REPORT OF THE STATE ENTOMOLOGIST 1903 109 



periods when the imagos are more abundant, but in the absence of 

 more data nothing but a surmise can be advanced. 



The large number of females taken in the trap lantern reduces 

 its value as a means of destroying noxious insects. I)r Packard 

 observed that the bean-shaped egg of this insect was attached to 

 the skin of the larval host by a pedicle, and that the newly 

 hatched grub does not entirely leave the eggshell till it has eaten 

 a hole into the side of its victim. It would therefore appear as 

 though the sharpness of the ovipositor was largely for defensive 

 purposes. The females can inflict a slight sting that will smart 

 for half a minute or more, but the pain is by no means severe. 



Hosts. This insect has been most frequently brought to notice 

 as a parasite of the very destructive army worm, H e 1 i o p h i 1 a 

 unipuneta Haw. on which it is a very efficient check. The 

 army worm was abundant in many localities throughout the 

 country in 1896, when the numerous oblong, silken cocoons of this 

 parasite attracted Professor Lugger's attention in Minnesota 

 fields infested by army worms. This is the best evidence obtain- 

 able of its value as a parasite. We have reared it from the zebra 

 caterpillar, Mamestra pi eta Harr. another injurious 

 species, the grub emerging from the larva and pupating July 24, 

 the adult appearing Sep. 13. Records indicate this to be one of 

 the most valuable species of the genus, since it preys on several 

 insects of considerable economic importance. It has been reared 

 in addition to those named above, from Mamestra trifolii 

 Rott, Scoliopteryx libatrix Linn., Schizura con- 

 cinna Abb. & Sm., and S. unicornis Abb. & Sm. It has 

 also been bred from a dipterous Solidago gall and several uni- 

 dentified lepidopterous larvae. It probably has a number of other 

 hosts. We have also seen a specimen reared from the Polyphemus 

 caterpillar, T e 1 e a p o 1 y p h e m u s Cram., in the Museum of 

 Comparative Zoology at Cambridge Mass. 



Description. Fulvo-ferruginous ; stigma small; two subtriangu- 

 lar, opaque chitinous spots in the cubitodiscoidal cell. 



Head medium ; antennae nearly as long as the body ; ocelli 

 black, about equidistant from each other and the eyes ; dorsal and 

 posterior portions of head yellow ; mandibles bidentate and tipped 



