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LouNSBURY (C. P.). The Phoracantha Beetle. A Borer Pest of Euca- 

 lyptus Trees. — Union S. Africa Dept. Agric, Div. Entoni. [sine 

 loco], Local Series no, 24, 10 pp., 2 figs. [Received SOth 

 Mt.7 1918.] 



Phoracantha semiptmctata is a native of Australia, where it is known 

 as a firewood beetle, and was probably introduced into S. Africa in 

 newly-cut railway sleepers shortly before the South African War. 

 It closely resembles in appearance and habits P. reciirva, Newm., 

 the commoner Australian species, which, so far as is known, has not 

 become estabhshed in South Africa. The damage done by this borer 

 is of a secondary nature, as it attacks newly felled timber from which 

 the bark has not been removed, and sickly or dying trees. Dry wood, 

 even though there is bark adhering, is not attacked. 



A native South African Cerambycid beetle, Phryneta .spinator, 

 attacks fig and willow trees and has become confused with Phoracantha 

 sonipunctata. The eggs of the latter beetle are laid in crevices of the 

 bark in large groups. The young larvae tunnel through the bark to 

 the cambium and then burrow in all directions between the bark 

 and the wood, a form of injury which, if it surrounds the trunk, 

 results in the death of the tree. The full-grown larvae remain in 

 their burrows throughout the winter and pupate as soon as the 

 weather becomes warm. After a short pupal stage the adults emerge 

 and continue to do so throughout the summer. 



Most, if not all kinds of eucalyptus trees are liable to attack, though 

 Eucalyptus globulus appears to be damaged more often than others. 

 This may be however because it is the most frequently planted species, 

 attempts often being made to grow it in localities that are unsuitable, 

 the resulting unhealthy trees being readily attacked. E. viminalis 

 has suffered severely in places, and other species that become infested 

 are E. longifolia, E. rohusta, E. saligna, E. acmenoides, and E. diversi- 

 color. Vigorous trees when attacked exude gum, which is usually 

 fatal to the insects, besides betraying the points of entrance. Un- 

 healthy trees are attacked quite irrespective of their age, the beetles 

 however tending to avoid smooth bark. 



In its native country this beetle has important parasitic enemies, 

 but they do not Qccur in South Africa, and attempts cannot be made 

 to introduce them till shipping facilities again become normal. 



Remedial measures include proper drainage and cultivation and 

 protection from fire, though little can be done to keep up the vigour 

 of the trees by these means. Keeping down the numbers of the 

 beetles may be effected chiefly by the use of trap-trees, by keeping 

 the wood in water, by stripping off the bark, and by utilising infested 

 wood promptly, of which the last is by far the most important remedy. 

 Trap-trees are simply trees of little value that are felled and left 

 lying so as to attract beetles about to oviposit away from standing 

 trees. At the end of the summer the traps are dealt with so as to 

 destroy the larvae, and if this is neglected, the use of such traps 

 intensifies the trouble instead of reducing it. Submersion of logs until 

 they are required for use may be profitably employed if they are situated 

 near a dam, but experience has show^i that though the larvae between 

 the wood and bark are killed, those more than an inch within the 

 wood were unaffected. 



