ROUNDHEADED APPLE-TREE BORER. 17 



days. In 1912 the first beetles issued from the wood on May 14 and 

 eggs were still being deposited on July 1, 48 days after the first 

 beetles appeared. In 1913 beetles were observed on the wing from 

 May 12 to July 19, a period of 68 days. In 1914 a female issued on 

 May 27 and died July 24, living 58 days. In the same year a male 

 and female were alive on August 6, 76 days after the first beetle 

 issued. In 1917 the first beetle left the wood on May 25 and the 

 last beetle of the year died August 10, beetles thus being on the wing 

 for 77 days. In 1918 two females were observed to be alive and 

 active 61 days after leaving the wood. The beetles referred to 

 above were in all cases kept in roomy wire-screen cages over small, 

 growing apple trees, and it is presumed that their life periods 

 extended over the normal term. 



FEEDING HABITS OF BEETLES. 



The beetles feed to a considerable extent upon both tender and 

 tough bark of twigs and branches and upon leaf stems and leaf ribs, 

 and they frequently chew ragged holes through the tissues of the 

 leaf. (PL IX, A, C.) They were observed often working with 

 their mandibles at" the castings ejected from trees by larvse of their 

 own kind and were seen occupied in a similar manner with damp 

 soil; this was probably for the purpose of obtaining water. One 

 female beetle kept alone in a cage over a young apple tree lived for 

 58 days, and after her death a careful measurement was made of 

 the leaf and bark surface over which she had eaten. The total area 

 eaten was found to be 6.9 square inches. In another instance two 

 male and three female beetles, which had just issued from the pupal 

 quarters, were placed in a roomy cage over a young apple tree that 

 had been sprayed just before with lead arsenate at a strength of 3 

 pounds of the paste to 50 gallons of water. Two of the beetles died 

 the first day, one died on the second day, one on the third, and the 

 other, a female, died on the ninth day. All apparently succumbed 

 to the poison, as there was no mortality among beetles caged at the 

 same time over unsprayed trees. Death occurred to all the beetles 

 confined over the sprayed tree before any eggs were deposited. It 

 was noted frequently that beetles differed individually in the amount 

 of feeding done immediately following their emergence from the 

 wood, some proceeding to feed at once and others waiting several 

 days. It is probable that the female referred to above, which lived 

 nine days over the sprayed apple tree, did no feeding until a short 

 time before her death. 



COPULATION. 



Copulation may take place soon after the beetles issue from the 

 pupal chambers or it may be deferred a week or 10 days, the time 

 154187°— 20— Bull. 847 3 



