Cyclops bicuspidatus

Table 8.4. Triaenophorus crassus growth of procercoids in adult males and females of the copepod Cyclops bicuspidatus thomasi. Comparison of mean length and width of 21- to 28-day old procercoids. (Data from Rosen Dick, 1983,)...

Although laboratory studies have value for specific purposes, it is in the natural ecosystem that we must determine the behavior of a pesticide and its possible effect. Studies of the cycling of radionuclide-labeled pesticides in natural ecosystems are limited, since introduction of radionuclides into the environment involves public-health and public-relations issues as well as possibly difficult technical considerations. However, an ecosystem study was conducted by spraying a 4-acre marsh in western Sandusky Bay, Ohio, with Cl-labeled DDT. One aspect of the study involved the incorporation of the pesticide in some invertebrates of this aquatic ecosystem as determined by autoradiography (Webster, 1967). An amount of the pesticide suitable for mosquito control was applied to the study area by helicopter. Samples of leeches (Erpobdella punctata), am-phipods (Hyallela sp.), and copepods (Cyclops bicuspidatus, Diaptomus orga-nensis) were collected, fixed, sectioned, and autoradiographed. It was observed that leeches contained the pesticide or a Cl-compound, but none was detected in amphipods or copepods. 

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