INSECUTOR INSCITI^ MENSTRUUS 59 



10. Sericothrips piilcheUns Hood. — August Ifi; several spec- 

 imens of both sexes on leaves of Ptelea trifoliata. Recorded 

 only from Illinois. 



20. Scirtothrips ruthveni Sliull. — May 19 ; several females 

 from leaves of mountain laurel {Kalmia latifolia L.)- Known 

 previously only from Huron County, Michigan, where it was 

 taken in the terminal leaf clusters of red-osier dogwood (Cor- 

 nus sfolonifera Michx.). 



21. Scirtothrips niveus Hood. — May 18 ; both sexes, on the 

 under surface of leaves of flowering dogwood {Cornus florida 

 L.). Known only from Plummer's Island. 



22. Scirtothrips hrevipennis Hood. — May 18 ; eight females, 

 on red cedar (Juniperus virginiana L.). Known only from 

 Plummer's Island. 



23. Bchinothrips americanus Morgan. — July 13-September 

 14 ; both sexes common in all stages on under surface of leaves 

 of leaf-cup (Polymnia sp.) and touch-me-not {Impatiens bi- 

 flora Walt, and /. aurea Muhl.). Known previously from 

 Florida, Tennessee, Missouri, and District of Columbia. 



24. Heliothrips striatus Hood. — July 27-October 12 ; both 

 sexes common on the leaves of tulip-tree (Liriodendron tulipi- 

 fera L.). Described from Maryland and Illinois; identified as 

 H. fasciatus Pergande by A. C. Morgan, and recorded^ under 

 that name from Clarksville, Tennessee ; occurs also in Virginia 

 and the District of Columbia. 



25. Thrips tabaci Lindeman. The onion thrips. — May 19 ; 

 one female, in flower of fringe-tree (Chionanthus virginica 

 L.). A very injurious, cosmopolitan species, probably occur- 

 ring in every State of the Union. 



26. Thrips varipcs Hood. — March 30-April 6 ; eleven fe- 

 males, taken in flowers of Muscari racemosum (L.) Mill, and 

 dog-tooth violet (Erythronium sp.). Known only from Mary- 

 land and Illinois. 



27. Thrips impar Hood. — August 16-September 14 ; both 

 sexes abundant in flowers of touch-me-not {Impatiens sp.). 



'Russell, Bull. 118, Bur. Ent., U. S. Dept. Agr., p. 15, 1912; and Morgan, 

 Proc. U. S. Nat. Mus., Vol. 46, p. 43, 1913. 



