400 
Psyche 
[December 
From that rearing effort we present information on the biology of 
this parasitoid and a description of an interesting structure on the 
female abdomen that presumably aids in oviposition. 
Materials and Methods 
Lygaeid adults and nymphs were collected from several dry, 
disturbed habitats in each of three Wisconsin counties. Ligyrocoris 
diffusus and Perigenes constrictus (Say) were collected from Dane 
Co. in southern Wisconsin; L. diffusus, L. sylvestris (L.), P. 
constrictus, Sphaerobius insignis Uhler, and Zeridonius costalis 
(Van Duzee) were collected from Wood Co. in central Wisconsin; 
and L. diffusus, L. sylvestris, and Z. costalis were collected from 
Vilas Co. in northern Wisconsin. Field collected bugs were 
maintained and reared individually or in small conspecific groups at 
26 ± 1° C and 16L:8D photoperiod in glass crystalizing dishes (90 X 
50 mm) with plastic lids. Each dish was provided with a vial of water 
stoppered with a dental wick, hulled sunflower seeds, and several 
thin squares of methyl cellulose. The dishes were checked daily for 
tachinid pupae, which were transferred to clean vials to prevent 
fungus infestation. Upon eclosion adult flies were supplied with a 
dental wick moistened with sugar water. Whenever both sexes of 
flies became available concurrently they were placed together with 
laboratory cultured L. diffusus nymphs and adults. 
Scanning electron photomicrographs of Catharosia were obtained 
from gold-palladium-coated preparations viewed on a Jelco JSM- 
U3 scanning electron microscope. 
Results and Discussion 
Catharosia were reared from all myodochine species collected in 
Wood Co. and Vilas Co., but none emerged from any bugs collected 
in Dane Co. Ligyrocoris sylvestris is a new host record for the genus 
Catharosia. Sweet (1964) reported rearing Catharosia from L. 
diffusus and L. dipictus Barber in New England, but not from L. 
sylvestris or L. caracis Sweet. Sweet also reported rearing Catharosia 
from the other 3 myodochine species collected in this study. 
The rates of parasitism of L. diffusus, the myodochine most 
commonly collected at the Wood Co. site on 19 June and 22 August 
1978, were 60% and 16% respectively (Table 1). The difference in 
