The Genus Massospora Entomopathogenic for Cicadas. Part. II. Biology of Massospora levispora and Its Host Okanagana rimosa, with Notes on Massospora cicadina on the Periodical Cicadas1,2,3

Abstract

A study was made of Massospora levispora and its host, the northern cicada Okanagana rimosa , between 1962 and 1970. The northern cicada O. rimosa is morphologically and ecologically distinct from Okanagana canadensis. Although O. rimosa generally has 5 instars, it occasionally produces a supernumerary instar. The 1st and 2nd stadia each require 1 yr for development, the 3rd and 4th, 2 yr each and the 5th, 3 yr, making a total generation time of 9 years. This species is associated with a blueberry sweet-fern habitat and produces broods whereby usually the cicada is present only every 2 years. Other parasites, predators and pathogens were also investigated. The only parasitoid occuring in this cicada was a previously undescribed sarcophagid, Colcondamyia auditrix . This fly locates its host by the sound produced by the ♂ cicada. Birds and spiders constituted the most important predators. Pathogens found in the cicada nymphs were the fungus Paecilomyces farinosus and a bacterium identified as Corynebacterium okanaganae . The Massospora pathogen occurs only in the above ground population, i.e., adults. Cicadas become infected just prior to emergence by resting spores which then produce conidia; initial infection usually results in production of conidia. Adults cicadas infected by the conidia in turn normally produce only resting spores.