ASPERGILLUS INFECTING MALACOSOMA 

 AT HIGH TEMPERATURES 



Wilson P. Gee and A. Ballard Massey 



In some experiments on the relation of temperature to the life- 

 cycle of the apple tent-caterpillar {Malacosoma americana 

 Fabr.), a serious difficulty presented itself in the mortality among 

 the specimens at the higher temperatures due to the infection of 

 the caterpillars with the fungus Aspergillus flavescens Eidam. 

 With regard to the injurious nature of the fungi of the genus 

 Aspergillus, DeBary^ has the following to say : " A number of 

 species of Aspergillus, all of which occur chiefly as saprophytes 

 and in that mode of life reach their full development, in some 

 cases even forming sporocarps, are able to migrate to the bodies 

 of warm-blooded animals and live at their expense. Their vege- 

 tation causes or promotes a diseased state of the parts known to 

 physicians as mycosis. A. flavus, A. niger, and A. fumigatus, 

 Eurodium repens, and Aspergillus glaucus are characteristic pro- 

 moters of the disease of the human ear which bears the name 

 of Otomycosis aspergillina:' In regard to the specific fungus 

 with which we are dealing, he states that " Gaffky and others, 

 Lichtheim especially, obtained characteristic phenomena of de- 

 velopment, in this case phenomena of disease, when the gonidia of 

 Aspergillus fumigatus and A. flavescens Eidam, two species dis- 

 tinguished by the high optimum of their vegetative temperature, 

 over 37° C, were introduced by injection into the blood of ani- 

 mals, such as rabbits and dogs." 



In the above mentioned experiments, the larvae were subjected 

 continuously to a temperature of 35°-37° C, and were thus at 

 the optimum developmental condition of A. flavescens. Al- 

 though careful search was made in several nests of Malacosoma 

 americana, only two specimens which showed any infection what- 

 ever from this fungus were secured, among many hundreds, and 



^ Comp. Morph. and Biology of the Fungi, Mycetozoa and Bacteria, 369, 

 370. 1887. 



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