Journal of Agriculture. [8 Feb., 1908. 



SPRAYING FOR THE PUMPKIX BEETLE. 



The following report dealing with spraying for the Pumpkin Beetle 

 has been received by the Entomologist from Inspector Wallis of Wan- 

 garatta. 



" I have the honour to re^wrt the results of my experiments with several 

 mixtures on the Pumpkin Beetle which is now doing much damage to 

 pumpkins and other plants. 



The mixtures used were as follow : — Paris Green, Arsenite of Lead, 

 " Carbysol " and crude oil of tar emulsion. I cannbt say that the arsenical 

 mixtures have been effective although repeated trials have been made. This 

 is rather perplexing as the eperdermis of a leaf is soon destroyed when 

 attacked by a number of the beetles. However I find that if the beetles 

 are confined in an observation jar and a piece of leaf sprayed with the 

 Arsenite of Lead mixture is put in with them, they sobn eat the leaf and 

 die. " Carbysol " is not effective either as a contact remedy or in making 

 the food obnoxious. I am glad, however, to report that the oil of tar 

 emulsion has given verv good .results both as a contact remedy and a 

 deterrent in making food obnoxious to the beetle. 



The habits of the beetle are such as to make it easy to destroy it by 

 contact. The beetled congregate in large numbers on a single leaf whilst 

 the other leaves of the plant may remain untouched and only a few of the 

 beetles attempt to take flight when iplant is sprayed. I ha.ve seen as many 

 as 1 70 beetles on a pumpkin leaf the other leaves of plant being untouched. 



I have found that from 80 per cent, to 90 per cent, of the beetle.<i are 

 killed on the spot when a strength of i — 80 of the tar emulsion is used 

 and the healthy leaves of plant are in no way injured. The beetles had 

 not attempted to attack the plant during the week following the day of 

 spraying. I tried this same emulsion with a lesser strength (i- — 160 and 

 I — 120) also a greater strength (i — 50). The former strengths proved too 

 weak simply stupifying the beetles for a few minutes. The i — 50 strength 

 if allowed to remain in any quantity on leaves, caused foliage to burn. 



The following is the formula which I have used successfully : — Crude 

 oil of tar, | pint ; Soft soap, J lb. ; Caustic soda, i oz. ; water,. 5 gallons. 

 Make as follows: — Boil one pint water and in it dissolve soap and soda; 

 add oil of tar, and agitate well. Then add the mixture to remainder of 

 water (hot), agitate and use. Confine attention chiefly to leaves on which 

 beetles have swarmed and use a good garden syringe to spray mixture t>n 

 plant. The price of crude oil of tar is about 5s. per gallon at wholesale 

 places. 



At Messrs. Swan Bros, orchard, Londrigans, I found the beetle attack- 

 ing cherries, the crbp O'f one tree being almost destroyed, whilst the 

 cherries on the other trees were mo're or less infested. I saw as many as 

 six beetles attacking one cherrv. When the beetle has done its destructive 

 work the cherry somewhat resembles a raisin in appearance. When attacking 

 a cherry, the beetle does not eat awav the surface but eats a hole into the 

 fruit and then appears to eat or suck away the flesh leaving the skin to 

 become wrinkled and drv. 



I have not found the beetle attacking fruit at any other orchard." 



