Previous identifications in North America of Trichomalus perfectus (Walker, 1835) and Mesopolobus morys (Walker, 1848) (Chalcidoidea: Pteromalidae), the principal chalcid parasitoids of the cabbage seedpod weevil (Ceutorhynchus obstrictus Marsham, 1802) in Europe, are shown to be misidentifications of Trichomalus lucidus (Walker, 1835) and Mesopolobus (Xenocrepis) moryoidessp. nov., respectively. Necremnus duplicatus Gahan, 1941 (Chalcidoidea: Eulophidae) is synonymized formally under Necremnus tidius (Walker, 1839) syn. nov., confirming a previous, tentative synonymy. Both sexes of N. tidius, M. moryoides, and T. lucidus are illustrated and compared with those of similar species using macrophotography and scanning electron microphotography. Hypotheses are offered to explain why the principal chalcid parasitoids of the cabbage seedpod weevil differ between North America and Europe and how the three treated species came to be in North America.

The four species from China of the genus Paralaevicephalus Ishihara, 1953 are reviewed; among them, two species, P. longistylussp. nov. and P. gracilipenissp. nov., are described. Paralaevicephalus prima (Rao, 1989) is reported for the first time from China. The genus Khasiana Rao, 1989 (Deltocephalinae: Paralimnini) is synonymized with Paralaevicephalus Ishihara, 1953 syn. nov. A key is given to distinguish the species, and illustrations of genitalia are provided.

A taxonomic study of the Oriental genus Amurta Dworakowska, 1977 is given. Five species are considered, one of which is reported for the first time in China, and two species, Amurta bimaculatasp. nov. and A. upunctatasp. nov., are described. All species are listed and a key for their separation is given.

Three buprestid species, Actenodes acornis (Say, 1836), Dicerca asperata (Laporte et Gory, 1837), and Dicerca lepida LeConte, 1857, are newly recorded from Canada on the basis of a collection of 57 buprestid specimens taken from females of the crabronid wasp Cerceris fumipennis Say, 1837 in Rondeau Provincial Park, Chatham-Kent region, Ontario, in July 2004. Nine additional buprestid species were taken from wasps that were intercepted as they approached their nests, demonstrating the effectiveness of C. fumipennis nest sites as sampling stations for buprestid beetles. We suggest that this sampling method could be applied to efficiently monitor the spread of the emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) in eastern North America.

The role of vision in the flight initiation sequence of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), was assessed by comparing the behavioral sequences and frequencies of takeoffs of untethered and tethered beetles with and without vision. Results showed that vision plays a critical role in the successful completion of the launch and the maintenance of lift for the adult Colorado potato beetle. The sequence was interrupted immediately before or during the lifting of the mesothoracic legs or before the launch for most blind beetles. Liftoffs of untethered beetles over a 1-h period in a flight chamber were reduced significantly, by 77%, in blind beetles compared with normal beetles. In addition, the preponderance of upward (dispersal) flights following successful liftoffs of normal beetles was replaced by a preponderance of downward (short) flights for blind beetles. Blind beetles that did not have to launch themselves because they were tethered initiated flight as frequently as tethered normal Colorado potato beetles. The duration and repeatability of flights initiated by tethered blind Colorado potato beetles were also similar to those of flights initiated by tethered normal Colorado potato beetles in a stationary environment. Together, the results of the tests with untethered and tethered beetles indicate that vision is a key factor during flight launching and for flight continuation.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is the most serious insect pest of dryland wheat (Triticum aestivum L.; Poaceae) in the southern Canadian Prairies and the northern Great Plains of the United States. We characterized the spatial distribution pattern of C. cinctus eggs and larvae throughout the adult flight period in three dryland winter wheat fields in Montana. Cephus cinctus females laid eggs in wheat stems until a few weeks before wheat maturity, and most wheat stems received only one egg. Wheat stem samples collected along the field edges represented 12%–16% of the samples but 40%–95% of the infested stems. The highest numbers of C. cinctus eggs and larvae found in a single wheat stem were 16 and 4, respectively. On a field scale, both C. cinctus eggs and larvae were significantly aggregated along field edges in most of the sampling events. A comparison of indices of aggregation revealed that C. cinctus larvae were significantly more spatially aggregated than C. cinctus eggs. Based on our spatiotemporal analysis, we speculate that the majority of the eggs are initially laid along field edges, and ovipositing C. cinctus females do not distinguish between previously infested and uninfested wheat stems. Gradually, these eggs hatch and the larvae begin feeding; at the same time, the later emerging C. cinctus females oviposit farther into the wheat fields. One explanation is that ovipositing C. cinctus females avoid stems containing feeding larvae. The analysis of the temporal changes in the spatial distribution patterns of C. cinctus eggs and larvae is discussed in the context of possible integrated pest management strategies.

Despite the importance of native pollinators in agricultural systems, little is known about the potential competitive interactions among them or the way they exploit crops' floral resources. This study determines the temporal use of floral resources by, and interspecific interactions between, native bees and Apis mellifera L. (Hymenoptera: Apidae) in experimental plots of squash, Cucurbita moschata (Duchesne ex Lam.) Duchesne ex Poir. (Cucurbitaceae), and watermelon, Citrullus lanatus (Thunb.) (Cucurbitaceae). General and specific niche overlap analyses were done to determine whether temporally differential use of floral resources occurred. Direct displacement interactions at the floral level were quantified. The species with the greatest abundances were Peponapis limitaris Cockerell (Apidae), Partamona bilineata Say (Apidae), and A. mellifera. Overall, the niche overlap analyses in both crops suggested that floral resources are not used simultaneously by different bee species. Winner events during aggressive encounters suggested a hierarchy among bee species, with A. mellifera being one of the species with more winner encounters in both crops. It is suggested that those deciding whether or not to introduce A. mellifera into crops should consider whether the abundance of native bee species is sufficient to ensure efficient fruit production.

In the Mediterranean Basin, two species of true seed bugs in the genus Orsillus Dallas, O. maculatus Fieber and O. depressus Mulsant et Rey, share the exploitation of seed cones of Cupressaceae for feeding and reproduction and may carry spores of the pathogenic fungus Seiridium cardinale Sutton & Gibson, responsible for the cypress bark canker disease. We compared the life history of the two species. A total of 89 cone collections carried out in 10 Mediterranean countries confirmed that O. maculatus is most closely associated with Cupressus sempervirens L., although it may also infest some other Cupressus L. species and, more rarely, species of Chamaecyparis Spach. Orsillus depressus appears to be less host-specific, being capable of feeding and ovipositing on most of the native and exotic species of Juniperus L., Cupressus, and Chamaecyparis. On C. sempervirens, the abundance of each Orsillus species follows an inverted longitudinal gradient along the Mediterranean Basin, probably corresponding to the pathway of introduction of this tree species from its native eastern range towards western Europe. The dominance of O. maculatus progressively decreases from east to west, whereas O. depressus becomes dominant in the Iberian Peninsula. By contrast, O. depressus is the dominant seed bug on other Cupressaceae all over Europe and the Mediterranean Basin. In the area in which C. sempervirens has been introducted, both Orsillus species may live on the same tree, but morphological variability of both adults and nymphs often hinders accurate identification of the species. Based on frequency distribution, the relative length of the rostrum compared with that of the body seems to be a diagnostic character for specific identification of nymphs of the last two instars.

The western tussock moth, Orgyia vetusta Boisduval (Lepidoptera: Lymantriidae), formerly known as Hemerocampa vetusta (Boisduval), occurs primarily in coastal areas of central California and south into Mexico, with occasional records east of the central Sacramento and San Joaquin valleys (Ferguson 1978). Two biotypes, feeding on perennial yellow bush lupine, Lupinus arboreus Sims (Fabaceae), or silver dune lupine, Lupinus chamissonis Eschsch. (this study), and on California live oak, Quercus agrifolia Née (Fagaceae), respectively, have been recognized and were originally considered two separate species (Edwards 1881; Ferguson 1978). Various fruit and nut trees have also been reported as host plants (Atkins 1958)

Caged assays and field tests were used to evaluate the effectiveness of organophosphorus, pyrethroid, neonicotinoid, and biologically derived insecticides for reducing populations of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), a new pest of canola in Canada. Complete mortality of caged weevils occurred 48 h after treatment with disulfoton, deltamethrin, carbofuran, oxydemeton-methyl, and chlorpyrifos. Under field conditions, using plots or large strips in commercial fields from 1998 to 2001, only deltamethrin and cyhalothrin-lambda (both pyrethroids) consistently reduced weevil densities, even at high population levels. Chlorpyrifos also significantly reduced weevil numbers and damage in some years, but results were variable and efficacy was too low to manage weevils under outbreak densities. Other insecticides such as spinosad provided moderate weevil control and may have a role in weevil management depending on their effect on beneficial insects relative to more efficacious insecticides. Treatment of canola seed with imidacloprid, lindane, or acetamiprid did not reduce weevil damage. Further research is needed to establish economic thresholds for C. obstrictus in canola, to assess the effect of insecticides on nontarget natural enemies of canola insect pests, and to assess the potential for integration of chemical agents with biological and cultural control strategies.

The alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), can severely damage the first cutting of alfalfa, Medicago sativa L. (Fabaceae), in much of Iran. The pest has been parasitized by several parasitoids including Oomyzus incertus (Ratzeburg) (Hymenoptera: Eulophidae), a gregarious larval endoparasitoid. This wasp can parasitize up to 30% of weevil larvae in alfalfa fields in northern Iran. It produces three to four generations per year, and the female prefers the fourth instar of the host for oviposition. Each female lays 2 to 22 eggs per host, which hatch within 47–60 h. The life cycle is completed in about 2 weeks, upon pupation inside the host. This species is predominantly present during the summer months in alfalfa fields (Streams and Fuester 1967).

The western conifer seed bug, Leptoglossus occidentalis Heidemann (Hemiptera: Coreidae), is a polyphagous pest of coniferous trees (Hedlin et al. 1981). Native to western North America, the seed bug has expanded its range to include eastern Canada and the United States (McPherson et al. 1990; Gall 1992; Marshall 1992; Ridge-O'Connor 2001; Bates 2002) and was recently introduced into Europe (Taylor et al. 2001). Both adults and nymphs feed by inserting their stylets into cones and digesting the contents of developing seeds, and they can cause serious economic losses in high-value seed orchards (Strong et al. 2001; Bates et al. 2002; Bates and Borden 2005).

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is an insect pest in dryland wheat cropping systems in the southern Canadian Prairies and the northern Great Plains of the United States (Morrill 1997). Yield losses caused by C. cinctus are due to reduced head weight (Holmes 1977; Morrill et al. 1992) and lodging, which decreases harvest efficiency. Estimates of yield losses in Montana alone are about US$25 million per year.