title: Harvestman (Opiliones) fauna associated with Maine lowbush blueberry fields in the major production areas of Washington and Hancock counties.
abstract: Over a period of 19 yr, the harvestman (Opiliones) community associated with the lowbush blueberry agro-ecosystem in Maine was studied. Eight species representing five genera, four subfamilies, and two families of harvestmen belonging to the suborder Eupnoi were collected. The harvestman  community was dominated by two introduced, synanthropic species: Phalangium opilio in all but 1 yr (that year dominated by Rilaena triangularis). Rilaena was recorded for the first time from eastern North America. Relative abundance of harvestman adults increases throughout the season and  the temporal pattern of trap capture does not refute speculated life cycles of the harvestmen being univoltine with overwintering eggs. Some blueberry management practices were found to affect trap capture. We did find that on average (with opposite results 1 yr) trap captures are greater  in pruned fields than in fruit-bearing fields. Organic fields were found to have higher relative abundance of harvestmen than conventionally managed fields. Conventionally managed fields with reduced-risk insecticides showed no difference in harvestmen relative abundance compared with those  conventionally managed fields using the older more persistent organophosphate insecticides. Insecticide trials with common insecticides used in blueberry insect pest management showed that the organophosphate insecticide, phosmet, and the pyrethroid insecticide, esfenvalerate, were detrimental  to P. opilio adults when exposed to leaf residues, whereas the reduced-risk insecticide, spinosad, showed no negative effects compared with nonsprayed foliage.
authors.affiliation: School of Biology and Ecology, University of Maine, 5722 Deering Hall, Orono, ME 04469, USA. frank.drummond@umit.maine.edu
authors.forename: F A
authors.initials: FA
authors.lastname: Drummond
authors.forename: J A
authors.initials: JA
authors.lastname: Collins
authors.forename: B
authors.initials: B
authors.lastname: Choate
authors.forename: D
authors.initials: D
authors.lastname: Woodman
authors.forename: D T
authors.initials: DT
authors.lastname: Jennings
authors.forename: H Y
authors.initials: HY
authors.lastname: Forsythe
authors.forename: J C
authors.initials: JC
authors.lastname: Cokendolpher
mesh_terms: D000818:Animals; D001097:Arachnida / Q000254:growth & development / Q000502:physiology*; D058448:Biota; D029798:Blueberry Plants; D004777:Environment; D020387:Food Chain; D007300:Insect Control / Q000379:methods; D007306:Insecticides / Q000009:adverse effects; D008281:Maine; D009758:Nymph / Q000254:growth & development / Q000502:physiology; D010063:Ovum / Q000254:growth & development / Q000502:physiology; D011157:Population Dynamics; D012621:Seasons; D013045:Species Specificity
chemical_list: D007306:Insecticides