92 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
that on calli, but in these specimens the longitudinal median red ray 
has likewise been eradicated, or does not extend beyond middle of 
disk. Differences in the male genital claspers have already been des- 
cribed under the technical description of Perillus bieculatus. 
Notes on the Life History of Perillus circumecinctus 
On June 28, 1923, the writer found Perillus circumcinctus 11 some 
numbers on the high prairie at Fort Snelling, Minn. On that date 
several nymphs and two adults were taken. These specimens were all 
found on goldenrod where they were feeding on the goldenrod beetle 
(Trirhabda canadensis Kirby). his beetle was very abundant on 
certain large clumps of goldenrod and Perillus circumcinctus was con- 
centrated in these places. Upon visiting the same locality on July 3, 
twelve nymphs and five adults were taken. The nymphs were kept 
for rearing and the last one matured July 1o. All specimens collected 
were kept in cages and supplied with fresh goldenrod to which was 
added numbers of Trirhabda canadensis, their favorite food. How- 
ever, it soon became apparent that P. circumcinctus would not rear a 
second brood, for no mating was observed among the several pairs. 
By the end of July several individuals showed distinct indications that 
they were preparing for hibernation. Fewer of the beetles were fed 
upon and the bugs began to crawl under dead leaves and cellu-cotton 
with which the cages were provided. One or two of the bugs were 
active until August 10, on which date they were last observed to feed 
on the goldenrod beetles. A collecting trip to the high prairie was 
made August 3, and while the goldenrod beetle was abundant, not a 
single specimen of P. circumcinctus could be obtained. No doubt all 
the bugs had retired preparatory to hibernation, as was noted in the 
breeding cages. At the present time, August 25, all the bugs, five 
pairs, remain in a hibernating position, with legs drawn up and antennae 
closely pressed against rostrum and ventral side of thorax. 
‘These observations indicate that Perillus circumcinctus develops only 
one brood each year. Mating will not take place until next spring. 
This is very different from P. bioculatus, which species may frequently 
be found mating on the last warm days of September, some days after 
the last potato beetles have disappeared. 
