Insects 193 



Wasps (Vespoidea and Sphecoidea) 



The term wasp (derived from the Latin vespa) is used in a 

 very broad sense, to include two quite distinct series of Hymenop- 

 tera. The Vespoidea, including the more typical wasps, are them- 

 selves exceedingly diverse. The Sphecoidea or digger wasps are 

 related to the bees, which appear to have been derived from some 

 ancient sphecoid stock, no doubt during Mesozoic time. Some 

 of the principal families of Vespoidea are: 



(1) Masaridac. Very much like ordinary "yellow jacket" 



wasps, but easily known by the clubbed antennae. 

 Pseudomasaris vespoides Cresson is a large yellow and 

 black species found in Colorado. It makes cylindrical 

 cells of clay, or sand, fastened to the stem of a plant. 

 Other, smaller, species may be found in the mountains. 



(2) Vespidae. The "yellow jacket" and related wasps, the 

 wings of which fold lengthwise in repose. Vespa has the 

 base of the abdomen broad and truncate; Polistes, which 

 makes bell-shaped nests, has a narrower abdomen, not 

 broadened at the base; Mischocyttarus (often called 

 Polybia) has the abdomen with a long petiole. All are 

 commonly found about houses, Polistes variatus Cresson 

 being excessively common. 



(3) Eumenidae. Also with wings folded lengthwise, but 



averaging smaller, usually with the abdomen conspic- 

 uously broadened in the middle. The claws are toothed 

 on the inner side, whereas in Vespidae they are simple. 

 A remarkably handsome member of this group, black 

 and bright red, with black hair, was discovered by Roh- 

 wer at Troublesome, and described by him (1915) as 

 Odynerus margaretellus. Many Eumenidae have been 

 observed to provision their nests with caterpillars. 

 Many years ago, when I was spending the summer on a 

 ranch in New Mexico, I had a curious experience with 

 one of these wasps. Taking up my pen to write, a green 

 caterpillar dropped out of the hole between my fingers. 

 The next day the same thing occurred, and it was several 

 days before the persistent wasp concluded that my pen 

 was not a suitable place for the rearing of its young. 



