COST Action 819: Entomopathogenic nematodes, supercedes Action 812: Cold active lines of insect parasitic nematodes in Agriculture and Biotechnology. It functions in the field of Agriculture and Biotechnology and began in July 1994 and will end in May, 1999. The main objective is to combine interrelated European expertise to increase the use of entomopathogenic nematodes (EPNs) in integrated pest management and to reduce the need for chemical control. Coordination of the Action is the responsibility of a management committee in accordance with a Memorandum of Understanding, which has been signed by representatives of 17 countries: Austria, Belgium, Czech Republic, Finland, France, Germany, Hungary, Ireland, Italy, The Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland and the UK. A research institute in Israel is also participating. Over 40 research institutions and 10 commercial companies participate in Action 819. The EU funding meets the costs related to coordination including the scientific secretariat, workshops, management committee and working group meetings, publications, short term scientific missions and evaluations.

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.

SUMMARYSoil from 403 hedgerow, roadside verge, woodland, heathland or field sites was assessed for presence of entomopathogenic rhabditid nematodes with aGalleria larva baiting technique. Steinernematids were recovered from 48 % of the sites but only one site yielded Heterorhabditis sp. The species recovered most frequently was Steinernema bibionis (Bovien). Another unidentified Steinernema sp. was also isolated. Prevalence of steinernematids in the different types of habitat formed continuum so that roadside verges harboured them most often while heathland sites yielded them least often. Mean soil temperatures at 5 cm were about 15 °C in fields and verges, 13 °C in hedgerows and heathland and 12 °C in woodland. Prevalence of the nematodes varied in different parts of Britain and was influenced by soil type. They were associated with calcareous soils, especially those with a calcareous subsoil horizon. Soils which are periodically or seasonally water-logged were suitable. Soils enriched by humus and hence high in organic matter frequently harboured the nematodes and some suitable soils had significant clay contents or subsoils high in clay. It appears that the two steinernematids are relatively unspecialized species, occurring in diverse habitats and soil types and are adapted to cooler temperatures.

SUMMARYThe presence of entomopathogenic nematodes in soil from 15 sites on 10 sampling occasions over a period of 28 months was documented. Sites were chosen to represent habitats classified as heathland, hedgerow, roadside verge, pasture or woodland. Bioassays utilized Galleria larvae and most of the nematodes obtained were identified asSteinernema (= Neoaplectana) bibionis (Bovien). A sibling species which fails to interbreed with S. bibionis was also found at 2 of the sites. Bioassays were at 15 and 20°C and there was no significant difference in the results at these temperatures. There was no evidence for seasonality in the presence of the nematodes and at 2 sites they were found on every sampling occasion. Otherwise, sites converted unpredictably from positive to negative or negative to positive over the 28-month sampling period.

No abstract

Entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) were isolated from Sri Lankan soils using the Galleria baiting technique. Samples collected from different agro-ecological regions and different habitat types revealed that the presence of nematodes was restricted to sandy coastal soils. Two heterorhabditid and three steinernematid RFLP types were discovered within 5–100 m of the sea. Members of both families were equally prevalent. However, no parasitized insects were found although insect species were encountered which are potentially natural hosts. These nematodes were present at high temperatures (some above 30°C) and neither the monsoon rain nor the drought had any effect on their prevalence.

Entomopathogenic nematodes were isolated from soil samples collected during three separate surveys, two in the United Kingdom and one in the Netherlands. The nematodes were identified by their restriction fragment length polymorphisms on hybridization of Southern blots with a ribosomal DNA repeat unit clone. A total of eight steinernematid species/RFLP types and two heterorhabditids were isolated. The distributions of the majority of these species/RFLP types were significantly different between the three surveys and some of the species displayed a close association with certain habitat types.

The presence of naturally occurring entomopathogenic nematodes (epns) was surveyed in the West-Flanders province in the north-west of Belgium. In 21 sites of different agronomical situations, 130 soil samples were taken. Using the Galleria larva bait technique, 16 soil samples were found positive for epns. Fifteen samples were found to contain Steinernema spp. (nine S.feltiae, five S. affinis, one Steinemema species B3). The remaining positive sample contained Heterorhabditis sp. (North West European strain). The morphometric characters of the isolates were highly variable and did not correspond precisely to the original descriptions; however, biochemical characterization confirmed their identity. The epns were isolated from 50%, 18.8% or 12.3% of the samples taken in sand dunes, grassland or woodlands, respectively. S. feltiae and S. affinis were isolated in these three habitats; Heterorhabditis sp. was found in a grassland habitat. Steinernema feltiae was prevalent in loamy sand soils with a wide range of organic matter content; S. affinis, Heterorhabditis sp. and Steinernema species B3 were isolated in sandy loam soils. All the positive sample sites were in the pH range of 4.0–8.1. This is the first report of naturally occurring entomopathogenic nematodes in Belgium.