200 



Note on the Drone Fly. 



I send a cage of insects which made their advent in onr greenhouse -with the bloom- 

 ing of Farfugium grancle in the economy of which flower they are apparently in some 

 manner concerned. They act like bees, and greatly resemble them not only in the 

 busy way in which they work among the flowers, but in the way they fly, and carry 

 their hind legs — imitating the pollen-freighted limbs of the bee. All whose atten- 

 tion I have called to them, or to whom I have shown the insects mistake them for Honey 

 Bees. I And, however, they have no sting, and have the head and proboscis of a fly. 

 They evidently fulfill the same office with relation to the composite above-men- 

 tioned as the Honey Bee, of which they are such a good imitation. * * * — [Ernest 

 Walker, Indiana, October 27, 1892.] 



Reply. — The insect is a true fly known as the Drone Fly, Erislalis tenax. The larva 

 of this insect is one of the rat-tailed maggots, so called for the reason that the anal 

 segments of the body are attenuated and telescopic, the spiracles being situated at 

 the tip, thus enabling the larva to breathe while its body is embedded in liquid filth. 

 The adult fly is frequently found in greenhouses, and is supposed to be a valuable 

 aid in the fertilization of chrysanthemums and several other plants. Its resemblance 

 to the Honey Bee is common to other members of the Dipterous family Syrphida-, as 

 well as the family Bombyliidai.— [October 31, 1892.] 



Another irregular Appearance of the Periodical Cicada. 



During last June the Periodical Cicada was quite common here; in an oak grove 

 on my place I could sometimes hear four or five singing at once. I captured several 

 imagos and found a number of pupa cases attached to leaves and twigs. 



I thought it was unusual to find them in such numbers four years after their regular 

 visit. The last regular year was 1888. I would have sent the above sooner, but 

 although it was interesting to me I did not know it would be worth sending, till I 

 read your note in last Insect Life (p. 50). — [H. J. Giddings, Iowa, October 6, 1892. 



Eeply. — The instance which you mention is very interesting if true, but your ex- 

 planation that these Cicadas are laggards from brood V (1888) is probably incorrect. 

 It is much more likely that they ai-e the precursors of Brood XI, which will appear 

 in parts of North Carolina, Virginia, Maryland, Indiana, Illinois, and Colorado next 

 year (1893). Your locality will be a new one for the brood, and we shall be glad to 

 be notified next year in case you see any specimens. In 1876 this brood was not 

 observed even in Illinois, but in 1842 and 1859 it was seen near Alton. — [October 10, 

 1892.] 



The New York Pear-tree Psylla. 



* * " Will you please give me the reference to Foerster's description of Psylla 

 pyricolaf A'e you quite sure of the reference of our Hudson River species to py- 

 ricola? The front wings are not as Loew describes them, " without any markings 

 whatever," but are distinctly marked with the spots in basal cell shown in the fig- 

 ure given by Thomas in the Eighth Illinois Report, p. 13, and less plainly on the 

 hinder wings. I have an example in which the wings are without markings, but 

 unfortunately with no date or locality. — [Dr. J. A. Lintner, New York, October 24, 

 1892. 



Reply. — * * * The common Pear-tree Psylla of Massachusetts and New York 

 is unquestionably P. pyricola Foerst., and agrees perfectly with European specimens 

 sent me by Dr. Loew. It was originally described by Foerster in "Uebersicht der 

 Gattungen und Arten in der Farailie der Psylloden," Verhandl. d. naturh. Vereines d. 

 preuss. Rheinlande, 1848, Vol. V., p. 77. This citation is taken from Loew's "Revi- 

 sion der palfiarktischeu Psylloden" since our only copy of Foerster's paper has been 

 mislaid. The blackish spot in the clavus and posterior basal cell of the front wing 



