Pathogenicity of Neoaplectana carpocapsae (nematoda) for the flea, Xenopsylla cheopis

IOURNAL

OF INVERTEBRATE

PATHOLOGY

42, 133-134 (1983)

NOTE Pathogenicity

of Neoaplectana carpocapsae Xenopsylla cheopis

1. infective larvae of Neoaplectuna

for the Flea,

and only ecological diversity of the occurrence of the nematodes and eventual hosts

Steinemematid nematodes infecting insects have a wide range of susceptibie hosts

FIG. cheopis.

(Nematoda)

carpocapsae inside body cavity of the rat flea, Xenopsyliu 133 0022-201 l/83 $1.50 Copyright 0 1983 by Academic Press, hc. All rights of reproduction in any form reserved.

134

NOTE

limits the distribution range to a more or less classical array of situations. The most important limiting factor is the moisture. This is the reason why the experience of B. Skierska and M. Szadziewska (Bull. Inst. Mar. Trop. Med. Gdynia 27 207-227,

1976) with a very high susceptibility of triatomid bugs for the DD-136 nematode provides rather academic information without much potential for field applications. Some other vector insects have a much better chance of coming in contact with infective larvae of Neoapfectana, which in principle is a soil-inhabiting animal. In a series of experiments, we used the rat flea, Xenopsylla cheopis, for experimental infections with a laboratory-reared strain of Neoaplectana carpocapsae. The nematodes were introduced to different stages of the flea on moistened filter paper placed on the bottom of the rearing container or in a layer of soil placed in a Petri dish in the rearing container. The infection of adult fleas under conditions of this experiment was not achieved, mainly because they were bound to the dry layer of the rearing medium. To the contrary, the exposure of larval fleas was highly positive. In the rather artificial and relatively dry conditions of the experiment,

10 of the 20 larvae present in the experiment were killed during the first 24 hr and 18 were dead in 48 hr. Infective larvae occurred in the infected larvae of the flea at a quantity of 2 to 15. They moved inside the host’s body actively and destroyed the tissues. The large number of the minute nematode larvae caused the death of the hosts and subsequently the death of the infective larvae. The nematodes appeared not to be able to develop to sexual maturity. The susceptibility of flea larvae to invasion by N. carpocapsae and the relatively moist and suitable climate of rodent burrows gives a good chance for eventual application of this nematode to control flea larvae in terrestrial burrows. Mermithids are known from fleas from some areas and there is no evidence of development of steinernematid nematodes in fleas in the literature . ZDEN~K JAROSLAV Department of Insect Puthology Institute of Entomology Czechoslovak Acudemy of Sciences Prague, Czechoslovakia Received December 12, 1979; accepted 1982

MRA~EK WEISER

May

II.