56 



THE NATIONAL GEOGRAPHIC MAGAZINE 



Some of these big wasps hawk about 

 searching for their prey, much like a sharp- 

 shinned hawk hunting for small birds. Hav- 

 ing discovered a tarantula, they hover over 

 it awaiting an opportunity to strike. 



STING LIKE A HIGH-VOLTAGE SPARK 



In South America I once saw a tarantula 

 running rapidly along a path. Well above 

 it and a little iDehind flew a tarantula hawk. 

 The spider stopped, exhausted. The wasp 

 hovered above it. 



Suddenly it descended. The instant it 

 struck, the great spider was completely 

 parah'zed. The sudden action of the sting 

 of these tarantula hawks has been com- 

 pared to the snap of an electric spark. 



Sometimes there is a slip, and then a 

 furious fight takes place. If this occurs, 

 bet on the wasp and you probably wont 

 lose. 



After the battle the paralyzed spider is 

 hauled to a suitable place, a hole is dug, 

 and the victim is dragged into it. An egg 

 is laid upon its body and the hole is closed. 

 Then the wasp starts off on a hunt for an- 

 other spider. 



One kind of these giant wasps, having 

 found a tarantula that has strayed some 

 distance from its burrow, alights between 

 the spider and its home, facing the poor 

 frightened creature. If it is possible for 

 you to entertain feelings of sympathy for 

 a huge and ugly spider, now is the time to 

 do it (pages S2 and S3). 



They watch each other closely, the spider 

 and the wasp. Each is capable of killing 

 the other. But the spider is frightened — 

 it is facing a serious crisis and knows it. 

 The wasp, by nature cannier and quicker, 

 is quite composed. It is simply about to 

 undertake a routine performance. Sud- 

 denly it strikes, and all is over; or there 

 may be a short tussle, with the wasp the 

 victor. 



The now paralyzed spider, after deliber- 

 ate examination, is dragged by the wasp, 

 always walking backwards, into the vic- 

 tim's own home, now become its tomb. An 

 egg is laid upon the helpless though still 

 living body, and the hole is closed. 



Another tarantula hawk is a serious 

 enemy of the trapdoor spiders in the West.* 



Spiders are very much in demand as food 

 for baby wasps, and many different kinds 



* See "California Trapdoor Spider Pcrform.s 

 Engineering Marvels," Ijy Lee Pas.smore, in The 

 National Geocraphic Magazine, AuKU.st, 19. 5,!. 



of wasps stock their nurseries with them. 

 Among these are the common mud daubers, 

 the cells of which are often seen in barns, 

 about verandas, in attics — indeed, in pro- 

 tected situations generally (Plate VIII). 



What is the story of these unsightly and 

 unwelcome lumps of mud? A story of tire- 

 less industry and maternal solicitude, with 

 a sad background of villainy and tragedy, 

 for the careful little mothers that construct 

 these cells have their share of troubles. 



Trim and slender wasps with yellow- 

 banded legs, they are seen in numbers on 

 muddy spots in summer. Each one is 

 standing on her head, digging out a ball 

 of mud. When she has gathered a sufficient 

 load she flies away to the scene of her ar- 

 chitectural operations. 



Each load of mud is flattened out into 

 a thin band that reaches halfwav around 

 the cell (Plate \TII, middle left)'. These 

 bands are added first on one side and then 

 on the other, so that the cell when finished 

 has a sort of herringbone pattern. 



Usually several or many cells are con- 

 structed, parallel to each other, side by side, 

 or in a mass. Then the mother wasp brings 

 more mud and plasters the whole structure 

 smoothly over, sometimes studding the sur- 

 face with numerous little pills of mud by 

 way of ornament. 



After each cell is finished there is a pause 

 in building operations. Mother goes spider 

 hunting. She catches and stings a spider 

 and packs it in the cell. She lays an egg 

 upon it. Then she catches more spiders 

 and fills the cell with them. When the pro- 

 spective baby's larder is complete, mother 

 seals the cell with mud and begins another. 



The group of cells shown in the upper 

 left-hand corner of Color Plate \TII was 

 found by Mr. Murayama and me in the 

 Astrophysical Observatory of the Smith- 

 sonian Institution at Washington, D. C. It 

 was made up of two lots of cells. The first 

 group, attached to the board, was small. 

 From these cells the wasps had all emerged 

 some time before. About them was a larger 

 group of cells, all of which were closed. 



As 'Sir. ^Nlurayama worked, the wasps 

 one by one bit their way out of the cells, 

 just in time to have their portraits painted. 



ENTER THE VILLAIN 



When we were looking for the mud- 

 daubers' nests, I noticed an active, nervous 

 little wasp, vivid metallic green in color, 

 taking an interest in the cells. This is the 



