6 
developed. Two or three weeks before that time the lower half of 
the tree bore only a few leaves. 
This same form of injury was repeated in 1908, the tree looking 
considerably worse than shown in figure 2. 
NATURAL ENEMIES. 
The predaceous and parasitic insect enemies of the red spider, men- 
tioned below, were observed by the writer on the Kentucky coffee 
tree at Washington, D. C., during July and early August, 1906. 
Scymnus punctum Lee., a very small black ladybird, was observed 
July 21, chiefly as a nearly full-grown larva, and was the most active 
natural enemy. At that time it was for the most part attached to the 
leaves for pupation, and a single pupa was found then and many a 
few days later. Nearly all the larve had transformed and the beetles 
had begun to issue by the 1st of September. An illustrated account 
of this species was given by J. C. Duffey in 1891.4 
Cecidomyia coccidarum Ckll. (?).—-The larva of this small cecido- 
myiid fly was reared at Washington, where it was fairly abundant. 
It was secondary in importance only to the ladybird mentioned, as a 
destroyer of its red-spider host. 
With the latter was reared a minute chalcis fly, Aphanogmus va- 
yipes Ashm., a species recorded as parasitic on cecidomyiids. 
Chrysopa rufilabris Burm., a lacewing fly, was also reared and the 
larva was observed in numbers attacking the red spider. 
Thrips seemaculata Perg. has been recorded as an enemy of the 
red spider by Pergande ’ and by Duffey. 
METHODS OF CONTROL. 
DIRECT REMEDIES. 
Red spiders are more resistant to fumigation, either with tobacco 
or hydroecyanic-acid gas, than are aphides, thrips, and small forms 
of insects generally. Only a portion of these creatures are usually 
killed by the ordinary use of the gas in greenhouses—never more than 
80 per cent, so far as our records go. The remainder may be stupefied 
for a time, but eventually recover. They are, however, extremely 
sensitive to sulphur, applied either dry or as a wash, or in connection 
with other poisons. Soap is also a good remedy. 
Sulphur.—F lowers of sulphur, mixed with water at the rate of an 
ounce to a gallon, and sprayed over infested plants, is of great value 
in the eradication of this pest; or the sulphur may be combined with 
strong soapsuds. For the application of this spray a force pump 
with spraying nozzle is a necessity and the current should always be 
directed to the lower surface of the leaves. 
Soap solutions —Potash, fish-oil, whale-oil, and other soap solutions 
are valuable against the red spider, and the addition of sulphur in- 
a@Trans. St. Louis Acad. Sci., Vol. V, pp. 540-542. b Psyche, Vol. IIT, p. 381, 1882. 
[Cir. 104] 
