Journal of the Entomological Society of British Columbia

An annotated checklist of clearwing moths (Lepidoptera: Sesiidae) in British Columbia and Yukon Territory

Tyler D. Nelson — 2023-12-30

The clearwing moths (Lepidoptera: Sesiidae) are infrequently documented wood-boring insects. Some species achieve pest status in managed ecosystems across North America, threatening agricultural and forestry sectors. The invasive apple clearwing moth, Synanthedon myopaeformis (Borkhausen), is one such pest species; its larvae damage domesticated apple (Malus spp.) (Rosaceae) trees in the southern reaches of British Columbia, Canada. Future management of this pest with classical biological control requires an understanding of ‘non-target’ sesiid distribution. To that end, we have produced an annotated checklist of species distribution and host-plant records in British Columbia and Yukon Territory, Canada. We report a total of 22 sesiid species in these two jurisdictions, based on more than 2000 records from entomological museums, online community science databases, and the primary literature. This annotated checklist will be used to inform the biological control programme of S. myopaeformis but will also be a valuable resource for understanding sesiid diversity in western Canada.

Temperature requirements for western balsam bark beetle (Dryocoetes confusus Swaine (Coleoptera: Curculionidae: Scolytinae) development in southern British Columbia

Lorraine Maclauchlan — 2023-12-30

The western balsam bark beetle, Dryocoetes confusus, is the primary biotic disturbance that is causing accelerated subalpine fir mortality in northern and high elevation forests in southern British Columbia. B.C.’s climate has warmed dramatically over recent decades and is affecting many biological processes including those of D. confusus and its host subalpine fir. D. confusus generally undergoes a two-year life cycle, with larvae and teneral adults each overwintering once. To determine if it could have a univoltine life cycle, we reared D. confusus from field and laboratory-infested logs at five constant temperature regimes between 18°C and 24°C, with and without cold treatments. In the coolest 18°C regime, development was arrested in the late larval stage indicating that an environmental cue was needed for development to proceed or not. At temperatures higher than 21°C D. confusus displayed continuous development to teneral adult and emergence without requiring a cold period. Our results demonstrate that D. confusus does not have an obligatory diapause, requiring 1,200 degree-days to complete development and that under warming field conditions it may be able to switch to a univoltine life cycle. A life cycle contraction could have enormous implications to the future health of subalpine fir forests.

Biodiversity and community composition of ground-dwelling invertebrates across three disturbance regimes in a sub-boreal spruce forest

Andrew Mitchell — 2023-12-30

Natural and anthropogenic disturbances are closely tied to changes in biodiversity and ecological communities. Previous research has reported that ground-dwelling invertebrates exhibit a range of responses to different disturbance regimes. To investigate changes to community composition and biodiversity following forest harvest, we used pitfall traps to sample ground-dwelling invertebrates in the Aleza Lake Research Forest in British Columbia’s central interior. We collected and compared pitfall trap catches using family-level identifications in new plantations (11 years post-harvest), stands with a harvest history (>40 years since harvest), and old growth stands (no record of harvest). Community compositions differed among the three disturbance regimes and Bray-Curtis dissimilarity indicated that β-diversity was highest in new plantation stands. A small but non-significant increase in α-diversity was also observed in new plantation stands compared to the other two forest types. These findings are consistent with previous work in the boreal forest, which reported increases in ground-dwelling invertebrate biodiversity following disturbance. Three families (Agriolimacidae, Formicidae, and Lycosidae) were significantly associated with new plantation stands and could potentially be used as indicators of forest disturbance or to monitor stand succession post-harvest. This study provides a foundation for future work on invertebrate biodiversity in sub-boreal spruce forests, which would benefit from using species-level identifications and measuring environmental conditions associated with disturbance regimes.

First Reported Infestation of a Native Honeysuckle by a native Rhagoletis Fly (Diptera: Tephritidae) in North America

Joshua Milnes — 2023-12-30

Sympatric host plant shifts have been hypothesized to often be a critical factor initiating population divergence and speciation in specialized frugivorous Diptera in the genus Rhagoletis (e.g., Bush 1992, Feder et al. 2003). The apple maggot fly Rhagoletis pomonella (Walsh) is a model organism for host race formation via host plant shifts, but its sibling species Rhagoletis zephyria Snow has not been implicated as having shifted host plants since its evolution from R. pomonella ancestors (Bush 1966, Feder et al. 1999). Thus far, R. zephyria has been reared only from snowberry, Symphoricarpos spp. (Caprifoliaceae), specifically S. albus var. laevigatus (Fernald) Sidney Fay Blake, S. albus var. albus (L.) Sidney Fay Blake, and S. occidentalis Hooker (Bush 1966, Gavrilovic et al. 2007, Yee and Goughnour 2008). This includes R. zephyria populations native to the Pacific Northwest of the U.S.A. that attack native S. albus var. laevigatus (Yee and Goughnour 2008).

The invasive strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), uses Dasiphora fruticosa for reproduction in British Columbia

Aysha McConkey — 2023-12-30

The first North American report of the Eurasian strawberry blossom weevil, Anthonomus rubi Herbst was in the Fraser Valley of British Columbia (BC), Canada in 2019. This weevil feeds on and reproduces in closed developing flower buds of plants in the family Rosaceae, including small fruit crops, ornamental plants, and non-crop plants outside of crop fields. In its native range, A. rubi has been observed feeding and ovipositing on shrubby cinquefoil, Dasiphora fruticosa. In the Fraser Valley, D. fruticosa is a commonly grown landscaping shrub and therefore could serve as an important non-crop host for A. rubi. To investigate the potential of D. fruticosa as a host for A. rubi, we monitored four landscaping beds containing D. fruticosa for A. rubi adults, immature stages, and parasitoids that target immature stages of A. rubi during the 2022 growing season. We collected damaged flower buds weekly and monitored for weevil and parasitoid emergence. We observed A. rubi adults feeding on flowers and ovipositing in D. fruticosa buds at all field sites. Adult weevils emerged from 45% of collected clipped buds and two species of parasitoid wasps from the genus Pteromalus Swederus (Hymenoptera: Pteromalidae), emerged from A. rubi damaged buds. Parasitism levels were low at all surveyed sites, with a mean parasitism rate of 1.4%. This is the first report of A. rubi using D. fruticosa as a host plant in North America and suggests that this plant could be an important non-crop host for A. rubi in the newly invaded range, where attack by natural enemies is low.

Distribution of the genus Paraleuctra (Plecoptera: Leuctridae) in Canada

David Burton — 2023-12-30

The distribution of the genus Paraleuctra (Hanson, 1941) in Canada is examined based on specimens in the Canadian National Collection (CNC), the University of Guelph BOLD website (UOG), the Royal Museum of British Columbia (RMBC), the Illinois Natural History Survey (INHS) and distribution records presented in previously published research. The female of the species Paraleucta alta Baumann and Stark, 2009 is identified for the first time.

Pissodes strobi attack on lodgepole pine in the Kamloops Timber Supply Area

Lorraine Maclauchlan — 2023-12-30