JOURNAL OF ECONOMIC ENTOMOLOGY 
514 
[Vol. 16 
in evidence, but it has not been able to maintain itself in controlling- 
numbers. 
While conditions have made it practically impossible for the Aphycus 
alone to control the scale in the “uneven-hatch” areas it has been of 
unquestioned value as an aid to mechanical treatment. Due to the 
unevenness of the hatch of the scale, fumigation results are not always 
satisfactory. If the fumigator waits for the last egg to hatch, those 
scale which hatched out first often develop to a size immune to such 
treatment. Aphycus, attacking the adult scale during the period of 
oviposit ion, which averages approximately sixty days, has destroyed 
them before egg laying has been completed. This has a marked ten¬ 
dency to even up the hatch and at the same time advance the date of 
beginning fumigation operations, thus extending what is ordinarily an 
altogether too short fumigation period. Scale development is so rapid 
under coast conditions that many of the Aphycus which escape the fumi¬ 
gation in the pupal stage, are able to bridge the short gap as adults and 
parasitize those scale which owing to their size escaped the treatment. 
Interior or “Even-hatch” Conditions 
While the State Department of Agriculture was confining its libera¬ 
tions of the limited amount of Aphycus available for distribution to the 
coastal areas, the growers in those areas were passing on their enthusiasm 
to those of the “even-hatch” areas together with a large number of 
parasites. These were enthusiastically received in spite of the Depart¬ 
ment’s warning of an entirely different field condition to be met and a 
certainty from the results of early experiments that very little should be 
expected of them. Evidence of the faith of some growers in the reports 
which filtered into the newspapers is found in the following short, concise 
letter received at the State Insectary at Whittier from a grower in one 
of the farthest inland citrus districts. The letter follows: 
“Gentlemen:— 
Please send me sufficient Aphycus for eight hundred acres and oblige, 
Very truly yours,” 
The “even-hatch” areas embrace the interior sections which have a 
much wider seasonal temperature range and much lower humidity 
than the coastal sections. By far the greater part of the citrus acreage 
in Southern California lies within these areas. It was early found that 
the single uniform generation of scale in these areas limited the period 
of attack by the Aphycus to approximately two and one-half months in 
the spring. It is necessary that control be obtained before oviposition 
by the scale, for the reason that if the scale were allowed to reproduce 
