Biology, Life Cycle and Redescription of, Neoaplectana bibionis Bovien, 1937 (Nematoda: Steinernematidae).

A greater knowledge of the morphology and the development of the infective third larval stage of Neoaplectana bibionis Bovien, 1937, a parasite of arthropods, makes it possible to recognise the second larval stage and present a description of all the developmental stages in the life cycle of the species. Four larval stages can be recognised. L1 hatches from the egg. In a suitable host, when the population density is low, it develops directly into L4. When the population density is high, it develops into L2. The L2 is a non-feeding stage that precedes the resistant infective L3 larvae. L3 is free-living and characterised by a distinct lateral field with nine longitudinal lines. In the L4 the sex can be recognised. The first adults developing in a fresh host are usually larger than those developing later. Generally no more than two generations are completed in one insect. Youngg females in a fresh host lay eggs. In older females, and in females developing in a decaying host, endotokia matricida is common. A redescription of the species is presented on the basis of a population from New Zealand reared on Galleria mellonella larvae. All stages of the life cycle are described and illustrated. Proposed new synonymy includes Neoaplectana leueaniae Hoy, 1954 a synonym of N. bibionis Bovien, 1937 and Neoapleetana affinis Bovien, 1937 a synonym of N. menozzi Travassos, 1932.