506 



Phylum Arthropoda 



While it is realized that the equipment and methods herein described 

 and referred to are somewhat expensive and elaborate, they are recom- 

 mended where mass production of parasites is to be undertaken. For 

 small numbers of cocoons when these are not practical, storage for hi- 

 bernation in smaller containers is recommended. These can be stored in 

 an ordinary cool cellar, and humidity can be kept fairly constant by the 

 use of moist sphagnum moss. In any case, however, the cocoons keep 

 best if stored in individual vials. Frequent examination is recommended, 

 to check on the moisture of the moss and to curtail any fungous growth 

 that might appear. The writer has reared Tiphia successfully in the tin 

 salve boxes already referred to, but mortality in the cocoons is usually 

 high when these are allowed to remain in moist soil. 



The conditions under which the different species of Tiphia mate are 

 not uniform for the groups. Some species mate readily in captivity 

 under almost any conditions, whereas with others it is difficult to induce 

 mating. In general, the more difficult species seem to require heat 

 and strong light or even full sunlight for mating; even starving such 

 females for 2 to 3 days prior to mating is advantageous. The females 

 appear ready to mate very shortly after emergence, but in some instances 

 the males have to be 4 to 5 days old. Females should therefore be 

 subjected to males of different ages in numbers considerably in excess 

 of the females. 



A box of convenient size in which to mate Tiphia may be made of 

 %-inch soft pine 1 1 inches by 7 inches by 6% inches deep. The cover 

 of the box is of glass and slides in a snug-fitting groove, or the lid may 

 be made as a separate unit which rests on the edge of the box and is 

 prevented from slipping laterally by fitting over metal pins. If a lid 

 of the latter type is used it is well to line its edge with felt to insure tight 

 fitting, as Tiphia wasps are capable of making escape through small 



