A contribution to our knowledge of the Stylopidae. 943 
occurence of these ‘parasites and the local nature of their distri- 
bution. 
The parasitized Polistes were kept alive in a glass jar covered 
with a cloth and surmounted by a glass plate. They greedily fed 
upon a solution of sugar that was given to them on a camel’s-hair 
brush. They seemed to have quite as good an appetite as the normal 
specimens from the other nests but continued to be nearly as feeble 
as freshly emerged individuals. After waiting in vain for nearly a 
week for some of the Xenos to emerge from their pupa cases, we 
were agreeably surprised one morning to see nearly half a dozen 
males lying upon their backs on the bottom of the jar with their ex- 
tremely delicate wings stuck to the moist surface of the glass, kicking 
violently and making an occasional nervous flutter in their vain end- 
eavors to free themselves. A couple of them evidently more recently 
emerged than the others, were excitedly darting about in the jar. 
Meanwhile the Polistes rested unconcerned upon their paper nest, or 
crawled complacently about in the jar, and evinced not the slightest 
animosity towards the numerous Xenos in the cage. The manner in 
which these wasps acted towards their parasites appears to be so 
extremely at variance with the observations made by HuBBARD (’92) 
upon a Florida species of Xenos'), that it involves some interesting 
questions concerning the habits and intelligence of the Polistes. 
Husparp states that the specimens of Xenos which he bred in 
Florida were viciously pounced upon and devoured by the Polistes, 
which became infuriated whenever they perceived one of the parasites 
near them. 
There seem to be but two ways to account for such a remarkable 
disparity in the way the parasites were treated in the two cases. 
The wasps might possibly have been actuated by hunger in the one 
instance, for my specimens were fed every afternoon with as much 
sugar and water as they would eat; but HuBBARD mentions feeding 
his wasps upon the same food. There is however, one other possibility, 
the Polistes which I possessed were infested with only male parasites, 
and it was really immaterial whether the males should approach them 
or not, as there were no females to be fertilized. It would be wrong 
to suppose that the wasps could be influenced by this, even if they 
were coguizant of the facts, which of course they are not. Had not 
1) The species here described as X. pallidus may possibly be 
identical with the species observed but not described by Huzsarp. 
