64 MASS. EXPERIMENT STATION BULLETIN 347 



spring of 1937 and were attacked for oviposition purpo^ for the first time when 

 the above-mentioned logs were attacked for the secon^'fime. Emergence continued 

 until late in November when occasional live, newly emerged adults were found 

 in the outdoor cages. 



The results of scouting work carried on in 1935, 1936, and 1937 to determine the 

 distribution of elm bark beetles in Massachusetts show that Scolytus muUistriatus 

 Marsh., the smaller European elm bark beetle, is distributed over a wide area in 

 eastern Massachusetts, and is also found in southwestern Massachusetts; Egre- 

 mont, Great Barrington, New Marlborough. The identity of the finding previously 

 repor ed in Westfield, based on the occurrence of two empty brood galleries in an 

 American elm, typical of those of Scolytus muUistriatus, is now considered uncer- 

 tain, due to the fact that Westfield is approximately twenty-five miles distant 

 from known limits of the infestation centering at New York City; intensive 

 scouting in the vicinity since then has failed to reveal the presence of the beetles; 

 and detailed study made by this office of the types of brood galleries dug by 

 Hylurgopintis rufipes shows that occasionally they construct a single unbranched 

 egg gallery parallel to the grain of the inner bark such as Scolytus muUistriatus 

 digs instead of the two-branched, more or less transverse egg gallery usually con- 

 structed. Until further scouting reveals the actual presence of the Scolytus mul- 

 listriatus beetles in Westfield, this office will consider the previous report uncertain. 

 Adult beetles were collected in all the other towns mentioned. Eastern Massachu- 

 setts: Merrimac, Haverhill, Methuen, Tyngsborough, Tewksbury, Andover, 

 North Andover, Boxford, Georgetown, Topsfield, Wenham, Beverly, Danvers, 

 Billerica, Reading, Woburn, Stoneham, Saugus, Revere, W^inthrop, Lexington, 

 Sudbury, Weston, W'altham, Belmont, Newton, Brookline, Boston, Wellesley, 

 Natick, Dover, Westwood, Walpole, Canton, Easton, Abington, Rockland, 

 Brockton, Marshfield, Bridgewater, East Bridgewater, Halifax, and Plymouth. 

 Hylurgopinus rufipes was found in every section of the State scouted. The only 

 sections not scouted were Cape Cod and the islands off the coast. 



A bulletin of a popular nature dealing with the Dutch elm disease and its insect 

 vectors was prepared in conjunction with Doctor M. A. McKenzie of the Botany 

 Department. 



Other Elm-Boring Insects. Studies on the habits of two elm-boring insects, 

 Saperda tridentata and Magdalis sp., were continued. In one cage experiment with 

 5. tridentata the adult beetles confined their feeding to the leaves and the current 

 season's twig growth. In some indoor experiments, adult Saperdas which emerged 

 in late winter, when given leafless winter twigs to feed on, attacked only the 

 twig growth of the previous season. 



Insect Pests of Shade and Ornamental Trees. A detailed survey was made of the 

 insect pests of tha shade and ornamental trees on the campus as a basis for the 

 development of a seasonal spray program. 



Fifty-six species of insect pests of various shade and ornamental trees and in 

 addition six types of insect pests of house timbers were sent to the laboratory 

 for identification and information on control. 



Apple Leaf-Curling Midge. (W. D. Whitcomb, Waltham.) The apple leaf- 

 curling midge {Dasyneura mali KiefTer) was normally abundant in the infested 

 area. In one of the oldest infested orchards, however, the first generation was 

 apparently less abundant than previously, but with the development of the fol- 

 lowing generations the infestation was equal to that in other years. 



In Westford, the activity of this insect began about a week later than in 1936, 

 the first eggs being found May 25, and the first appreciable number of mature 

 maggots was collected under bands on June 22. Eggs of the second generation 



