Changes in Haemocyte Counts in Galleria Mellonella (L.) (Lepidoptera: Galleriidae) Larvae Infected With Steinernema Sp. (Nematoda: Steinernematidae)

Abstract

Samples of the haemolymph of Galleria mellonella (L.) (Lepidoptera: Galleriidae) larvae, force fed with approximately 50 surface-sterilised infective Steinernema sp. Travassos, 1927 larvae, showed that 30 min after force feeding, the number of haemocytes in the body cavity of the host decreased to almost 20% of that of the controls. After 4 hrs the nematodes moved from the alimentary tract into the body cavity and the number of haemocytes increased gradually up to 160% of that of the control. From then on haemocyte counts decreased linearly. After 24 hrs, shortly before death of the host, it dropped to about 1-2% of that of the control. There are two maxima, a relative one after 2-3 hrs and an absolute one after about 16 hrs. There was no observable defensive reaction against the nematode and no phagocytosis of the symbiotic bacteria.