66 THE ENTOMOLOGIST. 



reference to the great heat of last summer in breeding Notodonta 

 dictcea. Having taken and watched the life -history of this species 

 for several seasons, I have observed that warmth is indispensable 

 to the successful rearing of the insect ; hence I fully hoped that 

 the warm weather of August and September, 1880, would produce 

 a good spring brood in 1881. That wish was realised, for I easily 

 took two or three each evening during the latter part of last May, 

 from which were obtained a plentiful supply of eggs. From these 

 emerged 140 larvae, which in a few days were "sleeved" out on 

 Popidus dilatata. The rapid manner in which they grew during 

 the great heat of the 3rd, 4th and 5th of July was very con- 

 spicuous. Upon the last-named date the thermometer was 922-° 

 in the shade, but on the 6th it fell to 56°. This sudden change 

 caused an equally sudden result upon the larvae, for in the 

 evening I found, to my regret, that six were dead, and the 

 remainder in a semi-torpid state ; to arouse them it was quite 

 essential to place them at no great distance from a fire. By 

 the ilth the temperature was again high, and the N. dictcea once 

 more in a thriving condition. The next instance worthy of note 

 occurred on the 15th ; here it will be remembered that this was 

 the hottest day on record in this country, and, as I have since 

 found out, too hot for success in procuring perfect imagines of 

 this species, as the following facts will show. On the evening of 

 the 14th all the larvae were feeding ; but on looking in the breed- 

 ing cage twenty-four hours later there were actually seventeen 

 changed to pupae, and lying wholl}' exposed on the surface of the 

 mould. These ultimately produced fifteen deformed, and only 

 two perfect, specimens. After July 16th the temperature did not 

 exceed 89° in the shade, a maximum which was registered for the 

 three succeeding days. This period was long enough to enable 

 about 100 to pupate, nearly all of which followed the usual rule 

 of forming a subterranean cocoon, and in due time, with few 

 exceptions, yielded fine imagines. The first moth appeared on 

 July 25th, and the last on September 6th. There are two pupae 

 left, which are alive and passing the winter in that state. In 

 conclusion I ma}' add that to secure N. dictcea in proper condition 

 it was necessary to arouse oneself between the small hours of 

 2 and 3 a.m., as the great majority persisted wdth the utmost 

 regularity in emerging from 12 to 13.30 p.m. Now to kill them at 

 once was out of the question, and to leave them to enjoy the 

 length of time essential for rest in order to resuscitate the 



