34 THE ENTOMOLOGIST. 



Polyommatus icarus, much below the average. In south Devon 

 Pararge egeria and Pararge megcera were plentiful, particularly 

 the latter, whilst Pijrameis atalanta, Pyrameis cardui, Aglais urticce 

 and the " Whites" were comparatively scarce. At sugar in South 

 Hants all Noctuidfe were very scarce, in South Devon Caradrina 

 ambigua, Agrotis saucin, Agrotu svffnsa, Noctua c-nigrum, Noctua 

 ruhi, etc., were plentiful, whilst Aporophyla nigra, Aporophyla 

 lutidenta, Epnnda liclienia, Polia flavicincta were scarcely seen. 

 In both counties, on the whole, Geometridae were well up to the 

 average, both as imagines and as larvse. What were the causes 

 of these somewhat remarkable discrepancies ? Larvae were not 

 unusually scarce in the autumn of 1918 and the weather of last 

 winter might be regarded as favourable to bibernating larvae and 

 pupae. In my experience the percentage of imagines reared from 

 wild dug pupae differs very much in different years. Does not 

 this point to some fatal influences apart from those prevailing 

 whilst they are pupae having affected the insect, say, whilst in 

 the larval stage '? On the whole, the results show that insects 

 produced from hibernating larvae were more numerous than those 

 l^roduced from hibernating pupae. This result was not due to an 

 over-wet season. Was it due to an over-dry one or to the 

 ground being so hard at the time of emergence that a great 

 many insects were unable to make their way out ? 



This is borne out, to some extent, by the greater scarcity of 

 Noctuidae as compared with Geometridae, which, as a rule, pupate 

 at no great depth in the soil. In our local woods Hyhernia 

 defoliaria was scarcely seen this season. On the other hand, 

 Apocheima hispidaria, which also pupates at some dejath, was 

 remarkably abundant in the same woods. The ravages of 

 Tortrix viridana might explain the local scarcity of certain oak- 

 feeders. This cause can be greatly exaggerated, as I found 

 larvae swarming on the bushes below Viridana -infested trees and 

 feeding heartily on hazel, etc. — Tricliiura cratcegi, for example. 

 From this we may assume, incidentally, that larvae are much 

 more general feeders than we suppose. 



An unusual preponderance of ichneumon might also account 

 for a large number of larvae. In certain years the proportion of 

 stung larvae is certainly much greater than in others. Are wild 

 larvae ever subject to parasitical plagues '? I have found it 

 difficult to account, otherwise, for the failure in certain seasons 

 of large numbers of wild larvae, notably those of Boarmia ahietaria, 

 Macruthylacia ruhi and Hylophila hicolorana. 



To say that unusual seasons have unusual results ento- 

 mologically savours somewhat of an axiom. As a rule, we 

 regard an unusually hot or dry summer as a favourable one 

 entomologically. Last year we had an unusually dry winter 

 followed by a more than average dry summer. The ento- 

 mological result was not encouraging. It would be interesting 



