525 



kill the borers in the tree and prevent others from entering, a,nd is a 

 cheap method. Piling the logs and scorching the bark sufficiently to 

 destroy the broods is efficacious in the case of small thin-barked trees 

 such as lodge-pole pine [Pinus murrayana], but is not applicable to 

 large, thick-barked species such as yellow and sugar pine [Pmus 

 lambertiana]. A good method of maintaining an uninfested area in 

 healthy condition is to injure a tree by girdling it during the time of 

 flight of the beetles so as to attract them to this one tree rather than 

 to the green timber. The number of such trap-trees required would 

 however be too great to render their use possible over very large areas. 

 As the beetles normally prefer dying bark it is suggested that all 

 prunings and refuse should be piled over the stumps and fallen logs 

 and burnt at the proper season. In the case of insects having two 

 generations in a year, these burnings should be carried out in July and 

 August and again between October and April. How far the beetles 

 will be attracted to this refuse has not yet been determined, but it is 

 evidently a distance of some miles. It is suggested that saw-mills 

 might be used to advantage in heavily infested areas, the infested trees 

 being cut and converted into lumber on the spot. An example is 

 given of successful control of bark -beetles in the Ochoco National 

 Forest, all the operations being described, with the labour necessary 

 for each. A set of rules and regulations found useful for employes in 

 insect control work is appended. 



Mum (F.). Report of Entomological Work in Australia, 1919-1920. — 



Hawaiian Planters' Record, Honolulu, xxiii, no. 3, September 1920, 

 pp. 125-130, 1 fig. 



An account is given of the author's journey to AustraUa for the 

 purpose of collecting a colony of Drypta for introduction into Hawaii 

 as a control of the sugar-cane leafhopper, Perkinsiella sacclu^ricida. 

 Owing to unfavourable chmatic conditions, difficulties of transport, 

 etc., this object was not accomphshed ; but the investigation led to the 

 discovery of a small bug, Cyrtorhinus mundulus, that will probably 

 prove of greater value than Drypta in the control of the leafhopper. 

 This bug apparently does not attack sugar-cane but lives entirely on 

 the eggs of leafhoppers, of which it sucks out the contents, leaving the 

 eggshell unbroken, the puncture being so minute that it is unrecognised. 



The eggs of C. mundulus are laid in crevices in the oane leaf, often 

 in the sht made by the leafhopper. These eggs are parasitised by a 

 Mymarid parasite very similar to Paranagrus sp. infesting Perkinsiella, 

 but specifically distinct. The young bugs are bright scarlet and very 

 active, and hide at the base of the cane leaf. The heavy rains 

 experienced in Hawaii are too severe for the minute egg-parasites that 

 might otherwise control the leafhopper, and in North Queensland 

 both Paranayrus and Drypta were very scarce after the rains. 

 C. mundulus, on the other hand, seems to be unaftected by storms, and 

 in the author's opinion this msect is the chief cause in Queensland of 

 keeping P. saccharicida in check, being evidently responsible for 

 reducing the numbers by about 80 per cent. 



The possibilit}^ of C. mundulus destioy'mg Paranagrus ^ and so doing 

 more harm than good, has been considered, but even if it entirely 

 supplanted the latter parasite it would still be a gain, as it is the more 



