DISTRIBUTION AND MORPHOLOGY OF A PHORETIC MITE, ANOETUS HALICTONIDA (HISTIOSTOMATIDAE) ON AN URBAN POPULATION OF HALICTUS RUBICUNDUS IN CENTRAL SASKATCHEWAN
Date
2018-01-11
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
The ground-nesting activities of a sweat bee, Halictus rubicundus [Christ], and data about its commonly associated mite, now tentatively identified as Anoetus halictonida (Woodring, 1973), were investigated at two sites on the University of Saskatchewan campus in Saskatoon during 2014 and 2015, thereby representing the first such study of this relationship in western Canada. Plaster of Paris casting was utilized to identify and excavate 78 subterranean nests of H. rubicundus throughout the springsummer of 2015, to reveal nest architecture, phenology of the bee’s life stages, potential social interactions among bees, plus the types and proportions of pollen that contribute to the larval diet of this polylectic bee species. Microscopic examination of bees and brood cells revealed various life stages (eg. Tritonymphs; gravid females) of A. halictonida, but only deutonymphs resided on adult bees, in specific body locations according to host sex. Mite loads on adult females (96.3%) predominated on the lower surfaces of hind wings in a symmetric fashion, but also dorsally at the mesosomal-metasomal junction. Phoretic loads of deutonymphs on adult males (57.1%) averaged 1/3 that of females and instead were concentrated ventrally on the thorax and lower head. Mites residing on pre-adults (pupae and pharate bees), however, were surprisingly scattered and equal among host sexes, suggesting an eventual net mite transfer from adult male to female bees, possibly at copulation. Even the largest load of deutonymphs (167) was considered negligible (<0.5% the body weight of an adult female bee). Scanning electron microscopy revealed new information about the flexibility and microstructure of the caudal suckerplate and legs of deutonymphs of A. halictonida, allowing attachment to H. rubicundus. A brief comparison to other halictid-anoetid interactions involving H. confusus and Sphecodes in the same study area and the possibility of interspecific transfer is discussed.
Description
Keywords
halictus, deutonymph
Citation
Degree
Master of Science (M.Sc.)
Department
Biology
Program
Biology