fiAfeitS OF PHORA ALETlie. 119 



mentioned parasites, and a great many Phoras. At the same time a very 

 large number of chrysalides were examined which had webbed up in the 

 leaves of Artemisia tridentata and other weeds and shrubs adjacent to 

 the devastated fields. Kot a single rotten chrysalis was found among 

 them, by far the largest number being healthy, and only the usual pro- 

 portion contained Chalcis or TacMna larvae or pup£e. JSTot one of them 

 contained Phora larvae, nor whs any Phora raised from about 150 chrys- 

 alides which I took indoors and preserved in a tight jar. The fact that 

 the greater portion of the chrysalides which were on the naked leaf- 

 ribs of the devastated fields proved to be rotten, while at the same 

 time those which had regularly webbed up in the leaves of the adjacent 

 weeds were healthy, is probably due to the influence of sunshine and 

 rain on the unprotected chrysalides. A large portion of these hung 

 downward, suspended only by one thread or the remaining portion of 

 the web. This unnatural position causes them to be stretched, the soft 

 ligaments between the segments thus exposed offers a convenient place 

 for the young Phora larvae to enter the interior of the chrysalis. 



*'After it has once been asserted that Phora is a true parasite of 

 Aletia, and since it is an undisputed fact that Phora has actually been 

 raised from chrysalides of Aletia, it is, of course, difficult to prove the 

 contrary. My observations prove only that Phora lives as a scavenger 

 on other dead and decaying insects as well as in decaying chrysalids 

 of Aletia." 



