200 



The company ofifcr the very Hkely reason for this difference 

 by saying- that prol)a]:)ly the weaker fibres only have Ix'en 

 broken by the saw gin, which when remo\e<l in the al)o\e pro- 

 cesses lea\-e the saw-ginned cotton with a higher average 

 strength than has the roller-ginned. 



It might he w^ell to add here, however, that only in case the 

 ginning is very carefully done upon the saw-gin is such a 

 small dift'erence likely to be shown. To do as little damage 

 as possible to the cotton it is necessary that the gin be run 

 at a lower rate of speed than the manufacturers have recom- 

 mended since in their recommendation they were thinking of 

 short staple cotton. The higher speed would give a greater 

 capacity to the gin, Init it might result in greater damage to 

 the staple. 



PARASITES OF IXSECTS ATTACK IX G SUGAR CAXE^ 



Bv R. C. L. Perkins. 



In this bulletin is described a number of very minute para- 

 sites, nearly all of which were bred from eggs of insects attack- 

 ing cane in countries other than these islands. 



The American species were obtained by Mr. Koebelc, when in- 

 vestigating insects in the cane fields in Mexico, where he spent 

 a short time during the winter months of 1908. All the rest were 

 obtained by Mr. Muir in Vi]\, China and the Malay islands. Many 

 of these parasites are of great interest and importance, sir.ce they 

 are important agents in limiting the numbers of injurious species 

 which, if introduced into the islands without their ])arasites, 

 would be likely to cause great loss to the sugar plantations. It 

 has been advisable, therefore, to work out these insects and put 

 them on record, so that in the event of any of the species which 

 they attack turning up in the islands, information would be at 

 hand as to where to look for natural enemies without delay. Al- 

 though there is now a regular inspection of all imi)orted plants 

 and, without doubt, the vast majority of injurious insects is in- 

 tercepted and destroyed, yet there are means of introducticMi 

 which no ins])ection can provide against. .Msn ihere are some in- 

 sects which are liable to be passed over by the most shrewd in- 

 s])ector and again.st which treatment by fumigation is ineffective. 

 W'e know that in spite of the fact that there has been a systematic 

 inspection of introduced plants for nine years, during the last 

 few years numerous insects have a])peared and become abundant, 

 liecause this is the case there is no reason to regard insi)ecti()n 

 as futile. \i<y as has been said, there is no doubt that thr Diajnrity 

 of imi)orteil species is thereby prevented from hiTtuniiig (.'slab- 

 lished. With the opt'ning nf tlir Taiiania canal and with (|uick 



* Report of work of llii> KxinMiincnl .Stiitiim of the Ilawiiiiiiii SuRnr PliiiiliTs' 

 ARSOfintion. Iiilnxlnitidii to Unlli'tin in. Kntomoloci*'"! Scrii-s. (Printed liy pi-r- 

 iniKNion H. S. I'. .\. Kxpniiticiil Station.) 



