Edited by Peter Merrett. Praha, Peres, 2002, 351 pages.

Many species of chironomids undergo their immature development in habitats that rapidly change in suitability, such as rain pools, phytotelmata, freshly filled ponds or soil layers that seasonally dry out. Strategies for the utilization of these habitats can be divided into two groups: i) physiological or behavioral adaptations of larvae, which enable them to survive unsuitable conditions (in situ resistance) or ii) repeated recolonization of temporarily suitable habitats. In situ resistance, includes desiccation or frost resistance, often in combination with cocoon building and migration of larvae into the sediment. Generally, the species that use the recolonization strategy tend to be better at migration and have a higher fertility and shorter development. Recolonization may include only temporary habitats or temporary habitats and some more stable habitats as well.

The genus Anthelephila Hope, 1833 and its type species, Anthelephila cyanea Hope, 1833, are redescribed. Based on examination of the type material, the following new synonymy is proposed, Anthelephila Hope, 1833 (= Formicoma Motschoulsky, 1845 syn. n.) and A. cyanea Hope, 1833 (= Notoxus caeruleus Thunberg, 1787 syn. n.). Five genus-group names are regarded as unjustified emendations and are placed as synonyms: Anthelephila Hope, 1833 (=Anthelephilus LaFerté-Sénectère, 1849; Formicosoma Motschoulsky, 1845; Myrmecosoma Mannerheim, 1846; Formicomus LaFerté-Sénectère, 1849; Orthauchen Krekich-Strassoldo, 1925 syn. n.). A lectotype is designated for Anthelephila cyanea Hope, 1833.

I hypothesized that sibling cannibalism is one of maternal investment in that a female controls sibling cannibalism. To test the hypothesis, I conducted a laboratory experiment and field observations to investigate sibling cannibalism in relation to cluster size and cluster site in the ladybird beetle, Harmonia axyridis Pallas. In the laboratory experiment, cluster size significantly affected the number of cannibalized eggs per cluster (R2 = 0.516), while cluster size was significantly affected by the oviposition interval. Furthermore, there was a marginally significant positive relationship between cluster size and the percentage of sibling cannibalism per cluster. In the field, cluster size and the direct distance from a cluster site to an aphid colony (an indicator of intensity of non-sibling cannibalism) significantly affected the number of cannibalized eggs per cluster (R2 = 0.472). Furthermore, there was a significant positive relationship between the direct distance from a cluster to the nearest aphid colony and cluster size. However, there was not a significant relationship between the distance and the percentage of sibling cannibalism. These results may be caused by the weakness of the female's power to control sibling cannibalism. Thus, a female H. axyridis controls cluster size through the intensity of non-sibling cannibalism, which may be one of oviposition strategies in this species.

The Japanese species of Asteiidae are revised. Six species of Asteia Meigen, 1830, are recorded here in addition to Astiosoma okinawae Sabrosky, 1957, hitherto recorded from Japan. Among them, Asteia gemina, A. longistylus, A. lunaris, and A. nigrigena are described as new to science. Asteia angustipennis Duda, 1934, and A. megalophthalma Duda, 1927, are recorded from Japan for the first time. There are conspicuous morphological differences in the male and female genitalia of the seven species of Asteia. It is suggested that Asteia angustipennis, A. concinna, and A. gemina are very closely related and may be reproductively isolated because of their body markings and male genitalia. These species are assigned to the concinna group of Asteia, newly designated in this study. A key to Japanese species and distribution maps are provided.

Potential involvement of circadian clock genes in so far unknown mechanism of photoperiodic time measurement is an important question of insect life-cycle regulation science. Here we report about the cloning of full-length cDNA of the structural homologue of the Drosophila's timeless gene in Chymomyza costata. Its expression was compared in two strains: a wild-type strain, responding to short days by entering larval diapause and a npd-mutant strain, showing no photoperiodic response. The timeless mRNA transcripts were not detectable by Northern blot analysis in the fly heads of npd-mutants, while they were detectable and showed typical daily oscillations in the wild-type strain. After disrupting the normal process of timeless transcription in the wild-type strain by injection of timeless double-strandRNA into early embryos of wild-type (RNAi method: Kennerdell & Carthew 1998, 2000), a certain proportion of the individuals adopted a npd-mutant phenotype, showing no-diapause in response to short-daylength. Cloning of genomic DNA fragments revealed that npd-mutants carry a different allele, timeless^npd, with a 13-bp insertion in an intron positioned within the 5'-leader sequence. Genetic linkage analysis showed that the 13-bp insertion (a marker for timeless^npd) and the absence of response to short days (a marker for npd-phenotype) are strictly co-inherited in the F2 progeny of the reciprocal crosses between wild-type and npd-mutant flies. Such results indicated that the locus npd could code for the timeless gene in C. costata and its product might thus represent a molecular link between circadian and photoperiodic clock systems in this fly.

Ten species of Cixiidae, formerly placed in Trirhacus Fieber, 1875, are redescribed and one additional species is described. They belong to seven genera: Trirhacus s. str. with T. setulosus Fieber, 1876 (type species), T. dubiosus Wagner, 1959, T. biokovensis Dlabola, 1971 and T. peloponnesiacus sp. n., Apartus gen. n. with A. michalki (Wagner, 1948) comb. n. (type species) and A. wagnerianus (Nast, 1965) comb. n., Nanocixius Wagner, 1939 stat. n. with N. discrepans (Fieber, 1876) comb. n., Neocixius Wagner, 1939 stat. n. with N. limbatus (Signoret, 1862) comb. n., Sardocixius gen. n. with S. formosissimus (Costa, 1883) comb. n., Simplicixius gen. n. with S. trichophorus (Melichar, 1914) comb. n. and Sphaerocixius Wagner, 1939 stat. n. with S. globuliferus (Wagner, 1939) comb. n. The phylogenetic relationships of these genera to other Cixiidae are briefly discussed and a key to the genera of European Cixiidae is provided.

Cephalic chaetotaxy of nymphal and adult stages of species from all the subfamilies of Cydnidae s. str. (sensu Froeschner, 1960 and Lis, 1994), namely Garsauriinae, Cephalocteinae, Cydninae, Sehirinae, and Amnestinae, was studied. Two types of setae, primary and secondary, are described, and changes they undergo during ontogeny reviewed. The adaptive, taxonomic and phylogenetic significance of the cephalic setae in the Cydnidae s. str. is discussed. A ground-plan of the original cephalic chaetotaxy of the family, and its evolution within the family Cydnidae s. str. are proposed.

Comparative analyses of interspecific data in evolutionary biology usually require specific methods to remove the effects of phylogenetic inertia. When phylogenetic inertia is not considered, the Canarian Pimelia species show a positive, and almost significant (Prob. = 0.066) correlation between nuclear genome size and body size. However, after controlling for phylogenetic inertia there was a negative and significant correlation (Prob. = 0.007 to 0.017, depending on the DNA fraction considered). Such a change in the relationship after controlling for phylogenetic inertia is rarely reported. Moreover, the relationship usually reported is positive and thought be a consequence of species having a similar number of cells at the same stage of development. The aim of the present study is to report a case of a negative correlation, but not to explain the causal mechanism involved in genome size variations or propose a formal hypothesis on the specific links between DNA content and body size. However, a common explanation of the change in the relationship, i.e., positive to negative, is suggested. Moreover, the data available on the highly repetitive, non-coding satellite DNA allows us to analyse the specific pattern exhibited by this fraction.

In the laboratory, not all females of the seed bug Lygaeus simulans Deckert, 1985, produced fertilized eggs after copulation: 26.7% of the females were not inseminated and 5% were inseminated but did not lay fertilized eggs; only in 40% of the couples did copulation result in fertile eggs. The remaining 28.3% of couples refrained from mating. Duration of copulation was associated with insemination and fertilization: (i) fertile eggs were produced by only one couple that copulated for less than 60 min and all those that copulated for more than 360 min, (ii) probability of fertilization increased steadily with duration of copulation between 60 and 360 min, and (iii) duration of copulation was significantly different for couples that showed different insemination status.
A possible morphological explanation for this rime dependency was revealed by examining the genitalia of 69 couples freeze-fixed in copula after different periods in copulation. Because of the intricate structure of the genitalia in L. simulans, a male takes a long time to manoeuver its intromittent organ into the narrow insemination duct of the female. Only if completely inserted is the tip of the intromittent organ close enough for successful ejaculation of sperm into the spermatheca. The freeze-fixing experiment revealed that it usually took the male more than 30 min to locate the entrance to the insemination duct and another 30 min for full penetration. This explains why copulations that lasted less than 60 min failed, since insemination began only after intromission was complete.
The experiments, therefore, indicated that there is a relationship between the complex morphology of the genitalia and the low rates of insemination and fertilization in L. simulans.

Oviposition behaviour of Delia radicum is not only influenced by host plant duality but also by the duality of the substrate in which the plant grows. Direct behavioural observations showed that the females partition their visits to a host plant (cauliflower) into ovipositional bouts separated by exploration of the host plant surface. Ovipositional bouts were further partitioned into acts of egg deposition separated by exploration of the substrate. While the mean number of ovipositional bouts per visit (2.6), and eggs laid per egg deposition event (1.4) were stable, the mean number of egg deposition events per ovipositional bout significantly varied (from 2.1 to 7.3) with the duality of the substrate and the physiological state of the female (egg load). Ovipositing females adjusted the final number of eggs laid around the plant during the behavioural stage of substrate exploration. Additional experiments using plant surrogates treated with methanolic extract of Brassica leaves mounted in different substrates showed that: (a) the presence of living Brassica, Hordeum or Allium roots in a substrate enhances the number of eggs laid into this substrate, but females do not discriminate between the different plants; (b) females avoid both wet and dry substrates and prefer the substrates with a dry surface and moist particles directly accessible at a depth of about 5 mm; (c) substrates rich in organic matter are preferred to sand; (d) olfactory perception of volatile chemicals from the substrate must at least partial

Salt D.T. & Whittaker J.B.: Insects on Dock Plants. Naturalists' Handbooks 26. The Richmond Publishing, Slough, 1998, 56 pp.

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

A comparative study of the direct influence of single, non-repetitive changes of light and/or temperature on the daily pattern of adult eclosion was conducted in laboratory conditions with the egg parasitoid, Trichogramma embryophagum (Hartig). In all experiments, the entire development occurred under the same regimen (12L : 12D, 20°C). However, just in the day when records of eclosion were made, the time of light-on was changed (from the total absence of a dark period to the 12-h-long scotophase). In addition, in different treatments of each experiment a thermophase (30°C during 2 or 4 hours) was applied in various positions relative to light-on. Results showed that light-on or a temperature step-up could induce eclosion in a certain percentage of individuals practically at any time of the 24-h-long cycle (masking effects). The fraction of adults emerging during 2 h after the beginning of the action of an exogenous factor depended not only on the preceding scotophase duration, but also on the stimulus itself (light, temperature or both). The temperature stimulus was found to modify the responsiveness to light considerably, depending on the order of application of the stimuli. The simultaneous action of light-on and a temperature step-up exerted a more considerable influence than could be expected based on their separate impacts. On the contrary, a high temperature pulse preceding the onset of the photophase inhibited the response of individuals to light-on, evidently acting by phase delay of a circadian rhythm of light responsiveness. These effects were more pronounced in the first half of the 12-h-long scotophase. The data suggest a complex interaction between the exogenous factors in their influence on the daily pattern of adult eclosion.

Typically, the relationship between insect development and temperature is described by two characteristics: the minimum temperature needed for development to occur (T_min) and the number of day degrees required (DDR) for the completion of development. We investigated these characteristics in three English populations of Thrips major and T. tabaci [Cawood, Yorkshire (N53°49', W1°7'); Boxworth, Cambridgeshire (N52°15', W0°1'); Silwood Park, Berkshire (N51°24', W0°38')], and two populations of Frankliniella occidentalis (Cawood; Silwood Park). While there were no significant differences among populations in either T_min (mean for T. major = 7.0°C; T. tabaci = 5.9°C; F. occidentalis = 6.7°C) or DDR (mean for T. major = 229.9; T. tabaci = 260.8; F. occidentalis = 233.4), there were significant differences in the relationship between temperature and body size, suggesting the presence of geographic variation in this trait. Using published data, in addition to those newly collected, we found a negative relationship between T_min and DDR for F. occidentalis and T. tabaci, supporting the hypothesis that a trade-off between T_min and DDR may constrain adaptation to local climatic conditions.

Pulsations of dorsal vessel were monitored by the noninvasive techniques of contact thermography on the dorsal cuticle and by strain gauge detection of abdominal elongation movements. Diapausing pupae exhibited periods of forward-oriented, or anterograde pulsations (average duration of each pulsation 5-8 min, frequency of individual systolic strokes 10-15 per min) alternating with somewhat slower, backward-oriented or retrograde cardiac pulsations (average duration of each pulsation 6-10 min, frequency of systolic strokes 7-12 per min). The highest rate of hemolymph flow was associated with the anterograde pulsations. We studied cardiac functions in diapausing pupae because of the almost complete absence of extracardiac hemocoelic pulsations, which are much stronger and could interfere with the recordings of heartbeat in all other developing stages. The movement of abdomen associated with the heartbeat was extremely small, only some 0.14 to 0.9 µm (i.e. from one 428000^th to one 66000^th of the body length) and thus was not practical for routine recordings of heartbeat.
Simultaneous recordings from multiple thermographic sensors revealed the complete absence of retrograde cardiac pulsations in the head region. There are some indications that the retrograde pulsations were also lacking in the thoracic region of the aorta. The retrograde peristalsis appeared to be used for circulatory functions in the abdomen alone. By contrast, the anterograde cardiac pulsations underwent a profound amplification in the anterior part of the abdomen, entering thoracic aorta with considerable strength before reaching the final destination in the head region. The amplification of anterograde peristalsis was manifested by enhanced hemolymph flow towards the head associated with a two-fold increase in frequency of anterograde heartbeat before reaching the head region. The sensors distributed along the dorsal vessel revealed that the rate of the backward-oriented, retrograde cardiac flow of the hemolymph was also location specific. The rate of flow was lowest at the front of the abdomen, medium in the middle and highest close to the end of the abdomen. The finding of lowest hemolymph circulation at the beginning of the cardiac peristaltic waves suggested that the physiological "raison d' être" for heartbeat reversal was a need for differential enhancement of hemolymph flow towards the extremities of the immobile pupal body. The switchovers from the retrograde to anterograde cardiac pulsations were usually immediate, while the reciprocal, antero- to retro-switchovers were mostly associated with a brief cardiac arrest. Increasing temperature gradients (in 5°C steps) progressively diminished duration of both reciprocal heartbeat periods. The amplitudes of the cardiac systolic strokes also decreased with increasing temperature while the frequencies were substantially elevated.

Aquatic Coleoptera in shallow lakes associated with the Canal de Castilla (Palencia Province, Spain) in the northern Iberian Meseta were sampled over the course of a year (spring 1998-winter 1999). These waterbodies are typical plateau wetlands with dense vegetation and vary in permanence and area (from 3.3 ha to 29.35 ha). Oxygen concentration, conductivity and pH were recorded at the time of sampling. Lake area, depth, water permanence and type of vegetation were also taken into account. Ninety two species were collected. Species richness was high in comparison with other wetlands in Spain. The assemblage structure was assessed in terms of three community parameters: richness, abundance and diversity (Shannon index). Their relationships with environmental variables were explored using correlation coefficients. The assemblage composition was analysed by multivariate techniques. First, the sites were classified by means of TWINSPAN. The presence of each species in the different TWINSPAN groups was used to assess their habitat preferences. Second, the sites and species were ordinated by Detrended Correspondence Analysis (DCA) using the CANOCO statistical package. Richness was significantly correlated with water permanence, conductivity and aquatic macrophyte cover. The first DCA axis was significantly correlated with water permanence and conductivity, but not with any of the other parameters. Conductivity was significantly inter-correlated with permanence. Therefore, water permanence and aquatic vegetation cover seem to be the main factors influencing richness, but only water permanence appears to determine species composition.

A series of experiments were conducted to compare the susceptibility of P. regina larvae reared in isolation or in groups to the effects of diet-borne metabolic inhibitors: chlorogenic acid (CGA) and mimosine. Larvae were presented with diets containing 0.4 mM CGA or 0.4 mM CGA in combination with 22 mM lysine or methionine or with diets containing 1.5, 15 or 30 mM concentrations of mimosine. Methionine and CGA caused significantly reduced pupal weights when compared with larvae presented with lysine and CGA. All concentrations of mimosine resulted in 100% mortality with larvae unable to successfully complete pupation even at the lowest concentration. In general, larvae reared in groups were less susceptible to the toxic effects resulting from diet-borne metabolic inhibitors. The results are discussed in relation to the chemical factors that result from the feeding activity of saprophagous dipterans.

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

Two new species (Hemiptera, Fulgoromorpha, Cixiidae) included in a new genus, Meenocixius gen. n., and associated with Acanthophœnix rubra (Bory) H. Wendl. (Arecaceae) are described from the island of La Réunion: M. bebourensis sp. n. and M. virescens sp. n. This genus shows several autapomorphies in its tegmina venation, very particular within the Fulgoromorpha. Borbonomyndus gen. n., is proposed for another new species, B. pandanicola sp. n. associated with Pandanus purpurascens Thouars (Pandanaceae), and B. pallidus (Synave), previously described as a member of the genus Eumyndus Synave. According to morphological and ethological data, E. bistriatus is synonymized with B. pallidus, of which three different forms are recognized. All species of Borbonomyndus are found associated with Pandanus. These two new genera are endemic to La Réunion. Without taxonomic standing, the subspecies of Brixia belouvensis are synonymyzed and restricted to four different forms. A key is proposed for the Cixiidae of La Réunion, which now includes 12 species belonging to 6 different genera: Achaemenes, Aselgeoides, Brixia, Oliarus (but we show that the species placed in this genus need to be reviewed), Borbonomyndus, and Meenocixius. Monophyly of Eumyndus, from which E. perinetensis Synave is excluded, is substantiated. Following the new interpretation, this genus is now restricted to Madagascar. The species Cubana insularis Muir, from the island of Rodrigues, is transferred to a new genus: Achaebana gen. n. Finally, cixiid endemism and their host-plant associations in the Mascarenes are discussed.

Previous behavioural tests indicated that strain recognition and aggregation behaviour could be induced by cuticular hydrocarbons. The aim of this study was to document and to compare cuticular hydrocarbon profiles between different strains of Blattella germanica (L.) (Dictyoptera: Blattellidae) and to relate variations in the general profile of cuticular hydrocarbons with strain discrimination during behavioural tests. Profiles of different strains were remarkably similar qualitatively but presented slight quantitative differences over the 25 identified components. Important differences were observed in dimethylalkane components and these allowed separation of the strains into two groups using multivariate methods. Although we were not able to demonstrate a relationship between strain discrimination ability and differences in cuticular hydrocarbon profiles, we assumed that cuticular hydrocarbons could play two major roles in B. germanica strains. Less variable hydrocarbon profiles could play a role in species recognition and aggregation behaviour and the more variable part could play a role in strain discrimination.

The first instar larva, or triungulin, of Stenodera puncticollis (Chevrolat, 1829) is described. Its characters indicate that Stenodera is the most primitive member of the subfamily Nemognathinae and support the recognition of the monotypic tribe Stenoderini, as previously proposed on the basis of adult morphology. The bionomic information on this genus is summarized, and an annotated catalogue and key to the species based on adults are presented.

Larvae of Rhipsideigma raffrayi are described in detail and those of Distocupes varians are re-examined. Their morphological structures are evaluated with respect to their functional and phylogenetic significance. Larvae of Rhipsideigma are wood-borers with a straight body and a wedge-shaped head capsule. Most of their apomorphic features are correlated with their xylobiontic habits. The strong mandibles, the sclerotized ligula and the wedge-shaped head enable the larvae to penetrate rotting wood. The broadened prothorax, prosternal asperities, tergal ampullae, the short legs, and eversible lobes of segment IX play an important role in locomotion in galleries within rotting wood. Leg muscles are weakly developed, whereas the dorsal, pleural and ventral musculature is complex. The larval features allow Rhipsideigma to be placed in the clades Archostemata, Cupedidae + Micromalthidae, Cupedidae, Cupedidae excl. Priacma, and Cupedidae excl. Priacma and Distocupes. The monophyly of Cupedidae and Cupedidae, excluding Priacma, so far is only supported by apomorphies of the adults. However, the presence of glabrous patches on the prosternum and of a medially divided field of asperities may be larval apomorphies of the family. A clade, which comprises Rhipsideigma, Tenomerga and probably other genera of Cupedidae with hitherto unknown larvae, is well supported by larval apomorphies such as the broadened prothorax, the presence of coxal asperities and the presence of a distinct lateral longitudinal bulge. Increased numbers of antennomeres and labial palpomeres are apomorphies only found in larvae of Distocupes.

Secondary plant metabolites (allelochemicals) play a major role in plant-insect interactions. Glucosinolates (GLS) and their degradation products from Brassica species are attractants and feeding stimulants for Brassicaceae specialist insects but are generally repellent and toxic for generalist herbivores. The impact of these compounds on crucifer specialist insects are well known but their effect on generalist predators is still not well documented. The influence of the prey's host plant on both development and reproduction of an aphidophagous beneficial, the hoverfly Episyrphus balteatus, was determined using the cabbage aphid, Brevicoryne brassicae (a specialist) and the peach aphid Myzus persicae (a generalist) reared on two crucifer plants, Brassica napus and Sinapis alba containing low and high GLS levels respectively.
The prey and its host plant differently influenced life history parameters of E. balteatus. The predator's rates of development and survival did not vary when it fed on the generalist aphid reared on different host plants. These rates decreased, however, when the predator fed on the specialist aphid reared on the host plant with high GLS content plant versus the host plant with lower GLS content. This aphid host plant combination also negatively affected hoverfly reproduction; lower fecundity was observed. As a result, the fitness of the hoverfly was strongly affected. This study illustrates the importance of tritrophic relations in pest management involving predators. The host plant of the prey can have a major influence on the potential of a biological agent to control herbivore species such as aphids.

Circellium bacchus is a flightless telecoprid (ball-rolling) dung beetle, endemic to the afrotropical region, where it is found in a few restricted populations in the eastern Cape of South Africa. Its apterous condition and large size (mass ranges from 6 to 12 g) are considered to be adaptations to a semi-arid habitat. This beetle is active in the sun for long periods, walking between widely scattered dung pats, thus is under selection pressure to reduce water loss.
C. bacchus has eight spiracles on each side of the body. The metathoracic spiracle and six abdominal spiracles open into the subelytral cavity, which is closed. The mesothoracic spiracle is the largest and most exposed, occurring ventrally in the membrane connecting the prothorax and mesothorax.
When at rest a cyclic form of respiration, known as discontinuous gas exchange cycle, is used by C. bacchus, releasing a burst of carbon dioxide approximately once an hour when the spiracles open for about 33 minutes. Flow-through respirometry was used to measure water loss from the thorax (being the head, prothorax and mesothorax) and elytral case (containing the metathorax and abdomen) separately. The total water loss of C. bacchus could be divided up as 65% cuticular water loss from the thorax, 35% cuticular water loss from the elytral case, 4% respiratory water loss from the thorax and no measurable respiratory water loss from the elytral case. 1.51 µg of water is lost for every µl of CO₂ emitted during respiration in the thorax. Thus, the main avenue for both respiration and respiratory water loss is via the mesothoracic spiracles, suggesting that the primary function of the subelytral cavity is not to reduce respiratory water loss.

The impact of the arrival of the exotic coccinellid Harmonia axyridis on the biological control and dispersion of apple mites and aphids, and on the vertical distribution of the established coccinellids Coccinella septempunctata and Coleomegilla maculata have been studied. Assemblages of adults of the three coccinellid species were tested on apple saplings and on apple trees against Aphis citricola and Tetranychus urticae. The presence or substitution of adults of H. axyridis for adults of C. maculata or C. septempunctata did not reduce the predation impact on mite or aphid prey. H. axyridis was a more efficient predator of mites than was C. septempunctata and generated lower prey dispersal from host plants. Substitutions of adults of H. axyridis for those of C. maculata, and in some cases of C. septempunctata, resulted in greater reduction in number of aphids. On apple trees, the three coccinellid species occurred at different heights. Neither C. maculata nor C. septempunctata modified their vertical distribution on apple tree over a 24 hour period in response to the presence of H. axyridis.

Insect dormancy responses, in the broad sense of modifications of development, are examined from a general perspective. The range of responses is extraordinarily wide because environments are diverse, different taxa have different evolutionary histories, adaptations are needed for both seasonal timing and resistance to adversity, and not only development but also many other aspects of the life-cycle must be coordinated. Developmental options are illustrated by examining the wide range of ways in which development can be modified, the fact that each individual response consists of several components, and the different potential durations of the life-cycle. The concepts of alternative life-cycle pathways (chosen according to current and likely future environmental conditions) and of active and passive default responses are treated. Also introduced are aspects of variation and trade-offs.
Some general conclusions that help in understanding dormancy responses emerge from such an examination. Many options are available (cf. Table 1). The nature of the habitat, especially its predictability, determines the potential effectiveness of many of the developmental options. Any particular set of responses reflects evolutionary history and hence depends on past as well as current environments. It is not necessarily obvious what kinds of selection, especially requirements for timing versus resistance to adversity, explain a particular life cycle. Life-cycle pathways have multiple components, so that components cannot be analyzed in isolation. A given feature, such as delayed development, can have multiple roles. Default responses can be either active (development continues unless signalled otherwise) or passive (development stops unless signalled otherwise), making necessary a broad approach to understanding the action of environmental cues. Even relatively minor effects that fine-tune dormancy responses enhance survival, but may be difficult to detect or measure. Trade-offs are not inevitable, not only when certain resources are surplus, but also because resources in very short supply (constraints) cannot be traded off. Life-cycle components are widely, but not universally, coordinated. These conclusions confirm that the range of dormancy responses is wider, more complex and more integrated than has often been recognized.

In this paper six new species of the genus Brachystomella Ågren from the Neotropical region are described : B. desutterae sp. n. (Peru), B. mataraniensis sp. n. (Peru), B. pefauri sp. n. (Venezuela), B. purma sp. n. (Peru), B. saladaensis sp. n. (Argentina) and B. zerpa sp. n. (Venezuela). Brachystomella honda Christiansen & Bellinger, 1988 is synonymised with Brachystomella baconaoensis Gruia, 1983. Diagnoses and comments on the original descriptions as well as remarks on 22 species are included.

The species of the genus Argyra Macquart from China are revised. The following 3 species are new to science: Argyra (Argyra) serrata sp. n., A. (A.) pallipilosa sp. n., A. (A.) nigripilosa sp. n.