Hemocytes of 2nd (L2) and 3rd (L3) instar larvae of Dermatobia hominis were studied and compared with other insect species. In L2 and L3 weighing up to 200mg there are five cell types: Prohemocytes, Plasmatocytes, Vermicytes, Oenocytoids and Squamous. In older L3 Granulocytes and Adipohemocytes begin to appear in this sequence and Prohemocytes are seldom found in L3 weighing more than 500mg. Besides there are cells intermediary between Prohemocytes and Plasmatocytes as well as between Granulocytes and Adipohemocytes; this suggest that Plasmatocytes originate from Prohemocyte, differentiate into Granulocyte that through accumulation of fat droplets become Adipohemocyte. We found no precursos of the Oenocytoids. We found no transitional cells between fusiform Plasmatocytes and typical Vermicytes as has been described in other species. Squamous cells do not have the features of true hemocytes but were found in L2 and L3.
hemocytes; Dermatobia hominis; Diptera