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.

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.

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

The Dermaptera are a small order of insects, marked by reduced forewings, hindwings with a unique and complicated folding pattern, and by pincer-like cerci. Hindwing characters of 25 extant dermapteran species are documented. The highly derived hindwing venation and articulation is accurately homologized with the other pterygote orders for the first time. The hindwing base of Dermaptera contains phylogenetically informative characters. They are compared with their homologues in fossil dermapteran ancestors, and in Plecoptera, Orthoptera (Caelifera), Dictyoptera (Mantodea, Blattodea, Isoptera), Fulgoromorpha and Megaloptera. A fully homologized character matrix of the pterygote wing complex is offered for the first time. The wing venation of the Coleoptera is re-interpreted and slightly modified. The all-pterygote character analysis suggests the following relationships: Pterygota: Palaeoptera + Neoptera; Neoptera: [Pleconeoptera + Orthoneoptera] + [Blattoneoptera + (Hemineoptera + Endoneoptera)]. Blattoneoptera share at least 15 wing apomorphies with the sistergroup Hemineoptera + Endoneoptera and none with the Orthoneoptera and Pleconeoptera; Blattoneoptera: (Grylloblattodea + (Dermaptera + Dictyoptera)); Dictyoptera: (Mantodea + (Blattodea + Isoptera). Dermaptera share 13 wing apomorphies with the sistergroup Dictyoptera. In order to document the intra-ordinal relationships of Dermaptera, 18 new characters of venation and articulation are added to an existing data set and analyzed cladistically. The following relationships are suggested (43 characters, tree length 72, CI 0.819 and RI 0.935). Dermaptera: Karschiellidae + ("Diplatyidae" + ("Pygidicranidae" + (Allostethus indicum + (Anisolabididae + ("Labiduridae" + [Forficulidae + (Chelisochidae + Spongiphoridae)]))))). The taxa in quotation marks are probably paraphyletic. Fossil Dermaptera and "Protelytroptera" show that wing-folding characters were already present in Permian ancestors. The evolution of the dermapteran wing-folding mechanism is discussed and the hindwing is presented as a working "origami" model, which will fold as in living earwigs. The functional role of the wing base in wing folding is examined. Characters in orders and other higher taxa are not independent and cannot be analyzed out of context with their groundplans. Higher systematics is dealing with diametrally different problems than species-level systematics. The necessity of using a different methodology for species-level and higher-level phylogenetics is discussed and recommendations are made.

An analysis of morphometric and bionomic data (as well as the genetic evidence discussed in a companion paper) clearly shows that Meligethes matronalis Audisio & Spornraft, 1990 and M. subaeneus Sturm, 1845 (members of the Meligethes coracinus complex: Coleoptera, Nitidulidae, Meligethinae), recently synonymised by Kirejtshuk (1997), are distinct species. The two species are also compared with the closely related M. coracinus Sturm, 1845. Meligethes matronalis is strictly associated with Hesperis matronalis L. (Brassicaceae) in early Summer, whereas the larvae of the frequently syntopic M. subaeneus develop on Cardamine spp. (Brassicaceae) in Spring; M. coracinus is a more polyphagous species, developing from early Spring to late Summer mostly on Brassica spp., Sinapis spp., Barbarea spp. and Sisymbrium spp. (Brassicaceae).

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

We determined if mature ladybirds use colour to initially find suitable host plants. We also determined whether ladybird beetles are capable of associating characteristics such as colour with the presence of prey. Here, we show that the multicoloured Asian ladybird beetle, Harmonia axyridis, has a differential response to yellow compared to green colours. Naive ladybirds, of both sexes, make significantly more visits and spend more time on yellow vs. green coloured pillars. After pairing yellow and green colours with the presence or absence of aphid prey, ladybirds alter their foraging behaviour. Beetles conditioned to having food on both pillar colours exhibited the same responses as naive beetles, while beetles conditioned to only yellow or green pillars did not exhibit a preference for visiting or spending time on different colours. However, there was a trend towards females spending more time on pillar colours on which they received reinforcement, and males spending more time foraging on colours opposite to that which they were reinforced. Thus, H. axyridis is capable of responding to cues such as colour, and its foraging behaviour can be altered as a result of prior experience.

Pea aphids (Acyrthosiphon pisum) have been reported to produce winged offspring in the presence of predatory ladybirds. These offspring may leave host plants by flight after they have developed into winged adults. The inter-generational nature of this response raises the question about the chances of survival of aphids developing in attacked colonies. We studied the behaviour of predatory ladybirds on host plants by releasing adult 7-spot ladybirds (Coccinella septempunctata) on bean plants hosting either no prey individuals or colonies of 10 or 30 pea aphids. Interactions between predator and prey were recorded until the ladybird left the plant. Ladybird patch residence time increased with the number of aphids present on a plant but beetles generally left a plant before all aphids were eaten. The time budget of the ladybirds revealed a high proportion of time not spent in feeding activities. Predation rate was about one aphid killed per 10min residence time in both treatments with aphid-infested plants. Aphids that survived an attack by the predator or that were alarmed when a conspecific was attacked often emigrated from the host plant, and their number was of the same magnitude as the number of aphids killed by the predator. On average, pea aphid numbers at the end of an experiment were reduced to less than a third of the initial value. The results of the experiment show that attack by single ladybirds does on average not cause immediate extinction of small aphid colonies. The short patch residence times of on average less than two hours show that a predator individual that induces winged-offspring production in an aphid colony will not any longer be present in the colony when the induced offspring mature. To understand the adaptiveness of predator-induced wing development in pea aphids the probabilities of subsequent attacks on an aphid colony need to be investigated.

The reproductive biology (drumming call, mating behaviour, fecundity and egg structure) of Isoperla curtata, an endemic species from the Southern Iberian Peninsula, is described. The male's mating call has a diphasic pattern, with a mean of 17.3 beats per call (range = 8-27; SD = 4.7) and a duration of 792.9 ms per call (range = 228-1312; SD = 307.9). This call differs from that of other species of Isoperla in having two distinct phases with different millisecond intervals, and is species-specific. Mating lasts between 131 and 3864 seconds (mean = 2180.9 s and SD = 1027.8). Since males and females mate more than once (mean number of matings per female was 1.85 and per male 2.25), the species is polyandric and polygynic. The position adopted by the male during mating is different from that described for other stonefly species. Other mating behaviours are interpreted as displacement manoeuvers, tactile stimulation and possibly sexual selection by cryptic female choice. There was a statistically significant correlation between size and the number of matings in females (r = 0.849; p = 0.016), but not in males. Each female laid between one to four egg masses composed of an average of 88.7 eggs. Maximum fecundity was 319 eggs. The mean egg volume was 80.5 × 10⁵ µm³ which is very similar to that of other Isoperla species. An outstanding morphological characteristic of the egg is the lobed outline of the chorion cells.