21 



-are considered injurious, beneficial or neutral, accordinfr to the 

 habits of the insects or animals they prey upon. 



The horse guard has received nnich discussion from a prac- 

 tical standpoint in some of the agrienltural ])ap('rs, besides be- 

 ing mentioned frequently in entomological journals. While lo- 

 cated at the Gulf Biologic Station in June and July, 1905, this 

 species was abundant, and I made some observations on its life 

 liistory and haliits, and especially on the number of flies it 



•carries into a singl(^ burrow as food foi- its young. My attention 



Fig. 12. — Horse guard (Moticdula Carolina): a, egg; b, larva; c, cocoon; 

 li, adult ; enlarged to one and a half diameters. 



was first attracted to the species in 1903 at the same place, when, 

 for the first time, I observed the adults fiying around cattle and 

 horses. I soon saw^ wliat they were after, and that they were 

 ezpert at catching flies from around these animals. It is some- 

 what amusing to see how peaceably an animal stands when three 

 or four of the Avasps are flying around, each making more noise 

 than a botfly or some of--the small Tabanids which they show so 

 much nervousness about. 



During my stay at the place in 1905 several breeding 



• colonies of the wasps were located and various ages of the larvae 



were observed in their burrows, together with the remains of 



flies they had been feeding upon. These colonies were situated in 



