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Brooks (F. E.). Spotted Apple-tree Borer. - L'^. 5. Dcpt. Af!;ric:. 

 Washington, D.C., Bull. 8S(S, 21st October 1920, 12 pp., 5 plates. 

 [Received 22nd February 1921.] 



The Cerambycid, Sapcfdci cn'taia, Ncwm. (spotted apple-tree borer), 

 occurs locally throuj^liout the a]ii)le-growing districts of the central 

 and eastern parts of the United States, and is closely allied in its 

 biology to the round-headed apple-tree borer (5. Candida). It appears 

 to be entirely absent from many localities within its general range, 

 while in others it is abundant, occasionally replacing to a great extent 

 the round-headed species. In the vicinity of Lansing, Michigan, 

 the author found it vastly outnumbering Saperda Candida. There it 

 was found in abundance in cultivated and roadside seedling apple 

 trees, and rather less abrmdantly in wild crab-apple and Crataegus. 

 It has also been recorded from juneberry and thorn. 



The injury is very similar to that of 5. Candida, except that it usually 

 occurs higher on the trees, the central and upper portions of the trunk 

 and the branches being affected. The eggs are placed between the 

 bark and the wood at the side of the punctures made by the female, 

 and on hatching, the larva begins to feed in this situation. Towards 

 the end of the first season or in the spring of the second the larva enters 

 the wood and works its way to the heart of the branch. Badly 

 infested trees are sickly in appearance, individual branches, and 

 occasionally small trees, dying as a result of attack. The adults issue 

 from the wood by day in spring and early summer, and emergence 

 has been observed f-rom 1st May to the end of June. After emergence 

 the beetles feed on the bark of twigs and leaf-petioles, and occasionally 

 on the leaves. Mating occurs about a fortnight after emergence, 

 and oviposition about a week later. The eggs hatch in about three 

 weeks. The larval period may extend from two to four years. In 

 spring the mature larvae enter the pupal stage, which lasts four to 

 six weeks. The adults remain in the pupal chamber for one to two 

 weeks before emerging. 



Woodpeckers appear to be the most effective natural check on this 

 borer, which feeds in positions easily accessible to these birds. During 

 the author's studies every attempt to rear larvae in unprotected trees 

 met with a loss of all the individuals from this cause. On one occasion 

 a newly-emerged female was found in the jaws of a spider, Xystictis 

 ferox. In several cases larvae of the clearvving moth, Aegeria pyri, 

 Harris, were found as the sole occupants of burrows recently made by 

 S. cretata, and there is good reason for believing that they had devoured 

 the original occupants. 



There is little doubt that in apple orchards where arsenical sprays 

 arc used many adults may be killed, as they feed freely on exposed 

 surfaces. The beetle has a rather prolonged feeding period prior to 

 oviposition, and this affords a chance to kill it with poison sprays 

 before it has provided for a succeeding generation. 



While small, the borers may be removed by paring away the bark 

 over their burrows, which can be found by the castings and by the 

 swollen appearance of the wood. Badly infested branches may be 

 removed and burned. Breeding places, such as are provided by 

 neglected seedling apple trees and thorn and wild crab-apple thickets, 

 should not be allowed near orchards. 



