PRESERVING INSECTS 



*5 



insects mounted on points can be fixed at uniform hights by using a 

 pinning block composed of three pieces one fourth the length of the pin, 

 and with holes through the center of each step. The lower one can be 

 used for spacing insects and labels, the second one also for labels and 

 the third for small insects on card points. 



Rules for pinning. Many entomologists prefer to have about one 

 fourth of the pin above the specimen, and this can be secured easily 

 by using the pinning block described 

 above. Experience has taught that not 

 all insects can be pinned alike with the 

 best results. As a rule the pin is thrust 

 through the middle of the thorax, care 

 being taken to have the insect straight 

 on the pin. Among beetles however 



this procedure would result in spread- Fig. 16 Method of pinning beetles (original). 



ing the elytra or wing covers and would produce very unsightly speci- 

 mens. The rule for this large family is to put the pin through the right 

 elytron or wing cover. Examples of the suborder 

 heteroptera, or the true bug family, are usually pinned 

 through the scutellum, the triangular piece near the 

 base of the wings. 



Spreading apparatus. Butterflies and moths re- 

 quire some arrangement before they are fit for the 

 cabinet. As taken from the bottle or papers and pinned, 

 the wings are but partially expanded and frequently 

 so folded that but few of the markings can be seen. This is remedied 

 by the spreading board, composed of two boards with a crevice between 

 large enough to admit the body of the insect, and having below the 

 slit a strip of cork through which the pin holding the insect is thrust. 

 The boards and cork are held in place by end and middle pieces. 

 The points of the pins extending through the cork should be protected 

 by a light strip underneath. Spreading boards are made in various 

 styles and sizes to give sufficient room for the body and ample space for 

 the wings. Three very convenient sizes have widths of 4-5-, 8 and n 

 cm (i£, and \\ in.) with body spaces for the insects of 3, 6 and 10 

 mm \ and f in.) and have a uniform length of 44^ cm {\%\ in.). 

 Many prefer to have the wings spread exactly horizontal and others in- 

 sist on a slight upward slant in order to counteract the natural tendency 

 of the wings to droop after the specimens are removed from the boards. 



Fio. 17 Method of 

 pinning true bugs 

 (original). 



