AET. 20 EEVISION OF THE GENUS WINTHEMIA — EBINHAED 5 



The genus shows about the same combination of external charac- 

 ters as ZeniUia Robineau-Desvoidy ; in the latter, however, the para- 

 facials are entirely bare and the genitalia are of a different type. 



Biology. — As has already been stated, species of Winthemia are 

 frequently encountered in economic work, and our literature of the 

 past 30 years contains a list of several hundred rearing records from 

 40 or more different hosts. Unfortunately, several species have been 

 confused under the name quadripiistuJciita and a large majority of the 

 reported rearings are subject to verification. Several authors have 

 called attention to the importance of the so-called " red-tailed tachina 

 fly" in controlling infestations of the army worm. It seems quite 

 certain that this common army-worm parasite is not quadripustu- 

 lata^ as it has been commonly determined, but a distinct form redis- 

 cribed as rufopicta in the present paper. In the files of the United 

 States National Museum there are several records of rearing Winthe- 

 mias from coleopterous larvae and adults, but the vast majority 

 of the rearings are from lepidopterous larvae. So far as is known, 

 the reproductive habits are the same in all the species. The females 

 deposit flattened macrotype eggs on the body of the host. This is 

 Pantel's first group, which includes Ne7norilla^ Exorista, etc. 



KEY TO SPECIES OF WINTHEMIA 



MALES 



1. Venter of abdomen withovit defined patches of dense liairs 2 



Venter of abdomen with defined patches of dense hairs IS 



2. Abdominal hairs long and erect 3 



Abdominal hairs depressed, if erect not unusually long 6 



3. Scutellum bearing three lateral bristles 4 



Scutellum with only two lateral bristles ; sides of front and face 

 plumbeous ; ocellars weak or hairlike ; third antennal joint 

 three times the length of second (California). 



antennalis Coquillett (p. 10) 



4. Legs wholly black or tibiae at most obscurely reddish 5 



Tibiae pale yellow, the middle pair with two stout bristles near 

 middle on outer front side ; abdomen densely gray poUinose 

 (? Massachusetts) tibialis, new species (p. 11) 



5. Sternopleurals three; uppermost froutals large, erect or recli- 



uate; front very narrow, 0.127 of the head width; abdomen 

 largely black, strongly tapering to apex, the hairs rather fine 

 and dense (Canada and United States, widespread). 



fumiferanae Tothill (p. 12) 

 Sternopleurals two; uppermost frontals reduced in size situated 

 before triangle; front 0.2 of the head width; abdomen dis- 

 tinctly reddish on sides and apex, the hairs coarse (Europe, 

 New England to Washington, and New Mexico). 



quadripustulata Fabricius (p. 14) 



6. Prosternura with only fine hairs at sides 7 



Prosternum bearing one or more bristles on either side ; ab- 

 domen largely reddish (North America, widespread). 



deilephilae Osten Sacken (p. 33) 



