OBSERVATIONS OF SEED-BUG (HEMIPTERA: 
LYGAEIDAE) 
PARASITISM BY A SPECIES OF 
CATHAROSIA (DIPTERA: TACHINIDAE) 1 
By Kevin W. Thorpe 2 and B. Jane Harrington 
Department of Entomology 
University of Wisconsin 
Madison, Wisconsin 53706 
Introduction 
Tachinids of the genus Catharosia Rondani are infrequently 
collected parasitoids of seed bugs (Hemiptera: Lygaeidae). Sweet 
(1964) was the first to publish biological information on flies of this 
genus. He reared Catharosia from 15 species of bugs in 11 genera 
and, after communicating with Dr. Paul H. Arnaud, Jr., concluded 
that a large complex of Catharosia species was probably involved. 
Later Ashlock and O’Brien (1964) reported rearing 35 Catharosia 
lustrans (Reinhard) from field collected Thylochromus nitidulus 
(Barber) and Eremocoris opacus Van Duzee (Lygaeidae: Rhy- 
parochrominae: Drymini). These authors also reared a single fly 
through a complete life cycle on a laboratory culture of an 
undescribed species of Eremocoris. 
During the summers of 1977 and 1978, we reared 51 adults of a 
tachinid species from field collected individuals of four closely 
related lygaeid genera of the rhyparochromine tribe Myodochini. 
We reared an additional 16 flies through a complete life cycle on 
laboratory cultured Ligyrocoris diffusus (Uhler). Samples from 
these rearings were identified as a single species of Catharosia (P.H. 
Arnaud, personal communication). Voucher specimens were de¬ 
posited in the collections of the California Academy of Sciences, 
San Francisco and the University of Wisconsin, Madison. 
'Research supported by the College of Agricultural and Life Sciences, University 
of Wisconsin-Madison and by a grant from the University of Wisconsin Graduate 
School (Project Number 190381). Part of a thesis submitted by K. Thorpe in partial 
fulfillment of the requirements for the MS degree. 
2 Present Address: Beneficial Insect Introduction Laboratory, Building 417, 
BARC-East, Beltsville, Maryland 20705. 
Manuscript received by the editor May 6, 1980. 
399 
