50 SECOND ANNUAL REPORT OF 



(Noclurtites I, p. 77) overlooking the former's description, and re- 

 garding it as a new species, named it Leucania extranea. Of course 

 Haworth's name takes the precedence. It is considered a common 

 species even in European collections, and Guen£e mentions it as oc- 

 curring in Brazil. A variety without the white spot occurs in Java 

 and India, and still another, lacking the white spot, and having a 

 dark border on the hind wings, occurs in Australia; while an occa- 

 sional specimen has been captured in England. A figure is given 

 in Stainton's Entomologist's Annual for 1860, of one captured there 

 in 1859, but if the figure be a correct one, the specimen is much 

 lighter than ours, and the characteristic white spot is not nearly so 

 conspicuous. 



PARASITES OF THE ARMY-WORM. 



The Red-tailed Tachina Fly — Exorlsta leucaniae, Kirk. — To one 

 who has never before seen the Army-worm in its might, the sight of 

 the myriads as they return thwarted in their endeavors to cross, or 

 of the living, moving and twisting mass which sometimes fills a ditch 

 to the depth of several inches; is truly interesting. At Hannibal 

 I was much surprised to find that fully nine worms out of every ten 

 had upon the thoracic segments, just behind the head, from one to 

 four minute, narrow, oval white eggs, about 0.04 inch long, attached 

 firmly to the skin ; and my companions were equally surprised when 

 I informed them that these were the eggs of a parasite, and that 

 every one of the worms which had such eggs attached to it, would 

 eventually succumb to one of the maggots these eggs produced. The 

 eggs are no doubt deposited by the mother fly just behind the head, 

 so that the worm may not reach the young maggots when they hatch, 

 and be enabled to destroy them with its. jaws. I have found several 

 different kinds of cut- worms with just such eggs attached invariably 

 on the back just behind the head. They are glued so strongly to the 

 skin of the worm that they cannot be removed without tearing the 

 flesh. 



The large two-winged parasitic flies which deposited these egg», 

 were wonderfully numerous, buzzing around us and about the worms 

 like so many bees, and the moment, one was caught, I recognized it as 

 the Red-tailed Tachina Fly. This is one of the most common and 

 abundantof the Army-worm parasites, and attacks itin widely different 

 parts of the country. I have also bred the same fly from the Variga- 

 ted cut-worm (larvaof Agrolis inermis*), and a variety of it from our 

 common large Cecropia worm, which is often found on apple and other 

 fruit trees. It was first very briefly and imperfectly described as Exor- 

 i&ta leuca[i](B, by the late J. Kirkpatrick, in the Ohio Agricultural 

 Report for 18G0, page 358, and was subsequently much more fully de- 

 scribed as Senometopia [Exorista] militaris by Mr. Walsh, in his 

 Army-worm paper already referred to. Of course Mr. Kirkpatrick'a 



•First Report, p. 72. 



