38th Annual Meeting of the Society for Invertebrate Pathology

225 species of arthropod-pathogenic Entomophthorales are described. They are attributed to four families, however, the large majority belongs to the families Entomophthoraceae (196 species including 38 species of Tarichium) and Neozygitaceae (18 species). Morphological studies and a compilation of the literature data led to the description of three subfamilies of the Entomophthoraceae and to the description of a new genus in the family Neozygitaceae. Further, “weak” points in the systematics were localised and research gaps addressed.

The European COST Action 842 on Entomophthorales had as one aim to reveal novel information about the ecology of Entomophthorales. This was done by:

1) Workshops on practical sampling and diagnosis of Entomophthorales
2) Workshop discussions on methodologies for prevalence assessment
3) Initiation of new research programmes
4) Joint actions between scientists from different countries

With respect to 1) collection trips were performed in Switzerland and Poland, for example in the nature reservation of Białowieza with high biodiversity of Entomophthorales. Concerning 2) we tended to develop consensus about terms like ‘prevalence’ and the practical implications of these for studies on Entomophthorales. With respect to 3) new Danish projects on the genetic composition of host and pathogen in an aphid-Pandora neoaphidis system as well as the winter survival of the fungus will be presented. In addition, we will report on a Swiss project on the development of cultivation independent genetic tools for the study of P. neoaphidis in the environment. Finally, the action supported the possibilities for joint projects between European laboratories 4). One example of this is a co-operation between a Swiss and a Danish team to explore PCR techniques for cultivation independent tracking of Entomophthoralean species in soil samples.

Reforms to the Common Agricultural Policy in Europe encourage farming practices which protect the environment and maintain biodiversity in agroecosystems. This includes the planting of flower and seed rich field margins supporting insects and birds. With small adjustments these margins could also maintain populations of beneficial organisms such as entomopathogenic fungi, thereby contributing to pest management. We hypothesised that Pandora neoaphidis, a common aphid pathogenic fungus in temperate field crops, could be exploited in this way. Fundamental ecological studies on host range, dispersal and transmission were required to underpin this strategy. Field margin plants with potential as reservoirs of P. neoaphidis were identified, e.g. Yorkshire fog (Holcus lanatus), legumes such as bird’s-foot trefoil (Lotus corniculatus) and stinging nettles (Urtica dioica). Cross transmission and dispersal of the fungus between aphid species occuring in margins and crops and positive interactions with other natural enemies were demonstrated. Pest and non-pest aphids varied in their susceptibility to P. neoaphidis but there was no biological or molecular relationship between original host of an isolate and host range suggesting that free movement of P. neoaphidis between different aphid hosts was possible. These data underpin the exploitation of field margins as reservoirs of P. neoaphidis for aphid control.

Invertebrate pathogens and their hosts are taxonomically diverse. Despite this, there is one unifying concept relevant to all such parasitic associations: both the pathogen and host will adapt to maximize their own reproductive output and ultimate fitness. The strategies adopted by pathogens and hosts to achieve this goal are almost as diverse as the organisms themselves but studies examining such relationships have traditionally concentrated on aspects of host physiology. Here we report on a review of examples of host-altered behavior and consider these within a broader ecological and evolutionary context. Research on pathogen-induced/host-mediated behavioral changes demonstrates the range of altered behaviors exhibited by invertebrates including behaviorally induced fever, elevation seeking, reduced or increased activity, reduced response to semiochemicals, and changes in reproductive behavior. These interactions are sometimes quite bizarre, intricate, and of great scientific interest.