Behaviour of locally occurring adult females of seven species of coccinellids was assessed on wooden dowel and paper models that mimicked branching patterns and arrangements of leaf attachments to stems. Ambient temperature and hunger of the beetles were controlled. The movements up or down the main branch of the branch models when contacted from a side branch, duration of searching, and method of leaving leaf models were recorded for 20 beetles of each species.Each species responded to the seven models with different frequencies of behaviours that reflected species-specific modifications of the taxes that lead coccinellids to the tops and terminal parts of plants. Some beetles consistently modified the pattern of responses on die models that was displayed by die species as a whole. The individual modifications could be selected for. The differences in frequencies of behaviours were judged to be sufficient to result in differences in the efficiency with which plants with different architectures were searched.

Diamondback moth, Plutella xylostella (L.), commonly occurs at relatively low population densities in areas of canola (oilseed rapes, Brassica rapa L. and Brassica napus L.) production in western Canada, but occasionally can reach outbreak densities (Madder and Stemeroff 1988). The most severe outbreak of P. xylostella in recent years occurred in Alberta and Saskatchewan in 1985 when approximately 467 860 ha were treated with insecticide, at a cost of approximately $11.9 million (Madder and Stemeroff 1988).

Damage to canola is the result of larval feeding. Leaves are the preferred feeding sites, and plants can withstand substantial damage before yield is affected (Philip and Mengersen 1989). However, late in the season when the leaves become senescent, larvae feed on pods and this can result in significant yield reductions. Plutella xylostella is multivoltine, capable of completing at least three generations per year in Alberta (Philip and Mengersen 1989), and four to five in Ontario (Harcourt 1986).

Development of eggs of 35 species of Nearctic and Palearctic Pentatomoidea are described. Eggs are discussed in relation to the number of ovarioles of each species, characteristics of eggs, incubation time, diapause, embryonic development, embryonic orientation, hatch, and parasitism, and are classified into two groups in relation to then-form, position of egg-burster, and hatch. Emergence of first-instar larvae is described in representatives of five families.

On 27 May 1993, a normal, healthy woman in her early 30s put packages of groceries just purchased on the car seat beside her. As she sat in the driver's seat, she “…felt something painful sticking into her behind her knee.” She looked and saw something there, brushed it, but when it did not come off, she grabbed it into a soft tissue paper, and folded the paper over so the animal could not escape. She went immediately for medical assistance.

The second author, a physician, examined the animal and thought it to be a dead spider, as he could not prod it into moving (many clubionids “play dead”). However, when he put it into alcohol, it writhed violently for a few moments before dying. He sent it to the Department of Entomology, University of Alberta. The spider was determined to be a female of Cheiracanthium inclusum (Hentz, 1847), a first record for Alberta, and only the second record for Canada.

Tenthredo retura Ross is here placed in synonymy under T. maxima (Norton) as the subspecies T. maxima retura Ross (syn.nov., stat.nov.). The range of T. maxima is associated with montane meadows or semi-open forest habitats in the montane zone of the Rockies, the Cascades, and the Sierra Nevada. Following the analysis of 24 characters from 2405 specimens, we recognized 12 geographically distinct populations, clustered into two subspecies, T. m. maxima and T. m. retura. Originally included in the originalis group of the genus Tenthredo, T. maxima is characterized as a group of its own with no close relatives in North America. We describe the species and its subspecies, give their distribution, discuss their geographical variation, and attempt to reconstruct their zoogeographical history during the Pleistocene.

Neomeoneurites dissitus sp.nov., the second known species of the genus, is described from Neuquén territory, Argentina. The generic diagnosis is revised to accommodate the species. The structure of the male postabdomen of Neomeoneurites is discussed and some errors in previous interpretations of the postabdomen are corrected. Synapomorphic characters of the male postabdomen in Neomeoneurites include extensive fusion of the hypandrium and sternite 8, loss of the phallic guide, well-developed posteroventral hypandrial projections, and surstyli that are completely fused with the epandrium.

Nine species of Ceromya Robineau-Desvoidy (Diptera: Tachinidae: Siphonini) are recognized in the Nearctic region, including four new species, and one described species known previously only from the Palearctic region. The species are arranged into three species groups, with each group hypothesized to be monophyletic and each containing extralimital members. The three species groups and nine Nearctic species are as follows: the bicolor-group with C. bicolor (Meigen) (a Holarctic species newly recorded from the Nearctic region); the flaviseta-group with C. Ontario (Curran) and C. palloris (Coquillett); and the americana-group with C. americana (Townsend), C. balli sp.nov. (type-locality Masham Township, Quebec, Canada), C. elyii (Walton), C. flava sp.nov. (type-locality Masham Township, Quebec, Canada), C. oriens sp.nov. (type-locality Masham Township, Quebec, Canada), and C. occidentalis sp.nov. (type-locality Lakelse Lake, British Columbia, Canada). The bicolor-group has an Old World – Nearctic distribution, the flaviseta-group has an European–Nearctic distribution, and the americana-group has a Neotropical–Nearctic distribution. Adults of the nine Nearctic species of Ceromya are keyed and described, known hosts are listed (including corrections to published records), distributions are mapped, and taxonomically useful features are illustrated.

In a recent revision of the genus Timema (Phasmatoptera: Timematodea) (Vickery 1993), an important reference inadvertently was omitted. It contained the following information on T. boharti Tinkham.

Rentz (1963) reported capturing a large series of T. boharti at Pinon Flats, Riverside County, California, during the latter part of April 1962. (The specimens were included in the revision of the genus.) The habitat is “xeric pinyon-juniper with chaparral intrusions”, at approximately 915 m. The series was taken at night. Rentz found mating pairs as well as last-instar numphs, some moulting. He noted that this species had previously been known only in a grey colour phase but there he found both greyish and green specimens with no intergrading. Mating pairs were segregated by colour. As noted in the revision (Vickery 1993), fading subsequent to death produced a brownish colour in all individuals so that detection of original colour is impossible.

I review reports on the genetic basis for species differences in the Lepidoptera. In the six best-studied species complexes, more than half of all ecological, behavioral, or physiological differences among species are controlled by X-linked genes. Because Lepidoptera have about 30 pairs of chromosomes, this finding clearly indicates strong bias toward X-linkage of genes for species differences. The proportion of X-linked species differences ranges from complete X-linkage in Colias butterflies, to almost none in Yponomeuta moths. Four other complexes all have at least one X-linked gene that is crucial to species differences, including the Choristoneura fumiferana Clemens, Papilio glaucus L., and Papilio machaon L. species groups, and Ostrinia nubilalis Hübner pheromone strains. The mechanisms that account for this phenomenon are open to speculation. Nonetheless, an interesting implication of disproportionate X-linkage is that reproductive isolation may frequently arise by selection on linkage complexes, rather than as a random byproduct of evolution in geographically isolated populations. If confirmed, the bias toward X-linked species differences may also help efforts to find characters that distinguish host races and sibling species, as well as provide an avenue by which genes crucial to speciation can be more easily mapped and characterized at the molecular level.

The apple brown bug, Atractotomus mali (Meyer), is an economic pest of apple in the Annapolis Valley of Nova Scotia (Rogers 1990). Feeding on developing fruit of sensitive apple varieties induces persistent corky scar tissue that reduces the quality of affected fruit. Forty-five percent of Annapolis Valley apple orchards monitored in 1992 required chemical insecticide applications to control the pest complex of A. mali and the mullein bug, Campylomma verbasci (Meyer) (Craig 1992).

Female-produced sex pheromones occur in several mirid species, including the mullein bug (Smith et al. 1991) and Lygocoris communis (Knight) (Boivin and Stewart 1982). The sex pheromone of C. verbasci has been identified as a 16: 1 blend of butyl butyrate and crotyl butyrate (Smith et al. 1991). Our objective was to determine if a sex pheromone occurs in A. mali.

The naturally occurring weevil (Curculionidae) fauna of Dade and Monroe counties in southern Florida is composed of 100 genera and 222 species. Another 20 species are adventive; their presence is due to the unintentional action of humans. Twenty-eight species occur only on the islands of the Florida Keys, 118 species occur only on mainland south Florida, and 76 species are shared by the mainland and the islands. Greater habitat diversity on the mainland accounts for its higher species diversity. The species distributions and faunal affinities are 60% Nearctic and 40% Neotropical or West Indian. Thirty-five species are known to occur only in southern Florida. This probably reflects poor knowledge of their distribution in the Caribbean rather than southern Florida as an important site for species origin. Most of the weevil species (133; 60%) are habitat specific and few species (22; 10%) are found in three or more habitat types. Wetland-inhabiting species are predominant (76; 34%), followed by hardwood hammock species (47; 21%). Flightlessness in adults is uncommon (35 species; 16%), but more prevalent in the species endemic to southern Florida (12 species; 34%). Extrapolation from data on weevil diversity yields a conservative estimate of over 5000 species of insects in southern Florida.

To study the development of stem- and branch-damaging insects and their parasites under near natural conditions it is useful to confine the insects on their host for close observations. The ideal cage should totally confine or exclude insects, allow easy addition or removal of insects, and not damage the plant. During recent studies our requirements necessitated caging 50 trees, which ranged in height from 3 to 7 m. Large whole-tree cages are costly, difficult to construct, and difficult to access repeatedly to sample insects for developmental studies. A more practical method is to cage the branch, stem, or leader to confine the attacking insects, then collect emerging parasites and young eclosing adults.

Carabid taxa inhabiting the montane forests of México and Central America are analyzed using cladistic biogeographic methods. Taxa exhibiting the Nearctic, Meso-American Montane, and Paleo-American distributional patterns are included in the analysis. Widespread taxa are assumed to indicate that the areas of endemism they inhabit are closely related, and the general pattern of area relationships is determined using parsimony analysis. Of the nine areas of endemism recognized in the analysis, the Sierra Madre Oriental is considered the most distinct. The northern Sierra Madre Occidental, Arizona Mountains, and Sonoran Desert comprise one monophyletic set of areas, as do the more southerly areas of the Sierra Transvolcanica, Sierra Madre del Sur, Chiapan–Guatemalan highlands, and Talamancan Cordillera. The southern Sierra Madre Occidental area of endemism is equivocally related to both areas to the north and areas to the south. Biogeographic information derived from widespread species is as congruent with the general area cladogram as information derived from groups with precinctive species, indicating that the same biogeographic barriers often limit distributions of both widespread species and more inclusive clades comprising precinctive species. Taxa exhibiting the Meso-American Montane Pattern are more congruent with the general area cladogram than those representing the Nearctic Pattern, even though they exhibit less fidelity to highland habitats.

Six major subgroups of the Brachycera are recognized under the names Stratiomyomorpha, Vermileonomorpha new infraorder, Tabanomorpha, Nemestrinoidea, Pleroneura, and Eremoneura. Recent suggestions regarding the possible sister-group of the Brachycera are reviewed, and all found to be inadequately supported. Characters used to support possible relationships between the major subgroups (i.e. possible synapomorphies) are reviewed with respect to morphological interpretation and polarity. On the basis of this analysis, five partly conflicting possible groupings are discussed: (1) all other Brachycera as the sister-group of the Stratiomyomorpha; (2) Muscomorpha sensu Woodley (Nemestrinoidea + Heterodactyla); (3) inclusion of Nemestrinoidea in Tabanomorpha; (4) Heterodactyla sensu Lameere (Pleroneura + Eremoneura); and (5) an asilotabaniform group (Vermileonomorpha + Tabanomorpha + Nemestrinoidea + Pleroneura). Resolution of conflicts among these possible groupings will require critical morphological studies of the phallic complex and embryological studies of groups of Brachycera other than Cyclorrhapha. Because of present uncertainties, it is recommended that authors consider alternatives rather than rely on a single preferred concept of phytogeny at this time. Autapomorphies of the major subgroups are discussed in an appendix.

We describe a litter-washing technique for collecting quantitative samples of ground-beetles (Carabidae), and compare the results with those from liner extraction by Tullgren funnels and pitfall (rapping. We also compare performance of four types of pitfall traps across five habitats. Carabid species composition from litter washing and funnel extraction was similar but washing revealed higher densities. Large-bodied species predominated in pitfall samples and small-bodied species predominated in litter samples. Uncovered, round pitfall traps yielded generally higher catches than rectangular or covered, round traps but the pattern was not consistent over all species or the five habitats. Ecological studies of carabid populations and assemblages using pitfall traps may be improved if they are both designed and interpreted in light of the biology of the group and with regard to the deficiencies of pitfall trapping as discussed here and elsewhere.

Carabhydrus mubboonus, new species (Coleopiera; Dytiscidae; Hydroporinae) from small. closed, forest streams of the Great Dividing Range of northern Queensland. Australia, is described. A key to the five described species of Carabhydrus is presented. The systematic position of the genus Carabhydrus Watts is reviewed. Although it resembles members of the Bidessini Sharp in some characters, others indicate the genus belongs in the tribe Hydroporini Erichson (1837) and has affinities with the subtribe Sternopriscina Van den Branden, However, no clear synapomorphy was discovered that unequivocally identifies the sister taxon.

Courtship displays of empidine dance flies (Diptera: Empididae), which include transfers of nuptial gifts during mating, are reviewed in light of sexual selection theory. Sex-role reversed courtship behavior, involving female swarming and male choice, appears to be correlated with certain female secondary sexual characters that are widespread throughout the Empidinae. The tendency to shift mate choice from females to males, and the apparent development of autogeny in many empidine species, are both hypothesized to have resulted from males monopolizing the proteinaceous food source of non-hunting females, through transfers of nuptial gifts of prey. The autogenous condition appears to have led to the ritualized presentation of various types of inedible nuptial gifts by males of several species, possibly including the development of secreted nuptial gifts, or balloons, as displays of male fitness.

Except for emphasis (as in “. . .very, very good”), it is usual in languages that every following word in a sentence is different. The preceding sentence, this sentence, and the following sentence, are examples of this.

Chinese has double, triple, and quadruple juxtaposed characters, most often for emphasis, but also for changing the meanings (G.-C. Lo, T. Mah, J. Yu, pers. comm.; Fig. la, b, c, and d). The Czech, Slovak, and German languages (M. Pospisil, pers. comm.), and the Ukrainian language each have at least one pair of juxtaposed identical words (see below).