The hemlock looper, Lambdina fiscellaria, is one of the most economically damaging defoliators of North American coniferous forests. Basic information on its reproductive biology is an essential prerequisite for understanding its population dynamics. Realized fecundity for the two major hemlock looper ecotypes varies along a latitudinal gradient in eastern Canada, but their daily oviposition patterns are similar. Mated females lay eggs after a short pre-oviposition period, with daily oviposition peaking in the first 3 days. Mated females lay significantly more eggs than unmated ones, the latter laying their eggs more evenly throughout their life. Eggs deposited early in the oviposition period are larger than those deposited near the end. This may influence over-winter survival of hemlock loopers and should be considered in studies to better understand the population dynamics and improve management of this defoliator.

In a trapping study conducted in the experimental research forest of the Tohoku Research Center, Morioka, Honshu, Japan, we investigated the effect of heterospecific pheromone on pheromonal attraction of male Japanese gypsy moth, Lymantria disparjaponica (Motschulsky), and male pink gypsy moth, L. mathura Moore (Lepidoptera: Noctuidae: Lymantriinae). Traps baited with synthetic pheromone of L. d. japonica ((7R,8S)-cis-7,8-epoxy-2-methyloctadecane = (+)-disparlure (100 µg)) or L. mathura ((9R,10S,3Z,6Z)-cis-9,10-epoxynonadecadiene = (+)-mathuralure (20 µg) and (9S,10R,3Z,6Z)-cis-9,10-epoxynonadecadiene = (−)-mathuralure (80 µg)) attracted male L. d. japonica or L. mathura, respectively. Traps baited with synthetic pheromone of both species captured significantly fewer male L. mathura than traps baited solely with synthetic L. mathura pheromone. Numbers of male L. d. japonica captured in traps baited with (+)-disparlure were unaffected by the addition of L. mathura pheromone. (+)-Disparlure is a behavioral antagonist to pheromonal attraction of male L. mathura, whereas male L. d. japonica are indifferent to the presence of synthetic L. mathura pheromone.

Two new ichneumonid species in the genus Jezarotes Uchida are described from Korea: J. dentatusn. sp. and J. tetragonisn. sp. Photographs of diagnostic characters of the two new species, a key to the six known species, and a diagnosis of the genus are provided.

Fecundity and biomass of nine species of aphids (Hemiptera: Aphididae) feeding on six species of plants were compared to assess whether the two measures are equally effective for quantifying aphid performance. Performance was quantified by measuring both fecundity (the number of offspring born over a defined interval) and biomass (the dry mass of offspring produced) using three variables expected to affect performance: host-plant genotype, aphid genotype, and aphid density. The efficacy of the performance parameters was assessed by comparing their ability to discriminate among treatments for the three variables. Biomass usually provided a more effective measure of performance than fecundity, but for one aphid species, fecundity was more effective than biomass. Biomass of offspring is the preferred measure of performance, but biomass and fecundity should both be recorded whenever practical.

Pseudips mexicanus (Hopkins) is a secondary bark beetle native to western North and Central America that attacks most species of pine (Pinus L. (Pinaceae)) within its range. A pair of life-history studies examined P. mexicanus in other host species, but until now, no work has been conducted on lodgepole pine (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson). Pseudips mexicanus in lodgepole pine was found to be polygynous. Galleries were shorter, offspring smaller, and the eggs laid per niche and the potential progeny fewer than in populations from California and Guatemala. Development from the time of female attack to emergence of adult offspring took less than 50 days at 26.5 °C, and the accumulated heat required to complete the life cycle was determined to be 889.2 degree days above 8.5 °C, indicating that in the northern portion of its range P. mexicanus is univoltine. Determination of these life-history traits will facilitate study of interactions between P. mexicanus and other bark beetle associates in lodgepole pine.

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.

Larvae of the gall-inducing moth Gnorimoschema gallaesolidaginis (Riley) (Lepidoptera: Gelechiidae) attack ramets of Solidago altissima L. and S. gigantea Aiton (Asteraceae), initiating stem galls early in ramet growth. We examined the relationship between ramet size (as an indicator of plant vigour) and galling rate over 3 years at a field site in Toronto, Ontario, Canada. We marked Solidago ramets along line transects, measured their stem diameter, and recorded their fate (galled or ungalled) during the season. For S. altissima, galls were numerous enough for analysis in 2 years, and the frequency of galling increased monotonically with ramet stem diameter in both years. For S. gigantea, galls were numerous enough for analysis in all 3 years, but attack rate - stem diameter relationships were complex. In 2004 the galling frequency peaked at intermediate stem diameter, but in 2005 the galling frequency increased monotonically with stem diameter (and in 2006 the nonsignificant trend was similar). Overall, our data are most consistent with the plant-vigour hypothesis, but the 2004 data for S. gigantea lend some support to the suggestion that herbivore attack might sometimes be most intense on intermediate-sized modules.

The perpetuation of symbiotic associations between bark beetles (Coleoptera: Curculionidae: Scolytinae) and ophiostomatoid fungi requires the consistent transport of fungi by successive beetle generations to new host trees. We used scanning electron microscopy and culture methods to investigate fungal transport by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins. MPB transports its two main fungal associates, Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx, in sac-like mycangia on the maxillary cardines as well as on the exoskeleton. Although spores of both species of fungi were observed on MPB exoskeletons, often in pits, O. montium spores were generally more abundant than G. clavigera spores. However, a general scarcity of spores of either species on MPB exoskeletons compared with numbers on scolytines that lack sac-like mycangia indicates that fungal transport exteriorly on MPBs is incidental rather than adaptive. Conidia were the dominant spore type transported regardless of location or species; however, our results suggest that once acquired in mycangia, conidia may reproduce in a yeast-like form and even produce hypha-like strands and compact conidiophore-like structures. Fungi that propagate in mycangia may provide beetles with a continual source of inocula during the extended egg-laying period.

Host preferences and reproductive performance of the juniper bark beetle, Phloeosinus bicolor (Brulle), on logs from different parts of the bole of indigenous Cupressus sempervirens L. (Cupressaceae) and exotic C. arizonica Greene and C. sempervirens var. atlantica (Gaussen) Silba were experimentally studied in the field and laboratory in Tunisia. Attack densities were around 1/dm2 in the field, fecundity was 10 – 25 eggs per female’s gallery, with a sex ratio close to 1. There was no effect of cypress taxon or log category on host selection or attack parameters (attack density, density of systems, density of galleries, rate of successful attacks), although values for C. sempervirens tended to be higher than those for C. arizonica. Reproductive performance (gallery length and fecundity) was highest in C. arizonica and lowest in C. sempervirens var. atlantica, with C. sempervirens in an intermediate position; egg densities did not differ. Gallery length and fecundity showed a significant linear correlation but were lower in C. sempervirens var. atlantica than in the other two taxa. Thus there seems to be no relationship between host preference and host suitability in P. bicolor: its ability to choose and oviposit in various cypress taxa fits with its polyphagous status.

Grasshoppers (Orthoptera: Acrididae) are hosts to many internal parasites, including nematodes. However, the effects of nematode parasitism on grasshopper fecundity and how these effects vary with population density are unclear. I report on the fecundity of Melanoplus dawsoni (Scudder) infected and uninfected with mermithid nematodes in northern Wisconsin from 2002 to 2005. Each year grasshoppers were stocked over a range of five densities into field enclosures. Fecundity, body size, and nematode prevalence were measured for female grasshoppers. Nematode prevalence was moderately high, ranging from 15% in 2003 to 37% in 2004. Fecundity was measured by examining grasshopper reproductive tracts. On average, past reproductive activity (number of eggs laid) and current reproductive activity (number of eggs forming) of parasitized grasshoppers were reduced by 40% and 48%, respectively. Interestingly, the reduction in fecundity was less for parasitized females in the low-density treatments (25%-50% of field density) than for those in the moderate- and high-density treatments, suggesting that grasshoppers can compensate somewhat for negative effects of parasites on fecundity when per-capita resources are high. No difference in hind-femur length between parasitized and unparasitized females was observed, indicating that nematode infection did not affect grasshopper body size.

Kleptoparasitism (one organism stealing prey from another) is especially common in birds. Avian kleptoparasites should be especially likely to target insects such as digger wasps (Hymenoptera: Sphecidae) that occur in large aggregations and repeatedly deliver large prey to the same nesting site. We document kleptoparasitism of digger wasps (Sphex pensylvanicus L.) by sparrows (Passer domesticus (L.)) and catbirds (Dumetella carolinensis (L.)). During summer 2008, we observed 697 wasp provisioning attempts (return of a prey-laden wasp to a marked nesting site) in a mown field. One-third (244/697) of attempts were intercepted by birds, primarily sparrows, which increased their hourly total number and hourly number of successful attacks per capita. Wasps maintained a consistent rate of successful provisioning attempts but may not have been able to do so indefinitely. Energetic costs related to kleptoparasitism may exert strong selection pressures on affected digger wasps.

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.

We studied the effects of forest height and forest gap on assemblages of flying beetles in an American beech (Fagus grandifolia Ehrh. (Fagaceae) – sugar maple (Acer saccharum Marsh. (Aceraceae)) forest in Quebec. From June until August of 2005, beetles were collected in Lindgren funnel traps placed in the canopy (20–25 m height) and upper understorey (3–5 m height) in proximity to five forest gaps (15–30 m in diameter) (at the edge of the forest opening or within the closed-canopy forest). We collected 1852 beetles representing 38 families and 172 species. Based on rarefaction curves, species richness was significantly higher in the canopy than in the upper understorey. Nonmetric multidimensional scaling ordination revealed a change in species composition in relation to vertical stratification but not to the forest gaps. Our findings confirmed the importance of the vertical forest gradient to overall diversity of forest coleopterans.

Periodic sweep-net sampling and capitula sampling were conducted between April and October 2007 to determine the seasonal phenology of Urophora quadrifasciata (Meigen) (Diptera: Tephritidae) on spotted knapweed, Centaurea stoebe subsp. micranthos (Gugler) Hayek (Asteraceae), in the Arkansas Ozarks of the United States of America. Urophora quadrifasciata produces up to three generations in Arkansas, rather than being bivoltine as in the northern United States of America. The first, second, and third generations of U. quadrifasciata reached peak adult numbers around 26 May, 29 June, and 27 July, respectively. Males tended to emerge earlier than females but the female:male ratio was approximately 1:1 for most of the season. The majority of the offspring of the three generations emerged between June and October, while approximately 38% entered diapause and emerged as adults in April-June of the following year; 3.4 ± 0.1 (mean ± SE) (range 1–12) flies emerged from each infested capitulum. The absence of other, competing knapweed biological control agents as well as very low rates of parasitism, mild weather conditions, and a longer knapweed growing season likely contributed to the adaptation and establishment of U. quadrifasciata on spotted knapweed in Arkansas.

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 Brullè, 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.

The only known Canadian population of the white flower moth, Schinia bimatris Harvey, a federally listed endangered species, was rediscovered in 2003 in the dune area of Spruce Woods Provincial Park and Canadian Forces Base Shilo in Manitoba. Little is known about the biology or habitat requirements of this moth in North America. The dune area in Manitoba was surveyed for adult and immature stages of the species during July 2007 using light traps and daytime visual searches. A detailed vegetation survey was also completed in areas where moths were active. Whereas individuals caught in light traps were predominantly males, both females and males were observed to be very active during daylight hours. This is the first record of diurnal activity of the white flower moth in Canada. Adults were observed flying above dune crests and also resting on vegetation between open dunes. Although the current population appears robust, given the number of adults observed, a previous population approximation of up to 5000 individuals may be an overestimate because sand-dune habitat is limited. We were unable to locate immature stages or determine which host plant(s) were utilized by larvae.

A simple and inexpensive non-destructive trap to catch insects as they ascend tree boles is described. The trap was tested in a capture–mark–recapture experiment on the Warren root collar weevil, Hylobius warreni Wood. A high percentage (77%) of marked H. warreni were recaptured at least once during a 12-day period and 54% were recaptured more than once, with one weevil recaptured eight times.

We investigated parasitism of the purple loosestrife beetle, Neogalerucella calmariensis (L.) (Coleoptera: Chrysomelidae), an introduced weed biological control agent, at 13 sites in eastern Ontario and western Quebec, Canada. Beetles were parasitized by gregarine gut protozoans (Apicomplexa: Eugregarinida) and much less commonly by nematodes (Nematoda: probably Mermithidae) and ectoparasitic mites (Acari: Erythraeidae). Female beetles had more gregarines than did males and the gregarine load was marginally higher in individuals from the original release sites than in individuals from recently colonized sites. Despite its overall success as a biological control agent, N. calmariensis harbours a substantial parasite load.

The effects of the horticultural oil Purespray Green on oviposition behaviour and egg development in the obliquebanded leafroller, Choristoneura rosaceana (Harris), were investigated through dual-choice and no-choice bioassays and topical applications of oil to developing eggs. A residual 2% (v/v) oil spray on wax-paper and apple-leaf substrates significantly reduced both the number of eggs laid and egg survival in no-choice assays; however, this effect diminished 3 days after treatment. In dual-choice assays, females laid significantly fewer eggs on oil-treated apple leaves than on control leaves, but laid equal numbers of eggs on the oil-treated wax paper and the untreated wax-paper controls. Topical application of oil caused significant dose-dependent mortality of both newly laid eggs and eggs just before hatch, and these two egg stages were equally susceptible to the oil. Topical application of 2% oil caused >99% egg mortality. Our data indicate that gravid female C. rosaceana can assess and reject oil-sprayed surfaces and that the oil can kill eggs through both contact toxicity and suffocation. These characteristics suggest that highly purified horticultural oils like Purespray Green could play a role in an integrated pest management program for this important pest species.

A 2-year field study was conducted using sentinel traps to determine the seasonal distribution of the egg parasitoid (Hymenoptera) complex attacking hemlock looper, Lambdina fiscellaria (Guenée), throughout eastern Quebec and western Newfoundland. Hemlock looper populations remained low in all areas over the course of the study. Parasitism of eggs in sentinel traps was generally lower in fall than in spring. Trichogramma Westwood (Trichogrammatidae) as well as Telenomus flavotibiae Pelletier and an unidentified species of Telenomus Haliday (Scelionidae) only parasitized eggs in the fall. Telenomus droozi Muesebeck only parasitized eggs in the spring, whereas T. coloradensis Crawford attacked eggs during both fall and spring. Telenomus coloradensis was the most abundant parasitoid species collected and was far more abundant in spring than in fall collections.