Abstract. We investigated egg sac clutch size of the brown widow spider, Latrodectus geometricus C. L. Koch, in southern California from June through October 2012 by counting eggs from 214 field collected egg sacs. Clutch size was fairly constant over this five-month period averaging 129.0 ± 51.0 eggs per sac with the only significant monthly difference being more eggs in September than June. Determining the relatively constant egg production for this period contributed knowledge to another project involving application of pesticide to brown widow egg sacs in attempted control of this newly established invasive pest species.
Danielsen, Douglas W. R.; Clarke, Daniel E.; Valle, Stephan J.; Anselmo, Amy A.; Vincent, Leonard S.; and Vetter, Richard S.
"Natural egg sac clutch size of the brown widow spider, Latrodectus geometricus (Araneae: Theridiidae) in southern California,"
Bulletin of the Southern California Academy of Sciences:
Available at: http://scholar.oxy.edu/scas/vol113/iss2/5