144 



PSYCHE. 



[Novtmber — December iSSS. 



ENTOMOLOGICAL ITEMS. 



Two SUGGESTIONS TO STUDENTS OF ENTO- 

 MOLOGY — Some years ago we used the follow- 

 ing method for studying the venation of 

 the wings of small lepidoptera. We have told 

 it since to many friends, but believe it has 

 not been published. It is in some respects 

 preferable to the so-called "Dimmock pro- 

 cess" and particularly as a time-saver. It is 

 also in this respect preferable to denudation 

 with a brush. The wing is removed and moun- 

 ted upon a slide in Canada balsam, which 

 should be preferably rather thick. The slide is 

 then held over the flame of an alcohol lamp 

 until the balsam spreads well over the wing. 

 Just as it is about to enter the veins, however, 

 the slide is placed on ice, or, if in the winter 

 time, outside the window for a few moments. 

 This thickens the balsam immediately and 

 prevents it from entering the veins, which 

 remain permanently' filled with air and appear 

 black with transmitted light. With a little 

 practice one soon becomes expert enough to 

 remove the slide and cool it at just the right 

 time, when the scales will have been ren- 

 dered nearly transparent, by the balsam 

 while the veins remain filled with air. 

 We have done this satisfactorily not only 

 with tortricidae and iineuiae, but with noc- 

 tuids of the size of Aletia and Leucania. 

 The mounts are permanent, and we have 

 some which have remained unchanged since 

 1880. Professor Riley had for some years 

 before this been in the habit of mounting 

 wings in balsam, in which, of course, the 

 scales cleared after a time. With apliids 

 and coccids, which are covered with an 

 abundant waxy secretion which can not be 

 readily brushed away, we have adopted the 

 plan of melting the wax. We place the 

 insect on a bit of platinum foil and pass it 

 once over the flame of the alcohol lamp. 

 The wax melts at a surprisingly low tempera- 

 ture and leaves the insect perfectly clean for 

 study. This method is particularly of use in 

 the removal of the waxy cocoon of the pupae 

 of male coccidne, and is quicker and more 



thorough than the use of any of the chem- 

 ical wax solvents which we have tried. L. 

 O. Howard, in Insect Life, Nov., 1888, p. 

 151-152- 



Habits of Termites. — Mr. P. H. Dudley, 

 in an article read before the New York mi- 

 croscopical society and published in its Jour- 

 nal for July i8SS, describes some of the habits 

 of white ants, especially of those found on the 

 Isthmus of Panama. He writes of a slide of 

 woody fibre, or pulp, from a termites' nest : 



"The wood has been so thoroughly com- 

 minuted, that it is doubtful whether it could 

 be recognized as woody particles under the 

 microscope, unaided by chemical reagents. 



" A study of similar slides throws some 

 light upon their work of destruction on many 

 kinds of wood, in structures. 



" The particles of wood do not have as 

 sharp, angular corners as one would naturally 

 expec( of chips cut from solid wood; on the 

 other hand, they seem as tho made from 

 softened wood, or that undergoing decay. 

 The particles have more the appearance of 

 little pellets than cuttings, which in some 

 measure is doubtless due to the form, motion 

 and pressure of the mandibles. After they 

 are cut the next step is not clear. Some cut- 

 tings serve as food for the insects, as they 

 are found in the alimentary canal. Others 

 are mixed with some substance which causes 

 the particles to adhere, and then are fash- 

 ioned into the walls, which Ibrm the galleries 

 of the nest. 



"The walls are built up of a number of 

 thin layers of the cuttings, give evidence of 

 being prepared with great care, and become 

 quite hard and solid. A fragment thrown 

 into water does not disintegrate by soaking, 

 and after manv hours it requires trituration 

 to separate the particles. 



"On \u'"niiig" ^ piece, nearly all of the \\r 

 substance is consumed ; the residuum, how- 

 ever, being much more than the natural ash 

 of the wood — some clay is present. Phloro- 

 glucin gives a reaction, showing some lignin 

 is still in the woody particles. In many of 

 the specimens I found fragments of the my- 

 celium of a fungus, and upon examining the 

 stick of yellow pine, 6X II inches, which con- 

 tained the nest, found it was in process of 

 deca}' at the point of attack." . . . 



No. 149-150 were issued 9 Nov., 1S88. 



