Notes on Insects Damaging Sugar Cane in Queensland. 



Section A. — Insects boring Cane-stalk and Mid-rib of Leaf. 



(1) " Noctiiid Moth-Borer." (Phragmatiphila truncata. Walk,) 



(2) " Moth Stalk-Borer." (Diatraea saccharalis, Fabr.). 



(3) " Beetle Borer." {Rhabdocnemis obscurus, Boisd.). 



(4) " Moth Shoot-Borer." {Polyocha sp.). 



(5) "Bud Moth," No. 1. {Opogona glycyphaga, Meyr.). 



(6) " Bud Moth," No. 2. [Loxostoma .?sp.). 



(7) " Leaf-Rib Borer." {Cosmopteryx sp.). 



(1) PHRAGMATIPHILA TRUNCATA, Walk. (Family NOCTUIDAE). 



Sjaionyniy — Nonarfria exitiosa, Oliff.: Leucania leonma. Walk. 

 Plate I., Fig. 1, p. 6. 

 This species has long been familiar to entomologists under the name 

 of Nonagria exitiosa, and as far back as 1891 was recorded as a serious 

 cane pest in New South Wales. It has been taken also in South Aus- 

 tralia and Tasmania, and in our own State occurred injuriously in the 

 Mulgrave district in 1907, and later (1909) at Bundaberg, but up to the 

 present has not, I understand, occasioned serious damage in Northern 

 Queensland. 



In the course of investigation at Pyramid it was noticed that larvae 

 of this insect generally gnaw one or more holes about a sixteenth of an 

 inch in diameter through the sides of affected shoots, usually close to 

 the ground, but sometimes just above it. Happily for the grower, these 

 tiny holes — which apparently act as safety valves for the escape of car- 

 bonic acid gas, and admittance of fresh air to the interior — afford a 

 ready means of ingress to parasitic and predaceous foes, which doubtless 

 destroy large numbers of the caterpillars. The notorious ant PJieidole 

 megacepJiala is not slow to take advantage of so ready a means of invad- 

 ing the tunnels, and I am of opinion that in the event of its thorough 

 establishment on a plantation might prove an important controlling 

 factor in this connection. Its presence, however, is undesirable in cane- 

 fields infested by the ' ' beetle borer ' ' Rhahdocncniis ohscurus, as this 

 ant is known to seriously check the increase of certain dipterous para- 

 sites that help to control the ravages of weevil borers. 



Two kinds of hymenopterous insects have been previously recorded 

 as parasitic on P. truncata in New South Wales. 



One of these, Apanteles nonngriae, is credited with destroying about 

 fifty per cent, of the caterpillars, while the other hymenopteron, 

 Euplectus hoivardi, attacks the pupa, effectually preventing the 

 emergence of myriads of moths that would otherwise cause immense 

 damage. Probably these, and other valuable parasites, occur also in 

 Queensland. Larvae collected at Pyramid yielded specimens of a large 

 tachinid fly, not yet identified. 



