Based on a large number of specimens deposited in many collections, and on material collected in a sampling program in Yucatán Peninsula, Mexico, 19 North American species of Clistopyga Gravenhorst, 1829 (Hymenoptera: Ichneumonidae) are reported. Five species, C. aenigmatica, C. arizonica, C. juliana, C. maya, and C. oaxacana, are described as new. Clistopyga covarrubiasi Khalaim and Hernández, 2008 is synonymysed with C. recurva (Say, 1835) and C. sauberi Brauns, 1898 is once again re-synonymysed with C. canadensis Provancher, 1880. Data on diagnosis, variation, distribution, and hosts of all species are provided. All previously known species are re-described. The present revision extends the distributional range of the Neotropical species C. calixtoi Gauld, 1991, C. fernandezi Gauld, 1991, and C. henryi Gauld, Ugalde, and Hanson, 1998 to the southern part of the Nearctic Region (northern Mexico), and the area of the Nearctic species C. manni Cushman, 1922 to the northern part of the Neotropical region (southern Mexico). An illustrated identification key to all North American Clistopyga species is provided.

The eastern foothills of the Cascade Range in Washington State, United States of America are west of the State's major fruit-producing region. Alders (Alnus Hill (Betulaceae)), an important floristic component of riparian communities in the Cascade Range foothills, were surveyed for leafrolling caterpillars (Lepidoptera: Tortricidae) that might serve as alternate hosts for parasitoids of orchard pest leafrollers, particularly the nonnative wasp Colpoclypeus florus (Walker) (Hymenoptera: Eulophidae). Tortricid leafrollers were abundant on alder, but reared parasitoids did not include C. florus. Survey results also revealed that rolled leaves were secondarily colonised by a wide variety of predatory and phytophagous arthropods. Rolled leaves were almost 10-fold more likely to be occupied by predatory arthropods than adjacent, roll-free leaves. Phytophagous thrips and mites showed a similar preference for rolled leaves. The most abundant predaceous arthropods in the leafrolls were Anthocoris antevolens White (Hemiptera: Anthocoridae), found in 4.4% of leafrolls, and the spider Clubiona pacifica Banks (Araneae: Clubionidae), found in 8.3% of leafrolls. Both species, and several other predatory insect and spider species found in the rolled leaves, also occur in eastern Washington orchards where they contribute to biological control. Because of its frequent colonisation by beneficial arthropods, alder may prove useful in conservation biological control programs.

Three new species of Pipunculidae (Diptera) are described (one named), from the early Eocene (Ypresian) Okanagan Highlands of British Columbia, Canada and Washington State, United States of America: Metanephrocerus belgardeaenew species from Republic, Washington; and Pipunculidae species A and Pipunculinae species A from Quilchena, British Columbia. We re-describe the late Eocene (Priabonian) species Protonephrocerus florissantius Carpenter and Hull from Florissant, Colorado, United States of America, and assign it to a new genus proposed here, Priabonanew genus. Pipunculinae species A is the oldest known member of the family whose wing lacks a separated M2 vein; previously this had been known in species only as old as Miocene Dominican amber. This is a presumably derived character state that is predominant in modern species. Molecular analysis indicates an origin of the Pipunculidae in the Maastrichtian; the morphological and taxonomic diversity seen here in the Ypresian is consistent with an early radiation of the family. This is concordant with the radiation of Auchenorrhyncha, upon which they mostly prey, which is in turn associated with the early Paleogene diversification of angiosperm-dominated forests recovering from the K-Pg extinction event.

Population parameters of ectoparasites on feral pigeons, Columba livia Gmelin (Aves: Columbiformes: Columbidae), were estimated from 1995–2012 in southern Manitoba, Canada. The ectoparasites are chewing lice (Phthiraptera): Philopteridae – Campanulotes compar (Burmeister), Columbicola columbae (Linnaeus), and Coloceras tovornikae Tendeiro; Menoponidae – Hohorstiella lata (Piaget). We tested the hypotheses that both abundance and population stability are species-specific traits. Over 10 years, the four species of lice had distinct population dynamics. Campanulotes compar and C. columbae were more abundant than C. tovornikae and H. lata, had higher male to female sex ratios and higher ratios of nymphs to females, different levels of aggregation, and more stable populations. Campanulotes compar was more prevalent than C. columbae and its prevalence was more stable, and the two species also showed differences in the levels and stabilities of male and nymph to female ratios. Coloceras tovornikae had a higher prevalence and male to female sex ratio than H. lata, but the two species showed similar levels of stability for these parameters. The level of stability of these populations was relatively high compared with many other organisms, and in particular higher than for plant ectoparasites (Hemiptera: Aphididae). Although the four species occupy similar habitats, often on the same bird, and three of the four feed in a similar way, the population biology of each species is distinct. The life history traits that lead to these differences have yet to be determined.

The European Fire Ant, Myrmica rubra (Linnaeus) (Hymenoptera: Formicidae), is an invasive stinging ant that has only recently been recorded in Newfoundland, Canada. The goal of the present study was to investigate the origins of M. rubra ants in Newfoundland. We analysed mtDNA sequences from the cytochrome b and cytochrome c oxidase I genes of ants from six localities in Newfoundland, and neighbouring regions of eastern Canada and the United States of America, and compared them with mtDNA data from a recent wide-scale phylogeographical study of the ant throughout Europe. There is evidence for at least four distinct sources of ants on the island. The putative routes of colonisation of the ant to Newfoundland are discussed, as are the possible reasons why it went undiscovered for many decades.

The sunflower stem weevil, Cylindrocopturus adspersus LeConte (Coleoptera: Curculionidae), reduces sunflower, Helianthus annuus Linnaeus (Asteraceae), yields by spreading pathogens, damaging vascular tissues, and promoting lodging of sunflower plants. To assess weevil populations for host plant resistance and insecticide field trials, larvae are dissected out of stems and counted; a process that is slow and limits experimental designs. To improve efficiency of sunflower stem weevil sample processing, field-collected sunflower samples were used to evaluate whether digital radiographs (X-rays) of stem sections or population estimates from rearing out overwintering stem weevils are suitable substitutes for dissection of complete stems. Digital X-rays of small stem pieces (15 cm above soil level) split longitudinally were found to explain over 75% of the variation in numbers of weevil larvae from dissected stem samples (50 cm), but required less than one-fifth the time of manual dissection. Use of small emergence boxes to estimate weevil populations was similarly time efficient, but may not be easily related to weevils per plant because of parasitism and other mortality. Results suggest for large field trials with sunflower stem weevils, digital X-rays provide much more time-efficient larval population estimates.