December, '16J SELL: DIABROTICA 12-PUNCTATA 553 



Hibernating, How They Spend The Winter 



Preliminary investigations seem to indicate that not much is defi- 

 nitely known as to how the 12-pu7ictata spends the winter. A large 

 part of the observations made upon the hibernation of this insect con- 

 sists of inferences drawn from the behavior of allied species that have 

 been carefully studied in many localities but such analogies cannot 

 always be relied upon to hold even with a very closely allied species. 

 It is quite probable that the way of spending the winter for this beetle 

 depends upon many conditions as: duration and intensity of cold 

 weather, rainfall and sunshine and the prevalence of food plants. 

 Mr. F. H. Chittenden of the U. S. Department of Agriculture is col- 

 lecting data from several localities concerning the habits and life- 

 history of the 12-punciata. If this method is pursued for a few years 

 the exact effect of the various factors that control hibernation can be 

 ascertained. 



With Mr. George Findlay Simmons of Rice Institute the writer 

 undertook to observe the hibernating of a number of 12-punctata. In 

 the early part of December when the beetles became scarce it seemed 

 that they would soon hibernate. The great storm of the preceding 

 August had destroyed most of the fohage, and the leaves, grown after 

 that, were too tender to stand the frost, hence the woods were much 

 more barren than usual. The last wild plant that they really worked 

 on was the coffee bean {Daubentonia longijolia) and throughout the 

 entire winter if a coffee bean plant could be found, in some sheltered 

 spot in the woods, it would be tenanted by one or more of these beetles 

 and some fresh gnawed notches along the edges of the leaf would show 

 where the insect had worked. At first the belted cucumber beetle 

 {Diahrotica halteata) could be found with the 1 2-punctata but these 

 disappeared about December 15. 



The Department of Biology of Rice Institute has constructed an 

 outdoor vivarium with a portion enclosed only by wire screen. In 

 this enclosure where the conditions were essentially the same as out- 

 doors, thirty-two beetles were installed. First they were supplied 

 from time to time with fresh leaves but as they showed no disposition 

 to hibernate the supply was not renewed. They were active at all 

 times. On dull days a beetle would take a position on a twig with its 

 thorax drawn forward as though it was about ready to raise its wing 

 covers, and draw its forelegs slightly above its body with the antennae 

 either forward or twitching slightly. While it might hold this position 

 for hours it was by no means asleep. The position of this beetle when 

 asleep is that of repose-^the abdomen is relaxed, the wing covers care- 

 fully drawn together and the legsfirmly planted against the resting twig. 



This position seemed to indicate Si response to some instinct for 

 hibernation and was carefully watched for several weeks but they did 



