268 
Psyche 
[September 
of these were repeat trials using spiders that had eaten one bug pre- 
viously, but in both cases the mirid lived only 5 days before being 
eaten. 
Discussion 
The time from the first appearance of nymphs to the first appear- 
ance of adults in the field was 70 days in 1967, and 46 days in 1968; 
this compared to an average laboratory development time of 26.3 days 
(range 22-36 days). It seems likely that growth, after hatching in 
early spring, is retarded by climatic conditions and/or lack of food. 
The first nymphs appeared before the hedge started to bloom, and 
the supply of insects caught in the webs was very low. As the 
warmer weather arrived, the hedge started to bloom and, in addition 
to dropping stamens in the webs, the flowers attracted a greater 
number of insects to the spiders’ webs. The last of the first instar 
nymphs were seen in the field in early June and had developed to 
adults by the end of June. This period of less than 30 days agrees 
more closely with the laboratory rearing data. 
Field and laboratory data agree in general on adult longevity. The 
period from the time the last nymph had reached maturity to the 
time the last adult was seen was 70 days in 1967, 60 days in 1968. 
Laboratory longevity for female adults averaged 41.3 days (range 
13-56 days). 
Only one generation occurs in this locality per year and indirect 
evidence indicates that overwintering occurs in the egg stage. No 
adults were seen in the early spring and nymphs and adults were 
absent from the webs from early September to mid March of the 
following year. Dispersal may occur in the fall, since flying was ob- 
served in the laboratory. 
As previously stated by Bristowe (1941) for another arachnophi- 
lous bug, the large numbers of first instar Ranzovious moerens in 
the webs indicated that the eggs are laid in or near the webs. Since 
female adults possess a fully developed ovipositor, it can be further 
assumed that the site of oviposition was plant tissue in or near the 
webs. 
Field observations and laboratory rearing showed that the mirids 
are relatively omnivorous, eating both plant and animal material. 
Laboratory rearing studies confirmed this when the bugs passed 
through five molts to maturity when fed on either of two plant sources 
or the insect host. The type of food used for rearing affected both 
the time to mature and the adult life span. Both males and females 
took over 5 days longer, on the average, to mature when reared on 
