19 



Wednesday ^ August 15th, 1883. 



The members of the Club met at 2 p.m., the President in the chair. 



A paper was presented by Prof. S. A. Forbes entitled " Memoranda with regard to 

 the contagious diseases of caterpillars and the possibility of using the virus of the same 

 for economic purposes." The writer had adopted the results of Pasteur's discoveries in 

 relation to the disease affecting silk-worms as the foundation for his researches. M. 

 Pasteur some time since demonstrated the constant presence of a parasite in the intestines 

 of silk-worms affected by this disease, which has at times threatened the silk industry in 

 Europe. This parasite was not only the indispensable accompaniment of the disease, but 

 is its originating cause and the means by which it can be and is conveyed to other indi- 

 viduals of the species. 



By placing healthy silk-worms in contact with those suffering from the disease, by 

 sprinkling them with the dust of excreta derived from the latter, or by moistening their 

 food with an infusion of the fermented mulberry leaves upon which these had fed, he 

 proved the possibility of conveying the disease from one subject to another. 



In pursuance of this Prof. Forbes has vidtnessed instances of epidemic disease in 

 different species of insects, as for instance in the Chinch Bug and the ' Yellow-necked 

 Caterpillar, which disease was invariably dependent upon some form of bacteria or 

 micrococcus, possible of cultivation and reproduction, and by means of which the disease 

 can be indefinitely conveyed. These facts give rise to the suggestion that the specific 

 micrococcus or bacteria causative of these fatal diseases may be used for the infection and 

 destruction of insect pests. 



Prof. Osborn called attention to the fact that he had noticed Bomhus Pennsylvanicus 

 inhabiting a deserted wren's nest, situated under the roof of a porch, and at least twelve 

 feet from the ground, it being the first instance he was aware of where they nested away 

 from the surface of the ground. 



Mr. D. S. Kellicott "had noticed the same or some allied species of Bomhus inhabiting 

 a mouse's nest in the brace of a barn. 



Miss Murtfeldt had also seen them domiciled in a martin's nest. 



Dr. Hoy presented for inspection the larvse, pupae and imagines of Plusiodonta 

 compressipalpis. He had watched the insect through its transformations and had noted 

 that through its early larval stages its prevailing colour was a pea green varied with 

 uniformly placed black spots, which increased in number with each successive moult. 

 Only during the last stage of its larval life was the insect usually noticeable by other than 

 professional eyes ; since then its colour was reddish brown ornamented with creamy 

 white. Menispermum Canadense was its usual food plant. The cocoon was formed by 

 firs t building two nearly parallel walls and then uniting them at the top. Some larvse 

 which had been displaced after beginning to pupate, had apparently become exhausted, or 

 their teeth had become loosened in anticipation of their approaching new condition, and 

 they were willing to accept bits of paper held to them on a pin, with which they finished 

 the cocoons already begun. The species in Racine cannot be more than two-brooded. 

 The larvse are not distinguishable from those of Geometrid moths, as they are true loopers. 

 Their transformations in some particulars were exceedingly prompt. 



.d Prof. Riley stated that he had known certain moths, notably Leucania unipuncta, to 

 go through their entire transformations in fourteen days, and in some instances in only 

 ten days. 



Prof. Herrick made enquiry as to what are sometimes known as frost-flies. 



Mr. Kellicott called attention to a monograph by T. Rymer Jones, and one by E. 

 Ray Lankester, to be found in the Quarterly J ournal of Microscopical Science, and stated 

 that the species common at Buffalo was Gorethra plumicornis. 



Prof. Forbes had noticed the larvse of Gorethra abundant in the stomachs of fishes. 



Adjourned to meet at the call of the President. 



