390 



Transformation to tlie pupa took place two or three days after the 

 receipt of the spccinicu, and the general characteristics of this stage 

 are snt'liciently indicated in the illustration (Fig. 43 e). The pupa was 

 preserved in alcohol, but the adults, from previous observations and 

 rearings, issue, as indicated in the article cited at the outset, from the 

 middle to the last of May. Arrangements have been made with Mr. 

 Treat to continue the study of this insect, and i)articularly to deter- 

 mine whether the great mortality in the eggs, in last season's experi- 

 ence, may be relied on as a normal feature. 



Three nearly full-grown larva' of this insect in currant twigs were 

 received August 10, 1892, from Mr. E. W. Claypole, Akron, Ohio. 

 One of these, which was saved to rear the adult, spun up in August, 

 indicating an early completion of larval growth and a larval dor- 

 mancy of upward of nine months. 



OBSERVATIONS ON CERTAIN THRIPID^. 



By Tri. Pergande. 



Thus far only two species belonging to the genus Heliothrips have 

 been described. 



The most common and destructive of these two species to the foliage 

 of hothouse plants in general, both in Europe and in this country, was 

 described by P. Fr. Bouche, in his Naturgeschichte der schiidlichen 

 und niitzlichen Garten -Insekten, in 1833 (p. 42) under the name of 

 Thrips Jtarnonhoidalis. It is a rather stout, black species, with pale 

 yellow Jegs, almost colorless wings, and the end of the abdomen red. 



The other species, much less common, although it may be found in 

 almost every hothouse, becomes sometimes also quite destructive to 

 various kinds of plants, particularly the Dracaenas. It was described 

 by E. Heeger (Sitzungsb. d. mathem.-naturw. Klasse d. Wisseusch., vol. 

 XIV, 1854, p. 365) under the name of Heliothrips dracccnce. This is a 

 yellowish-brown species with rather long and narrow white wings, 

 which are ornamented with a brownish band across the basal third; 

 two brownish spots or interrupted baud beyond the middle and a spot 

 near the apex. 



Both were probably introduced with ornamental plants from the 

 ■warmer regions of America, at least the first-named species, which is 

 found upou wild and cultivated plants in Brazil. 



HELIOTHRIPS CES'IRI SP. NOV. 



To those I have to add now two additional new species. One, which 

 I shall call HeUothrips cesfrij has been known to me since 1884, when 

 specimens were presented to me by Mr. B. P. Mann, who discovered 

 them infesting a ])lant of Cestriini nocturnum^ brought from Massachu- 

 setts. About the same time it was also sent me by Prof. O. M. Renter, 

 Helsingfors, Finland. 



