THE MONTHIiY BULLETIN. 



209 



lamp chimney cages are of the type shown in Figure 37, and were 

 made by placing a wire gohlet-shaped spiral, in an earthenware 

 saucer and then pouring plaster Paris over the base of the spiral. 

 Before the plaster had per- 

 fectly set a channel was cut in 

 the still workable plaster by 

 revolving a lamp chimney in 

 the soft plaster. Where it was 

 desired to separate the plaster 

 plaque from the saucer, the 

 saucer was first lined with 

 wrapping- p a p e r. The Avire 

 ppiral serves as a support fo!- 

 the infested lemon. Over the 

 lemon and into the channel of 

 the plaque is fitted a lamp 

 chimney with the upper end 

 covered by means of cheese 

 cloth pasted down with shellac. 

 To guard against outside inter- 

 ference it is best to f^ll the 

 channel with soft paraffine or 

 beeswax as the addition of 

 either of these s u b s t a n c e s 

 makes a very tiglit joint. An 

 improvement on this outfit 

 would be a double spiral in- 

 stead of a single spiral, the one 

 spiral over the other, so that a 

 non-infested lemon could be 

 placed over an infested lemon 

 to take up the surplus of mealy 

 bugs from the infested lemon. 



Life Cycle. 



From the laying of the egg to 

 the death of the adult the 

 shortest time noted is 41 days 

 and the longest time 63 days, 

 the adult having been found to 

 live from 20 to 34 days. The 

 time from the laying of the egg to the emergence of the adult was 21 

 to 49 days. Judging from these findings, it is quite possible that from 

 41 to 83 days may elapse between the laying of the egg and the death of 

 the adult, according to the temperature and the abundance of food. 

 Temperatures favorable to the increase in mealy bugs at the same time 

 increase the frequency of generations in this parasite. 



Longevity, 



As pointed out above the f.dult may live from 20 to 34 days. 



Parthenogenesis, 



This species is arrenotokous, unfertilized females producing only 

 males. 



Fig. 36. — Type of cage used in the Insec- 

 tary Division of tlie Commission of Horticul- 

 ture for breeding colonies of Leptomastix sp. 

 (Original.) 



