74 PSYCHE [August 



THE CALLS OF SPIDERS. 



BY FRED. H. LAHEE, NORTH CAMBRIDGE, MASS. 



During the months of April and May, there is a certain spider, namely Lycosa 

 kochii (of the family Lycosidae), which is very abundant in our oak woods. On a 

 warm, sunny day at this time of year, if you watch the male of this species, you will 

 notice that he is earnestly engaged in something that occupies his entire attention. 

 He runs a little distance, then stops, moves on again, and again pauses a moment, 

 generally on the surface leaves ; and thus he continues, often covering many yards 

 in an hour or two. If the air is very still a certain clicking or purring will be heard 

 every time the spider rests. Since this operation has, I believe, never been fully 

 described before, it may not be out of place to give an account of it here. 



The sound is made by the male's tapping or drumming upon the dry leaves 

 with the tips of his palps. It is very similar to the low stridulation of a cricket 

 when it is beginning to chirp. The sound is continuous while it lasts, but varies 

 in quality and loudness. It consists of, first, a steady, but extremely faint purring, 

 which seems to be produced by very rapid and very short strokes of the palps. 

 Then the sound grows rather louder, but is still so low that the ear must be less 

 than a foot distant in order to hear it. Lastly, the whole concludes with a much 

 sharper purr or click, varying according to the number of times the palps strike 

 the leaf. Sometimes only the first, or the first and second portions are produced 

 on the same leaf, sometimes all. The last part is nearly always accompanied by 

 an up-and-down motion of the abdomen. This at first misled me to believe that 

 the abdomen was the only instrument employed, but, although this frequently even 

 touches the leaf, the palps are, nevertheless, the principal organs. Of this fact I 

 am fully convinced in reference to the last portion of the sound. I have seen the 

 performance at close range with a lens. The palps are curved to form an arc of 

 perhaps 60 to 72 degrees. They are moved up and down like a hammer and strike 

 the leaf directly downwards. It is the blow of their horny tips which causes the 

 sound. As nearly as I could make out, they are used together, not alternately. 

 They are not scraped or drawn across the surface of the leaf. In the preceding 

 description the terms "click" and "purr" have been employed merely to indicate 

 the frequency of the impact, not at all the method or means of producing it. 



Although personally I am of the opinion that these are sexual calls, I shall let 

 the subject rest here until further researches have been carried out. I shall be 

 very much obliged to any person who sends me additional information in regard to 

 this matter. 



