INSECTS ETC., IN7URIOUS TO VARIOUS CROPS I561 



T151 - Dacus vertebratus (cucumber and vegetable marrow fly), a Dipteran which 

 is Harmful to Cucurbitous Plants in South Africa. — gunn, d in I'n-inn of South 



Africa, Deportineni of A'.ricuUure, Division of Entomolo«y,l<So. 9, pp. 2-6, Pretoria, 1916. 



Dacus venebrattis causes considerable damage to the cucumbers, 

 inimpkins. water melons and in general to all the Cucurbitous plants that 

 are cultivated in South Afiica The female lays her eggs, 10 to 25 at 

 the same time, in the rind of the fruit : the incubation period is from 2 to 

 4 days. The larvae bore long galleries in the rind, which grows soft and 

 shrivels \ip, the}^ also bore in the pulp which becomes a semi-licjuid mass 

 with a rancid smell. The larvae when they are mature crawl into the 

 ground where they pupate. The adults come out after 5 or 7 days and 

 live from t to 5 months 



It is advisable as a means of control to spread over the plants in need 

 of protection sweet substances (sugar etc.) of which the insect is very fond, 

 mixed with poison. The following formulae have been successfulh' em- 

 ployed : 



1) I/ead arseniate (in a pasted 3 oz. 



Molasses 2 lbs. 



Water 2 gallons 



2) I^ead arseniate iin a pi/.i.) 3 oz. 



Molasses - lbs. 



Glj'cerine 3 oz. 



Water 2 gallons. 



3) I,ead arseniate (in a paste) 2 oz. 



Sugar 2 14 lbs. 



Water 2 gallons. 



When the weather is warm and dry the applications must be made every 

 12 to 14 days. But if the weather is wet they should be renewed as often 

 as possible immediately after the rain. 



1152 -Coleoptera Harmful to Fruit and to Flowering Plants Cultivated in South Africa. 



— Gunn, D.in C7m"owo/ South Africa Department of Agriculture, Division of Entomology, 

 No. 8, pp. 1-6, I pi. Pretoria, 191 6. 



In South Africa in the summer several Coleoptera cause serious damage 

 to the fruit trees and flowers in the orchards and gardens. Their favour- 

 ite host is the peach tree, whose harvest they spoil to the extent of about 

 20 to 50 per cent, by attacking the ripe and the ripening fruit. Among 

 other hosts are rose trees, dahlias, pears, plums, nectarines, apricots, 

 figs, oranges (buds) and vines (leaves). 



The species most often observed in the neighbourhood ot Pretoria 

 during the period 1913 to 1914 were the following : Rhabdotis antica, Pa- 

 chnoda, imP'^-essa, P. cincta, P. carmelita, Heterorrhina llavomacidata . Plae- 

 siorhina recurva var. plana, Oxythyrea niarginata and 0. dysenterica. 



As a method of control the direct capture of the adults is advised ; 

 this is effected by means of special butterfly nets fastened to the ends of 

 long canes which can be used easily even by the natives. 



