328 The Large Poplar Longhorn 



were laid in a single day, and the female, after she had laid these, re- 

 sumed feeding, and then returned to the base of the stem to complete 

 her egg-laying. Sometimes egg-laying females were noticed to cut 

 vertical notches much resembling egg-incisions, and so nourish them- 

 selves. 



Colouration in the Sexes. 



From a careful examination of a very large number of specimens of 

 Saperda carcharias in the Aboyne areas, I have come to the conclusion 

 that there are two colour varieties in the male. The majority of the males 

 are covered with an ashy or white-grey pubescence, but others show a 

 pubescence of a colour similar to the female, namely, greenish-yellow. 



While the variety with ash-grey pubescence is the predominating 

 variety in the Aboyne district, in other areas* this variety is not nearly 

 so plentiful. 



In the Waterhouse Collection in the Entomological Department of 

 the University of Edinburgh, none of the male specimens of S. carcharias 

 show this ash-grey or white-grey pubescence. 



Through the courtesy of Dr Clahan an examination was made of the 

 collection of S. carcharias in the British Museum (Natural History 

 Museum, South Kensington), but in only one example in the British 

 collection was there any approach to the ash-grey variety, all the other 

 specimens showed the greenish-yellow pubescence. Among the S. car- 

 charias specimens from Central Europe, however, there were several 

 males with ash-grey pubescence. 



Professor Hudson Beare informs me that E. Reitter in his Fauna 

 Germanica,\o\. xiv. p. 64 refers to this asb-grey pubescence (ab. grisescens, 

 Mulsant). Reitter states that specimens of this colour occur but rarely 

 in Germany. Evidently the describer, Mulsant, makes no reference to 

 or had not noticed this colour to be peculiar to the males. Professor 

 Hudson Beare, in collecting specimens of S. carcharias, in England, has 

 not yet met with males showing this ashy-grey pubescence. 



On account of their colouration, while feeding on the leaves of their 

 host plants, the males showing the greenish-yellow pubescence similar 

 to the females, and the females themselves are rendered very incon- 

 spicuous (Plate XX, Right). Even while at rest on the twigs during 

 pairing their mottled greenish-yellow colouring is to some extent effective 

 as a means of concealing them. 



In the case of the males of the ash-grey variety their concealing 

 colouration is not conspicuous while feeding on the leaves of their host 



