A new genus and species are described within the extinct tribe Haidomyrmecini, and tentatively placed within the subfamily Sphecomyrminae (Hymenoptera: Formicidae). Haidoterminus cippusnew genus and species expands the distribution of the bizarre, exclusively Cretaceous, trap-jawed Haidomyrmecini beyond their previous records in mid-Cretaceous Burmese and French amber, and into Laurentia. The new material from the Grassy Lake, Alberta, Canada collecting locality also provides evidence that these highly specialised, likely arboreal, ants persisted for an additional 20 million years, reaching the Late Cretaceous. Morphological features of H. cippus, such as the presence of an elongate antennomere II (pedicel), further support the argument that Haidomyrmecini may not actually belong within the subfamily Sphecomyrminae, and may warrant recognition at the subfamily level or inclusion as a highly autapomorphic clade within another subfamily. Despite the introduction of new fossil material, and the clarity of preservation in Canadian amber, the mystery of how Haidomyrmecini fed remains unsolved.

Exploration practices for oil sands developments in the boreal forest of western Canada create a network of thousands of kilometers of linear features, particularly seismic lines that dissect these forests posing significant environmental challenges. As wildfire is one of the prevalent stand-replacing natural disturbances in the Canadian boreal forest, it is an important driver of environmental change and stand development that may contribute to the mitigation of such linear industrial footprint. Here, we evaluate the short-term cumulative (also known as combined) effects of seismic lines and wildfire on biodiversity and site conditions. One year after the Horse River (Fort McMurray, Alberta, Canada) fire event in the spring of 2016, we compared dissected and undisturbed forests in burned and unburned boreal peatlands, assessing changes in overall stand structure and the responses of a variety of organisms. Soil moisture was significantly higher on seismic lines than in the adjacent forest, suggesting why most of the study sites within the fire perimeter showed little evidence of burning at the line in relation to the adjacent forest. Low fire severity on seismic lines seemed an important driver of local species diversity for ants, beetles, spiders, and plants in disturbed peatlands, resulting in similar species composition on seismic lines both within and outside the burned area, but different assemblages in burned and unburned adjacent forests. Our results suggest that fire did not erase seismic lines; rather, wildfire might increase the influence of this footprint on the recovering adjacent forest. Longer-term monitoring will be necessary to understand how boreal treed peatlands respond to the cumulative effect of wildfire and linear disturbances.

A new genus and species are described within the ant subfamily Dolichoderinae (Formicidae). Chronomyrmex medicinehatensis gen. et sp. nov. McKellar, Glasier & Engel provides a solid example of Dolichoderinae within the Campanian Grassy Lake amber of southern Alberta (Late Cretaceous, 78-79 Ma). The new species fills a void in the dolichoderine fossil record left by Eotapinoma canadensis Dlussky, a putative dolichoderine whose taxonomic placement has been questioned, and whose type material has been lost. As such, C. medicinehatensis provides a constraint for divergence times of the subfamily and Leptomyrmecini, one of its recently resurrected tribes. This discovery greatly extends the proposed divergence time for Dolichoderinae, and likely Leptomyrmecini, to more than 78 Ma -contrary to some of the more recent estimates inferred from molecular phylogenies.•

No abstract

Little is known about the associations of ants (Hymenoptera: Formicidae) with subterranean aphids and mealybugs (Hemiptera: Sternorrhyncha: Aphididae and Pseudococcidae), particularly in Canadian grasslands. Knowledge of host plants for these sternorrhynchans is equally rare. We carried out a plant-based survey of ants and belowground aphids and mealybugs in a native fescue grassland in east-central Alberta, Canada. We found 23 species of ants, 12 of which (species of Lasius F., Myrmica Latreille, Tapinoma Förster, and Temnothorax Mayr) were in association with subterranean sternorrhynchans. Twelve species of aphids and mealybugs were collected; 3 are new records for Canada and 2 are possibly undescribed. Most ant species associated with sternorrhynchans were found with more than one species of sternorrhynchan, sometimes in the same nest. Almost all sternorrhynchans were found on graminoid hosts (Poaceae and Cyperaceae); there was little observed plant-specificity beyond this. There were no significant correlations between presence of subterranean sternorrhynchans and percent cover of different plant types, soil moisture content, slope, aspect, or visible entrances to ant nests.