April, ’23] 
CLAUSEN: THE CITRICOLA SCALE IN JAPAN 
225 
THE CITRICOLA SCALE IN JAPAN, AND ITS SYNONYMY 
By Curtis P. Clausen, Yokohama , Japan , United States Department oj Agriculture> 
Bureau of Entomology 
During the seasons of 1916-17 the writer had occasion to make a 
study of the citrus insects of Japan with particular reference to the secur¬ 
ing of parasites for use against these pests in California. The number of 
soft scales attacking citrus is quite large, and infestations almost in¬ 
variably comprise several species. Chief among these are the Pulvinaria 
spp., which always occur on every tree. Prior to the formation of the 
ovisac certain of these are not readily distinguishable in the living 
condition from several species of Coccus infesting the same host plants. 
Among these latter were occasional individuals which bore a striking 
resemblance in coloration and form to the citricola scale of California. 
Later observations also revealed the fact that the eggs hatched almost 
immediately after being laid, this feature of the life history also being 
identical with that of the above mentioned species. A quantity of 
adult females in alcohol were forwarded to Prof. H. J. Quayle for 
examination, but unfortunately their condition was not such as to 
permit of a positive determination. Dr. S. I. Kuwana expressed the 
opinion that it might possibly be his Lecanium pseudomagnoliarum. 
During 1920-22 further observations have been made and a series of 
specimens in balsam forwarded to the Bureau of Entomology for de¬ 
termination. Mr. H. Morrison, who made the examination, states 
that they agree perfectly with specimens of Coccus citricola Campbell, in 
morphological characters but that the specimens show some characters 
not conforming to the description of L. pseudomagnoliarum. 
The latter species was described from Oji, near Tokyo, on Poncirus 
trifoliata, and an examination of the hedge from which the type material 
was taken showed only C. citricola such as had been collected elsewhere on 
this plant. No other species of Coccus were present. Arrangements 
were made to examine the type slides in the collection of the Nishigahara 
Agricultural Experiment Station and to compare them with specimens 
from the same series as had previously been determined by Mr. Morrison. 
This detailed comparison was made both by Dr. Kuwana and by the 
writer, and the conclusion arrived at that the two series differed in no 
greater degree than is common within a species of this genus. Coccus 
citricola Campbell (Entom. News, Vol. XXV, No. 5, p. 222-24, May 
1914) therefore becomes synonymous with Coccus {Lecanium) pseudo¬ 
magnoliarum (Kuwana) (Jl. Entom. & Zool., Pomona Col., Vol. VI, 
No. 1, p. 1-8, 3 pi., March 1914). 
