10 
BULLETIN 110. 
first falling to the ground. Prof. Garman found a goldfinch’s nest 
covered on the outside with nests of Pulvinaria. Mr. Hubbard believed 
that spiders were the chief means of transportation. 
ENEMIES 
As might be expected, the cottony maple scale, being a native 
insect, is preyed upon by a wide range of enemies which includes both 
those which prey upon insects in general, and the groups which confine 
themselves to a smaller range of hosts. 
The only instance of a vertebrate being among the group was 
observed by Dr. Howard, when he saw an English sparrow eating the 
waxy masses in Washington. That these birds do not offer much hope 
of relief is evident when we remember that the most serious outbreaks 
of the pest have occurred in those places where this sparrow is most 
abundant. 
The Arachnida have come to the rescue but once and that was 
when the harvest mites were found by Miss Murtfeldt feeding upon the 
eggs in Missouri. 
The larvae of a species of lace winged flies ( Chrysopa ) and two 
species of assassin bugs ( Reduviidc ?) were found by Mr. Putnam to 
feed upon the scales. In Denver, the nymphs of what Mr. Ashmead 
has determined as Corizus hyalinus were found working among the 
egg masses. 
Probably more important than any of the foregoing are the ever 
faithful ladybirds. Chilochorus bivulnerus during all stages of its 
life, but especially while young, feeds upon this insect. Several species 
of Hyperaspis notably H. signata, //. bigeminata and //. binotata do good 
service, while to these must be added Rhizobius ventralis. 
The larvae of a species of'small moth, described by Prof. Com¬ 
stock (*) as Dakruma (. Lcstilia ) coccidivora did very effective service in 
Washington, D. C. According to Dr. Howard: 
“This caterpillar flourished upon the twigs upon which the scales were close¬ 
ly massed together, and ate its way through the mass from one scale to another, 
spinning a close rather dense web as it progressed. Each caterpillar in this way 
destroyed very many scale insects. The writer has always thought that it was due 
to this insect alone that the cottony cushion scale ‘ almost disappeared from the 
Washington shade trees in the close of 1879, and was never seen here again until, 
in the summer of 1898, nineteen years later, it became once more rather conspic¬ 
uous, although by no means as abundant as in the former year. The Dakruma 
not only destroys the old wornout female, but devours her eggs and young larvae 
with avidity. The caterpillars are very active, moving about freely within their 
silken passages. They were to be found full grown on June 24, spun their cocoons 
within the silken tunnel, and remained ten days in the pupal state. The moths 
issued from July 17 to August 13, soon thereafter ovipositing and laying their eggs, 
which hatched in six days. Whether another generation of moths issues the same 
year has not been determined.” 
Prof. Riley states that in Florida this larvae attacks “a large 
Lecaniuvi on magnolia, a coccid allied to Dactylopius and the com¬ 
mon “turtle back scale.” 
But the credit for the most, effective work of eradication of the 
cottony maple scale is due after all to the chalcid parasites. The 
general insect enemies are helpful at all times, and in some cases be¬ 
come quite important, the Daknnna larvae have been locally beneficial, 
(*) Report Dept. Agr., 1879, 241-243. 
