1969] 
Davis and Russell — Commensalism 
265 
It is likely that mirids killed and ate small insects without the 
spider’s help. In one instance, several small flies were stunned and 
thrown on a web. One of the struggling flies was attacked by a 
mirid nymph. During the few seconds in which the mirid was 
fighting with the fly, the spider rushed to the scene, took the still 
struggling fly from the mirid, and returned to its funnel. After 
having seen mirids feeding on honeysuckle stamens, we placed a 
group of three stamens on a large web away from where any mirids 
were walking. Within 15 minutes, 8 mirids had gathered on top of 
the web and 7 on the bottom to feed on the stamens. 
One possible predator was seen on a large web at night. This was 
a male club-footed spider (Clubionidae) ? several of which were seen 
to be active on several parts of the hedge throughout the night. The 
clubionid was seen on the underside of an agelenid web, along with 
several mirids, but apparently was scared off by the light. 
Laboratory Studies 
Materials and Methods 
In the spring of 1968, mirid nymphs were collected by tapping the 
web over a small glass vial. They were reared using a method modi- 
fied from that of Yonke and Medler (1964), being kept individually 
in the laboratory in small glass cages made of 38 mm diameter glass 
tubing, 50 mm high, the tops of which were covered with O.i mm 
mesh plastic screen. The cages were set on a. 23 X 35 cm plastic 
box, filled with water, out of which 10 dental wicks projected, one 
for each of ten cages. The cages were placed in a Thelco Model 4 
(Precision Scientific Co.) growth chamber at 30°C. dz 2°C., with 
a 15 hour light, 9 hour dark daily photoperiod. 
Table 1. Duration (days) of the nymphal stadia of 20 Ranzovius 
moerens * reared to maturity. (AfterWilkinson and Daugherty, 1967) 
Stadium 
Range 
Mean 
± s 
Cumulative 
mean age 
1* 
2-7* 
3.8 
± 
1.06 
3.8 
2 
3-6 
4.0 
± 
0.98 
7.8 
3 
3-13 
5.0 
± 
1.60 
12.8 
4 
3-16 
5.4 
± 
1.65 
18.2 
5 
6-12 
8.1 
± 
1.34 
26.3 
Total nymphal period 
22-36 
26.3 
Adult female 
28-56 
41.3 
± 
10.96 
67.6 
Adult male 
1-18 
7.8 
± 
6.12 
34.1 
^Reared from 1st instar nymphs 
collected 
from webs. 
Time in stadium 
1 began with day collected. 
