1965] 
Gardner — Phidippus 
135 
similar in coloration, and this is also true of P. apacheanus. It is 
more usual for the males of Phidippus to have irridescent chelicerae 
and a distinctive adult coloration while the females of this genus 
remain similar to the immature spiders (e.g., P. clarus Keyserling, 
P. opifex, P. whitmanii Peckham and Peckham). 
From the second instar on, Phidippus coccineus spiderlings have a 
brownish-gray cephalothorax and limbs, and a red abdomen with 
markings limited to the posterior portion. These consist of a pair of 
black stripes, each bearing two conspicuous white dots, separated by a 
light region. The light region may be gray, white, or even golden; 
immediately anterior to the black stripes it is enlarged into a con- 
spicuous light dot. While the abdomen of very young spiderlings 
appear bronze, the red color of the abdomen is striking in later instars. 
In one of the later instars, the 5th or perhaps the 6th, a red cap 
appears in the eye region, but this marking disappears in the following 
molt. The light basal band and side bands of the adult are also 
present in immature spiders, and, in the two instars preceeding ma- 
turity, the chelicerae are also irridescent. 
Methods of collection 
Phidippus coccineus can be collected by sweeping bushes with an 
insect net. These hunting spiders are active from mid-morning until 
dusk, and can be seen in bushes running along branches or poised near 
their tips. Running is interrupted frequently: the spider stops, turns 
to one side and then the other, apparently scanning its surroundings. 
In the laboratory, the spiders are active between io A. M. and 4 
P. M., and are still in a closely-woven retreat at other times. 
Adults and large immatures are found on heavier branches near 
the center of the brush, and are not accessible to the sweeping net. 
Certain characteristic aspects of their escape behavior can be used in 
capturing them. When approached slowly by a forefinger or a pencil, 
the spider backs away while facing the oncoming object, and will 
back right into a collecting tube held behind it on the branch. How- 
ever, once the spider backs sufficiently far from the object (about 
8 cm), it turns away. Then it will run a short distance along the 
branch, attach a thread of silk, and plunge down toward the leafy 
debris at the base of the bush, where it becomes extremely difficult 
to find. 
Phidippus coccineus can also be collected in its retreat, or nest. 
The spiders will be found within a slightly flattened tube of silk, which 
is surrounded by guy-lines that attach it to the twigs or leaves of the 
bush. The molting nest and the nest that houses the female and her 
cocoon of eggs are of the same basic shape as the sleeping nest, but 
much more silk is used in their construction. Such prominent white 
