L^ ( D 



of the melon fly [Dacus cncurhitae] from which were bred 1,009 indi- 

 viduals of Opius fletcheri. The parasites distributed inchided :^ 

 Optus fletcheri, 1,391 : Diachasnia tryoni, 58; D. fidlaicayi, 45; and 

 Paranagrus (corn leaf-hopper parasite), 3-1,500. 



Agee (H. p.). Director's Report. — Rept. Expt. Sta. Committee, 

 Hawaiinn S'igar Planters' Assoc, for Year ending September 30, 

 1917, Hovohdu, 12th October 1917, pp. 6-25. [Received 30th 

 April 1918.] 



The beetle, Anomala [orientalis] has been gradually spreading in 

 sugar-cane fields in Hawaii ; although some fields formerly attacked, 

 are now free^rom it, the badly infested area is a little larger than 

 last year. The spread of this pest has recently been chiefly in the 

 direction of irrigation ditches and along railways and other lines of 

 comnumication from infested fields. But for the fact that oviposition 

 has usually occurred prior to flight, the damage done by this beetle 

 would be much more severe than it is. During 1916 a great deal of 

 work was done in connection with the introduction of parasites [see 

 this Review, Ser. A, v, p. 426]. By the end of the year one wasp, 

 Scolia manilae, had become so well established that introduction was 

 discontinued. Other parasites imported include Tiphia ashmeadi, 

 about 6O0 cocoons of which were received from the Philippiiles. The 

 host of this parasite is a different beetle, but it breeds on Anomala 

 spp. to -some extent. T. segregata breeds upon grubs of Anomala, 

 but the emergence of this species is slow and irregular, A few how- 

 ever were liberated. Another species of Tiphia from Japan was 

 liberated in a field infested with grubs of Anomala sp., as there was 

 no evidence of this species having become established from previous 

 importations. A species of Prosena from the Philippines was liberated 

 in sufficient numbers to become established. Dexia sp. was liberated 

 in small numbers, but its chance of becoming established is considered 

 small. An attempt has been made to establish a Japanese Carabid, 

 Craspedonotus sp., with what result is not yet kno\NTi. 



Outbreaks of the leaf-hopper [Perkinsiella saccharicida] have been 

 severe in a number of plantations. It is considered probable that this 

 species is able to multiply rapidly only under abnormal conditions 

 and then only until the parasites regain control. Heavy rainstorms, 

 particularly if accompanied by high winds, the harvesting of large 

 areas and migration of the leaf-hoppers to areas that have been free 

 from them and hence clear of parasites, are among the disturbing 

 factors. It is suggested that the parasites should be distributed arti- 

 ficially in large numbers in order to re-establish control of the pest. 

 Thirty colonies of Ootetrastichus sp. (Formosan leaf-hopper egg-para- 

 site) have been distributed and have been found to be established on V 

 two plantations, but on the whole results with this parasite are con- 

 sidered disappointing. The Chinese Dryinid is reported to be now 

 established in most plantations infestecl -^vith the cane leaf-hopper. 

 The cane borer [Rhabdocnemis obscurns] is fairly held in check by its 

 Tachinid parasite [Ceromasia sphenopJiori], except where rats facilitate 

 the work of the borer. Fresh colonies of the parasite continue to be 

 distributed. 



(C479) a2 



