PEACH PESTS 



1565 



■».*.v^iai:^iiei«iMs*«ft 



Fig 1. Terrapin Scale (Eulecanium nigrofas- 

 ciatum). Adult females on twig of peach. 

 (Purdue Experiment Station) 



central reddish boss. Occasionally indi- 

 viduals are found which are entirely red 

 or black. 



Food Plants 



For many years the terrapin scale has 

 been considered a specific enemy of the 

 peach and has been confounded by many 

 entomologists and others with Euleca- 

 nium persicae (Fab.), the pre-eminent 

 peach soft scale of Europe. At present 

 we know it as infesting a large number 

 of host plants, including many varieties 

 of peach and cultivated plums; various 

 species of wild plums and cherries, apple, 

 pear, quince, several species of Cratae- 

 gus, three species of maple, oriental and 

 western sycamores, Carolina poplar, olive, 

 blueberry (Vaccinium sp.). 



Distribution 



This scale has been reported from very 



nearly the entire section east of the 

 Rocky mountains. 



Parasites 

 Very small, parasitic four-winged flies 

 of the genus Coccophagus, family Chal- 

 cididae, are our greatest benefactors in 

 the control of this scale insect. 



Kemedies 



Unfortunately the lime-sulphur wash, 

 which is such an excellent remedy for the 

 San Jose scale and which at the same 

 time controls the peach leaf-curl, is 

 worthless for treating the terrapin scale. 

 Numerous experiments in the use of the 

 lime-sulphur wash against this scale on 

 various host plants have produced only 

 negative results. 



Kerosene emulsion has proved to be 

 the most effective remedy for the control 

 of this pest. This emulsion, when prop- 

 erly made according to the formula be- 

 low, can be sprayed with safety on any 

 tree during the dormant period — in win- 

 ter or early spring before the buds open 

 —at a strength of 20 to 25 per cent. A 

 nozzle throwing a fine spray should be 

 used. Care should always be exercised 

 to prevent the liquid from running down 

 the trunk of the tree and collecting about 

 the roots, as the oil, which will be re- 

 tained by the soil around the roots for 

 an indefinite period, might seriously in- 

 jure or kill the tree. 



KEROSENE EMULSION 

 Stock solution (66 per cent oil) 



Kerosene (coal oil, lamp oil) -2 gal. 



Whale oil or laundry soap (or 1 quart 



soft soap) v^ '"J- 



Water -^ ^^^' 



Dissolve the soap in boiling water, 

 then remove from the fire, add the kero- 

 sene immediately and thoroughly agitate 

 the mixture until a creamy solution is 

 obtained. This can be done by pouring 

 the mixture into the tank of a spray 

 pump and pumping the liquid through 

 the nozzle back into the tank. This is a 

 stock solution which must be diluted be- 

 fore using. In order to make a 20 per 

 cent emulsion, add to each gallon of the 

 stock solution and 2 1-3 gallons of water 

 and agitate thoroughly before using. For 

 a 25 per cent solution add to each gallon 

 of the stock solution 1 2-3 gallons of 



