THE CAMPHOR SCALE H 



of each stage from a consideration of the average temperature. The 

 method of prediction (7) offers a means of correctly timing the 

 applications of summer sprays, and will be discussed in a later 

 section. 



NATURAL ENEMIES 



The following hymenopterous parasites of the camphor scale have 

 been found in southern Louisiana : Aphelinus fuscipennis Howard, 

 Aspidiotiphagus citrinus (Craw), Prospaltella aurantii (Howard), 

 Prospaltella fasciata Malenotti, Aphelinus diaspidis Howard, and 

 Sigiiiphora favopalliata Ashmead. Of these, A. citrinus and P. 

 fasciata were the most frequently encountered, but none has yet given 

 any appreciable control. Metal aptus torquatus Malenotti has also 

 been taken from cages in which camphor scales were confined, but 

 this may be a parasite of psocid eggs. 



In limited areas a considerable decrease in infestation has occa- 

 sionally been caused by predators, the most effective being the orange 

 bagworm (Platoeceticus gloverii Pack.) (13), the twice-stabbed lady 

 beetle (Chilocorus bivulnerus Mills.) (fig. 7), and the pitiful lady 

 beetle (Microioeisea misella Lee). 



Two fungous parasites of the scale have been discovered. These 

 were determined by Vera K. Charles, of the Bureau of Plant In- 

 dustry, as Miwocera coccophila Desm. and Cladosporium sp., with 

 the following note : " Ordinarily the latter fungus is not truly para- 

 sitic, its injury being more mechanical in effect, that is, by interfer- 

 ence with respiration and locomotion of the scales." These, however, 

 have never been found to give permanently effective results over 

 any general area, and so direct, or artificial, methods must be used 

 to combat this pest. 



ARTIFICIAL CONTROL 



OIL EMULSIONS 

 METHODS OF PREPARATION 



The most effective sprays for controlling the camphor scale are 

 emulsions of petroleum oil in water. There are a number of ways 

 in which such emulsions can be prepared, and three of the most 

 suitable methods are given below. 



Formula 1. — The hot-pumped, or boiled, emulsion is made up as 

 follows : 



Oil gallons— 2 



Water do 1 



Potassium fish-oil soap pounds__ 2 



or 



Hard soap do 1 



The soap is dissolved in water, which should be heated if hard soap 

 is used, and the oil is added. The mixture is placed in a metal 

 container over a covered fire and heated until it begins to boil. It 

 is then removed from the fire and immediately pumped into another 

 vessel with a bucket pump or, for large quantities, with a power 

 outfit that is equipped with metal valves. The mixture should be 

 pumped once more while it is still hot to obtain a moderately thick, 



