238 



FOREST ENTOMOLOGY. 



(3) Caustic alkali wash.- Dissolve 1 lb. of commercial caustic soda 

 in water, then 1 lb. of crude potash or pearl ash in water. When 

 both have been dissolved, mix the two well together ; then add f lb. 

 of soft soap, stir well, and add sufficient water to make up to ten 



gallons. 



Caution. Do not mix in painted vessels of any kind. 



Genus Apterococcus. 



Adult female stationary, living within the ovisac. Legs persistent. 

 Antenna? six joints. Male apterous. Antennas seven joints. Male 

 puparium felted. 



Apterococcus fraxini (Newst.) 



In some parts of the country this scale is fairly common. I found 

 it frequently in Cheshire, and again in some instances in Northum- 

 berland. As a rule, it is gener- 

 ally found on isolated trees, or 

 otherwise extremely local on 

 hedgerow trees. It is found on 

 trees of varying ages, from fifteen 

 years upwards, but most abund- 

 antly on trees from thirty to 

 forty years of age with compara- 

 tively smooth bark. When it is 

 found on old trees, it is sparsely 

 scattered in the fissures of the 

 rough bark. The general appear- 

 ance of this scale somewhat re- 

 sembles the genus Dactylopius or 

 mealy bug, inasmuch as the bark 

 is spotted with numerous white specks (fig. 222). If an individual 

 sac be examined during the winter months, it will be found to 

 contain two or more female insects. 



The adult female is of a bright-red colour, somewhat globular in 

 shape, with six-jointed antennae, short legs, and very long rostral 

 filaments. A microscopical examination of a prepared female insect, 

 under high power, reveals special rings of spines surrounding the anal 

 orifice, and a few tubular spinnerets on the dorsal surface. 



The male is apterous, of a bright-red orange colour, with black 



Fig. 222. Apterococcus fraxini on bark of ash. 



