XXxii, '21] ENTOMOLOC.ICAI. NF.WS 227 



III has from 13 to 20 large circular sensoria scattered the full length 

 of the segment, IV has 2 to 4 secondary sensoria, V 1 to 2 secondary 

 sensoria and the usual primary sensorium, VI has the usual primary 

 and accessory sensoria. 



From all structural characteristics this is Dilachnus piceae 

 (Walker), but the host plant which Buckton records causes a 

 question. Practically all species of Dilachnus occur on coni- 

 fers, piceae being recorded from spruce. Whether Buckton 

 was mistaken in his host plant record, whether there is an actual 

 migration in this species between oak and spruce, or whether it 

 is a distinct but very closely related species is the question. The 

 only other species the writer calls to mind that migrates from a 

 conifer to a deciduous tree is Prociphilus vcnafnscus (Patch) 

 found on ash and Douglass fir in the Pacific Coast sections of 

 America. From all available evidence the writer feels that 

 Lachnns longipcs Dufour of Buckton is in reality Dilachnus 

 piceae (Walker). 



14. Dilachnus pinihabitans (Mordw.) Walker: two slides (2 alate, 

 1 apterous, several immature 99): "pinicola Kalt. ; Scotch fir ; South- 

 gate; June 4-47" and "pinicola Kalt.; Spruce, Southgate ; June 5-47." 

 Buckton, one slide (2 alate $ $ , 2 apterous oviparous 99,3 apterous 

 viviparous 99); "pinicola Kalt." 



These specimens do not agree very well with Kaltenbach's 

 description nor with Del Guercio's description of Eulachnus 

 pinicolus (Kalt.). The relative measurements of antennal seg- 

 ments in E. pinicolus (Kalt.) Del Guer. are 7, 7, 43, 22, 24, 18, 

 while in these specimens they are 11, 11, 64, 27, 29, 15 ; the main 

 discrepancy being in the last antennal segment, which is approx- 

 imately one-half the length of the fifth rather than three- 

 fourths. The actual measurements of two alate females are : 



I 1 1 .044 .658 .M4 .630 average .6365 



IV .266 .2M .266 .30S .2765 

 V .280 .294 .294 .308 .2940 



VI .154 .154 .168 .154 .1575 



Del Guercio states that the first joint of the hind tarsus is 

 half as long as the second, thus falling into his genus I-.ulach- 

 nits, while in these specimens it is but slightly more than one- 

 third (11-28). These specimens do agree, however, witli both 

 Mordwilko's" and Cholodkovsky's 12 descriptions of piniliabitans 



"Zool. Anzeiger, v. 18, p. 98, 1895. 



"Horae Soc. Ent. Ross., v. 31, pp. 638-640, 1898. 



