134 Psyche [August 



emitted from the mouths of a nmiiber of its hosts. The bodies of 

 army worms (Heliophila imipnnda Haw.) were seized between a 

 pair of broad, pronged forceps, whereupon the larvae ejected 

 through the mouth a green liquid which was accumulated in a con- 

 cave, center slide. One hundred eggs which had been deposited on 

 moist filter paper by Chaetogsedia were emersed in this green fluid. 

 The liquid containing the eggs was covered with a cover glass, 

 care being exercised that no bubbles of air remained beneath the 

 cover glass. In less than one minute some of the eggs began 

 to hatch. Three hours later the larvae were counted and it was 

 found that ninety-seven of the one hundred eggs had hatched. 

 The green liquid was tested with litmus paper and gave a decided 

 alkaline reaction. The eggs of Chaiogcedia monticola also hatched 

 in the akaline juices exuded from the mouths of the following 

 hosts: Vanessa cardui Linn, and Plusia chalcites Esp.^ 



A similar experiment was performed with milkweed caterpillars 

 (Anosia plexippus Linn.) from which the parasitic fly has not been 

 bred, but the eggs hatched in the alkaline juices emitted from the 

 mouth of the larvae. 



The eggs of this tachinid were fed to the imported cabbage worm 

 {Pontia rapw Sch.) and the larA-re of Herse cmgulata Fab. {= Sphinx 

 convolvidi Linn.) from neither of which Chaetogaedia has been bred. 

 A few days later, these caterpillars were dissected and the para- 

 sitic larvae were found embedded within the fat tissue of the body 

 wall. 



The next problem which we attempted to solve, was to determine 

 in what part of the alimentary tract of the host the eggs of Chae- 

 togaedia hatch. A caterpillar of the milkweed or monarch butter- 

 fly was fed a dozen eggs which had been placed upon a milkweed 

 leaf. The caterpillar was vivisected immediately after the last egg 

 was swallowed and three empty egg shells were found in the fore- 

 intestine and nine in the mid-intestine. An army worm was viv- 

 isected and eggs of the parasitic fly were introduced into the lumen 

 of the fore-intestine and mid-intestine. Under a binocular micro- 

 scope, maggots were observed emerging from these eggs. 



Xs there was a possibility that the digestive juices were regurgi- 



1 Chcctogmdia monticola has been bred from fourteen different hosts in the Hawaiian Islands. 

 "Kirkaldy (1, p. 49) reports a pupa of the butterfly, Vanessa cardui Linn, parasitized by this 

 fly" and Swezey (1, p. 49) bred this tachinid from Plusia chalcit(s Esp. 



