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[Vol. 95 
Fig. 2. Left; wax filaments of Plotococcus eugeniae. Note loose coating of wax 
powder on the central shafts (Phase microscopy). Right; isolated particles of wax 
powder (Dark Field microscopy). (Bar on left, valid for both = 50 jum). 
We observed two additional chrysopid predators in the Plotococ- 
cus colonies, both less numerous than C. cincta, as well as one 
abundant syrphid fly larva. One of the chrysopids, which we suc- 
ceeded in raising, proved to be Chrysopodes collaris. The syrphid, 
which we also raised, was identified as Ocyptamus parvicornis. 
Preliminary chemical work by H. M. Fales and R. T. Mason at 
the National Institutes of Health, Bethesda, Maryland, showed the 
P. eugeniae wax to consist of a mixture of triglycerides of 
even-numbered (Cio to Cm) fatty acids. 
Postscript and Acknowledgments 
We had initially hoped to undertake an in-depth study of Ploto- 
coccus and its associates, a plan that was thwarted by the tragic 
death of Robert E. Silberglied. The present paper, written by the 
senior author, is based on notes taken jointly with Dr. Silberglied. 
For identification of the chrysopids and syrphid, we are indebted, 
respectively, to Philip Adams (California State University, Fuller- 
ton) and F. Christian Thompson (U.S. National Museum of Natu- 
ral History). We thank the staff of the Archbold Biological Station, 
Lake Placid, Florida, for hospitality during our stay. Maria Eisner 
prepared the illustrations. 
References 
DeWitz, H. 
1885. Die Angelhaare der Chrysopenlarven. Biologisches Centralblatt 4 : 
722-723. 
