IOWA ACADEMY OF SCIENCES. 215 



FAM. II. STENOPTERID.B. 



A. Body above netted with elevated lines.. Gen. 2. Heliothrips. 



AA. Body above smooth. 



B. Abdomen clothed with silky hairs; apex cDnical, formed alike in 



both sexes Gen. 3. Sericothrips. 



BB. Body smooth; apex of abdomen unlike in the two sexes. 



C. Prothorax produced in front, and narrowed — 



» Gen. 4. Chirothrips. 



CC. Prothorax not produced in front and narrowed. 



D. Last segment of abdomen with a pair of spines in female; 



male, wingless... Gen. 5. Limothrips. 



DD. Last segment of abdomen unarmed. 



E. Last two segments of antenna? shorter than the sixth 



segment -.. Gen. 6. Thrips. 



EE. Last two segments of the antenna? longer than the 

 sixth segment Gen. 7. Belothrips. 



FAM. III. COLEOPTRATID-E. 



A. Antennae with nine distinct segments Gen. 8. Melanthrips. 



AA. Antenna apparently five jointed, the last four segments being 

 minute and compact 

 B. Body somewhat flattened; meso-metathorax broad; front wings 

 without fringe on costal border, and with four distinct cross 



veins; males with lateral abdominal appendages-. 



Gen. 9. Coleothrips. 



BB. Body cylindrical, mesothorax and metathorax constricted, wings 

 rudimentary... Gen. 10 Aeolothrips. 



SYNOPSIS OP IOWA SPECIES. 



GENUS PHLCEOTHRIPS, HAL. 



A. Proximal joint of anterior tarsi armed with a tooth on inner side ..1 

 A A. Proximal joint of anterior tarsi unarmed 2 



1. With postocular bristle; three bristles on each side of pro- 

 thorax; antennal joints 3-6 yellow ..verbasci, Osb. 



Without postocular bristle; a single bristle at each posterior 

 angle of prothorax; antennal joint 3 and base of joint 4, some- 

 times base of joint 5, yellowish nigra, Osb. 



2, Black; head slightly longer than wide; tube three times as 



long as wide ..caryiv, Fitch. 



Purplish-black; head one and one-half times as long as wide; 

 tube twice as long as wide ...ma//, Pitch. 



Plilmothrips vei'basci, Osb. 



Description follows this paper. 

 Phloeothrips nigra, Osb. 



Can. Ent, Vol. XV, p. 154 [1883]. 

 Phlmothrlps caryce, Pitch. 



[Third Report.] Trans. N. Y. State Agr. Soc. for 1856, Vol. 

 XVI, p. 446. 



