A new species of gall midge, Stenodiplosis phragmicola Sinclair and Ahee (Diptera: Cecidomyiidae), is described. The host plant, Phragmites australis (Cavanilles) Trinius ex Steudel (Poaceae), is a tall, widely distributed emergent aquatic macrophyte. An introduced subspecies of the plant is considered invasive in North America (although a native subspecies also occurs). Insect specimens were collected during September 2010 and 2011 from the florets of common reed at 12 sites around Peterborough, Ontario, Canada. Preliminary data on ecological interactions between the plant and the insect are presented. Out of 2400 florets sampled, 9.5% were host to larvae of S. phragmicola. Three sites had much higher rates of infestation, with between 20% and 30% florets, and up to 100% of sampled shoots containing fly larvae. The largest stands in the sample all hosted fly populations and there was a positive association between the reproductive output of P. australis stands (measured as the average inflorescence mass per stand) and the proportion of shoots per stand containing larvae. The occurrence of S. phragmicola on the native subspecies of P. australis is also documented. Insects that consume reproductive structures of the common reed have not previously been reported from the plant's introduced range in North America.

Larval morphology of the monogeneric subfamily Coptotominae (Coleoptera: Dytiscidae) is described and illustrated in detail, with particular emphasis on morphometry and chaetotaxy. Larvae of Coptotomus Say are unique within Dytiscidae in the presence of tracheal gills on the abdominal segments I–VI, a short bifid horn or nasale in instar I, long spinulae on the urogomphus in instar I, and rows of natatory setae on both the internal and external margins of the urogomphus in instars II and III. A cladistic analysis based on 125 larval characters sampled among representatives of other dytiscid subfamilies supports a sister-group relationship between Coptotominae and Laccophilinae based on the shared absence of setae LA10 and LA12 on the second labial palpomere and of pore ABc on the abdominal segment VIII. The clade Coptotominae + Laccophilinae resolved as sister to Lancetinae, all three subfamilies sharing the presence of an unusually low number of lamellae clypeales in the first instar (a condition called four-peg-pattern), postulated to have evolved secondarily within Dytiscidae.

The styli, often called the aristae, of the antennae of adult Sepedon fuscipennis Loew (Diptera: Sciomyzidae) are shown to possess mechanosensilla, the number and arrangement of which differ between the sexes. It is suggested that the mechanosensilla provide sensory input to the female regarding the touching, or appositioning, of her styli by the male with his forelegs during copulation. Among the Sciomyzidae, S.fuscipennis males are unique in appositioning the antennae of the female during mating. Large clusters of pollen found on the styli of both sexes suggest that mechanosensilla and chemosensilla also provide sensory information about potential sources of food such as nectar (i.e., carbohydrates).

The vector competence (VC) of Aedes aegypti (Linnaeus) (Diptera: Culicidae) varies geographically and is affected by both genetic and environmental factors. Understanding the molecular mechanisms that influence VC may help develop novel control strategies. The selection of susceptible and refractory strains is the first step in this process. We collected immature A. aegypti in the field and established strains that were susceptible and refractory to Dengue-2 virus by isofamily selection through several generations. Infection was detected by immunofluorescence of head or midgut tissues to determine infection barriers and the % of VC by tissue. We selected three strains: Susceptible (Cali-S) (96.4% susceptible at F19), Refractory with a midgut escape barrier (Cali-MEB) (44.1% refractory at F15), and Refractory with a midgut infection barrier (Cali-MIB) (40% refractory at F16). The effects of the infection were measured using Kaplan–Meier survival rates over the first seven generations. All selected strains showed a similar decrease in survival and in the number of eggs laid/female through the seven generations, suggesting that changes were a result of the selection process rather than the virus infection. The results of this study suggest that VC is associated with multiple genes, which have additive effects on susceptibility.

Seasonal patterns of abundance and population variability were determined for Macrosiphum euphorbiae (Thomas), Myzus persicae (Sulzer), and Aphis nasturtii (Kaltenbach) (Hemiptera: Aphididae) in potato plots from weekly samples for 28 years. All species showed a single annual peak, but arrived and reached peak abundance at different times. Population variability (PV, a proportion between 0 and 1) for the week of peak abundance was close to that of other sample weeks and mean seasonal abundance. Based on mid-season abundance, PV of 0.76 for M. persicae differed significantly from 0.80 for A. nasturtii, as well as from 0.59 for M. euphorbiae. A weekly time scale for abundance, initiated at an early stage of plant growth, produced slightly different estimates of PV early and late in the season than a scale centred on peak abundance for each species. PV at the time of invasion differed from estimates for the rest of the summer. The annual abundance used to estimate PV was best determined in the context of aphid life history. Nevertheless, PV provided a robust and precise metric for comparing population variability among the three species, regardless of their seasonal patterns of abundance.

The present study was designed to investigate the influence of mate choice in terms of age on reproductive performance and offspring attributes of parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae). Age-based mate choice was most evident in the middle-aged adults. Results revealed that middle-aged males and females were significantly preferred as mates by their middle-aged counterparts. Younger and older females did not show any preference for males of any age group. On the other hand, younger males showed a bias against old females, while older ones did not show any age-based preference for mates. Both fecundity and percent egg viability were significantly influenced by female and male age, respectively. Fecundity was highest in middle-aged females followed by young- and old-aged ones, with similar trend observed in relation to male age effects on egg viability. The development and survival of immature stages borne out of mate choice decisions of adults was influenced by mother's age. Offspring of middle-aged females developed fastest and survived longer than those of younger and older ones.

Variation in the seasonal occurrence of asexual and sexual phenotypes of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) is quantified for a local population in southern Manitoba, Canada. To survive winter, summer asexual generations must produce a sexual generation in a timely way at the end of the season, so that females can lay overwintering eggs. This transition is controlled by day length, which varies in a fixed seasonal pattern with latitude, and the local pattern of day length selects for an appropriate photoperiodic response. Substantial variation in the timing of production of males and mating females occurs among locally collected genotypes. Some of the variation is due to the arrival of long-distance dispersers (1000 km or more), and some is consistent with shorter but still long-distance dispersal. Some of the variation is due to year-to-year changes in late summer temperature. The critical day length in nature, which corresponds to critical photoperiod, increases as the average temperature decreases. This temperature modulation is adaptive because it allows many genotypes to produce some sexual phenotypes before the end of the season, although their photoperiodic responses are characteristic of long-distance dispersers and inappropriate to local day lengths.

Pupae of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), from Kennewick and Roslyn in Washington State, United States of America, were subjected to different soil and air moisture conditions to test the hypotheses that adult emergence from dry and moist soil is similar and is greater and occurs earlier at high than low relative humidities (RHs). Adult fly emergence from 0–57% saturated loam soil did not differ in Kennewick (64.8–75.1%) and Roslyn (81.7–86.6%) populations. Emergence did not occur from 76% saturated loam soil. In a RH experiment using dry soil, emergence of Kennewick flies was highest at 97% RH (76.8%), intermediate at 12–74% RH (66.4–69.6%), and lowest at 3% RH (58.0%). Emergence of Roslyn flies was higher at 97% RH (85.6%) than 3% (69.2%) and 12% RH (74.3%), but it did not differ from that at 33% (76.9%) and 74% RH (79.4%). Flies emerged ∼2–3 days earlier at 97% RH than at 3–12% RH. An unnaturally low RH of 3% caused more flies to be deformed than higher RHs. High emergence of R. indifferens in dry and moist conditions likely contributes to its presence in a wide range of native and nonnative habitats.

Within the family Cerambycidae (Coleoptera), (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol) and (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate) have been shown to attract several species in the subfamily Lamiinae. However, it is not yet clear whether beetles within the subfamily actually produce these compounds as pheromones or rather respond to them as kairomones. We report here that male Astyleiopus variegatus (Haldeman) produce both fuscumol and fuscumol acetate, suggesting that the compounds are indeed pheromones for this species. We also determined that the absolute configurations of these compounds are (S)-fuscumol and (S)-fuscumol acetate by synthesis of both enantiomers of each.

Site fidelity and long-distance homing are known to occur in nesting female Hymenoptera. We report here on the site fidelity and homing ability in males of five species of scoliid wasps (Hymenoptera: Scoliidae), a group whose females do not make nests but are ectoparasitoids of scarabaeid beetles (Coleoptera: Scarabaeoidea). The males of these wasp species patrol female emergence areas searching for mates. Based on mark-recapture data, we found that between 40% and 100% of marked males left the release area and travelled 50–800 m from the point of capture returning to their original patrol area. We discuss the adaptive significance of site fidelity and homing behaviour in Scoliidae, and propose hypotheses about the evolution of the homing behaviour in Hymenoptera. The homing ability of these primitive Aculeata may represent a case of convergent evolution with other Hymenoptera in which males patrol emergence areas in search of females. Additionally, this homing ability may serve as a preadaptation for the evolution of nest-provisioning and nesting habits in Hymenoptera.

Specimens of Chrysodeixis chalcites (Esper) (Lepidoptera: Noctuidae) have been found in different municipalities in southwestern Ontario, Canada since 2008. This nonnative species occurs in tomato and green bean crops where it has the potential of becoming an important insect pest.

We used field surveys in central New Brunswick, Canada to establish efficient sampling procedures for evaluating densities of balsam gall midge, Paradiplosis tumifex Gagné (Diptera: Cecidomyiidae), and its associated damage in balsam fir, Abies balsamea (Linnaeus) Miller, Christmas trees. Infestation was greater in larger trees than smaller trees and in mid-crown and upper-crown branches than in the lower crown. However, the relationship between gallmaker infestation and site, height class, and crown level was highly complex and may involve covariation of shoot length with height class and crown level. As a result, patterns in infestation did not lend themselves to simple interpretation. This complexity highlights the need to find sampling units that provide simpler but reasonably accurate predictors of gallmaker impact at the whole-tree scale. We identified such a sampling unit: gallmaker density in first-order current-year shoots of a mid-crown branch explained 81% of the variance in total infestation among trees.