OAK LEAF-BOLLER MOTH. 



241 



1879 (see my Eeport for that year, p. 5), bears very practically 

 on the subject. 



The following notes of temperature and rainfall, in connec- 

 tion with condition of the caterpillars, are also worth record. 

 On one of the trees at Claydon, which was especially badly 

 attacked, and especially under notice from historical interest, 

 the caterpillars were observed to begin falling off in great 

 numbers on the 11th of June, and lay putrefying beneath; 

 and specimens of the putrid mass, as well as of the healthy 

 chrysalids, to which some of the caterpillars had previously 

 turned, were sent me. 



Kegarding the special weather conditions, I was favoured by 

 Mr. Sharp with the following table of the maximum and 

 minimum temperature at Claydon during the time when he 

 observed the workings of the caterpillars : — 



in. 



From this it will be observed that there was rainfall on four 

 days after the max. temp, had risen to 83° in shade ; but to 

 continue in Mr. Sharp's own words, " It was on the morn- 

 ing of the 11th (of June), when our night temperature had 

 been at 34°, that I first observed the caterpillars falling off in 

 large numbers." 



The matter of the fall of the caterpillars from the tree is of 

 considerable interest, as an example of the effects of sudden 

 cold and wet in destroying these plant-vermin, which might 

 to some extent be copied artificially. 



The carnivorous caterpillars of the Dun-bar Moth, the 

 Cosmia trapezina scientifically, have been reported as some- 

 times doing great good in clearing away this attack. The 

 Cosmia traiiezina is a moth about an inch and a quarter 

 in the spread of the fore wings, which are very variously 

 marked with pale grey, rust-colour, or brown, with transverse 



