distribution of the species found was also represented and discussed. Generally, high M. persicae densities were recorded in August (mid-season) of both seasons. The mummification rate showed a specific increasing trend late in the season (August-September). In 1996, the percentage of mummification reached almost 61% at the end of the period, whereas in 1997 it remained at very low levels (<2%). The density of M. persicae was higher on the leaves collected from the upper part of the plants than on those from the lower part, but without significant difference. In contrast, the numbers of mummified M. persicae individuals were significantly higher on leaves collected from the lower part of the plants than on those from the upper part in both years. The relative abundance of the aphidiine parasitoid species differed between the two years.

The Large Copper butterfly, Lycaena dispar, is extinct in Britain and rapidly declining in the rest of Europe, due predominantly to loss of its wetland habitats. In the Netherlands the sub-species L. d. batavus is at the edge of its range in Northern Europe and, as with most marginal butterflies, has more specialised food plant and habitat requirements than the core populations of L. d. rutilus. We investigate reasons for the relative specialisation of L. d. batavus on Rumex hydrolapathum in a fenland habitat when compared to the more widespread and common L. d. rutilus. Host-plant choice by ovipositing females and by larvae are measured as well as larval performance on alternative hosts. Laboratory experiments reveal that larvae are able to feed on other Rumex species without detriment to their overall survival and can utilise these alternative host plants at least as efficiently as their natural host plant. This suggests that plant chemistry is not responsible for their lack of utilisation in the wild. Under greenhouse conditions, females showed an equal willingness to oviposit on host and alternative Rumex, expressing no significant preference for any particular plant species. However, in field experiments using free-ranging females in a fenland habitat, eggs were laid only on R. hydrolapathum. Our interpretation is that there are no short distance cues discriminating between the three Rumex species but longer distance cues in the field situation may operate to maintain this host-plant specialisation. The selection pressure maintaining L. d. batavus as a specialist on R. hydrolapathum in a wetland may underlie its current rarity.

Species of Pentatomidae are cytogenetically characterized by the presence of holokinetic chromosomes, a pre-reductional type of meiosis, and a great constancy not only in chromosome number (2n = 14 in 85% of the 250 species analyzed) but also in the sex chromosome determining system (XY/XX).
Edessa meditabunda and E. rufomarginata males have 2n = 14 = 12 + XY, and both species present small telomeric positively heteropycnotic bands which are DAPI and CMA bright. In E. meditabunda the NOR region is clearly revealed at the telomeric region of the largest autosomal pair by silver staining and CMA banding. Meiotic behaviour of both species follows the general pattern of the order: autosomes divide pre-reductionally, sex chromosomes are achiasmatic and divide postreductionally, and at both metaphase plates the autosomes become arranged in a circle with the sex chromosomes lying at its center. In E. meditabunda, however, the larger sex chromosome is generally observed at metaphase I forming part of the ring of autosomal bivalents. Bivalents with two chiasmata are frequently observed in E. meditabunda and E. rufomarginata; mean chiasma frequency (6.45 and 6.26, respectively) differ significantly between both species, but differences between populations within each species are not significant.
The metaphase plate arrangement of autosomes and sex chromosomes is rather constant in Heteroptera. However, our results in E. meditabunda together with previous reports in other species of the order led us to suggest that the metaphase plate arrangement is more liable to variation at the first meiotic division than at the second one, when it is almost constant. The presence of ring bivalents in both species here analyzed constitutes further evidence against the previous statement of only one chiasma per bivalent in Heteroptera.

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 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.

Membrane-bound proteases from preparations of the midgut of 5^th instar velvetbean caterpillars, Anticarsia gemmatalis (Hübner) were obtained by resuspension of the pellet obtained after 100,000 g centrifugation. As expected of trypsin-like proteases, they hydrolyzed casein and the synthetic substrates N-α-benzoyl-L-Arg-p-nitroanilidine (L-BApNA) and N-α-p-tosyl-L-Arg methyl ester (L-TAME). Higher activities were observed at 50°C, and at pH 8.5 and 8.0 for both synthetic substrates L-BApNA and L-TAME. The membrane-bound proteases were inhibited by EDTA, phenylmethan sulphonyl fluoride (PMSF), tosyl-L-lysine chloromethyl ketone (TLCK), benzamidine and aprotinin. TLCK and benzamidine were particularly active inhibitors. The K_M-values obtained were 0.23 mM for L-BApNA and 92.5 µM for L-TAME. These results provide evidence for the presence of membrane-bound trypsin-like proteases in the midgut of the velvetbean caterpillar, a key soybean pest in warm climates. The interaction between A. gemmatalis digestive proteases and soybean protease inhibitors has potentially important consequences for soybean breeding programs.

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.

During a study 20 hydrophilid beetle species and 2,457 individuals of beetles belonging to 4 genera: Cercyon, Cryptopleurum, Megasternum and Sphaeridium were collected. On the surface of the bodies of 59 beetles (2.40% of the beetles collected) belonging to six species, 174 cases of phoresy [55 deutonymphs of Uropoda orbicularis (Müller, 1776) and 119 pedicels without deutonymphs] were observed. New hydrophilid beetle carriers of phoretic deutonymphs of U. orbicularis are given. Most mites were carried by Sphaeridium species. The population dynamics of both groups of arthropods was also studied. Most cases of phoresy were recorded in May and in the second half of July. However, phoretic deutonymphs were not present on the body surface of hydrophilid beetles throughout the whole period of this study.

Ten ant species (Hymenoptera: Formicidae) from three subfamilies feed on honeydew excreted by nymphs of the leafhopper Balclutha punctata (Hemiptera: Cicadellidae). This relationship is facultative for the partners. Preliminary field observations suggest a mutualistic interaction that represents an intermediate stage in the spectrum of formicid-hemipteran mutualisms. Behavioural adaptations of the leafhopper (no escape reaction) and the ants (no predation of leafhoppers, protection from spiders) are evident, but characters of advanced facultative mutualism such as physical contact between the partners or ant-triggered excretion of honeydew were not observed.

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.

Coptotermes gestroi and Heterotermes tenuis (Isoptera: Rhinotermitidae) are important pests in southeastern Brazil causing serious economic damage. In this study we determined the demographic patterns and foraging activity of these species using mark-release-recapture and the consumption of wooden stakes. Using both the weighted mean and Lincoln index methods, population estimates ranged from ≈ 0.57 to 1.99 million individuals for C. gestroi and from ≈ 0.20 to 1.37 million for H. tenuis. Territory size of the colonies ranged from 172.5 to 5235 m² for C. gestroi and from 16 to 40 m² for H. tenuis. Our results also indicate that foraging activity was dependent on the minimum temperature; however, the existence of a compensation strategy in the foraging activities may permit foragers to exploit food sources under different environmental conditions.

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.

The genus Microplinthus Zherikhin, 1987 is revised. It is assigned to the tribe Aminyopini Voss, 1956, based on the female genitalia and the presence of appendiculate claws in one species. The following new species are described: M. parbatensis sp. n. (Central Nepal); M. kaligandaki sp. n. (Central Nepal); M. shiva sp. n. (India: Darjeeling); M. laurae sp. n. (India: Darjeeling; Sikkim; Central-western Nepal?). The genus is apparently the sister group to Falsanchonus Zherikhin, 1987. Mutual relationships among the nine species of Microplinthus are suggested based on a phylogenetic analysis.

Colletes anchusae Noskiewicz, 1924 and C. wolfi Kuhlmann, 1999 (Colletidae) are closely related bee species with vicariant distributions, the former occurring in east and southeast Europe and Turkey, the latter restricted to the Italian peninsula. Microscopical analysis of scopal pollen revealed that in Europe both species are monolectic collecting pollen exclusively from flowers of Cynoglottis barrelieri (All.) Vural & Kit Tan (Boraginaceae). In Turkey, C. anchusae possibly visits also Cynoglottis chetikiana Vural & Kit Tan. The distributions of the two bee species and of Cynoglottis coincide. The females of both Colletes species are equipped with stout, curved bristles on their foretarsi used for scraping pollen out of the narrow flower tube of Cynoglottis. Compared to other European species of Colletes the foretarsi of C. anchusae and C. wolfi are shortened, presumably an adaptation to the short corolla tube of their host plant.

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.

The effect of different wavelengths of light, white (control; broad spectrum), blue (ca. 475 nm), yellow (ca. 570 nm) and red (ca. 650 nm), at constant intensity (195 ± 5 lux) on developmental time, reproductive and non-reproductive periods, fecundity, egg viability, prey consumption and fitness of two aphidophagous ladybirds, Cheilomenes sexmaculata and Propylea dissecta were studied. Both ladybird species consumed most aphids, developed fastest and reproduced best when kept under white light, followed by yellow, blue and red light. Fitness of both the ladybirds was highest under white and lowest under red light. There were positive correlations between prey consumption and developmental rate, and prey consumption and fecundity.

We examined the occurrence of carabid beetles (Coleoptera, Carabidae) at the edges of oak (Quercus pyrenaica) and beech (Fagus sylvatica) forests in León, NW Spain. Pitfall traps were used to collect beetles from April to October 2002, and leaf litter cover and depth were measured. Traps were placed at three distances (0, 50 and 100 m) from the edges of eight forest patches. A total of 5436 carabids belonging to 43 species were collected. We found no statistically significant edge effect at the carabid assemblage level, i.e. the number of species and individuals was not higher at the edge compared to the forest interior. However, individual species were affected by distance from the edge. Five of the 14 species analysed responded predictably to the edge, three of them statistically significantly so. Four species did not respond in the predicted direction, two of them statistically significantly so. We found a considerable difference between forest types in terms of carabid assemblage composition and response to the edge. Oak forests were species richer and beech forests had a higher number of individuals. These differences were probably due to small-scale habitat heterogeneity in the oak forest patches, caused by man, and the homogeneous structure of beech forests. Leaf litter appeared to be one possible factor influencing the distribution of some species from the interior to the edge of forests.

The coexistence of discrete morphs within a species, with one morph more conspicuous than the other(s) is often thought to result from both sexual selection and predation. In many damselflies, sexual dimorphism occurs jointly with multiple female colour morphs. Typically, one morph is coloured like the male (andromorph), while the other(s) is not (gynomorph(s)). The mechanisms contributing to the maintenance of such female polymorphism in damselflies remain poorly understood, especially the role of predation. We tested the detectability of two different female colour morphs of the damselfly, Enallagma cyathigerum, using human observers as model predators; andromorphs were detected more frequently than gynomorphs. Field data on mortality of males and the two different female morphs due to predation or drowning were also collected, and these observations support morph-specific mortality. In natural populations predation risk was higher in males than females; gynomorphs, however, were more prone to predation than andromorphs. Differences in behaviour between morphs, rather than colour, may explain this result.

The sterrhine loopers Timandra griseata and T. comae have been treated as distinct species since 1994. However, morphological differences between the taxa are minor and therefore their status has often been disputed. Here, we present a molecular phylogenetic study, which separates T. griseata and T. comae into different clades. Altogether, 43 Timandra specimens from eight European countries were studied. The phylogeny is based on a comparative sequence analysis of mitochondrial genes coding for the cytochrome C oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1). Nevertheless, a single individual of both species was assigned to the "wrong" clade. The symplesiomorphy of T. griseata and T. comae is considered to be a result of introgressive hybridization. Conditions that could lead to the hybridization of T. griseata and T. comae are discussed, as well as the likely distribution history of these taxa in Northern Europe. Results of the current analysis are in favour of retaining the species status of T. griseata and T. comae.

In central Europe Adalia bipunctata (L.) occurs in two main colour morphs (typical, melanic), and A. decempunctata (L.) occurs in 3 morphs (spotted, chequered, dark). Temporal variation in the relative frequency of morphs was recorded in populations of the Czech Republic where geographic variation in morph frequency is low. Seasonal trends were investigated in samples collected by a light-trap run daily from March to November for 14 years. In A. bipunctata the melanic form was more abundant in autumn than in spring but the difference was not significant. In A. decempunctata morph proportions did not change seasonally. Samples were also collected by sweepnet from stands of many plant species. In both Adalia species the morph proportions did not differ significantly among collections made on different plants. Long-term changes in morph proportions were analysed by pooling annual samples over all host plants. In A. bipunctata, sampled in 15 years between 1971-2004, there was no significant change in proportion of typical (90.1%) and melanic (9.9%) forms. In A. decempunctata, sampled in 12 years between 1976-2004, the proportions of "spotted" (mean over the years 29.4%), "chequered" (42.2%) and "dark" (21.3%) morphs varied between years. There was a trend toward an increasing proportion of the spotted form in the 2000s compared to the 1970s and 1980s.

The black bean aphid, Aphis fabae, is polyphagous and its life cycle involves seasonal migration between summer and winter host plants. The aphids are regularly tended by honeydew-collecting ants. This study investigates whether differences exist in honeydew production and honeydew sugar composition for A. fabae subspecies feeding on various host plants and whether such differences reflect differences in the intensity of ant-atttendance (Lasius niger).
A. f. fabae feeding on the perennial summer host, Tanacetum vulgare, produced twice the amount of honeydew (ca. 110 µg per aphid ^. h^-1) than when feeding on the annual host plants Vicia faba or Chenopodium album. Honeydew production of A. f. cirsiiacanthoides feeding on the creeping thistle Cirsium arvense was the highest measured in this study (ca. 150 µg per aphid ^. h^-1). Total sugar concentration in the honeydew of A. f. fabae did not differ when feeding on various summer hosts, whereas the honeydew of A. f. cirsiiacanthoides on C. arvense contained a significantly higher amount of total sugars. The trisaccharide melezitose was the dominant sugar in all the honeydew samples, except for the honeydew of A. f. fabae and A. f. evonymi feeding on the woody winter host plant Evonymus europaeus. The highest proportion of melezitose (80% of total sugars) was found in the honeydew of A. f. cirsiiacanthoides feeding on C. arvense. In this subspecies, the intensity of ant-attendance was also highest. The results confirm our hypothesis, that the sugar richness of the honeydew (rate of honeydew secretion × total sugar concentration) along with the presence of the attractant sugar melezitose are the critical factors in determining the extent of ant-attendance.
In A. f. fabae feeding on the spindle tree E. europaeus, the total sugar concentration of the honeydew as well as the sugar composition differed significantly between generations.

The effect of removing the functional pair of Kalotermes flavicollis from an experimental colony for 12, 24 or 48 h and the repeated removal for a particular number of hours per day (2, 4, 6, 12, 18, 20, and 22 h) was studied. An absence of the functional pair for 12 h had no affect on the development of new neotenics, whereas 24-h absence induced the development of new neotenics in 5 out of 12 experimental groups. A 48-h absence induced development of new neotenics in all 12 experimental groups. Pseudergates and nymphs can be orphaned for up to 12 h a day without being stimulated to differentiate, after which the number of new neotenics increased gradually with the time for which the reproductive pair was absent. This suggests that the inhibitory process is continuous and cumulative. Both sexes showed similar sensitivity to the absence of reproductives. The study also tested, by exchanging pseudergates between groups with functional pairs and orphaned groups, whether pseudergates in experimental groups actively spread inhibitory factors; however, this was not proven. Only pseudergates and nymphs that were in direct contact with the functional pair were inhibited.

Goecke & Evers, Keltern, 2004, 288 pp., 266 colour photographs.

Continent-wide loss of traditionally managed humid meadows is raising concern for associated butterfly specialists across Europe. However, not all species associated with this biotope are threatened, and the Lesser Marbled Fritillary (Brenthis ino) has even spread locally. We employed mark-recapture and transect walks to study its population structure and patterns of landscape occupancy in a hilly region of western Bohemia, Central Europe, to determine which life history or demography traits might be responsible for its success. A population studied by mark-recapture harboured more than 1000 individuals and was interconnected with other populations. This was further supported by a fit of the inverse power function to dispersal data. Observations of adult behaviour revealed a broad host plant range: at least three species of plants were used by the single population. On a landscape scale, the butterfly exhibited an aggregated distribution matching its host plants. It was associated with the distribution of characteristic plants and butterflies of semi-natural humid meadows, but its frequency exceeded those of other humid grasslands specialists. The relatively broad host range coupled with varying biotope requirements of individual host plant species results in a wide biotope range for the butterfly, explaining its persistence in fragmented Central European landscapes.

Many areas of biology employ standard model organisms on which a majority of research effort is concentrated. However, there is invariably a danger associated with the use of too few or atypical models for studies of particular taxonomic groups, guilds or biological phenomena. Using aphidophagous ladybirds, I show that in this group, in the last ten years, 69% of research has been concentrated on just five species, all generalist ecotypes. Much research is now concentrated on invasive species, originally biocontrol agents, and over half the aphidophagous ladybird work on intraguild interactions is centred on two of the five predominant species, Coccinella septempunctata and Harmonia axyridis. Using examples from differing areas of research, I show that studies of more unusual, non-commercial specialists can enhance our understanding of the commonly studied groups. I suggest further areas where a similar approach may lead to equally illuminating results.

We studied the importance of forest structure (shape, edge length and orientation) and the crop mosaic (percentage of crops in the total land cover, within 100 and 2000 m from the forests) to the dynamics of an aphidophagous hoverfly Episyrphus balteatus. Adults were collected by Malaise traps located within and on the south- and north-facing edges of 54 forests. In winter, E. balteatus was only found on south-facing edges because of the greater insolation and temperature. In summer, it was more abundant on north-facing edges because of the abundant presence of flowers. In spring, more adults were found on long and south-facing edges than on northern edges. The presence of shrubs within 2000 m also positively affected abundance. In autumn, abundance was positively associated with length of the north-facing edge and forest shape. Emergence traps revealed that in southern France, E. balteatus may overwinter in the larval or puparial stage in forest edges. Overwintering was earlier reported only in adults. Landscape structure, length of forest edges and probably presence of shrub fallows, influence abundance of Episyrphus balteatus.

In Prorhinotermes simplex, tergal glands are present on the last three tergites (from the 8th to the 10th) in imagoes of both sexes. In addition, males possess posterior sternal glands of the same structure on sternites 8 and 9. The tergal and the posterior sternal glands consist of four cell types: class 1 and class 2 secretory cells, and class 3 cells with corresponding canal cells. The cytoplasm of class 1 cells contains smooth endoplasmic reticulum, elongated mitochondria and numerous microtubules. Apical parts of these cells are formed by dense and long microvilli with a central ductule. Class 2 cells contain predominantly lucent vacuoles (in females) or lipid droplets (in males). The structure of class 3 cells does not differ from class 3 cells found in other body parts.

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.