HR: 1330h
AN: NB33Q-04    [Abstracts]
TI: Scathophagid fly Larvae as Predators of Neophylax rickeri (Trichoptera: Uenoidae) egg Masses
AU: * Purcell, A H
EM: alisonp@nature.berkeley.edu
AF: University of California, Berkeley, Department of Environmental Science, Policy, and Management, 137 Mulford Hall, Berkeley, CA 94720-3114 United States
AU: Hoffman, A
EM: Andreas.Hoffmann@Wirtschafts-W.Uni-Magdeburg.DE
AF: Department of Economics, P.O. Box 4120 Otto-von-Guericke University,, Magdeburg, D-39106 Germany
AU: Resh, V H
EM: vresh@nature.berkeley.edu
AF: University of California, Berkeley, Department of Environmental Science, Policy, and Management, 137 Mulford Hall, Berkeley, CA 94720-3114 United States
AB: We examined the predator-prey interaction of an undescribed predator (Diptera: Scathophagidae) on egg masses of Neophylax rickeri (Trichoptera: Uenoidae). Over a two-year period, we regularly surveyed 14 riffles within a 200-m reach of Redwood Creek and Webb Creek (Marin County, California). In Webb Creek, scathophagid predators were absent despite the abundance of N. rickeri egg masses. However, in Redwood Creek scathophagid predators were found within 11% (n=1594 egg masses) of the N. rickeri egg masses collected. N. rickeri egg masses were more frequently found clustered in aggregations (86%) than singly (14%), and scathophagid predators were more frequently found within N. rickeri egg mass aggregations (23% infestation rate) than in singly deposited egg masses (5%). Scathophagid predators exhibited a bivoltine life cycle with an increase in abundance after the first winter rains (November/December) and again in late spring (May/June). The abundance of predator larvae in the winter coincided with the peak oviposition period of N. rickeri, but in the late spring when N. rickeri egg masses were absent, the predator fed on egg masses of several other trichopteran (Brachycentridae) and dipteran (Ceratopogonidae, Chironomidae) species.
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly