October, ’24] 
armitage: citrophilus mealybug 
557 
Riverside County 100 acres were recorded as infested and in Los Angeles 
County the infestations were scattered from the coast to the mountains 
through a belt including Long Beach, Los Angeles, Alhambra and 
Pasadena. 
In the interior areas adverse climatic conditions have tended to delay 
the spread and to minimize the seriousness of infestations of the past 
few years. In the coast areas the equable climate has permitted the 
development of rapidly succeeding and overlapping generations and the 
spread has been alarmingly rapid with many serious outbreaks. The 
map of Southern California at the present time shows, aside from the 
previously mentioned areas, a general distribution over Orange County, 
about 3500 acres infested in Los Angeles County and heavy established 
infestations at Oxnard in Ventura County and at Carpenteria in Santa 
Barbara County. In fact it now occurs in all of the citrus producing 
counties of the southern part of the State with the exception of San 
Diego and Imperial. In Orange County the infested acreage has in¬ 
creased from a few scattered trees over 10 acres in 1921 to over 8,000 
acres this season. 
Though the distribution is wide spread, as yet less than 5% of the 
total citrus acreage of Southern California is actually infested. The 
location of this infested acreage, however, is such that it forms a poten¬ 
tial source of spread to an exceedingly large adjacent acreage. 
Seasonal History 
In the interior valleys in which the original observations were made by 
both Clausen and Woglum as well as the writer (5) the seasonal history is 
confined to a heavy conspicuous generation in May and June preceeded 
by a light generation in February and March and with light succeeding 
and slightly overlapping generations during the summer months, in¬ 
creasing in intensity during the fall. Overwintering is carried out in the 
intermediate stages on citrus, under the buttons or in depressions in the 
fruit or between fruit clusters. Summer temperatures are without 
question responsible for a high mortality among the progeny of the 
heavy May and June generation which accounts for the light succeeding 
generations, with a slight increase as the weather moderates in the fall. 
With the advent of this species into the coast areas, however, we 
have an entirely different situation. While in the main, the periods of 
occurrence of the succeeding generations are similar to those in the in¬ 
terior areas, the mild climatic conditions permit an increased develop- 
