A Study of Mealworm Hemocytes with Phase Contrast Microscopy

Reliable data on differential hemocyte counts (hemograms) obtained daily from the same individual insects would be very desirable information for the evaluation of results of various experimental studies on these cells. The possibility that such data could be obtained by the use of phase microscopy on unfixed, wet coverslip preparations of hemolymph was the motive of the present study. The object of the study was fourfold: (1) to determine the criteria for recognition of the various kinds of hemocytes in wet preparations examined by phase microscopy; (2) to evaluate the reliability of hemograms taken by this method as compared to preparations made from heat-fixed larvae; (3) to compare the total numbers of hemocytes available without heat fixing with those following this procedure; and (4) to determine whether or not continued bleedings of individual insects would result in marked variations in the hemograms.