March, 1895. WASPS AND WEATHER. 179 



which my notes cease to remark abundance of females. It has been 



• 



observed already that wasps were plentiful up to May 7th. I note in 

 my weather-chart that on May nth there fell 0-42 inch of rain, while 

 between May 26th and June 6th (both inclusive) my rain-gauge regis- 

 tered 2-23 inches. It was precisely from this time forward that wasps 

 became conspicuous by their absence. During July they were in no 

 better state, and many nests which had survived till then must have 

 perished by drowning. The total rainfall for that month was 4-86 

 inches on 21 days; on one occasion 1-59 inch fell, on another 1*13 

 inch, on a third 0-43 inch, while on July 10th 0-48 inch fell in the 

 short space of ten minutes. 



With regard to temperature, the conditions were extremely 

 favourable to wasps. My screened thermometer registered no frost 

 after March 19th. This will be surprising to those who remember 

 the disastrous (horticulturally speaking) frosts of May 21st and 22nd. 

 These, however, were strictly " radiation " frosts. The exposed 

 thermometer on grass fell to 25 F., while that in the screen only 

 reached 32*8° F. Such a frost most assuredly could not affect wasps 

 injuriously, for the very slightest covering was a protection against 

 it, e.g., exposed leaves of potato plants and scarlet runners were 

 blackened and killed, but leaves vertically below these were 

 uninjured. 



From these observations it may, I think, be fairly concluded that 

 in spite of favourable conditions of temperature, heavy rains are 

 extremely fatal to wasp communities. It would be interesting to 

 note the effect of the converse conditions, viz., a dry spring and 

 summer accompanied by repeated late frosts of some severity, but 

 for this opportunity we must be content to wait. 



The present frost has furnished the opportunity of testing the 

 powers of endurance of cold by hibernating wasps. The results show 

 that, at any rate during the period of hibernation, severe cold has 

 little effect upon their vitality. 



January 12. — °. V. germanica placed in corked test tube and 

 embedded in a heap of snow, temperature 31*0° F., for four hours. 

 Completely recovered on being brought into a warm room. 



January 13. — Same wasp placed out of doors, temperature 34 F., 

 for one hour, then in heap of snow for one hour, and then for three 

 hours in a vessel containing mixture of snow and salt and surrounded 

 by snow ; temperature fell to —6° F. Wasp died. 



February 5. — ^. V. germanica found in corner of thermometer 



screen, apparently dead. Completely recovered during examination 



by a class of pupils on February 8, having been in the screen 



during the intervening days. Minimum temperatures, February 6, 



13-8° F. ; February 7, 10-4° F. ; February 8, 9-9° F. Maximum 



temperatures, February 6, 227°F.; February 7, 22-3° F. ; February 8, 



24-8° F. 



Oswald H. Latter. 



Charterhouse, Godalming. o 2 



