Conservation of biodiversity is growing in interest, and wetlands are disappearing at an alarming rate, so understanding how communities are assembled and how interactions among species and ecosystems influence evolution is critical to the management of threatened habitats. We compared diversity and assemblages of peatland Diptera within and between ecoregions in Québec, Canada. We then determined the phylogenetic structure of peatland Diptera communities and how the structure differed with spatial scale (trap, site, ecoregion). Finally, we tested alpha and beta diversity along environmental and spatial gradients to determine which processes influence Diptera communities and diversity. Bogs across the three ecoregions support similar abundance, species richness, and functional diversity. We found that the major forces structuring Diptera assemblages in bogs across Québec are stochastic processes such as dispersal limitations. However, those random patterns change to clustering when anthropogenic disturbances modify the landscape. Assembly rules are mostly dictated by patch and landscape parameters specific to each ecoregion affecting dispersal and establishment between sites. Conservation of mobile organisms in habitats such as bogs will depend on conservation plans focusing on both patch quality and surrounding landscape, and that different conservation strategies need to be applied in different ecoregions.

The necrocolous Coleoptera (attracted to carrion) are important to maintain balance in insect communities and in the recycling of soil nutrients; however, there is scarce data on the species that occur in Agave tequilana Weber (Asparagaceae) fields. The diversity patterns of beetles (Coleoptera: Scarabaeidae, Silphidae, and Trogidae) dwelling in 2–4-year-old A. tequilana plots were established by sampling specimens from May to November 2016. In total, 5509 individuals of 23 species were collected. The highest species diversity was found in Magdalena Municipality, followed by the Arandas and Tequila municipalities (Jalisco, Mexico), with significant differences in abundance among municipalities and crop age. The variability in Magdalena and Tequila assemblages was associated with the temperature, while in Arandas it was attributed to the precipitation. The beetle species diversity, species replacement, and dominance in different municipalities are the result of changes in habitat, the interaction of environmental variables, distribution affinities of species, and agronomic practices in A. tequilana fields.

Lygus Hahn (Hemiptera: Miridae) feeding in faba beans (Vicia faba Linnaeus (Fabaceae)) often results in a reduction in seed quality and economic losses. Traditionally, seed damage is assessed subjectively through visual examination by a trained individual, but the use of non-destructive imaging to evaluate seed quality is gaining momentum. The focus of this study was to determine the ability to quantify Lygus species damage in faba bean using shortwave-infrared imaging and two analysis techniques: (1) spectral angle mapper and (2) simple reflectance indices. Seed samples were visually assessed for damage before imaging in 242 wavebands between 980 and 2500 nm. Four spectral intervals, involving 102 wavebands, were identified as optimal for the detection of seed damage using spectral angle mapper. A strong relationship was obtained between the area of seed damage derived using spectral angle mapper and visually (R2 = 0.95). Seed damage derived by thresholding of two normalised faba bean damage indices involving reflectance at 1086 and 1313 nm and 2218 and 2342 nm also showed a strong relationship with the visual assessment (R2 = 0.92). The two image analysis techniques provided similar results. The study suggests that imaging in the shortwave-infrared wavelengths and the derivation of simple indices can effectively quantify faba bean damage by Lygus feeding.

Monarch butterflies (Danaus plexippus (Linnaeus) (Lepidoptera: Nymphalidae)) in eastern North America migrate each year from overwintering areas in Mexico to cover a large breeding distribution across the United States of America and southern Canada. In 2012, monarch butterflies migrated well beyond their usual range, resulting in an extended breeding distribution compared to typical years. We used stable isotope (δ2H, δ13C) measurements in wing chitin to determine the area of natal origin of these butterflies. Most monarch butterflies collected in May, June, and July from Manitoba and Alberta, Canada had natal origins in the North American Midwest. Monarch butterflies collected in Alberta and Saskatchewan, Canada in August and September had local natal origins indicating successful recruitment of offspring from colonising individuals. However, it is unknown whether these offspring migrated successfully to overwintering areas. Our work highlights the ability of monarch butterflies to colonise distant breeding areas and demonstrates how stable isotopes can be used to understand the dynamics of range-edge populations.

Many studies have investigated plant-pollinator interactions using visit records of insects contacting floral reproductive organs. However, these studies may not reflect the effectiveness of visits, since factors such as visitor behaviour and the composition of pollen on their bodies may influence conspecific pollen transfer required for fertilisation in plants. Here we study how pollen transport to a generalist wildflower, Camassia quamash (Pursh) Greene (Asparagaceae), is influenced by the behaviour and body pollen of five functional visitor groups (Andrena Fabricius (Hymenoptera: Andrenidae)/Halictidae (Hymenoptera), Apis mellifera Linnaeus (Hymenoptera: Apidae), Bombus Latreille (Hymenoptera: Apidae), Osmia Panzer (Hymenoptera: Megachilidae), and Syrphidae (Diptera). We found that functional visitor groups differed in their behaviour (Bombus and Osmia were legitimate visitors, contacting both anthers and stigmas) and in the amount of conspecific pollen on their bodies (A. mellifera had the highest levels and Andrena/Halictidae the lowest). Conspecific pollen receipt by C. quamash stigmas was high (>80%), and best explained by visitor behaviour rather than the proportion of visitors with high amounts of conspecific body pollen. Our findings highlight the utility of pollen analyses for understanding pollinator effectiveness.

Female Asian longhorned beetles, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), were observed rhythmically extruding their genitalia, resembling the calling behaviour observed in other species of Cerambycidae. We demonstrate that only female A. glabripennis adults perform this behaviour, which lasts up to nearly six minutes and typically includes two types: (1) extrusion of only the tip of genitalia and (2) genitalia fully extruded and deflexed. The frequency and duration of this behaviour are affected by temperature and posteclosion feeding experience, but do not vary with the female age. Anoplophora glabripennis adult males were observed flexing their abdomen downward while extruding their genitalia but only when exposed to the odour of live females with host twigs. In Y-tube olfactometer assays, the volatiles from live females or female genital extracts both attracted more males than the volatiles from live males, male genital extracts, or solvent controls, all in the presence of host-plant volatiles. These findings indicate that A. glabripennis females may produce volatile sexual attractants in association with genital extrusion.

It is known that diapause-inducing effect of ultra-long (16–18 hours and longer) nights on insects with a facultative winter diapause is often weaker than that of “natural” long (usually 10–14 hours) nights. The weak diapause-inducing effect of ultra-long nights can be explained, in particular, in the frames of the external coincidence model of photoperiodic time measurement with a circadian oscillator, which damps under ultra-long nights. Based on this model, it can be expected that (1) the first ultra-long night would have the same diapause-inducing effect as natural long night because the damping of the oscillator will not manifest itself before the next light–dark cycle and (2) the diapause-inducing effect would decrease with the increase in the number of succeeding ultra-long nights. However, these hypotheses have never been tested with any insect species. We investigated progeny diapause-inducing effect of single and multiple nights of different lengths on Trichogramma telengai Sorokina (Hymenoptera: Trichogrammatidae) pupae and adult females. The results of the study support the external coincidence model with a damping circadian oscillator and suggest that in T. telengai the oscillator damps out after one or two cycles.

Enaphalodes rufulus (Haldeman) (red oak borer; Coleoptera: Cerambycidae) is a native wood borer that colonises and develops in oaks (Quercus Linnaeus; Fagaceae) across southeastern Canada and the eastern United States of America. It is rarely considered a pest because it normally occurs at low population density levels in stressed or dying oak trees. In the late 1990s and early 2000s there was a large, historically unique outbreak of E. rufulus in the Ozark mountains of Arkansas and Missouri, United States of America. This outbreak provided an opportunity to investigate within-tree spatial distribution of attacks during unusually high insect population levels. Fifty trees from northern Arkansas were felled and destructively sampled. The locations of attack sites by female E. rufulus were standardised across varying heights and diameters for comparison across trees. Attack sites showed a significant clustered pattern within trees. Attack sites were aggregated towards the lower and middle bole, and on the south-facing side of trees. This pattern has been seen in other insects, including wood borers, and is potentially related to differences in temperature. These patterns of ovipositional behaviour in outbreak situations have implications for E. rufulus resource partitioning and facultative intraguild predation among larvae.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a serious invasive pest of many agricultural and horticultural crops in Canada and the United States of America. To mitigate economic loss for growers, effective management options for H. halys are needed. We evaluated the efficacy of 12 insecticides (Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Cordycipitaceae), boric acid, chlorpyrifos, clothianidin, flupryadifurone, λ-cyhalothrin, malathion, novaluron, sulfoxaflor, thiamethoxam, thiamethoxam + λ-cyhalothrin, and thiamethoxam + novaluron) currently used or with potential for H. halys management by determining their direct and residual contact toxicity to H. halys nymphs. Each insecticide was tested at its Canadian label rate and half and twice that rate. With the exception of chlorpyrifos, nymph mortality was low (< 40%) following direct or residual contact exposure to all insecticides and rates. All surviving nymphs were severely affected (i.e., knocked down) by direct and residual contact exposure to neonicotinoids, while approximately 66% of nymphs were severely affected following exposure to sulfloxaflor residues at label and twice label rate. However, few nymphs were severely affected by all other insecticides and rates. Overall, our results suggest that H. halys is not susceptible to many insecticides at current label rates for Canada. More research is needed to identify efficacious insecticides for H. halys.

In 2012, an unexpected outbreak of Lambdina fiscellaria (Guenée) (Lepidoptera: Geometridae) occurred in the Laurentian Mountains, Québec, Canada, known for its harsh climate. We wondered whether the eggs were sufficiently cold hardy to survive there and, if so, how long this outbreak would last. Therefore, we assessed the capacity of the eggs to supercool, to tolerate short exposures to low sub-zero temperatures, or to successfully overwinter in the field. The same assays were performed with eggs from the island of Newfoundland, Newfoundland and Labrador, Canada. The mean supercooling point of eggs from the two populations increased from −40.2 °C in mid-February to −33.7 °C in mid-May. These eggs may also die at sub-zero temperatures above their supercooling point, depending on exposure durations. In the fall of 2012 when eggs were put out in the field, < 10% survived in the Laurentian Mountains, whereas > 70% survived further south. In the spring of 2013, no parasitism was detected in the population. However, the two cold waves that swept across the Laurentian Mountains the preceding winter were likely responsible for the collapse of the population. This study demonstrates that L. fiscellaria eggs may succumb to sub-zero temperatures above their supercooling point under field conditions.

Life history traits, such as clutch size, egg size (weight), developmental periods of eggs, and female body (abdomen) size, were investigated in Japanese species of the genus Elasmostethus Fieber (Hemiptera: Acanthosomatidae): E. amabilis Yamamoto, E. brevis Lindberg, E. humeralis Jakovlev, E. interstinctus (Linnaeus), E. kerzhneri Yamamoto, and E. nubilus (Dallas). With the exception of clutch size, significant differences were observed in the traits among species. No species exhibited maternal care of eggs. These data form a solid basis for future comparative analyses in the family Acanthosomatidae, which contains both subsocial and asocial species.

Larvae of the swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), rely on environmental cues to initiate the diapause programme. This facultative diapause strategy, which provides opportunities for both bet hedging and multivoltinism, likely contributed to the successful colonisation and spread of this invasive pest in North America. Population diapause incidence is variable even under relatively stable conditions (especially at the critical day length), yet the mechanisms influencing the developmental trajectory of individuals under such conditions are unknown. Here we approach the non-environmental (i.e., heritable) controls of this variation by comparing diapause frequencies within and among full-sibling swede midge families reared in one of two stable environments. Under warm, long-day conditions > 99% of swede midges pupated directly, while 86% of swede midges entered diapause under cool, short-day conditions. In the latter condition, most families exhibited mixed developmental trajectories (ranging from 36% to 96% diapause). This developmental variation among siblings indicates that the diapause induction threshold does not follow simple Mendelian inheritance with complete dominance for a particular allele, but may follow incomplete dominance or a more complex heredity. Alternatively, within-family diapause variation may result from maternal bet hedging or factors such as maternal age or larval nutrition.

Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), also known as the citrus leafminer, is a serious pest in Citrus Linnaeus (Rutaceae) nurseries in Iran. Few studies have been performed on the life history of this pest on different citrus hosts. In this work, the infestation rate and biological aspects of P. citrella were investigated using four citrus hosts: Valencia orange (Citrus sinensis (Linnaeus) Osbeck), trifoliate orange (Poncirus trifoliata (Linnaeus) Rafinesque), grapefruit (Citrus paradisi Macfadyen), and sweet lemon (Citrus aurantifolia Swingle). Moths preferred laying eggs on leaves with a width ranging from 1–2 cm, and the highest oviposition was observed on the Valencia orange (51.2 eggs/female). The numbers of pupae and infested leaves were significantly higher on C. sinensis and C. aurantifolia. The entire developmental period of the immature stages was 13.8 and 15.4 days in C. aurantifolia and C. sinensis, respectively, while it increased to 21.8 and 24.7 days in C. paradisi and P. trifoliata. The rate of mortality of the immature stage was the highest in these two latter hosts as well (29–31%). Moths showed the highest emergence and longevity on C. sinensis and C. aurantifolia. The results indicate that C. sinensis and C. aurantifolia are susceptible hosts that can be recommended for the mass-rearing of this species in non-chemical pest control programmes.

Cranberry (Vaccinium macrocarpon Aiton (Ericaceae)) requires insect pollen vectors to maximise fruit yield. In many areas, commercial producers use managed bees (Hymenoptera: Apidae) to supplement native pollinators. On the island of Newfoundland, Newfoundland and Labrador, Canada, due to the small number of available honey bee hives and import restrictions on commercially reared bumble bees, the use of supplemental pollinators is rare. Four farms were studied for two years to identify key pollinators and determine the relationship between fruit yield and bee abundance. The most commonly collected bees were species of Bombus Latreille (Hymenoptera: Apidae), which buzz-pollinate and are likely the primary pollinator on these farms; thus, fruit yield was examined with respect to total Bombus abundance. Stigma loading was also used as a measure of pollinator effectiveness. Contrary to expectation, there was no relationship between Bombus abundance or stigma loading and either fruit set or weight, but there was significant year-to-year variation. Other factors were likely more important in determining yield, and further research is needed to identify those. Under current conditions, native bees provide ample pollination services for maximal yield.

A three-year field study in northeastern Saskatchewan, Canada, determined the effects of seeding date and seed treatment on feeding injury by Contarinia Róndani (Diptera: Cecidomyiidae) midges to canola, Brassica napus Linnaeus (Brassicaceae), and subsequent seed yield. Emergence cage monitoring indicated the presence of two generations of midges at the four locations observed. Intensity of midge injury to canola was low, but damaged plants were common. Field location and seeding date influenced probability of midge injury and canola growth stage. The wettest of the four locations had the greatest number of midges but low levels of probability of damage in two of three years. Early-seeded plots had higher injury probability than late-seeded plots, with the highest probability of injury occurring one to two weeks after flowering commenced. Seed treatment marginally affected midge injury ratings, suggesting that insecticide efficacy dissipated before the midges attacked. Seed yield was higher in early-seeded than in late-seeded plots in two of three years, despite the greater level of damage seen in early-seeded plots. Overall, the research showed that the agronomic benefits of early seeding outweighed the effects of the midge damage observed; therefore, producers in the Canadian prairie provinces should seed canola when conditions are most agronomically suitable.

Eleven of the 12 species of owls (Aves: Strigidae, Tytonidae) known to occur in Manitoba, Canada, were examined for chewing lice (Phthiraptera: Amblycera, Ischnocera) from 1976 to 2015: barn owl (Tyto alba (Scopoli); Aves: Tytonidae) (n = 2), snowy owl (Bubo scandiacus (Linnaeus); Aves: Strigidae) (n = 77), great horned owl (Bubo virginianus (Gmelin); Aves: Strigidae) (n = 262), great grey owl (Strix nebulosa Förster; Aves: Strigidae) (n = 142), barred owl (Strix varia Barton; Aves: Strigidae) (n = 10), northern hawk owl (Surnia ulula (Linnaeus); Aves: Strigidae) (n = 18), short-eared owl (Asio flammeus (Pontoppidan); Aves: Strigidae) (n = 74), long-eared owl (Asio otus (Linnaeus); Aves: Strigidae) (n = 67), eastern screech owl (Megascops aslo (Linnaeus); Aves: Strigidae) (n = 59), boreal owl (Aegolius funereus (Linnaeus); Aves: Strigidae) (n = 47), and northern saw-whet owl (Aegolius acadicus (Gmelin); Aves: Strigidae) (n = 44), a total of 802 owls. No lice were found infesting barn owl (Tyto alba (Scopoli); Aves: Tytonidae) or eastern screech owl (Megascops asio (Linnaeus); Aves: Strigidae). We collected a total of 113 810 lice of 12 species: Kurodaia Uchida (Phthiraptera: Menoponidae) – three species; and Strigiphilus Mjöberg (Phthiraptera: Philopteridae) – nine species. Overall prevalence of infestation ranged from 10.0% to 88.9%. Mean intensity for total lice ranged from 22.4 to 506.5. Infestation parameters for each louse–host combination are provided; prevalence and mean intensity were not related for louse–host species combinations. Distribution of louse infestations was highly aggregated. In all louse–host combinations but one, either females were more prevalent than males or there was no significant deviation from 50:50. Male Strigiphilus ceblebrachys Denny significantly outnumbered females in snowy owls. There was a tendency for louse species to co-occur on the same host specimen. Where sample sizes for owls were large enough, no seasonal patterns in abundance of lice were detected.

The pine bark adelgid, Pineus strobi (Hartig) (Hemiptera: Adelgidae), is an herbivore native to eastern North America that specialises on eastern white pine, Pinus strobus Linnaeus (Pinaceae). Little is known about P. strobi, especially in its southern range in the Appalachian Mountains, United States of America, and the composition of its predator complex has not yet been documented in this region. The current study identifies arthropod predators associated with P. strobi in Appalachian forests of Virginia based on a two-year survey. Predators were identified using morphology and DNA barcoding. Predator species include: Laricobius rubidus LeConte (Coleoptera: Derodontidae), Leucopis piniperda Malloch (Diptera: Chamaemyiidae), and Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), that are known adelgid specialists. Also found were predators from the families Cecidomyiidae (Diptera), Coccinellidae (Coleoptera), Chrysopidae (Neuroptera), Hemerobiidae (Neuroptera), and Syrphidae (Diptera). The Cecidomyiidae were especially diverse, with 14 different species inferred from their DNA barcodes. Knowledge of this predator complex is particularly valuable for anticipation and detection of potential interactions between native predator species and those that are being considered for the introduction for biological control of invasive adelgid pests within the southern Appalachian ecosystem.

Specimens (n = 508) of eight species of owl (Aves: Strigiformes) collected from 1994 to 2017 in Manitoba, Canada, were weighed and examined for chewing lice (Phthiraptera: Amblycera, Ischnocera). The relationship between host body mass and infestation by 12 species of lice was examined. Host body mass explained 52% (P = 0.03) of the variation in mean intensity of louse infestation among hosts, due primarily to a high abundance of lice on the heaviest owl species. The relationship was due to the mean intensity of lice, and neither species richness nor the prevalence of lice was related to host body mass. For individual louse species, the relationship was due primarily to Kurodaia acadicae Price and Beer, Kurodaia magna Emerson, and an undetermined species of Kurodaia Uchida (Phthiraptera: Menoponidae) (R2 = 0.997), but not the nine Strigiphilus Mjöberg (Phthiraptera: Philopteridae) species (R2 = 0.27). Louse intensity did not increase with body size for individual birds of any of the owl species. Mean intensity is expected to increase in proportion with the size, specifically the surface area, of the host. Why that relationship holds only for one louse genus, and not for the most abundant genus of lice on owls, and weakly compared with other families of birds, has yet to be determined.

Trypophloeus klimeschi Eggers (Coleoptera: Curculionidae: Scolytinae) was first discovered in China in 2003, and it exhibits strong species specificity to Populus alba var. pyramidalis Bunge (Salicaceae). To screen plant volatile compounds for monitoring and trapping T. klimeschi, the electroantennogram responses of adult T. klimeschi to eight plant volatiles, including nonanal, 2-methylbutanal, decanal, 2-hydroxybenzaldehyde, (Z)-3-hexen-1-ol benzoate, methyl benzoate, methyl salicylate, and geraniol were tested at various concentrations. Behavioural responses of female and male adults to various concentrations of these eight plant volatiles were also determined using a Y-tube olfactometer. We then tested the effectiveness of these compounds as lures for trapping T. klimeschi in the field. Electroantennogram tests showed that T. klimeschi possesses olfactory sensitivity for eight compounds. Additionally, walking T. klimeschi exhibited attraction to low concentrations (≤ 1 μg/μL) of all eight compounds in Y-tube olfactometer. Field experiment results indicated that baits composed of each volatile compound alone were more attractive to greater numbers of T. klimeschi than the control. The methyl benzoate bait was better attracted by T. klimeschi than other tested volatiles. These results suggest that these compounds could be used in attraction of this stem-boring pest. This study could have important implications for the development of an effective semiochemical-based management tool for T. klimeschi in the field.

The natural history of Corythucha juglandis (Fitch) and Gargaphia tiliae (Walsh) (Hemiptera: Tingidae) was studied in Ontario and Québec, Canada. These univoltine species overwinter as adults in leaf litter in a state of reproductive diapause and become active in April or May. They are specific to their host plants. Adults, eggs, and nymphs of both species were collected from the underside of leaves of host plants. The reproductive systems of both male and female, as well as eggs, nymphs, and operculum of the eggs of the two species, are described and illustrated. Fecundity, incubation period, development of nymphs, feeding, mating, and oviposition were studied. Mating was end-to-end at an angle of 35–40°. The reproductive potential, oviposition pattern, and site selection in the two species were investigated. Parental care of eggs and brood of G. tiliae is also reported and illustrated. Ocelli, true spermathecae, true egg micropyles, and true egg burster are absent in the two species. Fertilisation takes place before chorion formation. Adults, nymphs, and new generation aggregate on the underside of leaves of their host or nearby deciduous plants. In October they fly a short distance to overwintering sites within leaf litter.