Nematode parasites of Chrysomelidae

Abstract

Representatives of three groups of nematodes naturally parasitize Chrysomelidae; the Mermithidae of the order Mermithida in the class Adenophorca. the Allantonematidae in the order Tylenchida of the class Secernentea and the Steinernematidac and Hetcrorhabditidac of the order Rhabditida in the class Secernentea. Each one of these three groups possesses a distinct life cycle and host parasite relationship which will be covered below. Because of their conspicuous size, members of the family Mermithidae appear to be the first recorded nematode parasites of Chrysomelidae. The earliest of such reports was made by Holten in 1797 when he described Filaria chrysomelae from Agelastica alni in Denmark. Since the description was insufficient, the above name will have to remain ’species inquirenda’. In the 18th century, many mermithids were placed in the collective genus Filaria which has no nomenclatorial status at present. The first discussion of nematode-chrysomelid associations was presented in 1950 by Jolivet and Theodorides. who treated all helminth parasites including hairworms or members of the Phylum Nematomorpha. Superficially, hairworms often resemble mermithids however the former are not nematodes and will not be covered in the present work. Some of the early reports of chrysomelid parasites are difficult to interpret because of this similarity between mermithids and nematomorphs.