523 



destroying locusts has steadily progressed since its commencement in 

 1913 ; a few locusts were present during 1916 and were watched 

 carefully until the end of the year. Many districts are now 

 practically free from locusts, so that very little more work is required 

 there. 



Pettey (F. W.), The Quince Borer and its ContToh— Union S. Africa 

 Dept. Agric, Pretoria, Bulletinno. 2, 1917, 17 pp., 9 figs. [Received 

 26th September 1917.] 



For many years, probably as long as the quince hedge has existed 

 in the Cape Province, this fruit has been attacked by the larva of a 

 Cossid moth, Coryphodema tristis, Dru. {capensis, Feld.). C. puncfulata 

 recorded from the northern Transvaal may possibly prove to be the 

 same species. 



Though quince is the favourite food-plant, many varieties of apples 

 and a few pears are attacked, and this moth has also been recorded in 

 grapes, loquats and in Buddhia madagascariensis, which was introduced 

 from Madagascar. C. tristis is apparently distributed all over the 

 Cape Province wherever quinces or Wemmershoek apples are grown. 

 As it is not known to occur in any other country, it is believed to be 

 indigenous in South Africa and should therefore be found on a native 

 plant. The damage caused by its infestation is serious, as it kills many 

 of the branches, in which it bores, and impairs the bearing capacity of 

 the tree. The morphology and life-history of the insect were studied 

 from infested quince branches placed under wire-netting cages ; a 

 graph records the emergence of the moths during 1915 and 1916. The 

 adult moth apparently has rudimentary mouth-parts and lives a 

 maximum of six days, thus allowing only a short period for oviposition. 

 One female may lay from 104 to 316 eggs ; these are deposited in an 

 irregular mass formed of many clusters in any rough or sheltered place 

 in the bark of the branches and trunks of the trees, and sometimes in 

 the openings of old burrows in the angles where one branch joins 

 another, under the scales of the bark, and especially in the cracks of 

 rough swellings caused by the woolly aphis [Eriosoma lanigerum]. A 

 period of 63 days may elapse before the eggs hatch. The larvae upon 

 hatching immediately begin to feed on the empty egg-shells and 

 construct a thin layer of silk and sawdust-like i^articles that 

 completely covers them. In a few days they bore their way into the 

 bark, the accumulations of frass thus produced rendering the presence 

 of the insect evident. They feed in this manner for at least two months, 

 though a few individuals penetrate the woody tissue about five days 

 after emergence from the egg. If the covering be removed during 

 this period, the larvae escape into small holes that they have bored in 

 the bark, being evidently sensitive to hght. The area of decayed bark 

 injured by the insects at this time, if not cut away by a knife, spreads 

 and ultimately encircles the branch through the inability of the 

 cambium to heal over the dead area. Finally the ring of decay cuts off 

 the sap supply from the roots and the branch dies. After about eight 

 weeks the larvae begin to bore into the woody tissues, where they 

 remain active for about a year and a half before pupating. The 



