. Cranberries; : the national cranberry magazine. Cranberries. Dearness Scale, A Vine Pest of Cranberry: Bionomics and Spatial Distribution (Continuation of a Series) by J. 0. Jackson and C. F. Koval University of Wisconsin Madison, Wisconsin Dearness scale, Rhizaspidiotes dear- nessi (ckll.), was reported in Massa- chusetts over 50 years ago at which time observations by Lacroix (1926) indicated that injury to vines or fruit by the sparse popula- tions observed was of little conse- quence. This insect has probably been in Wisconsin for a consider- able time, also existing in sparse population
. Cranberries; : the national cranberry magazine. Cranberries. Dearness Scale, A Vine Pest of Cranberry: Bionomics and Spatial Distribution (Continuation of a Series) by J. 0. Jackson and C. F. Koval University of Wisconsin Madison, Wisconsin Dearness scale, Rhizaspidiotes dear- nessi (ckll.), was reported in Massa- chusetts over 50 years ago at which time observations by Lacroix (1926) indicated that injury to vines or fruit by the sparse popula- tions observed was of little conse- quence. This insect has probably been in Wisconsin for a consider- able time, also existing in sparse populations and causing little or no damage. Recent infestations in Wis- consin have been severe and have given impetus to collecting data and formalizing records on this insect. All interacting factors which main- tain the scale population below an economic level as well as the conditions allowing for outbreaks have not been firmly estabUshed. However, production practices may be indirectly responsible for recent population increases in Wisconsin. Such practices have influenced weed composition and may effect parasitoid success in certain areas. The parasitoid, Coccidencyrtus deamessi (How.) (Hymenoptera: Encyrtidae) was collected in vary- ing abundance from dearness scale from all infested sites. Adults of the parasitoid were dissected from and observed emerging from both fe- male and male scales. Emergence holes were observed in shells of immature scale (2nd instar). Al- though the wasp-like parasitoid was active during the time of crawler emergence (June 10-July 2), actual oviposition into the crawlers was not observed. Female parasitoid wasps were observed parasitizing mature female scale. The first step was the wasp's examination of the host by tapping its antennae over the scale's shell surface. If the scale was accepted as a host, the wasp reversed herself 180° and began boring through the scale's shell with her ovipositor. After inserting the ovipositor, a pumping action by the
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