The Nearctic species of Neophyllomyza Melander are revised and descriptions, illustrations, and an identification key are provided for the two included species, N. quadricornis Melander and N. gaulti n. sp. Large numbers of adults of both species were collected in emergence traps on decaying logs of sugar maple (Acer saccharum Marsh. (Aceraceae)) and American beech (Fagus grandifolia Ehrh. (Fagaceae)) in eastern Canada, indicating that the larvae of both species are saproxylic, although their exact food source is unknown. Although the two species are sympatric over much of their range and apparently use the same resources for larval development, their habits differ: N. quadricornis was collected from logs in both the early- and the advanced-decay stage from late May until September, with a peak of emergence in late June, whereas N. gaulti was reared almost exclusively from logs in the advanced-decay stage and from mid-July to mid-August. This suggests that N. gaulti is more specialized in its larval habits, which may reduce competition between the two species.

Spalangia dozieri Burks is newly recorded as a gregarious parasitoid in the puparia of Chrysomya albiceps (Wiedemann), C. putoria (Wiedemann), Lucilia eximia (Wiedemann), and L. sericata (Meigen) (Diptera: Calliphoridae), and represents the first report of gregariousness in Spalangia Latreille. The previously unknown males of S. dozieri are described and compared with females. Males have highly modified legs and several other sexually dimorphic features that differ from those of other Spalangia species. Most of the unusual features are hypothesized to be adaptations for grasping and holding and it is suggested that males either are phoretic on adults of their dipteran hosts or, possibly, that males exhibit aggressive or other atypical behaviour toward siblings that is correlated with being gregarious. Barbados, Brazil, Dominica, St. Lucia, St. Vincent, and Trinidad are recorded as new country distribution records for S. dozieri.

The Palaearctic species Phytomyza petoei Hering is newly recorded in the Nearctic Region. The specimens were reared from cultivated mint, Mentha cf. x piperita L. (Lamiaceae), in eastern Canada. This is the first Nearctic record of a Phytomyza species feeding on mint.

The fir coneworm, Dioryctria abietivorella (Groté), is a transcontinental pest of coniferous seed cones. Recently, the attractive pheromone components and lure blend for the fir coneworm in western Canada were identified as a 200 µg: 2000 µg ratio of (9Z,11E)-tetradecadienyl acetate (9Z,11E-14:Ac) and a polyunsaturated hydrocarbon, (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene (C₂₅ pentaene). A potential third component, (Z)-9-tetradecenyl acetate (9Z-14:Ac), which was detected in pheromone gland extracts, had no effect on males of the western population when added to the binary blend. In contrast, in eastern Canada (Quebec) we found that the 200 µg: 2000 µg binary blend was unattractive to male fir coneworms until 9Z-14:Ac was added. By means of several field experiments we established that a 67 µg: 200 µg: 2000 µg ratio of 9Z-14:Ac, 9Z,11E-14:Ac, and the C₂₅ pentaene was attractive to fir coneworms in Quebec. Gas chromatography - mass spectrometry analysis of pheromone gland extracts of fir coneworm from Quebec confirmed the presence of the three components in extracts in an approximately 1 µg: 4 µg: 10 µg ratio of 9Z-14:Ac, 9Z,11E-14:Ac, and the C₂₅ pentaene. Our results provide evidence that the eastern and western populations of D. abietivorella are distinct geographic pheromone races, with 9Z-14:Ac being required for attracting males of the eastern population but not males of the western population.

In two recent studies it was reported that feeding on foliage of multiple age classes can improve insect fitness, but it was not determined whether the increase in fitness was due to larvae obtaining a more balanced diet (the balanced-diet hypothesis) or to a difference in the nutritional requirements between young and old larvae (the ontogenetic hypothesis). To test these two hypotheses, we examined the foraging behaviour and performance of young (second or third to fourth instar) and old (third or fourth to fifth instar) larvae of the pale-winged gray moth, Iridopsis ephyraria (Walker) (Lepidoptera: Geometridae), on different-aged foliage of eastern hemlock, Tsuga canadensis (L.) Carrière (Pinaceae), during an outbreak in southwestern Nova Scotia. Defoliation attributed to I. ephyraria was highest on current-year foliage and gradually declined with foliage age. Young larvae were only observed feeding on current-year shoots but old larvae fed on foliage of all ages. When forced to feed on foliage of specific ages in manipulative field studies, survival rates of young and old larvae were highest on current-year and old (≥1 year old) foliage, respectively. However, both young and old larvae had higher survival rates when provided with access to foliage of all age classes than when they were forced to feed on only young or old foliage. Thus, this study supports both the balanced-diet and ontogenetic hypotheses.

Deux études récentes indiquent que l'alimentation sur du feuillage appartenant à plusieurs classes d'âge peut augmenter la fitness des insectes, mais elles ne mentionnent pas si l'amélioration de la fitness est due à un régime alimentaire mieux équilibré chez les larves (hypothèse du régime équilibré) ou à des besoins nutritifs différents chez les larves jeunes et âgées (hypothèse ontogénique). Afin de tester ces deux hypothèses, nous avons examiné le comportement de recherche de nourriture et la performance chez des larves jeunes (de second ou troisième à quatrième stades) et âgées (troisième ou quatrième à cinquième stades) de l'arpenteuse à taches, Iridopsis ephyraria (Walker) (Lepidoptera: Geometridae), sur du feuillage d'âges différents de la pruche, Tsuga canadensis (L.) Carrière (Pinaceae) durant une épidémie dans le sud-ouest de la Nouvelle-Écosse. La défoliation attribuée à I. ephyraria est maximale sur le feuillage de l'année courante et elle décline graduellement en fonction de l'âge du feuillage. Les jeunes larves se nourrissent seulement des pousses de l'année courante, alors que les larves âgées s'alimentent de feuillage des tous les âges. Lorsque forcées de s'alimenter sur du feuillage d'âge donné lors de manipulations de terrain, les jeunes larves survivent mieux sur du feuillage de l'année courante et les larves âgées sur du feuillage plus vieux (≥1 an). Néanmoins, les larves, jeunes et âgées, ont une survie plus grande lorsqu'elles ont accès à du feuillage de tous âges que lorsqu'on les force à se nourrir seulement de feuillage jeune ou vieux. Notre étude appuie donc à la fois l'hypothèse du régime équilibré et l'hypothèse ontogénique.

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In pheromone-based surveys for detecting multiple species of exotic lymantriine moths (Lepidoptera: Noctuidae: Lymantriinae), spacing between traps baited with species-specific pheromone lures must be sufficient to prevent antagonistic effects of heterospecific pheromone on lure attractiveness. Conducting field experiments with the Japanese gypsy moth, Lymantria dispar japonica Motschulsky, in northern Honshu, Japan, we first determined which congeneric pheromone components have strong antagonistic effects on attraction of male moths to the conspecific pheromone (7R,8S)-cis-7,8-epoxy-2-methyloctadecane (( )-disparlure). Since the most antagonistic compounds were pheromone/volatile components from the sympatric nun moth, L. monacha (L.), we then conducted experiments with paired traps baited with either a L. dispar (L.) pheromone lure (( )-disparlure (50 µg)) or L. monacha pheromone lure (a mixture of (7R,8S)-cis-7,8-epoxyoctadecane (( )-monachalure (50 µg)), (7Z)-2-methyloctadecene (5 µg), and ( )-disparlure (50 µg)). As spacing between paired traps increased (0, 0.5, 2, 7.5, 15, or 30 m), the antagonistic effect of the L. monacha lure on the attractiveness of the L. dispar lure decreased and finally disappeared. For pheromone-based detection surveys of multiple species of exotic lymantriine moths in North America to be effective, trap spacing of 15 m is recommended.

Siricids and their parasitoids were reared from Scots pine (Pinus sylvestris L. (Pinaceae)) trees infested by Sirex noctilio F. in central New York State. Sirex noctilio accounted for 94.3% of the siricid specimens emerging, totaling 1313 specimens from six trees, with a maximum of 495 from one tree. Of the individuals emerging per tree, 20.6 ± 5.2% were female. Two native siricids, Sirex nigricornis F. and S. edwardsii Brullé, also emerged from trees but in low numbers. Three hymenopteran parasitoid species that attack siricids emerged, totaling 21.8 ± 6.4% parasitism per tree. Ibalia leucospoides ensiger Norton (Ibaliidae) was by far the most abundant parasitoid, at 20.5 ± 6.3% parasitism per tree. The percentage of female S. noctilio emerging was positively correlated with wood diameter, whereas percent parasitism by I. l. ensiger was negatively correlated with wood diameter.

In field experiments at three sites in Michigan and Ohio we tested the activity of 1-octen-3-ol in combination with ipsdienol, the aggregation pheromone of the pine engraver, Ips pini (Say). When 1-octen-3-ol was added to funnel traps baited with ipsdienol, significantly fewer beetles of either sex were captured than in traps baited with ipsdienol alone. This result suggests that the compound is potentially repellent and interrupts the response of beetles to their aggregation pheromone, and is consistent with previous reports of its inhibition of aggregation behaviour in other bark beetles.

We describe aspects of the life history of Erynnis propertius (Scudder and Burgess) (Lepidoptera: Hesperiidae) by examining several populations over multiple years. We focused on peripheral populations of this species because they are isolated, are threatened by habitat loss, and may play an important role in driving poleward range expansion under increasing regional temperature. Our findings show that the annual larval growth rate does not vary directly with temperature, adult flight phenology and the timing of key resources respond to average daytime temperatures in spring, and population-density patterns among sites are robust over years across a broad region near the species' northern range limit. In addition, we provide descriptions of all larval instars for this species. This fundamental information about the biology, timing, and abundance of this species will facilitate further experimental study and improved assessment of its conservation status.

Colonization of a tree by bark beetles and their symbionts creates a new habitat for a diverse assemblage of arthropods, including competing herbivores, xylophages, fungivores, saprophages, predators, and parasitoids. Understanding these assemblages is important for evaluating nontarget effects of various management tactics and for subsequently evaluating how changes in climate, the presence of invasive species, and altered forestry practices and land-use tenure may affect biodiversity. We characterized the assemblage of hymenopterans attracted to logs of ponderosa pine (Pinus ponderosa C. Lawson (Pinaceae)) colonized by the bark beetle Ips pini (Say) and its microbial symbionts. In one experiment, the composition and relative abundances of species arriving at hosts colonized by I. pini, and possible sources of attraction, were determined. Treatments consisted of a log containing I. pini with its natural complement of microorganisms, a log alone, and a blank control. A second experiment was carried out to determine whether or not Hymenoptera were attracted to microbial symbionts of I. pini. Treatments consisted of a blank control, a log alone, a log containing I. pini with its natural complement of microorganisms, either Ophiostoma ips, Burkholderia sp., or Pichia scolyti, and a log inoculated with a combination of these three microorganisms. Over 2 years, 5163 Hymenoptera were captured, of which over 98% were parasitoids. Braconidae, Platygastridae, Encyrtidae, Pteromalidae, and Ichneumonidae were the most abundant. Seven known species of bark beetle parasitoids (all Pteromalidae) were captured. However, parasitoids of Diptera, Lepidoptera, Hymenoptera, and non-wood-boring Coleoptera were also common. Nineteen species showed preferential attraction to host plants infested with I. pini and its complement of microorganisms, host plants inoculated with I. pini microbial symbionts, or host plants alone. Interestingly, many of these species were parasitoids of phytophagous, fungivorous, and saprophytic insects rather than of bark beetles themselves. These results suggest that a diverse assemblage of natural enemies that attack various feeding guilds within a common habitat exploit common olfactory cues.