118 BULLETIN 67, UNITED STATES NATIONAL MUSEUM. 



paper. Food is placed in one room. The other room is kept for 

 the nursery. More elaborate nests can be made on this same plan, 

 with more rooms and with some slender partitions near the larger 

 walls to simulate ant runways. The roof may be fastened down 

 and the nest carried about, or several nests may be fitted into a 

 case especially made to carry them. 



Doctor Barth has kept ants in artificial nests made by placing a 

 glass jar or cylinder inside another glass jar of slightly greater diam- 

 eter, the space between the two filled with soil, or wood dust, in 

 which the ants can tunnel and form their nests. The inner jar is 

 shorter than the outer, and the inner space or well is used as a food 

 chamber. A stick leading from the bottom of the well to the top 

 of the inner jar permits the ants to go from the nest to well and 

 back. A net of wire can be placed over the top of the outer jar to 

 prevent the escape of the ants. A cylinder of dark paper can be 

 slipped over the outer jar to darken the ant burrows. 



To rear the predaceous beetles, like Cychrus and Carabus, one 

 should place them in wooden boxes with fine-mesh wire covering. 

 In the bottom of the box put about 2 inches of earth, moss, and 

 decayed wood. On the top of this sprinkle the ground with water 

 every two days. The Cychrus feeds on snails. Other forms will 

 eat meat, or the maggots on fly-blown meat. When eggs are observed 

 in the cage, remove the beetles and keep the cage in a dark, cool 

 place. When the larvae are a few days old, each should be kept in 

 a separate box. The principal enemies of breeding insects are mold 

 and mites. The mold must be prevented by using no more moisture 

 than necessary and by ventilation. The mites, often of the genus 

 Pediculoides, are kept out by thorough cleanliness and washing the 

 cages and jars in a solution of carbolic acid and later in hot water. 



Rearing aquatic insects is often more difficult than rearing terres- 

 trial species. In some cases one can take a large Mason fruit jar, 

 or purchase a glass jar from the dealers, and put some sand and peb- 

 bles in the bottom, and with a few fresh-water plants he can keep 

 a number of species for some time. The main difficulty is in the 

 water becoming stale. All decaying matter and uneaten food should 

 be removed with a pipette or long glass tube. It does not pay to 

 try to keep too many kinds of insects in the same aquarium. Some 

 of the dealers sell flattened jars, 2 or 3 inches thick and 6 or 8 inches 

 wide, and a foot or more high, which are very suitable for aquaria. 

 Any large predaceous species will, of course, soon free an aquarium 

 of its other inhabitants. Where one has a flow of water available, 

 he can arrange a siphon outlet and insure fresh water all the time. 

 Many aquatic larvae will not develop properly unless in running 

 water. If near a stream, one can arrange a cage of wire screening 



