28 BULLETIN 416, U. S. DEPARTMENT OF AGRICULTURE. 
Manner of travel.—An extensive series of experiments concerning 
the travel of red spiders has been performed. The female travels 
in a comparatively straight course, bemg influenced by the light. 
(Pl. VI.) The female travels faster than the maie and her effort is 
extended over a relatively large space in an apparent attempt to 
locate new food plants. The very frequent observance of solitary 
females on seedling plants is positive evidence that they establish 
themselves through the agency of ground travel. 
The male, on being removed from the host plant and tested on 
a comparatively smooth surface, confines his wanderings to a small 
area. The tracings made of male travel are seen to cross and recross 
until a maze of lines results. No evidence of phototropism has been 
observed in many cases of male travel. There seems to be an in- 
stinctive tendency to remain within a limited area. The entire area 
traversed in an hour by the average male on a smooth surface rarely 
exceeds in size that of a watch crystal. The aversion to roaming 
probably originates from the instinctive desire to remain with the 
females of the colony. It is not essential to the propagation of the 
species that migrating females, which failed to mate before under- 
taking their journeys, should become fertilized immediately upon 
establishing themselves on the new host. As has been emphasized 
previously, the early eggs of such sterile females produce only males, 
which, upon maturity, immediately fertilize the females, so that the 
subsequent progeny will be of either sex. 
Taste IV.—Distance and rate of travel of male and female red spiders on coarse paper 
surface.* 
Male. Female. 
Warm Day. Warm day. | Cool day. 
Exp. No | | | 
Time. | Dis- ie Exp. | Time. | Dis- oe E Time. | Dis- pe 
tance. | ninute No. tance. | ninute No tance mnie 
Mins. | Ft. In. Inches Mins. | Ft. In.| Inches Mins. | Ft. In | Inches. 
i eee 30] 4 23); 1.68 15 SL 10 td 4.25 || 27 60 9 0 1. 80 
Zits cee SOR ae Ouaae 250 16 26) 10. 7 4. 85 || 28 60 8 103 | aT ie/ 
a eae 30} 5 6 2. 20 17 60} 18 9 3.75 29 60 6 13 | 1. 23 
EES stp a) % 2. 06 18 60 | 26 O 5. 20 30 60 6 3 1. 25 
a= 12h 2 ee 2508 19 30;}13 9 5.50 | 31 30 | 4 4 1.60 
6 Simin 3.00 20 60 20. 93; 4.16 32 30 | 3 104 | 1.55 
7 LOO 4.47 21 30)13 WB) 5.25 33 45 | 9 1% 2. 43 
Ses ete 150) | Ao Passo 22 30} 8 103) 3.56 | 
Oe ee 40 | 12 7. 3.78 23 7A Vee! i Dai BL 6. 80 | 
1D See AG ales a 2.73 24 31 | 10 10 4,20 
iB Las eS 15; 5 4 4, 30 25 26; 10 7 4.90 \ 
EEA ae 150) e498 3. 73 | 26 30; 13 8 5.47 | 
Bae 45| 9 32] 2.48 | 
eRe” 30] 7 3 2.90 | | 
Boy ache voeud. eeaeere 2 Opyllent: oe, Maat | eee rey eee te i er os | 1.66 
_1 The mean temperature at the time of conducting the warm-day experiments was 91.2° F., and at the 
time of conducting the cool-day experiments was 62.7° F. 
ae A Ry A 
