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THE NATIONAL GEOGRAPHIC MAGAZINE 



A SCIENTIFIC G-MAN MAKES A RAID ON THE INSECT UNDERWORLD 



"Detective" Jenks, the author, in his search for parasites that murder trapdoor spiders in their 

 subterranean nests, dug up many hundreds of these cave dwellers' tubes of clay. Danny bosses the 

 job while daddy pries loose a small section of southern California. Several tubes are already in the 

 box and pieces of paper mark two others still to be dug. 



widow spiders in salad-dressing-jar breed- 

 ing cages, in a homemade laboratory with 

 apple-box cupboards, and that I had be- 

 gun an extensive investigation of the black 

 widow, and a search for a parasite that 

 might be used to control her increase. That 

 trail I am still following with a growing 

 probability of ultimate success. 



I became a sort of local institution. The 

 neighbors dubbed me ''The Spider Man," 

 or "The Black Widower." They seemed 

 to think that a man who put in about 14 

 hours a day collecting and studying spiders, 

 when he was not being paid for it, must 

 have soinething wrong with his head, and 

 many a time along that rocky road I felt 

 inclined to agree with them! 



TRAPDOOR HUNTING IN ADOBE HILLS 



All that is another story, but the con- 

 necting link is that I had collected about a 

 hundred black widow "layers" to provide 

 the egg sacs necessary for the parasite- 

 propagation experiments. These "hens" 

 had to be well and properly fed in order to 

 lay eggs, and it was difficult to obtain large 

 quantities of insect food during the rainy 



seasons. Trapdoor spiders proved to be an 

 ideal food for them, and I knew that there 

 were thousands in the surrounding hills. 



So the strong-arm work began. During 

 the fall and early winter of 1935 I dug up 

 my first thousand nests, an additional thou- 

 sand in 1936, and another thousand in 1937. 

 Of course that was far more than I needed 

 for feeding my black widow layers, but, 

 early in my first thousand, I became in- 

 tensely interested in an underground war- 

 fare between the trapdoor spiders and cer- 

 tain mysterious parasitic eneinies of which 

 I had found ample evidence in devastated 

 nests. So I Ivcpt right on digging whenever 

 I could steal the time from other work. 



But let's not sit here in the apple-box 

 laboratory and merely talk about it. Come 

 with me and see for yourself just how we 

 hunt the trapdoor nests for the parasites 

 they may contain. 



As usual, the car is packed and ready. 

 Danny has a wad of old papers for markers. 

 Down the winding canyon road, past the 

 Southwest Museum, over the Arroyo Seco 

 bridge, and on up the three-mile grade into 

 the high adobe hills, we rattle along. 



