68 INSECUTOR INSCITI^ MENSTRUUS 



13. Pseudothrips inceqtialis (Beach). — May 18- July 27; both 

 sexes, abundantly on leaves of black willow {Salix nigra 

 Marsh.), and rarely in flowers of fringe-tree (Chionanthus 

 virginica L.)- Recorded from Iowa, Florida, and Tennessee; 

 occurs also in Maryland, District of Columbia, and Illinois 

 (coll. Hood). 



14. Anaphothrips obscurus Miiller. The grass thrips. — June 

 8 ; four females taken in sweeping from grass. Abundant and 

 destructive in Europe and North America, producing the fa- 

 miliar "silver top" on many species of grasses. Recorded in 

 America from Maine, Massachusetts, New York, Ohio, Michi- 

 gan, Illinois, Iowa, Tennessee, Nebraska, California, and On- 

 tario; occurs also in Pennsylvania, Maryland, District of 

 Columbia, Virginia, Indiana, and North and South Dakota 

 (coll. Hood). 



15. Aptinothrips rufus (Gmelin), var. rufus only (^=var. 

 connaticornis Uzel). — April 20; on grass. Abundant and in- 

 jurious throughout Europe; in the United States it has been 

 recorded from Massachusetts, Michigan, Nebraska, and Cali- 

 fornia, but occurs also in Maryland, New York, and Illinois 

 (coll. Hood). 



16. Ctenothrips bridwelli Franklin. — March 30-April 6; fe- 

 males common on the under surface of the leaves of wake 

 robin or birthroot {Trillium sessile L.) and May-apple (Podo- 

 phyllum peltatum L.)> ovipositing in the latter plant. Re- 

 corded from New Hampshire, Michigan, and Tennessee; 

 occurs also in Maryland, Virginia and Illinois (coll. Hood). 



17. Scolothrips 6-maculatus (Pergande). — May 9-18; five 

 females, taken on red cedar (Juniperus virginiana L.)- Re- 

 corded from Iowa, Wisconsin, Missouri, Nebraska, South 

 Carolina, Florida, and the Hawaiian Islands ; occurs also in 

 New York, Maryland, and Illinois (coll. Hood). A predacious 

 species which has frequently been observed to feed on mites. 



18. Sericothrips cingulatus Hinds. — June 8; two females, 

 taken by sweeping grass. Recorded from Massachusetts, 

 Tennessee, and Nebraska; occurs also in Maryland and Illi- 

 nois (coll. Hood). 



