IV. 



Wasps and Weather. 



THE last two years have afforded in close proximity diametrically 

 A opposite conditions with regard to both weather and abundance 

 of wasps. It may, therefore, be of value to put on record a brief 

 summary of the climatic susceptibility of these insects. 



In Natural Science, vol. iii., pp. 273-275, I have already given 

 an account of the phenomena of the " Plague of Wasps " in 1893. I* 

 will there be seen that there was an absence of frost after March 23rd, 

 while the total rainfall from March 1st to June 30th, 1893, only amounted 

 to 2*38 inches, with never more than 0*34 inch on any one of the 27 

 " wet " days of the four months combined. 



In 1894 we again had fine warm weather in the early spring, and 

 the female wasps appeared on the wing in great abundance, these 

 individuals being in reality a legacy from last year's plague, and giving 

 further evidence, if such were needed, of the strength and vigour of 

 the nests last season — an abundant supply of food furnished by the 

 thousands of workers having resulted in the feeding up of an unusually 

 large number of perfect females. The daily press was full of warnings 

 to catch these " queens," and nip in the bud any recurrence of the 

 plague ! Referring to my own notes I find that I saw the first wasp 

 (sp. ?) of the season on the wing as early as February 7th, at Outwell, 

 Cambs. A few were noted during March and more in April, chiefly 

 Vespa vulgaris and V. gevmanica, with one or two V . vufa. Towards the 

 end of April they became abundant, so much so that a neighbouring 

 hawthorn hedge and oak fence were a source of terror to the nervous. 

 Between May 4th and 7th I captured rather over 50 females : V. 

 gevmanica 40, V. vulgaris 8, V . norvegica and V. sylvcstris 2 or 3 each. 

 Towards the end of May the numbers were diminishing. I first saw 

 workers (V. gevmanica) on the wing on June 7th. But the remainder 

 of the year was singularly free from wasps, and as a consequence, in 

 my opinion, aphides and earwigs were present in most destructive 

 abundance. 



The weather during the four months above named enables a 

 judgment to be formed on the conditions fatal, or the reverse, to wasp 

 life. Between March 1st and June 30th, 1894, there fell at Godalming 

 7*76 inches of rain on 56 days — roughly three times as much rain as in 

 the corresponding period of 1893, on only twice as many days — pointing 

 to heavy downpours. As a matter of fact, on six occasions during this 

 time the fall for one day exceeded 0*35 inch. Now it is most remark- 

 able that the heavy fall of rain exactly coincides with the period at 



