68 Some Solitary Wasps of Texas. 



ing by the scratching method and employing their forefeet as rakes 

 in excavation liave simple nests consisting of a tube running ob- 

 liquely down and ending in a dilation or pocket at the lower end of 

 greater or lesser diameter (Figs. 19 and 21.) Among the mud- 

 plastering wasps we may distinguish two methods of work again: 

 Some species build the entire nest of mud, as for example Agcriia, 

 Pelopacus, while others occupy convenient crevices, and use the mud- 

 mortar merely to close the mouth of their ready made nests, as ob- 

 tains in the case of Trypoxylon. The same genus may have species 

 some of which practice the one, some the other method (Odynerus, 

 Chap. I). And again the same species, as Agenia suhcorticalis 

 seems to do, may combine the two methods, for she builds complete 

 cells of mud not in the open air like Pelopatus but hidden away 

 in crevices. 



Some wasps always carry their prey on the wing and on their re- 

 turn to the nest alight directly in or over its entrance. Beinbex, 

 Monedula, Bemhidula, Iloplisoides, Microbemhex carry their prey 

 w^ith their middle pair of legs and press it closely to their venter; 

 Rhopalum ahdorninah and Notoglossa use their hind pair; Ody- 

 ncriis, Tnjpoxylon and Cerceris carry theirs with their mandibles 

 as does also Alyson, which alights some distance from the west and 

 completes her journey on foot. Larra americana and Microhembex 

 prefer flying to walking; but when the weight is great the advance 

 is in jumps or short flights, the distance of each advance being in- 

 versely proportionate to the weight of the burden. 



Other wasps always drag the victim over the ground regardless 

 of how light this may be and how absurd it may look (to us). Am- 

 rnopliila's method, to which that of Priononyx corresponds^ is shown 

 in Fig. 16. Some spider catchers (Miscophus, Agenia) walk for- 

 ward in dragging their prey; others (some species of Pompilus and 

 Pompilogaster) always walk backward. Agenia and some others 

 combine the flying and the walking means of progression. These 

 drag their victims over the ground, climb up the stems of herbs and 

 bushes in their path and fly off, parachute-fashion, from the highest 

 point obtainable in the direction of their course. The species dif- 

 fer greatly, too, in the ease or reluctance with which they betray the 

 locality of their nest, Miscophus and Tacliytes ab ductus being, for 

 example, experts in leading the observer astray. 



By the way in which a wasp enters the nest the species may often 

 be recognized, Bembedds as a rule, after having opened the nest 



