160 THE CANADIAN ENTOMOLOGIST. 



CORRESPONDENCE. 



on the honey tubes of some butterfly larvie. 



Dear Sir,- — 



In my paper in the July No. of the Can. Ent., p. 136, I stated that I 

 found a reference in "Newman's British Butterflies" to a mention by 

 Zeller of the ants licking a conical tube in Damon (I think it was). 



Zeller refers to C. E. Pezold in L. C. Scriba, Beitraege zu der Insecten 

 Geschichte, 1793, Heft 3, p. 230, who states that ants often indicate the 

 presence of the caterpillar of Papilio Biton = Lycaena Damon. " On the 

 nth (12th counting the head as 1st) segment are two small yellow spots. 

 I saw a caterpillar moving them while feeding, and with the microscope I 

 found them to be two whitish tubes protruded by the caterpillar and again 

 invaginated. When first protruded the tube is similar to a three-cornered 

 pyramid, the three sides of which can be opened and invaginated in the 

 cylinder. When the caterpillar feeds, the tubes are almost incessantly 

 thrust out and withdrawn. I never saw any fluid coming out, nor remarked 

 any smell. I found two similar wart-like parts on the next preceding 

 segment, but without any change of shape. The caterpillars of Lye. argus 

 and Theda Rubi possess the same movable tubes in the same place, but 

 I could not find them in Theclas Qiicrcus and Betulee. It is a question 

 what is the use of these organs. Are they for defence as in P. machaon ? 

 I do not know whether the tubes of Damon are excretive organs, but I 

 have some reason to believe they are — the more so as the ants are very 

 busy about the caterpillars and cover them often entirely without harming 

 them. Mr. Esper has observed the same in the caterpillars ot Lye. lea-us. 

 Perhaps it is here as with Aphides, where the ants sip up the secretion. 

 That I did not see any fluid is no reason that it does not exist." 



W. H. Edwards, Coalburgh, W. Va. 



Dear Sir, — 



I should be glad to exchange a large number of British butterflies and 

 moths in return for good typical specimens of Canadian Lepidoptera or 

 pupae. Address — 



A. J. Spiller, Mangotsfield, Bristol, England. 



