Ecology And Molecular Characterization Of Neozygites Tanajoae Entomophthorales Neozygitaceae A Fungal Pathogen Of The Cassava Green Mite

For the biological control of the cassava green mite (Mononychellus tanajoa, Bondar), Brazilian strains of the entomopathogen Neozygites tanajoae were recently introduced into Africa to improve the control achieved by predatory mites. In order to monitor the establishment of the Brazilian strains two PCR primer pairs, NEOSSU_F / NEOSSU_R and 8DDC_F / 8DDC_R were tested on N. tanajoae strains collected from several locations in Brazil and from three countries in Africa, Benin, Ghana and Tanzania. The first primer pair enabled the species-specific detection of N. tanajoae, while the second differentiated the Brazilian isolates from those of other geographical origin. The results confirmed that the two primer pairs tested are suitable for the detection of N. tanajoae and the differential identification of Brazilian and African strains. PCR can therefore be used to monitor the establishment and spread of the Brazilian strains in Benin and in other African countries where they have been introduced recently in order to improve cassava green mite (CGM) control. In this work the establishment and spread of Brazilian strains of N. tanajoae were followed in a countrywide survey in Benin in which a total of 141 cassava fields were inspected. Samples of M. tanajoa suspected of being infected by N. tanajoae were found in 60 fields distributed between the coastal Southern Forest Mosaic (SFM) and the Northern Guinea Savannah (NGS) zones. PCR analysis of DNA samples extracted from samples from these fields revealed that N. tanajoae is well distributed in Benin and that Brazilian strains were effectively established and have spread throughout the country. However, the highest rates of infection due to Brazilian strains were observed in the sub-humid and humid savannah zones of the country. Identification of N. tanajoae strains using molecular tools, however, is very costly. Hence, development of alternative techniques is desirable. Therefore, the difference in biocontrol performance and in host ranges was compared to discriminate between African and Brazilian strains of N. tanajoae. The results suggest that the biocontrol potential and the host ranges bioassays are suitable for evaluating the infectiveness of N. tanajoae on cassava green mite. However, those methods were not suitable for differentiating among different origins of strains of the entomopathogenic fungus. The establishment of N. tanajoae in Benin after its introduction for the control of cassava green mite resulted in co-occurrence with the predatory mite Typhlodromalus aripo in cassava fields. However, little is known on the interaction of the two antagonists and on the biological control potential of M. tanajoa. In a series of greenhouse experiments, effects of single and combined releases of N. tanajoae and T. aripo on their respective population dynamics and on the suppression of M. tanajoa populations were evaluated. In order to complement the greenhouse experiments, laboratory experiments were conducted to evaluate the feeding, oviposition and longevity of T. aripo fed with healthy or N. tanajoae-infected M. tanajoa. The results showed that simultaneous release of T. aripo and N. tanajoae in the same cassava field may be detrimental to the biological control of the cassava green mite. It is therefore preferable to release in each area only the antagonist species known to be well adapted to the prevailing environmental conditions. In conclusion, this thesis shows that molecular techniques are the most suitable methods to detect infection of CGM by N. tanajoae and to differentiate among strains. Molecular techniques are also useful for monitoring the establishment and dispersal of introduced N. tanajoae species in the field. Furthermore, this study increased our knowledge on the performance and host ranges of the African and Brazilian strains of N. tanajoae. It also improves our understanding of the interaction between N. tanajoae and the most effective predatory mite T. aripo as both biocontrol agents are sharing the same habitats. Future research should focus on in vitro production and cryopreservation of African strains of N. tanajoae in order to develop specific primers for detecting African isolates. Furthermore, studies of the genetic diversity of N. tanajoae populations in the cassava fields using molecular techniques could strongly improve our understanding of the interaction between exotic and native fungi in the cassava ecosystem. Further investigations are required on the interaction between the predatory mite T.aripo and the pathogen N. tanajoae at a larger spatial scale and under natural conditions, and on factors affecting the loss in biocontrol potential of exotic species of N. tanajoae when introduced in their new environment.

Understanding of the ecology of fungal entomopathogens has vastly increased since the early 1800’s, but remains challenging. The often complex interactions between pathogen and host are being unravelled through eloquent research and the importance of the often subtle interactions, in determining the success or failure of biological control, cannot be underplayed. The realm of ecology is vast and deciphering insect-fungal pathogen interactions within an ecological context will take us on voyages beyond our imagination. This book brings together the work of renowned scientists to provide a synthesis of recent research on the ecology of fungal entomopathogens exploring host-pathogen dynamics from the context of biological control and beyond. Dr. Helen Roy leads zoological research in the Biological Records Centre at the NERC Centre for Ecology & Hydrology, UK. The focus of her research is insect community interactions with particular emphasis on the effects of environmental change. She has been working on the ecological interactions between fungal entomopathogens and their hosts for 15 years; this continues to be a source of fascination. She has been an associate editor of BioControl since 2006. Dr. Dave Chandler is an insect pathologist at the University of Warwick, UK. He has studied entomopathogenic fungi for just over 20 years. He has particular interests in entomopathogenic fungi as biocontrol agents of horticultural crops, fungal physiology and ecology, and the pathogens of honeybees. Dr. Mark Goettel is an insect pathologist at the Lethbridge Research Centre of Agriculture & Agri-Food Canada, specializing in the development of fungal entomopathogens as microbial control agents of insects. In addition to this research, he has been extensively involved in the review and revision of the regulations for registration of microbial control agents and has addressed regulatory and safety issues at the international level. He is currently President of the Society for Invertebrate Pathology and has been Editor-in-Chief of Biocontrol Science & Technology since 2000. Dr. Judith K. Pell heads the Insect Pathology Group in the Department for Plant and Invertebrate Ecology at Rothamsted Research, UK. She leads research on the ecology of fungal entomopathogens, to elucidate their role in population regulation and community structure and to inform biological control strategies. Specifically: intraguild interactions; the relationships between guild diversity, habitat diversity and ecosystem function; pathogen-induced host behavioural change. Dr. Eric Wajnberg is a population biologist specialising in behavioural ecology, statistical modelling and population genetics. He is also an expert in biological control, with more than 20 years experience of working with insect parasitoids. He has been the Editor in Chief of BioControl since 2006. Dr. Fernando E. Vega is an entomologist with the United States Department of Agriculture, Agricultural Research Service, in Beltsville, Maryland, USA. He conducts research on biological methods to control the coffee berry borer, the most important insect pest of coffee throughout the world. He is co-editor, with Meredith Blackwell, of Insect-Fungal Associations: Ecology and Evolution, published by Oxford University Press in 2005, and serves as an Editorial Board Member for Fungal Ecology.

The Dictionary of the Fungi has been published continuously by CABI from it's outset in 1943 to the latest (tenth) edition in 2008. The primary feature of the Dictionary is an authoritative consensus classification of the fungi, that has been widely accepted as an enabling and informing framework for research into pure and applied mycology. Fungal Families of the World has been conceived as an illustrative and more approachable companion to the Dictionary. Second it provides further substantial information on the 536 currently accepted families of Fungi, with more detailed descriptions and notes on ecology, economic uses, and the like. Third (and perhaps most importantly), it depicts the extraordinary range of morphological structures found in fungi, celebrating myco-diversity and perhaps stimulating interest in mycology by those individuals outside the inner circle of fungal systematists. The taxonomic framework for Fungal Families of the World is based upon that of the ninth edition of Dictionary but has been substantially updated to confirm with the findings of two major US-led research projects on fungal systematics, popularly referred to as Deep Hydra and AFTOL (Assembling the Fungal Tree of Life). The book contains images for over 400 families of the Fung, representing substantially wider fungal diversity than has been achieved before in a single publication. Where practical illustration of both macroscopic and microscopic features have been included. Fungal Families of the World will be of great value to students and researchers in biology, ecology and conservation, to mycologists, agriculturalists and foresters and serves as an informative companion to the Dictionary of the Fungi.

Microbial Control of Insect and Mite Pests: From Theory to Practice is an important source of information on microbial control agents and their implementation in a variety of crops and their use against medical and veterinary vector insects, in urban homes and other structures, in turf and lawns, and in rangeland and forests. This comprehensive and enduring resource on entomopathogens and microbial control additionally functions as a supplementary text to courses in insect pathology, biological control, and integrated pest management. It gives regulators and producers up-to-date information to support their efforts to facilitate and adopt this sustainable method of pest management. Authors include an international cadre of experts from academia, government research agencies, technical representatives of companies that produce microbial pesticides, agricultural extension agents with hands on microbial control experience in agriculture and forestry, and other professionals working in public health and urban entomology. Covers all pathogens, including nematodes Addresses the rapidly progressing developments in insect pathology and microbial control, particularly with regard to molecular methods Demonstrates practical use of entomopathogenic microorganisms for pest control, including tables describing which pathogens are available commercially Highlights successful practices in microbial control of individual major pests in temperate, subtropical, and tropical zones Features an international group of contributors, each of which is an expert in their fields of research related to insect pathology and microbial control

The twenty-four papers in this book are a mixture of primary research articles and literature reviews. Taken together, they present a broad overview of almost all aspects of acarine diseases, stretching from basic pathology to microbial pest control.

This is a diverse presentation about the use of arthropod-specific pathogens for control and eradication of invasive arthropod species. Basic concepts supporting use of pathogens for microbial control are covered as well as societal and environmental concerns.