141 



scarcely an opportunity to doubt that they were subsisting upon the 

 jilant. A species which agrees with P. nigra Osboru in every respect, 

 so far as I can see, but in larval and pupal characters, occurs commonly 

 on Mullein, and this species I have bred from Qgg to imago with no other 

 food than that received from the mulle.in leaf, the injury to the leaf 

 showing as yellow blotches, similar to those produced by Tetranychus 

 telarius. I can therefore state positively that this species can mature 

 upon purely vegetable diet. The leaves were kept in water in my office 

 under constant observ^ation, and the Thrips developed to maturity on 

 the same leaves that the egg^ were deposited upon by the adults. 



The following summary of the species whose food habits have been 

 noted will show the state of our knowledge so far as the different species 

 are concerned and the records of which have come to my notice : 



Phloeothrips mali Fitch, gouging iuto youug cipples (Fitch). 



Phlocothrips caryoi Fitch, iu hickory galls, food ? (Fitch). 



Phloeothrips nigra Osborn, lives iu clover heads. 



Phlceothrips sp. uear nigra, feeding on leaves and blossoms of Mullein. 



Phhmthrips frumentaria Bel., larvfe suck grain in the ear (Lindeman). 



Phlceothrips armata Lindeman, affecting Compositte and Grasses (Lindeman). 



Thrips tritici Fitch, injurious to wheat and clover (Fitch), attacking styles of apple 



blossoms (Osboru), injuring strawberry (various writers). 

 TJirips cercalium Hal., very destructive to wheat in Europe (Kirby, Curtis, et al.). 

 Thrips minutissimus L., infests potato (Curtis). 

 Thrips ochraccous, destructive to melons, etc. (Westwood, Curtis). 

 Thrips striatus Osborn, "destroys onion plants" (Packard)."* 

 Thrips sp., very injurious to olive trees (Westwood). 

 Tlxrips sp., living on leaves of hop. 



Liinofhrips poaphagus Comstock MS., affecting grass (Comstock ei ah). 

 Limothrips graminea Pergande MS., affects corn, wheat, and grass (Pergande, Forbes 



in lit.). 

 HeVwthrips hwmorrhoidalis Bouch^, injuriousin greenhouses and on apple. 

 Heliothrips draca'iice, Heg., reported very destructive in hot-houses (Pergande). 

 Heliothrips adonidum -dracwna', {^.) infests greenhouse plants (Westwood). 

 Chirothrips antennata Osborn, in timothy heads (Osboru), timothy, wheat, and rye 



(Lindeman). 

 Aptinothripis rufa, subsisting upon Grass aud Compositse (Lindeman). 

 Coleothrips irifasciata Fitch, injurious to wheat (Fitch, Packard). 



The conclusion to be drawn from the evidence at hand seems to me as 

 follows : 



That the Thripidse as a group are normally herbivorous, aud their 

 presence on cultivated plants is a source of danger. 



That they feed mainly on the exuded nectar or secretions of plants, 

 when these are abundant, and on pollen, and at such times may do little 

 or no damage. 



That they will upon occasion attack the tissues of the leaves or the 

 essential parts of the blossom and pierce them for their contents, aud 

 at such times may cause serious damage. 



* Packard also mentions this species (Entom. for Beginners, p. 197) as injurious to 

 wheat, but I think it must be an error, and Thrips tritici intended instead. 



