62 



Lattin: Introduction 



1 



( r" plywood 



rh"^/ 



i%" 



outside dimensions 9" by 13' 



CONSTRUCTION OF 

 WOODEN BOX 



cork or balsa wood- 



-,;" plywood 



E~fV'i 



outside dimensions 9" by 13" 



wooden sides fy" or V thick 



top, bottom, and lid guide 

 are Vs" cardboard 



CONSTRUCTION OF 

 CARDBOARD-AND-WOOD BOX 



■/.•.; Vi" fiber wall board '..'.•.'..•'•■.•'.• 



Intro, fig. 92. Construction details of boxes for insect 

 storage (Ross, 1953). 



or may be held very low by dry ice or by various 

 coolers that are now available for motorists, or travel 

 may be arranged during the cool hours of the night 

 and early morning. 



Field cages. — Various cages have been designed 

 for rearing insects in the field. The simplest of these 

 is the "pillow cage" (intro. fig. 93) made of screen 

 and anchored in a stream with the lower part below 

 water and the upper part dry. Specimens are placed 

 in these cages to develop under conditions that are 

 in some respects identical to the natural habitat. 

 Nymphs of stoneflies, dragonflies, mayflies, and 

 caddis larvae have been reared successfully in this 

 way. Another type of cage consists of a cylinder of 

 window screen with the bottom made of the same 

 material. A cloth sleeve is attached to the top. The 

 sleeve is closed with a rubber band or piece of string, 



but is readily opened to remove specimens that havej 

 emerged. These cages are fastened to stakes drivem 

 into the bottom of streams or ponds, and a few clean 1 , 

 stones are placed in the cage to simulate natural) 

 conditions. Though there is no size limit to this type, I 

 small cages are particularly useful for rearing small 1 

 numbers of specimens of a particular species. Many 

 such cages can be carried in the trunk of a car. 



Cages for rearing adults from immature stages may 

 be designed like the "emergence traps" described 

 earlier. 



Laboratory rearing. — Most insects are difficult to 

 rear when removed from their natural environment. 

 Success can be attained only by paying close attention 

 to the temperature of the water, dissolved oxygen, 

 toxic substances, and seemingly endless details. 

 The size and shape of the aquarium may be important. 

 The kind of substrate should be as natural as pos- 

 sible, and the water should be from a natural source, 

 or, if from a domestic water supply, should be dechlo- 

 rinated by filtering through activated charcoal or by 

 allowing it to stand for several days. The temperature 

 should be maintained as nearly as possible like that 

 of the natural habitat for most temperate zone insects. 

 This means cooling by means of a cold-water bath 

 in which the aquarium is set or by means of a pumping 

 system with the water line passing through a refriger- 

 ator or cold water bath until the desired- temperature 

 is attained. 



Aeration is necessary for many insects, including 

 all stream forms. Fortunately various air pumps are 

 available for this purpose and may be obtained at 

 low cost from aquarium supply stores. Air is pumped 

 through a block of pumice and forms bubbles that 

 oxygenate the water and also agitate it to a certain 

 extent. 



Most stream insects require running water to com- 

 plete their development. Running water troughs, as 

 found in fish hatcheries, may be used for this purpose 

 but most laboratories are not equipped with such 

 facilities. For more limited operations a simple 

 circulating system can be set up. Water is broughl 



Intro, fig. 93. Simple "pillow" cage used for rearing insects 

 in the field (Ward's Nat. Sci. Est., 1940). 



