13-> 



PSrCHE. 



[ Januan.- — Februan- 1SS4. 



flies, is on the bouler of woods, open 

 gl.ides, meadow lantls, etc. 



Specimens should not he allowed to 

 remain over night unpinned. The 

 huge specimens may be pinned through 

 the thorax, preferably with japanned ' 

 iron pins, Thev should be placed on 

 the pin only low enough so tliat the 

 head may be grasped with the thumb 

 and forefinger without danger to the 

 specimen. The -Mings should never 

 be spread. Spreading not only renders 

 the specimens more difficult to stutlv, 

 but it spoils the natural appearance of 

 the insects, and is a positive injury to 

 them for the cabinet. All tliat is 

 necessary is to pusli aside the wings so 

 that they will not conceal the abdomen. 

 Minute specimens should be pinned 

 with fine iron wire from the imderside, 

 and then pinned upon small strips of 

 thin cork, the uppar surface of whicii 



has been covered with white paper, and 

 through the other end of which a pin 

 is thrust. Small specimens should 

 never be glued to bits of card-board, 

 as is commonlv done with coleoptera. 

 Only one specimen should be placed 

 on the piece of cork. 



The greatest enemy to dipterological 

 collections is dust : insects can be 

 guarded again.st, but it is difficult to 

 exclude dust, unless tight cases arc 

 used. Dampness and mildew do often 

 much mischief. 



A good dipterological specimen must 

 be unruhlicd, unmoistened, not dusty 

 nor greasv, and witli tlie wings un- 

 spread. It is quite as easy to collect 

 good specimens as poor ones and much 

 more satisfactory. 



[For other articles on the collection and 

 preservation of diptera. see Rec. 157. -},},$, 

 3396- 3404 and 3405.] 



MUSKIM ^PESTS OK SERVICE TO THE 



ENTOMOLOGIST. — Trogoderma tarsale 

 has heretofore been viewed with un- 

 mixed hatred by entomologists, but for 

 the last few davs I have been showering 

 blessings on the heads of a particular 

 colony which had established itself in a 

 pill-box containing some hundreds of 

 specimens of a pteromalid reared from 

 the cocoons of Apanteles aletiae Rilev. 

 It is true that nothing but fraginents of 

 the pteromalid remained after the Tro- 

 goderma liad been at work for a year 

 or more, but among these fragments 



I have found a number which illus- 

 trate points in the external anatomy 

 better than the most careful dissections. 

 Certain points concerning tlie form and 

 structure of the metanotum — always 

 hard to study in the complete insect, antl 

 very difficult to dissect out, owing to a 

 disagreeable tendency to break through 

 the middle as readily as at a suture — 

 are admirably exhibited by these acci- 

 dental anatomical preparations. Tridy 

 it is an ill wind that blows no good, 



L. O. Ho-xard. 

 Washinjtton. D. C. 25 Jan. 18S4. 



