Development of Diplotriaena tricuspis (Nematoda:Diplotriaenoidea), a parasite of Corvidae, in intermediate and definitive hosts

Abstract

Development of Diplotriaena tricuspis (Fedtschenko, 1874) Henry and Ozoux, 1909, of the American crow Corvus brachyrhynchos Brehm, occurred in capsules in the fat body of the migratory grasshopper Melanoplus sanguinipes F. and the African desert locust Schistocerca gregaria L. At 30 °C the first moult began at 4 days and the second at 8 days after infection in late-instar nymphal and young adult insects. One unusual feature was the rapid growth of the oesophagus which compressed the intestine of the third-stage larva. Grasshoppers appeared to be more suitable intermediate hosts than locusts. In crows, larvae of D. tricuspis apparently underwent their early development in the hepatic portal system and moved via the posterior vena cava to the heart. The third moult began at 4 days and the fourth at 20 days after infection. Subadult nematodes were in the right heart 25 days after infection. Nematodes broke out of arteries within the lungs and moved to the air sacs as early as 30 days after infection. The prepatent period was approximately 4 months. Attempts to transmit D. tricuspis to various noncorvids were unsuccessful.