120 [June, 



differences between either the larvae, or the male genitalia, of these 

 two species : in the case of the larwie this is not surprisino;, for the 

 same is true of concomiteUa and blnncfrrdella^ but it is so in the case 

 of the genitalia, which, as a rule, in this group show well-marked 

 distinctions. It is clear, however, that, although marked differences 

 between the genitalia are proofs of specific distinctness, the absence 

 of such does not prove the specific identity of forms when the weight 

 of positive evidence supports the view that they are really distinct. 



In my experience, pyrivorella, which is an exceptionally early 

 species, is much earlier than mespilella. On the only occasion on which 

 I have reared spring broods of both, side by side, from mines kept 

 under precisely the same conditions from the time they were gathered 

 in the previous &\ii\irax\, j^yrivorelln began to emerge on March 28th, 

 while the first mesjnlella did not appear until April 27th, and almost 

 identical dates for each have been obtained from other broods reared in 

 separate years. This spring, which is a late one, severa] pi/rivorella were 

 found already out on March 24th, although the mines had been kept in 

 cold outhouses throughout the winter, except for a few weeks, when 

 they were in a cold room facing north. The imago follows the general 

 rule, and emerges through the thin lower wall of the mine, instead of 

 through the upper-side of the leaf as does sorhi, Frey, leaving the 

 pupa-shell protruding, for about three-quarters of its length, near 

 one end of the mine, sometimes the end towards the midrib, and at 

 others the end away from it. The males, as a whole, emerge before 

 the females. 



I have observed that the virgin females of pyrivorella may be 

 found "calling" the males at any time between 6 and 10 a.m., but 

 most frequently between 7 and 8.30 a.m. When so engaged they sit 

 with the abdomen turned up as far as possible straight into the air 

 and the anal appendages protruded, the wings motionless, but just 

 sufficiently parted to allow of the abdomen to pass upwards between 

 their dorsal margins, and the antennae held free of the sides and 

 quivering. I failed to discover how long pairing lasts. 



L. pyrivorella is rather subject to the attacks of parasites, and I 

 have bred from its mines three distinct species of "ichneumon-flies," 

 but these have not yet been identified. 



Norden, Corfe Castle : 



April lUh, 1900. 



