Plays a role in vesicle-mediated protein trafficking to lysosomal compartments and in membrane docking/fusion reactions of late endosomes/lysosomes probably as part of the class C core vacuole/endosome tethering (CORVET) complex. Specifically required for endocytic trafficking in a subset of cells, such as hemocytes and nephrocytes, which are highly active in endocytosis. Component of the class C core vacuole/endosome tethering (CORVET) complex composed of at least dor/Vps18, Vps16A, Vps8 and car/Vps33A; unlike in other species, Vps11 is not part of the Drosophila complex. Localization to the early endosome is dependent on Rab5 and class C core vacuole/endosome tethering (CORVET) complex subunits such as dor/Vps18, car/Vps33A and Vps16A. Expressed in the larva, in the pupal wings and the adult fly (at protein level). High levels of expression are found in larval hemocytes and garland nephrocytes (at protein level). Semilethal: animals can complete metamorphosis, but most of them die as pharate adults unable to emerge from the pupal case; surviving flies are weak, fail to unfold their wings properly and die within 24 hr. The eye color is similar to wild type flies. In larvae, results in the development of hemocyte-derived melanotic tumors in body cavities, accumulation of crystal cells and lamellocytes and disorganization of the sessile hemocyte compartment which might be connected to the abnormal increase of circulating hemocytes. In garland cells, uptake from the hemolymph, endosome formation and endo-lysosomal trafficking are defective and result in enlarged cells; late endosomes and endolysosomes are fragmented and erroneously distributed in the cytoplasm instead of being found in a layer directly beneath peripheral early endosomes. In hemocytes, acidification of endocytic vacuoles containing bacteria is defective. In wing imaginal disks, there are no endosome defects. Belongs to the VPS8 family. Aberrant splicing at the N-terminus.