INFLUENCE OF A CYTOPLASMIC POLYHEDROSIS ON VARIOUS DEVELOPMENTAL STAGES OF CABBAGE LOOPER

When the relationship of infections with a cytoplasmic-polyhedrosis virus and the larval, pupal, and adult stages of the cabbage looper, Trichoplusia ni, were studied, the mortality of first-instar larvae was comparatively high and that of fourth-instar larvae was comparatively low. Also, infected larvae pupated as much as 5 days later than healthy larvae, and the pupal weight was lower. This decrease in weight was related to the time of pupation, the number of white fecal pellets excreted by a larva before pupation, the decreased rate of emergence, and the moth deformities. The importance of these effects in regards to prophylactic measures for rearing large numbers of insects is discussed. © 1969.