Notes on Insects Damaging Sugar Cane in Queensland. 9 



Description of Moth. 

 Fore-wings liglit yellowish silvery-brown, with a row of minute 

 Mack dots on edge of outer border, an oblique irregular row near centre 

 of wings, and a few dots on basal area. Hind-wings paler and without 

 spots. Antenna" setaceous in female and with two rows of pectinations 

 in male. Wing expanse variable, averaging li/. inches. The eggs of the 

 first Spring brood are laid towards the end of July. 



(2) DIATRAEA SACCHARALIS, Fabr. (Family CRAMBIDAE). 

 Plate I., Fig. 2, p. 6. 



Like the preceding insect this notorious moth appears to be under 

 ■effective natural control in Queensland and cannot be classed as a serious 

 pest. 



I have not yet had an opportunity of studying its life-history or 

 economy. It will be of interest to mention, however, with reference 

 to control measures, that experiments conducted in Texas, U.S.A., during 

 1914, showed that the average infestation of fields in which trash had 

 been buried was 30-6 per cent., as against 76 per cent, in burned fields, 

 the lower percentage being due to the destruction of egg parasites on 

 the foliage and in the egg masses of borers attached to the leaves. 



The small proportion of borers left in cane tops and stubble after 

 harvesting reappear the following season, and on plantations where 

 trash is buried, or better still raked to the headlands, are met by their 

 parasites, which are thus able to render great assistance by promptly 

 •destroying the eggs of the first brood of moths. 



(3) RHABDOCNEMIS OBSCURUS, Boisd. (Family CURCULIONIDAE). 

 Plate I., Fig. 3, p. 6. 



This formidable insect has apparently become firmly established in 

 the Johnstone River district, where it not only exercises an appreciable 

 influence on the quality and weight of crops but is said to annually 

 destroy thousands of tons of cane. It was troublesome locally at Mackay 

 and Mossman during 1909-11, and in June of the following year (1912) 

 occurred in various localities at lunisfail, attacking Badila cane and 

 •occasioning serious losses. 



The Queensland Government Entomologist, Mr. Tryon, whilst in 

 New Guinea discovered a tachinid parasite of this pest which subse- 

 quently received the name of Ccromasia sphcnophori, Vil., and in 1911 

 was introduced into Fiji, where it quickly spread and is now reported 

 to be successfully combating the beetle-borer. Larva? of this useful fly 

 were later (1914) brought to North Queensland by the Colonial Sugar 

 defining Company, and the imagines bred from same liberated among 

 infested cane on the Johnstone River. Control measures practised by 



