360 



expanded. This, it seems to us, would be of little advantage in wet 

 weather. The article on the Vancouver Island Oak-looj)er possesses 

 much interest on account of its novelty. This insect defoliates the 

 oaks in the vicinity of Victoria every 3 or 4 years. The larvae are most 

 abundant about the middle of August, pupate the latter part of this 

 month, and emerge as moths from the 20th of September on into Oc- 

 tober. We quote from the account given by Mr. W. H. Danby, a cor- 

 respondent of Mr. Fletcher's (page 176) ; 



On 20tli September the moths were emerging in every direction, and crawling up 

 the trees to find a favorable spot to expand their wings. I now counted one hundred 

 and twenty-seven, and this was the beginning of one of the most wonderful entomo- 

 logical sights I have ever seen. By 5th October the moths were in myriads, the tree; 

 being literally covered, not only on the trunks, but on every limb and branch as fai 

 as the eye could discern, so close together that the wings overlapped. On shaking a 

 branch they would iiy off in such numbers that you could positively hear them fly. 

 When the moths first appeared the males averaged 90 per cent of the whole, but on 

 24th October the females bore the same proportion to the whole. About this time 

 heavy fogs set in, and the ground around was strewn with dead bodies. 



The insect hibernates in the egg state, and is destroyed by three para- 

 sites : Ichneumon cestus^ Pimpla^ n. sp., and a Tachina. The eggs should 

 be sprayed in winter with kerosene emulsion, and the caterpillars may 

 be killed by the arsenical mixtures. 



We are pleased to notice that this year the report is printed on bet- 

 ter paper than the previous reports. 



The Mouth-parts of Diptera.* — lu his recently published (November, 

 1890), paper on this subject, Professor Smith criticises the hitherto 

 accepted homologies of the dipterous mouth -parts, and concludes that 

 the accepted terminology of these parts should be radically modified. 

 He has examined a large number of forms representing the main fam- 

 ilies of the Diptera, and claims that he shows that the mandible of pre- 

 vious authors is in reality the maxillary palpifer (or perhaps the stipes, 

 he is not certain which) ; that the so-called labium is really a modifica- 

 tion of the galea, while the so-called maxillse are, in point of fact, the 

 lacinise, and the epipharynx and hypopharynx are ligula and para- 

 glossse. He has also indicated what he believes to be the mentum and 

 the labial palpi, and he has found the true mandibles only in Simulium. 



Conclusions of so radical a character should be accepted or rejected 

 only after the most careful review of the entire ground, and cautious 

 and critical study of the types examined by Professor Smith, as well as 

 of forms of other groups. His work will doubtless cause a reexamina- 

 tion of the whole question. 



Professor Smith has put forth his paper in a sensible, straightforward 

 way, has illustrated all of his important dissections, has deposited his 

 slides in the liirational Museum, and thus invites investigation. 



* A contribution toward a knowledge of the mouth-parts of the Diptera. By Prof. 

 John B. Smith, Author's Extra from Trans. Am. Ent. Soc, XVII, 319-339. 



