670 . FAUNA HAWAIIENSIS 



If carded these insects dry and curl up very quickly and are of but little use for 

 study, it is therefore necessary to collect them by means of a small camels' hair brush 

 into a weak solution of formalin, or in from 60 to 70 '/„ alcohol. The majority of 

 flower-living thrips are very small — not infrequently less than a millimetre in length — 

 and therefore require careful search. The best plan is to shake plants, leaves, flowers, 

 etc., or the contents of one's sweep-net, on to a sheet of white paper, where the most 

 minute insect can be readily seen as soon as it moves. 



As mio-ht have been expected, excepting for the description of two species given in 

 a recent short paper by the late Mr Kirkaldy, the Thysanoptera of the Hawaiian 

 Islands are unknown. The material upon which the present contribution is based has 

 all been collected by Dr R. C. L. Perkins, and consists chiefly of about seven dozen 

 dried and mounted specimens, though later a small collection in alcohol was submitted ; 

 and because of the difficulty of satisfactorily dealing with dried material this latter 

 collection, though small, has been very helpful indeed'. 



Altogether twenty-one species are recorded ; fifteen of these are new ; two are 

 those described by Kirkaldy, whilst the other four are well-known pests and two of 

 them almost cosmopolitan in their distribution. This is probably only a small pro- 

 portion of the Hawaiian Thysanoptera; it is quite possible that energetic and systematic 

 search, giving particular attention to the minute forms attached to the various plants, 

 will bring to light five or six times this number. 



Further and considerable material would be very useful and welcome; not only will 

 new forms be discovered but we shall be able more fully and perfectly to describe some 

 of those species which through lack of material have herein been erected on single and, 

 in more than one case, imperfect specimens. 



It is evident that the Thysanopterous fauna of the Sandwich Isles is by no means 

 poor. In his Presidential Address for 1906, to the Hawaiian Entomological Society, 

 taking as his subject the " Insects at Kilauea, Hawaii"," Dr Perkins in speaking of the 

 Thysanoptera says that, as everywhere in the islands, they are very abundant and the 

 species are probably numerous. 



Distribution. A study of the distribution of these insects, in the islands forming 

 the Hawaiian group cannot but be interesting. The chief feature lies in the number of 

 species that are peculiar each to a certain island, a feature already strongly shown in 

 other groups of more familiar insects and which, though shown perhaps in an exaggerated 

 form here owing to want of material, will we think be substantiated to a large extent 

 when the Thysanopterous fauna is better known. Under the name of each island we 



' We are indebted to Mr Dudley Moulton for the records of Hdiothrips rubrocindus and Scolothrips 

 b-niactilatus. 



- Proc. Hawaiian Ent. Soc, vol. i. pt. 3, p. 8g. 



