61 

 Lattin: Introduction 



used for small insects, but larger insects may be 

 mounted on the stiffer No. 3 pins. As a general rule, 

 beetles are pinned through the right wing cover, true 

 bugs through the scutellum, and all other insects 

 through the main part of the thorax slightly off- 

 center (intro. fig. 88). 



Lepidoptera and some other insects with important 

 venational characters should be mounted on a spread- 

 ing board (intro. fig. 89). After pinning through the 

 thorax, the relaxed wings are spread out and held in 

 place by strips of paper until setting is complete. 



Specimens which are too small for No. 2 pins 

 should be mounted on Minuten nadeln pins (intro. fig. 

 90) or glued to paper points (intro. fig. 91). These 

 points are small paper triangles punched or cut from 

 thin cardboard or stiff drawing paper. The tip of the 

 point is bent downward to match the side of the 

 thorax of a particular insect. A drop of glue or other 

 adhesive (shellac, colorless nail polish, or the like) 

 is placed at the tip and the specimen is then fastened 

 at its side. Lepage's iron glue is very satisfactory 

 since it is water soluble, permitting the specimen to 

 be removed easily for closer examination. 



Locality labels are printed by hand or press and 

 impaled on the pin below the insect. The precise 

 locality, county when necessary, and state or country 

 are given on the label, and also the date of collection 

 and name of collector. Additional information as to 

 habitat, host plants, and so on is desirable but may 

 be given by means of a date or numbering cross index 

 system to field notebooks. 



Insect-proof boxes or trays, obtainable at a few of 

 the larger biological supply houses, should be used 

 for storage and for arrangement of the systematic 

 collections (intro. fig. 92). Individual units of card- 

 board facilitate handling, sorting, and arranging 

 large collections. A good grade of cork bottom is 

 idesirable as a pinning surface in all boxes and trays, 

 to prevent corrosion of the pins. However, pressed 

 ! wood-fiber boards may be used and even flat strips 

 of balsa wood. Insect collections should be inspected 

 from time to time for possible damage by museum 

 pests. Paradichlorobenzene is a satisfactory repellent. 



Intro, fig. 90. Details of mounting small insects on minuten 

 nadeln pins (Oman and Cushman, 1946). 



REARING METHODS 



Since most aquatic insects are in the immature stage, 

 they must be reared in order to make positive identifi- 

 cation. Usually it is sufficient merely to carry last 

 instar larvae or nymphs through to the adult stage, 

 saving cast skins to associate stages. In some cases, 

 however, it is desirable to work out complete life 

 histories. The techniques and equipment for life 

 history studies vary for each group of organisms and 

 even for each species so only the most generally 

 used methods are described here. 



Rearing of pupae in the field. — The pupae of black 

 flies and some other aquatic insects may be reared by 

 carefully removing them from objects in the water 

 and placing them on moist cotton or blotting paper in 

 a cotton-stoppered vial. Excessive water and high 

 temperatures should be avoided. 



Transporting live specimens. — The greatest mortal- 

 ity occurs when live specimens are carried from the 

 field to the laboratory. This is especially true of 

 stream forms. A bucket of water including some bottom 

 material may suffice for hardier specimens, such as 

 dragonfly nymphs. However, it usually happens that 

 water splashes in an automobile, temperatures rise 

 if the car is closed and stands in the direct sun, and 

 the supply of dissolved oxygen is depleted. These 

 problems may be solved by carrying aquatic insects 

 not in water but in moist moss and other aquatic 

 vegetation. Temperatures are reduced by evaporation 



slide points up to 



noil polish can be 



thinned or dissolved 



in amyl acetate 



bend tip to conform 

 to side of insect 



use cut off pill box 

 for height gauge 



1. bend tip of point 



2. dip in nail polish 



3. apply to right side of insect facing forward 

 Intro, fig. 91. Paper point mounting of small insects (Ross, 1953). 



