Entomopathogenic Nematodes: Biodiversity, Geographical Distribution and the Convention on Biological Diversity

Abstract

This pape r address es thre e m ajor issues. Firstly, m olecula r taxono m y and its applicat ion to elucidat e the biodiver sity and biogeog raph y of ento mopathog enic nem atodes is conside red. Accurat e identific atio n is fundam enta l for underst andin g biodiver sity , and becaus e these nem atodes are m orpholo gically conserv ative , molecula r techniq ues will provid e the insight s necessa ry to develo p a robust , morpholo gically base d taxono m y. Secondly, a review of the knowledg e on their biogeog raph y and habita t specific ity, includin g a conside ration of the lim itation s to the availabl e data is given . M uch of the infor mation is presente d in tw o table s which sum marize the distribu tion s of recogniz ed specie s at continen tal and nationa l levels. Thirdly , this pape r provide s a brie f conside ration of the Conventi on on Biologica l Diversit y and its im plication s for future work with ento mopathog enic nem atodes and biologic al control .K eyw ord s: Steinerne m a, H eterorha bditis, biodive rsity, geograp hica l distribu tion, m olecula r taxono my, habita t specific ity INTRO DU CTIO N K now ledg e of the biodiver sity and geograp hica l distribut ion of ento mopathog enic nem atodes is in its infancy , yet these are key issues for regulatory authorit ies. Even thoug h a num ber of survey s have been carrie d out, coverin g parts of every continen t, m ost of the w orld rem ains unexplo red. In m any of these surveys , m ajor question s regarding the identific atio n of the nematode s isolate d and the m ethods used to recove r them canno t be resolved . To add to the uncertai nty, the Conventi on on Biologica l Diversity , w hich cam e into effec t in December 1993, has legally bindin g regulati ons regarding ownershi p of organis ms, rights to collec t them and rights to involv e thir d parties . This will undoubt edly imping e on future w ork, but in an unkno wn w ay becaus e the mechanis ms for dealin g with the Convention are not yet in place.This pape r is structure d to deal w ith three m ajor topics :(1) m olecula r taxono m y and its applicat ion to elucidat e the biodiver sity and biogeog raphy of ento m opathog enic nem atodes ; (2) a revie w of curren t know ledg e of the biogeog raph y and habita t specifici ty of thes e nem atodes; (3) a brief conside ratio n of the C onventi on on Biologica l Diversit y and its im plication s for future work.

Soil moisture effects on the activity of three entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) isolated from Meghalaya, India

“…Entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis are obligate pathogens of insects (Poinar 1979) that have been found in many diverse climates throughout the world (Hominick et al 1996). Interest in EPNs as biological control agents of insect pests has increased rapidly because they possess many of the attributes of an ideal biological control agent, including broad host range, high virulence, host seeking capability, and ease of mass production (Gaugler and Kaya 1990;Kaya and Gaugler 1993).…”

Morphological characterisation of three isolates of Heterorhabditis Poinar, 1976 from the `Irish group' (Nematoda: Rhabditida: Heterorhabditidae) and additional evidence supporting their recognition as a distinct species, H. downesi n. sp.

“…Surveys for heterorhabditids, which have been conducted in many parts of the world, indicate that these nematodes have a global distribution (Hominick et al, 1996;Griffin et al, 1999;Stock et al, 1999).…”

Natural Enemies of Entomopathogenic Nematodes

“…These nematodes occur naturally in soils throughout the world (14) and can initiate epizootics in insect populations (1). Yet, very little is known about the factors that regulate these nematode populations in soil (21,23,24).…”