Glugea gasti sp. n., a Microspridan Pathogen of the Boll Weevil Anthonomus grandis1,2,3

Abstract

SYNOPSIS. Glugea gasti sp. n., a microsporidan pathogen of Anthonomus grandis Boheman (the boll weevil), is described and a probable life cycle presented. The alimentary canal, and probably the mesenteron 1st, is the initial site of infection, altho the disease later becomes generalized thruout most body tissues. Binucleate sporoplasms initiate the 1st schizogonic phase, characterized by mono‐ and bi‐nucleate schizonts. The 2nd schizogonic phase is characterized by mono‐, bi‐ and quadrinucleate schizonts, by prolific multiplication, by the dense compact nuclei early in this phase, and late in this phase by larger schizonts with less dense vesicular nuclei. This phase terminates in formation of diplokarya. The sporogonic phase is characterized by combination of the 2 nuclei in the diplokaryon followed by nuclear divisions in a sequence closely resembling meiosis. Two sporoblasts are produced from each sporont. Mature spores in wet mounts by phase contrast were 4.3 ± 0.3 μ long by 2.3 ± 0.2 μ wide. The polar filament averaged 76 μ long. Mature spores were present about 24 hours after infection. Some observations are presented on an external filament extending from one pole of the spore to host tissue and other events during the process of spore morphogenesis.