364 



THE STUDY OF INSECTS 



and coccids. The individuals in which the honey-dew is stored are kn< iwn 

 as repletes. The workers that collect the honey-dew swallow it and carry 

 it in their crop to the nest. There they regurgitate it and feed it to a 

 replete, which in turn swallows it and retains it in its crop. The crop of 

 the replete becomes so greatly distended that the gaster becomes a trans- 

 lucent sphere, as large as a pea, on the surface of which the sclerites 

 appear as isolated patches separated by the tense, pel- 

 lucid, yellowish, intersegmental membrane (Fig. 606). 

 The repletes are unable to go about but remain quietly 

 clinging to the roof of a chamber of the nest. When 

 the season for obtaining honey-dew is passed, these living 

 cells disgorge their supply through their mouths, for the 



Fig. 606. 



use of the colony. 



Family Vespid^e 



The Typical Wasps or Diploptera 



The family Vespidas includes our most familiar wasps, the hornets, 

 and the yellow-jackets, and their near allies. All members of this family 

 are winged and nearly all of them when at rest fold their wings length- 

 wise like a fan; for this reason they are often termed the Diploptera or 

 the diplopterous wasps. In the habit of folding their wings when at rest, 

 the typical wasps differ from nearly all other Hymenoptcra. The vena- 

 tion of a member of the Vcspidae is illustrated in Figure 607. 



Fig. 607. — Wings of Vespa diabolica: pr. I, preanal lobe; pr. exc, pre- 

 axillary excision. (From Bradley.) 



If we take into account only the habits of these insects the sub- 

 families of the typical wasps can be separated into two groups, the 

 solitary wasps, those in which a single female makes a nest for her young, 

 and the social wasps, in which many individuals work together to make a 

 nest. This grouping of the subfamilies, however, is not regarded as a 

 natural division of the family Vespidae, but this grouping is useful in a 

 discussion of the habits of these insects. 



THE SOLITARY VESPID WASPS 



Most of our species of the solitary vespid wasps belong to the group 

 known as the eumenids. The females of these wasps work alone, each 



