Abstract
A study was made of the effects of three fumigants, dichloroethyl ether, carbon tetrachloride, and methyl bromide, on the haemocytes of the Mediterranean flour moth. Cytological changes, total cell numbers, and the relative numbers of cells of each class were noted at intervals during fumigation and in recovering and moribund larvae after treatment. With each compound, fumigation caused passive–active cell changes and pathological conditions leading to cell degeneration and also resulted in significant decreases in cell numbers. Total cell numbers decreased further in individuals that failed to recover from fumigation. Recovery was associated with regenerative changes that resulted in increased cell numbers. The spheroidocytes were the principal cells involved in the increases and they were loaded with globules of neutral fats at that time. It is suggested that the spheroidocytes are associated with recovery, possibly through an ability to aid in the creation of fat reserves for energy metabolism under unfavorable conditions.