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BULLETIN 67, UNITED STATES NATIONAL MUSEUM. 



are also many of the Micro-Hymenoptera. The best way to get at 

 this hidden fauna is by sifting the material through a sieve net, 

 but one can obtain many specimens and learn a great deal about the 

 habits of these pygmies by getting down on his knees or lying prone 

 and picking away the moss. These specimens should be labeled 

 as from moss, and when possible one should give the name of the 

 moss. 



Nests. — A considerable number of insects occur in the nests of 

 birds, moles, mice, and other animals. The material can be sifted, 

 and sometimes, if kept in a jar, one may breed a number of these 

 insects. 



Excrement. — The droppings of cattle are rich in insect inhabitants. 

 Many of them breed or feed in the material, while quite a number 

 are predaceous and feed on the other insects. The manure may be 

 placed in a pail of water and the insect inhabitants will float to the 

 surface. Some of the species burrow in the soil under the manure, 



and if one wishes to rear them it is 

 necessary to take up this as well as the 

 manure to the breeding cage. 



Dead animals. — Many beetles and flies 

 are attracted to carrion and the parasitic 

 Hymenoptera to oviposit in their larvae. 

 One visit will not be enough, as later one 

 may find different species from those 

 captured on the first trip. Many species 

 that occur in carrion may be trapped by 

 placing a few bits of wood or bark on 

 the ground near the body. The speci- 

 mens if soiled may be cleaned in benzine or gasoline. 



Forest insects. — The collection and study of insects injurious to 

 forest trees has developed new tools and methods ; these are briefly 

 summarized by Doctor Hopkins as follows: 



The equipment for collecting specimens need not be expensive or 

 elaborate. The necessaries are: A hatchet or light ax, carried in a 

 scabbard, which may be fastened to a stout belt ; a hunting coat, or 

 an ordinary sack coat, with many pockets: a supply of collecting 

 vials of various sizes, fitted with the best cork stoppers; a small bottle 

 of alcohol; a medium and a small cyanide bottle; tweezers; camel's 

 hair brushes; a stout knife with small and large blades; a small saw; 

 a net, and umbrella; and last, but not least important, a notebook 

 and pencil. With this equipment, or such part of it as is required 

 for the special kinds of specimens desired, a good observer can go 

 out in the woods any day in the year and find plenty of material. 



The best places to collect species infesting wood and bark are along 

 the edge of the woods, or where trees have been girdled or felled a 



Fig. 161.— A Scolytid or engraver- 

 beetle, Xyleborus perforans, male 

 and female. 



