94 ENTOMOLOGICAL NEWS. [June, 



DOLERUS ARVENSIS Say and DOLERUS UNICOLOR Beauv. These flies 

 have been plentiful in this vicinity for the past ten days or more, and are 

 usually found resting upon dead weeds of all sorts. They have been es- 

 pecially abundant among the branches and in the vicinity of a low spread- 

 ing bur-oak tree, the buds of which are fairly dripping with a very sweet 

 liquid that has oozed from them as the result of the myriad punctures 

 inflicted by a minute gall-fly, Neuroterus vernus Gill. I visited this tree 

 on the 26th of April in company with a student, Mr. H. H. Raymond, 

 who called my attention to the mating of the black saw-fly with D. ar- 

 vensis. A few moments later we both saw two more of these two spe- 

 cies pair, and a day later we each saw the same thing repeated. The 

 males in every case were D. unicolor, and the females D. arvensis. I 

 had previously noticed that of about forty specimens of each of these 

 species in my collection all of the former were males and all of the latter 

 were females. Say also notes the fact that only the male of unicolor and 

 the female of arvensis are known. These facts with the above observa- 

 tions put it beyond a doubt that these two saw-flies are male and female 

 of the same species. As unicolor Beauv. was first described (1805), this 

 name will hold for the species, and arvensis Say will have to fall to the 

 rank of a synonym. While mating the male and female face in opposite 

 directions, and the wings and abdomen of the male are covered by the 

 wings of the female. The union lasts but three or four seconds. 



C. P. GILLETTE. 



EXCURSION. The committee from the Brooklyn, Newark and Philadel- 

 phia Societies have decided upon Upper Jamesburg, N. J., as the place 

 where the field-meeting of the entomologists of the three cities and neigh- 

 boring points is to take place on the 4th of July next. Jamesburg is on 

 the Amboy Division of the Pennsylvania Railroad, and may be reached 

 from New York via Perth Amboy and Rahway at 9.10 a. m., Newark at 

 9.36 a. m.; via Monmouth Junction, New York, 7.20 a. m., Newark 7.50 

 a. m. Leave Philadelphia from Broad Street Station at 6.50 a. m., z<ia 

 Camden, at 7.10 a. m. The 7.20 a. m. from New York via Monmouth 

 Junction, meets the 6.50 from Philadelphia at Monmouth Junction, and 

 this train is recommended, as it will bring the party into Jamesburg at the 

 same time. Excursion fare about $2.10 from New York and Philadelphia. 

 All the entomologists desiring to attend will be heartily welcomed, whether 

 members of the societies organizing the excursion or not, but in order that 

 the necessary arrangements for creature comforts can be made, all those 

 expecting to take part in the field-meeting will please notify one of the 

 members of the committee as soon as convenient. Further information 

 can be obtained from the committee: 



Dr. D. M. Castle, 2007 Arch Street, Philadelphia. 



C. P. Machesney, 65 Broadway, N. Y. 



C. H. Roberts, 235 W. i22d Street, N. Y. 



J. B. Smith, Rutgers College, New Brunswick, N. J. 



H. W. Wenzel, 1115 Moore Street, Philadelphia. 



