Effects of a novel microsporidium on the black vine weevil, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae)

• Published in: Journal of invertebrate pathology Vol. 98; no. 3; pp. 351 - 355
• Main Authors: Bruck, Denny J., Solter, Leellen F., Lake, Amanda
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.07.2008; Elsevier
• Subjects: Animals; Biological and medical sciences; Biological control; Black vine weevil; Canningia; Coleoptera; Coleoptera - microbiology; Control; Curculionidae; disease prevalence; disease transmission; dose response; entomopathogenic protozoa; fecundity; Female; Fertility; Fundamental and applied biological sciences. Psychology; Host-Pathogen Interactions; infection; Infectious Disease Transmission, Vertical; insect growth; Insecta; Invertebrates; Larva - microbiology; Longevity; Male; Microsporidia; Microsporidia, Unclassified - pathogenicity; Microsporidia, Unclassified - physiology; microsporidiosis; Microsporidiosis - microbiology; Microsporidiosis - transmission; Microsporidium; mortality; Otiorhynchus sulcatus; Pathogenicity; Pathology; Pest Control, Biological - methods; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; spore drench application; spores; Spores - pathogenicity; Spores - physiology; topical application; Vertical pathogen transmission; vertical transmission; Pathogenicity; Microsporidium; Vertical pathogen transmission; Black vine weevil; Canningia; Entomopathogen; Animal microorganism relation; Coleoptera; Insecta; Biological control; Parasite; Survival; Fungi; Pest; Microbiological control; Arthropoda; Otiorhynchus sulcatus; Vertical transmission; Curculionidae; Microsporidium;Canningia;Vertical pathogen transmission;Pathogenicity;Black vine weevil; Invertebrata; Fecundity
• ISSN: 0022-2011; 1096-0805
• DOI: 10.1016/j.jip.2008.04.009

A newly discovered microsporidium infecting the black vine weevil, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae), provisionally placed in the genus Canningia, was studied to determine its impact on O. sulcatus. O. sulcatus populations from several locations were sampled and evaluated for microsporidiosis. A very low prevalence of the disease was observed in all locations surveyed (<3.0%). Laboratory studies were conducted by orally exposing both larvae and adults of O. sulcatus to varying concentrations of Canningia sp . spores. Larval bioassays at a variety of dosages (0, 10, etc.) were performed to evaluate pathogen infectivity, larval survival and growth. Adult bioassays (dosages: 0, 10, etc.) were performed to evaluate longevity, fecundity and mechanisms of vertical pathogen transmission. Larvae and adults were infected in all spore treatments. Larval growth was significantly reduced at dosages above 10 spores/larva. Adults infected at all dosages experienced high levels of mortality and fecundity was reduced to zero. Greenhouse trials were performed to determine if larvae feeding in soil acquired infections when spores were topically applied as a drench application (0, 10 5, 10 6, 10 7 spores/pot). Established larvae feeding on plant roots in pots developed infections when exposed to drench treatments of 10 6 and 10 7 spores/pot after 14–21 days. Canningia sp. is an acute pathogen of O. sulcatus infective to both larvae and adults. Topically applied spores also infected larvae feeding on roots in soilless potting media, suggesting the possibility of using this pathogen in a microbial control program.