OBSERVATIONS ON THE HABITS OF SOME 
SOLITARY WASPS OF TEXAS. 
INTRODUCTION. 
On morphological grounds wasps may be divided into two main 
groups, the Sphecina or digger-wasps, and the Yespina or true 
wasps, the latter of which have their wings folded in plaits when 
at rest. (Compare Figs. 1 and 2.) For the purpose of this paper, 
which is a study on habit, wasps may best be divided into the 
social and the solitary. This classification, based on habit, does 
not coincide with that based on the condition of the wings, for 
while the Sphecina are all solitary, the Yespina also include a large 
group of solitary wasps, the Eumenidae. 
To render my account more complete, I shall briefly compare 
the habits of the social and the solitary wasps, transcribing from 
others. 
A social community includes three castes : queens, drones, and 
workers. The queens alone survive the winter after mating with 
the drones, which, with the workers, perish of hunger and cold. 
In the spring the queen builds the first comb and rears the first 
lot of workers. These immediately take up the work of building 
the nest and feeding the young, while the queen devotes herself 
exclusively to egg-laying. Before long, many hundreds of workers 
are busy in the nest, and, late in the season, many queens and 
drones also appear, and the cycle of life is started anew. 
The solitary wasps have only two sexes, the queens and the 
drones, and there is no division of labor, though some genera 
(Pelopaeus, Bembex and Microbembex) build their individual nests 
close together, forming colonies. There is a great diversity of 
habits both among the Eumenidse and the Sphecina. In either 
group the nests may be made of mud and attached, for shelter, 
under rocks, the eaves of buildings, or the hollows of trees, or 
they may be attached to the stems of plants. The nest may be 
tubes in the stems of plants, in boards or in the ground, either 
found ready made, or, as is usual, newly bored or dug by the 
individual wasps using them. 
The adult wasps live on the nectar of flowers or on animal food, 
namely the same insect prey which they give their offspring. This 
