Two European species of the genus Eteobalea Hodges are being tested as classical biological control agents for toadflax (Linaria spp.) in Canada. Permits for the release of these species apply only to an Italian population of E. serratella Treitschke and a Serbian population of E. intermediella Riedl. When these species are imported as larvae or pupae from an area where they are sympatric, such as around Rome, they must later be separated in the laboratory. This step is essential to establish a pure laboratory colony of the correct species, both to increase the rate of breeding success and to comply with conditions of the importation permit. Although the male and female genitalia and the egg chorion have good diagnostic characters, these characters are not useful for identifying immature stages or newly emerged adults before mating and oviposition. This problem has hampered the establishment of rearing colonies of these two species in Canada. We describe the development and application of four polymerase chain reaction – restriction fragment length polymorphism assays that have been used to distinguish between these two species. If and when either of these species becomes established in the field, the tests presented here should also prove useful for monitoring populations.

The fujiyamai species group is formed for two East Asian species of the genus Plagiophorus Motschulsky, P. fujiyamai (Kubota) from Japan, South Korea, and China (Beijing) and P. subcorticarissp. nov. from Taiwan. The fujiyamai group is unique in that the antennal club is not excavated in the male and antennomere III has two distinct sutures. A key to the species of the fujiyamai group is given.

The amygdalinus species group is formed for one new East Asian species of the genus Plagiophorus Motschulsky, P. amygdalinussp. nov. from Taiwan. The amygdalinus group is unique in that sternite IX is not externally visible in the male.

Bombus (Subterraneobombus) distinguendus Morawitz, 1869 is recorded from Attu Island, in the western Aleutian archipelago, and is recognised as a species new to both the Alaskan and the New World faunal lists. Colour variation and food plants are described and a key to females of Nearctic Subterraneobombus species is provided.

The first-instar larvae of Delia radicum (L.) and Delia antiqua (Meigen) enter host plants to feed in galleries. These galleries can be filled by a liquid resulting from the putrefaction of the host. In this study, we show that D. radicum and D. antiqua larvae have a metapneustic respiratory system in the first instar and an amphipneustic respiratory system in the second instar, as observed in the majority of cyclorrhaphous Diptera. In addition, we observed four spatulate, ramified structures on the postabdominal spiracles in all three larval instars. We propose that these structures facilitate gas exchange (CO2 and O2), especially in the first-instar larvae when they feed in liquid-filled galleries.

Based on circumstantial evidence, Neuragrion mysticum Karsch, 1891 is considered a junior synonym of Heteropodagrion sanguinipes Selys, 1885. Annotated wing scans for H. sanguinipes and Mesagrionleucorrhinum Selys, 1885, species originally compared to N. mysticum, are provided.

The intromission of the male's long, flexible, threadlike phallus into the female's similarly long, thin, S-shaped vagina in tephritid flies is mechanically challenging. The male of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann, 1824), folds the basal portion of his phallus back on itself, inserts the folded portion into the female, and then gradually unfolds his phallus inside her vagina. The site of the fold in the phallus gradually moves distally, deeper into the female, dragging the distal portion of the phallus into her vagina. At the same time, the male pulls the tip of the female's ovipositor distally with his surstyli, straightening her vagina. The male uses his phallapodeme and asymmetrical syntergosternite to periodically clamp and release portions of his phallus that have not yet entered the female. Once the entire distal portion of the male's phallus is inside the female, he unfolds it and then moves its distal tip even deeper, reaching the inner end of her copulatory bursa. Straightening movements of the phallus due to increases in fluid pressure probably supply at least part of the force that drives the phallus into the female.

Aleochara bipustulata (L., 1761) (Coleoptera: Staphylinidae) is a Palearctic species and a natural enemy of the cabbage root maggot, Delia radicum (L., 1758) (Diptera: Anthomyiidae). It has been identified as a candidate for introduction to Canada for classical biological control of D. radicum. Recent taxonomic studies assert that A. bipustulata is absent from the Nearctic; however, there are numerous publications reporting the presence of the species in North America. We examined voucher material relating to these publications and additional museum specimens labeled as A. bipustulata. In addition, we reared Aleochara spp. from D. radicum puparia collected in the Canadian prairie provinces. Specimens that, based on external anatomy, could be A. bipustulata were definitively identified using characters of the genitalia. All of the 141 museum specimens labeled A. bipustulata were found to be Aleochara verna Say, 1836. A total of 811 individuals of Aleochara spp. were reared from D. radicum puparia; of these, 690 were Aleochara bilineata Gyllenhal, 1810, 121 were A. verna, and none were A. bipustulata. We have found no evidence that A. bipustulata occurs in North America.

Batrachedra Herrich-Schäffer, 1853 (Lepidoptera: Batrachedridae) is a widespread genus with species concentrated in tropical areas. This genus of about 140 described species has been put in several lepidopteran families, most recently in the Batrachedridae (Hodges 1999; Koster 2002). Batrachedra has 25 Nearctic species (Hodges 1983; Koster 2002), 17 Neotropical species (Becker 1984), 6 Palearctic species (Koster 2002), and 29 Australian species (Edwards 1996). Additional species occur in other areas such as Indonesia (Baringbing 1986). Here I report that the Palearctic species Batrachedra pinicolella (Zeller, 1839) is established in Connecticut, United States of America. Until now the range of the species was restricted to European countries and the far eastern Palearctic region (Riedl 1969, 1996; Bolov and Sinev 1990). The disjunct Asian populations may represent accidental introductions.

The habitat of Bolitotherus cornutus Panzer consists primarily of sporophores of the shelf fungus Fomes fomentarius (L.:Fr.) J. Kickx fil. Each sporophore is discrete and often several are present on a single dead log or standing snag, especially of paper birch (Betula papyrifera Marsh.). An exploratory approach was used to examine habitat use at three scales (the single sporophore, a single log supporting up to several sporophores, and a group of logs supporting sporophores) by modeling incidence of adult B. cornutus. Sporophore volume and decay were important for the beetles at all scales. Patches containing a variety of states of sporophores from alive to dead and decomposing are probably most suitable to B. cornutus. Results are compared with those for the related European beetle Bolitophagus reticulatus (L.), which is similar ecologically and also occupies F. fomentarius sporophores.

The wheat stem sawfly, Cephus cinctus Norton, is a major insect pest in dryland wheat (Triticum L. spp.; Poaceae) fields in the northern Great Plains of the United States and in southern regions of the prairie provinces of Canada. Field infestations by this pest commonly show a distinct “edge effect”, with infestation levels highest at the field edge and declining inwards. In this study, we characterized the edge effect of C. cinctus infested wheat fields in Montana at four locations in two separate years. "Infestation level" refers to the average proportion of wheat stems infested with C. cinctus in samples collected in a given wheat field. The gradual decrease in C. cinctus infestation towards the centre of wheat fields is referred to as the “infestation slope”, and it was presented as a proportion of infestation level at field edges. We showed that (i) for most of the fields bordering grassland or fallow wheat, a simple exponential decline curve provided a significant fit to the infestation slope; (ii) the infestation slopes in different fields and in different directions within fields were similar and appeared to be independent of the overall infestation level; and (iii) the relationship between infestation level and the proportion of samples infested followed an asymptotic curve, which indicates a high level of dispersal of ovipositing C. cinctus females. The general perception has been that the edge effect of C. cinctus infestation is a result of ovipositing C. cinctus females being both weak flyers and short-lived, but our results do not fully corroborate this perception. Currently, the only reliable way to detect C. cinctus infestations is to dissect individual stems and look for developing instars. However, this type of sampling is extremely time consuming and labor intensive and therefore impractical for wheat growers. Increasing the understanding of the spatial patterns in C. cinctus infestations is a first step towards development of an optimal sampling plan for this important field pest. Thus, the results presented are relevant for researchers involved in sampling designs and integrated pest management procedures for field pests. We discuss behavioral and evolutionary factors that may contribute to the edge effect of C. cinctus infestations.

Urbanization causes the fragmentation of natural habitats into isolated patches surrounded by anthropogenic habitats. Fragment size and the intensity of human disturbance have been shown to affect both composition and diversity of arthropod communities, but most groups have been understudied. We investigated effects of urbanization on ant assemblages (Hymenoptera: Formicidae) in and around the Molson Reserve, a preserved maple-beech forest surrounded by residential properties near Montréal, Quebec. We studied how local ant assemblages differed in terms of composition, abundance, and species richness, depending on whether they were situated in the interior forest, in adjacent residential backyards, or at the edge between these two habitats. We also compared an intact forest interior with a younger and moderately disturbed forest (“buffer zone”) between the urban matrix and the interior forest. Few differences were detected between the buffer zone and the intact forest interior. Extrapolated estimates of species richness suggest that it is lowest in the forest interior and highest in urban zones. Community composition, as investigated with ordination analysis, revealed a clear difference between the fauna of urban sites and the fauna of edges and forest interiors, and analyzing the relative abundance of ants showed residential backyards to contain the most ants. Urban assemblages were characterized by several competitively dominant species, including one introduced or “tramp” species. The occurrence of aggressive and dominant species in urban sites and at the edges of the Molson Reserve could potentially interfere with the dispersal and immigration of ground-dwelling arthropods and negatively affect local diversity or community composition in isolated forest reserves in urban centres.

Corn rootworms, Diabrotica Chevrolat spp. (Coleoptera: Chrysomelidae), are major pests of corn, Zea mays L. (Poaceae), in North America. Overwintering eggs hatch in the spring, and larvae feed on the root system, where they complete development. Emergent adults feed on vegetative and reproductive aerial structures of corn and oviposit in soil cracks or at the base of plants. Although feeding on silks by adult corn rootworms reduces the yield of corn, most of the damage results from root injury caused by larval feeding (Levine and Oloumi-Sadeghi 1991).

Because the detectability of host eggs is low, egg parasitoids rely on infochemicals other than those from the host egg itself, such as host plant synomones (Nordlund 1994; Meiners et al. 2000) and adult host kairomones (Nordlund et al. 1983; Nordlund 1994; Colazza et al. 1999; Meiners et al. 2000). Egg kairomones are used only in the final stages of host selection (Kainoh et al. 1982; Strand and Vinson 1982, 1983; Nordlund et al. 1987; Meiners et al. 2000; Takasu and Nordlund 2001).

Pitfall traps containing a preservative have become the standard method of sampling for epigeal invertebrates such as carabid beetles and cursorial spiders. However, they often result in high levels of mortality for small mammals and amphibians. We compared the carabid, spider, and vertebrate captures within five pitfall trap types (conventional trap, funnel trap, shallow trap, Nordlander trap, and the ramp trap) to determine the trap type that would reduce vertebrate incidental catch without compromising the capture of invertebrates. We also examined the effect of a mesh screen over pitfall traps on carabid beetle and vertebrate catches. All modifications to the conventional trap design resulted in a reduction in both small mammal and amphibian captures. The shallow pitfall trap and the funnel trap captured a carabid beetle and spider fauna similar to that captured by the conventional trap. The species compositions of the ramp trap and the Nordlander trap were different from those of the other trap types, but these traps were more efficient, capturing more species per individual captured. The ramp trap appeared to be the method of choice for sampling epigeal spiders. Thus, the choice among trap designs for invertebrates depends on the objectives of the study. However, an alternative to the conventional trap design should always be considered to reduce small mammal mortality.

Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and “trap-shy” species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002).