PRAYING MANTIDS — GURNEY 351 



Fish and Wildlife Service, which for many years has assembled data, 

 largely as a result of analyses of stomach contents. In their labora- 

 tory at Patuxent, Md., special analysists have learned to recognize 

 most types of vegetable and animal food from the hard parts that 

 digest very slowly or not at all. In the case of mantids, the head 

 capsule, fragments of the pronotum, and pieces of the front legs do 

 not readily digest and may be detected in stomach contents or in fecal 

 pellets. These structures of newly hatched nymphs are poorly 

 sclerotized or hardened, and egg masses do not leave characteristic 

 hard parts. Consequently, in order to recognize these remains in 

 stomachs the contents must have undergone only a small amount of 

 digestion prior to examination. 



Records are available of M species of North American birds that 

 fed on mantids, of which 6 ate egg masses as well as the mantids them- 

 selves. Birds with numerous records of mantid feeding are the Ameri- 

 can crow, sparrow hawk, English sparrow, and wild turkey. The red- 

 winged blackbird, American magpie, woodpeckers, cowbird, and 

 several sparrows, quails, and prairie chickens are represented in the 

 list of bird predators of mantids. 



Available mammal records show that the following have eaten 

 mantids : White- footed mouse, wood rat, prairie dog, skunk, raccoon, 

 opossum, gray fox, red fox, and dog. All the mammals listed except 

 the wood rat and prairie dog had eaten egg masses too. The most 

 numerous records of feeding on mantids refer to the skunk and 

 opossum. 



In parts of the West lizards are important enemies of mantids, but 

 in the Eastern States lizards are not nearly as prevalent, or as numer- 

 ous in species. Wliile studying range grasshoppers in the great sage- 

 brush-covered valleys of Nevada and eastern Oregon I found a large 

 variety of lizards, most of them very fast and agile. The minor 

 mantid was also seen running about on the ground in both States. It 

 is quite natural that ground-inhabiting mantids in particular, of 

 which the minor mantid is the most widely distributed western species, 

 should often be captured by lizards. Stomachs of certain species of 

 Utah lizards examined by Dr. G. F. Knowiton have often contained 

 mantid fragments. 



Among insect parasites and predators of mantids, the best known 

 are small flies and wasps that feed on mantid eggs. These insects 

 insert their eggs into the mantid egg masses. The larvae, or grubs, of 

 the developing parasites feed on the mantid eggs and then the result- 

 ing adult flies or wasps emerge. Mantid oothecae collected after the 

 season of parasite emergence sometimes show one to many tiny round 

 holes a little smaller than the diameter of a pencil lead. These are 

 the holes made by the emerging parasites and predators. Some para- 

 sites always emerge from the side of the egg mass, others from the 



