Virus-like particles were found in apparently healthy Peregrinus maidis (Ashm.) in Venezuela. The particles were observed in the salivary gland, intestine, mycetome, adipose tissue, ovary, and hemolymph. In the cells, the particles occurred in the cytoplasm singly, in groups, free or within vesicles, and in hexagonally arranged crystals. In P. maidis from Hawaii such particles were not found. However, in these insects, single particles or crystals were observed after injecting suspensions of intestines from P. maidis from Venezuela. The particles were not observed in insects feeding on plants soiled with excretions from particle-containing P. maidis. Particles in organs of insects or in pellets of intestines were polygonal and showed a weakly contrasted envelope and a highly contrasted core. The particles had a diameter of 54 +/- 9 mmu. They are believed to represent a Peregrinus virus causing latent infection.