1917 ENTOMOLOGICAL SOCIETY. 51 



that beetles were in hundreds on the leaves as well as larvse and pupae, and a few 

 were brought home. A week later the plants were again examined and among the 

 many black and white beetles was one of a green color — not so brilliant as the July 

 ones, but still decidedly green. Things were looking interesting now, so I hunted 

 very earei'ully for nearly an hour and found two more green ones. These were 

 boxed and brought home alive along with scores of the black and white ones. The 

 following day when changing the food the green ones were looked for but instead 

 of three there were four in the box. My first thought was that possibly one had 

 been introduced into the box unnoticed beneath a leaf; but when they were taken 

 out of the box it was seen that while all were green, they" w^ere not all of the same 

 brilliancy. The four were then placed in a separate box from the black and 

 white ones to see what would happen next. Next day showed clearly what was 

 going on: the black and white ones were all slowly but surely assuming the green 

 color, the lower edges of elytre becoming green first and gradually spreading to 

 the suture, the black becoming an olive green and the white yellowish. As the 

 green brightens the yellow spots disappear and in a couple of days they are so 

 altered that one could hardly believe it possible unless the change was actually seen 

 going on. 



I can recall no reference to such a change of color in an apparently mature 

 insect, and would like to know what explanation can be given of the changes that 

 go on and will gladly try to furnish living material next year to anyone wishing 

 to investigate. The unearthing of the green one in the fall was now explained, 

 but I took the first opportunity of revisiting a Helianthus patch and poked around 

 a little amongst the dead leave.? and surface soil. Sure enough, the beetles found 

 on and below tlie ground were all green, while the 'nlack and white ones were 

 plantiful on the leaves and flowers. 



Among the hundreds of beetles observed on the plants during September and 

 the many kept alive at home there w&s no apparent disposition to mate, and it 

 seems certain that this does not occur till they emerge from winter quarters. It 

 also seems that instead of two annual broods we have but one in Montreal; the 

 glorious green beetles of midsummer are the transmuted black and white ones that 

 quitted the plants and entered the ground in the previous September. Like other 

 hibernating imagoes the time of appearance differs in individuals, and mating and 

 egg laying are spread over an extended period, hence the finding of the insects 

 simultaneously in all stages on the plants. It is, of course, possible that a partial 

 second brood occurs under favorable conditions, and this could easily be found out 

 by ])reeding from the egg. The larvce are not at all difficult to rear if one has a 

 supply of fresh Helianthus leaves at hand. I have never seen- the insects except 

 on Helianthus in the fields, but see that Blatchley* states that " it occurs on flowers 

 of Crataegus; on the horse-mint (Monarda) and on resin-weed — both larvw and 

 adults feeding on the latter." It is interesting to note that he refers to the color 

 of imago as pale greenish-yellow. 



*Coleoptera of Indiana, p. 1229. 



