The oribatid mite genus Zachvatkinibates, found in littoral, forest canopy, and forest litter habitats, includes some species showing distinct sexual dimorphism in the octotaxic system of dermal glands, and others lacking this dimorphism. Three new species in this genus are described on the basis of adults, each of which shows species-specific sexual dimorphism: Z. nortonisp. nov. and Z. schatzisp. nov. from beach debris in British Columbia, Canada, and Z. shaldybinaesp. nov. from the littoral in eastern and northeastern Canada. We discuss the association of sexual dimorphism with the littoral habitat of species in this genus and, more generally, the expression of sexually dimorphic porose areas in Ceratozetoidea. We revise the diagnosis for the genus Zachvatkinibates and present a revised key for adults of Zachvatkinibates species of North America north of Mexico.

A new genus and species of the mite family Tarsonemidae, subfamily Tarsoneminae, is described and illustrated. Its systematic position among genera of Tarsoneminae and its host association with bark beetles of the genus Pseudopityophthorus Swaine, 1918 in North America are briefly discussed.

The first-instar (triungulin), second-instar, and third-instar larvae of the South American monotypic genus Epispasta Selander, 1960 are described and figured. The triungulin of E. abbreviata (Klug, 1825) is highly adapted for phoresy on bees and resembles the triungulins of several other phoretic genera in the subfamily Meloinae. The second- and third-instar larvae of Epispasta are unique in that they retain the campodeiform phenotype of the first instar. These instars in other meloid genera are scarabaeiform. A discussion is provided on the similarity of the triungulin of Epispasta to that of other phoretic meloines. We argue that this similarity is a result of morphological convergence correlated with phoretic behavior and is not evidence of a relationship. The position of Epispasta in Meloinae remains questionable, as none of its larval or adult features ally it to any other genus.

Ceutorhynchus neglectus Blatchley is a weevil that is native to, and widely distributed in, North America. It has life-history characteristics similar to its alien invasive congener, Ceutorhynchus obstrictus (Marsham), the cabbage seedpod weevil. Our study was undertaken to compare the population structure of C. neglectus in North America to that of C. obstrictus, which, in contrast, was introduced only recently to North America and might be expected to have a simpler population structure. We also compared the population structure of C. neglectus to that of Pissodes strobi (Peck), which is known to possess high levels of intraspecific variation and is also a Nearctic weevil. We sequenced a 790-bp fragment of mtDNA (cytochrome oxidase I (COI) gene) and a 117-bp fragment of nuclear DNA (internal transcribed spacer region 1 (ITS1)). Nested clade analysis inferred contiguous range expansion and restricted gene flow with isolation by distance. Analysis of molecular variance also supported restricted gene flow between geographically distant populations. However, within-species variation in C. neglectus was lower than that for other weevil species including C. obstrictus. We also examined DNA divergences and phylogenetic relationships among 10 species of Ceutorhynchus using parsimony analysis of a 2.3-kb fragment of mtDNA (COI–COII) and a 541-bp fragment of nuclear DNA (elongation factor 1α).

Coneworms of the genus Dioryctria Zeller are important lepidopterous pests of conifer cones throughout the Holarctic region. Seventy-nine Dioryctria species are currently recognized and arranged into 11 species groups, but a globally unified classification of these species groups has not been attained. We surveyed 14 Dioryctria species belonging to 7 species groups recognized as being taxonomically problematic. Mitochondrial DNA sequences and morphological characters were used to resolve relationships among and within species groups and species. Sequences were obtained for 2.3 kb of the mitochondrial COI + COII genes and related to 52 morphological characters. Parsimony analyses of separate and combined data showed that (i) the five included Chinese species (D. abietella (Denis and Schiffermüller), D. rubella Hampson, D. nr. rubella, D. magnifica Munroe, and D. yiai Mutuura and Munroe) were distinct from the North American taxa, and their relationships were interspersed among Nearctic and European species; (ii) three of the four species groups represented by more than one species formed robust, well-supported clades (abietella group, sylvestrella group, and zimmermani group) for both mtDNA sequences and morphology; (iii) mtDNA and morphology gave conflicting interspecific and intergroup relationships for the auranticella, schuetzeella, ponderosae, and baumhoferi groups; (iv) all eight species for which more than one specimen was sampled were characterized by discrete clusters of mitochondrial DNA haplotypes, and mtDNA divergences among species in the same species group were generally less than those among species in different species groups; and (v) combining mtDNA data with morphological data increased support for most nodes in the phylogeny, with morphological characters providing support for species groups and mtDNA being essential for distinguishing species within species groups. This study demonstrates the value of a combined analysis of both mtDNA and morphological characters and establishes a phylogenetic framework for broader and more comprehensive studies of Dioryctria species.

The genus Dioscorea L. (Dioscoreaceae) is widely distributed throughout Africa and Asia and includes 500 to 650 species (Burkill 1960; Miège and Lyonga 1982), almost all of which are dioecious (Terauchi 1990). Pollination of species in this genus has received little attention because many of the cultivated species are propagated vegetatively from tubers. Insect visitors to flowers have been reported for two species, D. alata L. from India (Abraham and Nair 1990) and D. rotundata Poir. from Nigeria (Pitkin 1973; Segnou et al. 1992; Bournier 1994). Dioscorea japonica Thunb. is found throughout Japan, Korea, and China (Ohwi and Kitagawa 1983), but insect visitors to the flowers have not previously been reported. We investigated the insect visitors to flowers of D. japonica because the insect fauna associated with one species of a genus often differs from that associated with other species of the genus and may vary within a single species between different geographic regions (Kobayashi et al. 1999).

Several scolytid beetles (Coleoptera: Scolytidae) produce conophthorin, (E)-7-methyl-1,6-dioxaspiro[4.5]decane, and use it as an aggregation or antiaggregation pheromone or competition-mediating synomone (Francke et al. 1979; Kohnle et al. 1992; Birgersson et al. 1995; Pierce et al. 1995; de Groot et al. 1998; Dallara et al. 2000; Rappaport et al. 2000). Predators or associates of these beetles may use conophthorin as a host- or habitat-finding kairomone (Kohnle et al. 1992). Other conifer-infesting scolytid and predator species use chalcogran, 2-ethyl-1,6-dioxaspiro[4.4]nonane, a semiochemical with functions similar to those of conophthorin (Francke et al. 1977; Heuer and Vité 1984; Baader 1989; Byers 1993; Byers et al. 1989, 2000).

The spectral reflectance of phytophagous insects' host plants is usually quantified between 300–350 nm (ultraviolet, UV) and 700 nm (farred to infrared), and the shape and magnitude of the distribution of reflected light determine the hue, saturation, and intensity perceived by insects (Moericke 1969). Host perception also depends on the distribution of environmental light (Endler 1993) and on the constraints of the insects' visual system, which is usually described as dichromatic, with one type of photoreceptor responding maximally to blue light (λmax = ca. 400–470 nm) and another to green light (λmax = ca. 500–530 nm). UV receptors also appear to be common, if not ubiquitous (Briscoe and Chittka 2001; Mazza et al. 2002). Several phytophagous insects have been shown to use visual cues, including UV reflectance, to locate and (or) discriminate among plants (Prokopy and Owens 1983).

Odonates are obligate predators (Pritchard 1964), and the composition of their diet is reflective of their microhabitat and effectiveness in detecting and capturing prey (Griffiths 1973; Thompson 1978). In an intermittent woodland pond in southern Ontario, Canada, three species of Sympetrum (Odonata: Libellulidae) were found to coexist: S. internum Montgomery, S. costiferum (Hagen), and S. obtrusum (Hagen). Sympetrum species spend most of their life cycle in the aquatic stage and consume prey at all nymphal stadia (Pritchard 1964; Corbet 1999). They overwinter in the egg stage, hatch in early spring, and typically emerge in late June to late July (Walker and Corbet 1975). To better understand the role of coexisting Sympetrum nymphs in this intermittent pond environment, and to evaluate potential mechanisms behind their coexistence, we collected seasonal abundance and body size data for 2 years and analyzed gut contents of each species. In addition, we experimentally tested the prey selection and predatory rate of two different size classes of Sympetrum nymphs and two of their potential competitors, Lestes sp. (Odonata: Lestidae) and Acilius sp. (Coleoptera: Dytiscidae), in laboratory microcosms.

The use of the timing of moth catch in traps to predict the start of egg hatch by first-generation codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkh. (Rosaceae), was evaluated with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E,E)-8,10-dodecadien-1-ol (codlemone) lures. Two sets of paired traps baited with either lure were placed in each of seven orchards and checked daily during the spring flight in 2000 and 2001. Rearing of field-collected eggs and sampling of fruit for injury were used to estimate the date of first egg hatch. Moth catch in traps baited with codlemone and pear ester occurred approximately 144 and 105 degree-days prior to the start of egg hatch, respectively. The effectiveness of using the timing of sustained moth catch in traps baited with these lures as a biological reference point (Biofix) to predict the start of egg hatch when traps were checked every 3–4 d was evaluated in 11 orchards from 2000 to 2002. The calendar date for the start of sustained moth catch in traps baited with either lure varied widely among orchards and years. Significant differences in mean cumulative degree-days from first sustained moth catch until egg hatch were found among male moth catch in codlemone-baited traps and total and female moth catch in pear ester-baited traps. Adjusting the Biofix based on daily temperature thresholds significantly changed the cumulative degree-days required until egg hatch only for female moth catch. No significant differences were found in the accuracy of predicting the date of egg hatch using either the codlemone or pear ester lure or by adjusting the Biofix date using daily temperature thresholds. The cumulative degree-day totals required from Biofix until egg hatch had the lowest variability when the Biofix was (i) based on the sustained catch of female moths in a pear ester-baited trap and (ii) adjusted with a temperature threshold for moth activity.

Traps baited with either ethyl (E,Z)-2,4-decadienoate (pear ester) or (E,E)- 8,10- dodecadien-1-ol (codlemone) (Pherocon® CM-DA™ and Megalure CM™ lures, respectively) were used to develop action thresholds for codling moth (Cydia pomonella (L.)) in apple (Malus domestica Borkh.; Rosaceae) orchards treated with sex pheromones for control of this pest. Studies were conducted in 102 orchards treated with 500–1000 ISOMATE®-C PLUS dispensers per hectare during 2000–2002. Pairs of traps were placed within two 1.0-ha plots within each orchard. Fruit injury was assessed at mid-season and prior to harvest in each plot. The numbers of female and total moths caught in pear ester-baited traps and male moths caught in codlemone-baited traps were used to develop action thresholds. Thresholds were based on the minimum cumulative number of moths per trap in ≥95% of traps in unsprayed plots with no fruit injury. Specific thresholds were established for the first insecticide spray targeting the start of egg hatch and for the first and second moth flights. The proportion of plots with mid-season fruit injury that had cumulative moth catches below the action threshold at first spray and at second moth flight was determined using the established action threshold and thresholds reduced incrementally to ≥1 moth per trap. Moth catches below the threshold at first spray were less common in plots with high levels of fruit injury (>0.3%) than in plots with low levels of fruit injury and more common with codlemone-baited traps than with pear ester-baited traps. An action threshold of ≥1 moth in a pear ester-baited trap at first spray eliminated the error in predicting fruit injury in plots at mid-season. Conversely, a high proportion of traps baited with either lure failed to predict low levels of fruit injury at harvest in unsprayed plots regardless of the cumulative moth threshold used during the second moth flight.

The red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. In California, D. valens and the California fivespined ips, Ips paraconfusus Lanier (Coleoptera: Scolytidae), are sympatric and often colonize the same tree. In an unrelated study, we observed that I. paraconfusus attack densities in logging debris were inversely related to D. valens attacks on freshly cut stumps. In this study, we test the hypothesis that allomonal inhibition occurs between these two species. Components of the aggregation pheromone of I. paraconfusus (racemic ipsenol, (+)-ipsdienol, and (–)-cis-verbenol) inhibited the response of D. valens to attractant-baited traps. Substitution of racemic ipsdienol for (+)-ipsdienol did not alter this effect. Doubling the release rate did not enhance inhibition. Racemic ipsdienol was not attractive to I. paraconfusus. Temnochila chlorodia (Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, was attracted to the I. paraconfusus aggregation pheromone. These results could have important implications for the development of an effective semiochemical-based management tool for D. valens.

The wheat midge, Sitodiplosis mosellana (Géhin), is an infrequent but devastating pest that has been present in western North America for at least 100 years. This note provides the first published report of the presence of the wheat midge and its parasitoid, Macroglenes penetrans (Kirby), in Montana. Annual surveys were conducted in Daniels, Roosevelt, Sheridan, and Valley counties of northeastern Montana for 5 years (2000–2004) using a systematic soil sampling method to collect overwintering wheat midge larvae. In addition, in 2004, infested wheat heads were collected from 10 fields in Sheridan County, and wheat midges and parasitoids were reared. The wheat midge occurred in all four counties, though at relatively low levels. Densities fluctuated across years and locations, with the highest densities (>200 midge larvae/m2) occurring in Sheridan and Roosevelt counties. Macroglenes penetrans was found at all 10 sample sites and constituted up to 52% of the emerged adults (midges + parasitoids).