NATURAL CONTEOL. 73 
about the floor. The cockroach was captured and sent to the Bureau 
of Entomology, where it was identified by Mr. A. N. Caudell as a 
nymph of Thyrsocera cincta Burm., a species occurring in the south- 
ern United States, Mexico, and Central America. A similar habit by 
individuals of this species was subsequently observed by the senior 
author on one or two occasions, but the number of ants destroyed 
by this insect is certainly inappreciable. 
A jumping spider of the family Attidae was seen to capture a few 
workers, and various species of the cobweb weavers (Theridiidae) had 
the habit of reposing beneath the stands supporting our artificial 
formicaries and there depleting the colonies under observation. In 
fact, so persistent were they that it was necessary to examine the 
stands daily and destroy these spiders. Among the most abundant of 
these was one which was identified by the late Prof. B. H. Guilbeau, of 
the Louisiana State University, as Theridium tepidariorum. Spiders 
of this family were not observed destroying ants in outdoor colonies, 
but it is -possible that they do so. 
On one occasion Mr. G. A. Runner observed an English sparrow 
industriously picking up the Argentine workers from a trail which 
crossed a wide roadway at Baton Rouge. This habit is not, how- 
ever, a common one with this bird. 
The flicker or yellowhammer, Colaptes auratus, has often been seen 
industriously digging up shallow ant nests in lawns and grass plats, 
evidently for the purpose of obtaining the pupae and larvae, and 
should doubtless be credited with being the most important natural 
enemy which this ant has in the South. Our knowledge of the extent 
to which native birds subsist upon these ants is very limited as yet, 
and the subject is one well worth more complete investigation than 
we have been able to give it. 
EXPERIMENTS WITH PEDICULOIDES. 
The idea of finding some parasite which would destroy the ants 
naturally suggested itself early in our investigations. Owing to the 
readiness with which the small parasitic mite, Pediculoides ventricosus 
Newp., parasitizes the larvae of wasps and beetles whenever it can 
obtain access to them it was thought worth while to see if this para- 
site could be successfully used against the ant. For our experiments 
we first reared enormous colonies of these mites on living wasp larvae 
and thereafter placed these infested larvae in the formicaries, where 
they could be closely observed. The following experiment will illus- 
trate the results obtained: 
For the experiment we selected a large populous ant colony which 
was domiciled in a plaster of Paris Janet cage of several chambers. 
