THE CANADIAN ENTOMOLOGIST. 



LEPIDOPTEROUS GALLS COLLECTED IN THE VICINITY 



OF TORONTO. 



BY DR. WM. BRODIE, TORONTO. 



Gnorimoserema (Gelechia) Gallaesolidaginis, Riley. 

 (The Low Solidago Gall.) 



Galls usually on the lower third of the stems of S. Canadensis, 

 occasionally on the upper third, rarely at the summit of the stem. The 

 galls vary in form from spindle form to prolate and oblate spheroid ; and 

 in size from 10x21 mm. to 18 x 30 mm. 



When young the producer larva? are confined in small cells, but when 

 mature the cells are large, retaining the form o£the exterior of the gall, the 

 larva? moving freely about feeding on the interior surface. 



Some observers say the interior of the gall is lined with silk. I have 

 never found this, but preparatory to the exit, the mature larva before 

 pupating constructs a silken hammock in the upper end of the gall, at 

 right angles to the axis of the gall, and opposite the aperture of exit. 

 The larva resting in this hammock bites out a hole to the epidermis of the 

 gall, which is carefully left. This hole is bevelled towards the outside, 

 and then neatly filled up with the material gnawed out, mixed with a silk- 

 like substance, doubtless from a gland, which forms a tight-fitting, hard 

 plug which cannot be pushed in from the outside, but is easily pushed out 

 from the inside. 



The mature pupa places itself on the hammock, and using a part of it 

 as a fulcrum, pushes out the plug, and enters on mature life. 



A fair instance of the mental make-up of insects evidences two 

 important attributes of mind, memory and choice. 



I have kept up a somewhat continuous acquaintance with this 

 common Solidago gall, its producer, and parasites since the summer of 

 1856. I have found it in Essex, London, Owen Sound, Bruce Peninsula, 

 Manitoulin, St. Catharines, Napanee, Temagami and Algonquin Park. It 

 is common in Muskoka, we may say common throughout Ontario. 



Although most common on S. Canadensis, it is occasionally found on 

 S. nemoralis and S. serotina. 



From Manitoba, Saskatchewan and Alberta I had galls sent to me 

 collected from some species of Solidago, which in structure were similar 

 to Toronto galls. But as I failed in rearing producers, identity was 

 uncertain, although the parasites were the same as Toronto species. 



Records of annual collections of galb, from 1876 to 1896, showed 

 the time of emergence of the producers to be from about Aug. 20 to Sept. 

 r, in each year. 



January, 1909 



