

THE LIFE CYCLE AND MATING HABITS OF THE 

 MALE TARANTULA 



By W. J. BAERG 



University of Arkansas 



(Research Paper No. 78, Journal Series, University of Arkansas) 



THE tarantula, Emypelma cali- 

 fornica ausserer, is very common 

 in a number of our southwestern 

 states, such as California, Ari- 

 zona, New Mexico, Texas, Oklahoma, 

 Arkansas, and probably others. In Ar- 

 kansas it occurs in smaller or greater 

 colonies in various regions where con- 

 ditions with reference to shelter and food 

 are favorable. Hillsides in meadows, or 

 woodland not completely shaded, that are 

 relatively free from weeds and tall grass, 

 may be regarded as suitable ground, 

 especially if numerous flat rocks of 

 medium size are available for shelter. 

 Although the spiders can and do dig their 

 holes, they very frequently do no more 

 than dig an entrance underneath a large 

 flat rock, where they may live for several 

 years. 



A colony of from twelve to fifteen 

 spiders is located near the university 

 campus, and has been under fairly close 

 observation for nearly nine years. For 

 more intensive study, a varying number 

 of tarantulas have been kept in the labora- 

 tory where they are placed singly in large 

 battery jars, provided with an inch or 

 two of soil and a dish with water. The 

 jars are covered with screen wire tops. 

 If the spiders are kept in a cold room, they 

 will not require any food from early in 

 October till late in March. During the 

 rest of the year, they are fed on live grass- 



hoppers, cockroaches, caterpillars, and 

 some other insects. A full grown taran- 

 tula will require no more than one large 

 grasshopper, such as Melanoplm differen- 

 tialis, every five or six days. The small 

 tarantulas, up to two-and-a-half years 

 old, are fed on termites. 



The sexes in mature tarantulas are 

 readily distinguished by the fact that the 

 males have longer legs in comparison with 

 the size of the body, and by the relatively 

 short and somewhat club-shaped palpi. 



In the field observations the males have 

 till recently been very puzzling. In spite 

 of much diligent searching in many places, 

 I have never seen a male out of doors 

 except during the mating season. (In 

 the Canal Zone, I have seen the males at 

 night sitting presumably in front of their 

 own holes, just as the females were doing. 

 This was in August. Whether it was the 

 mating season, I cannot say.) At this 

 time the males may be seen sitting near 

 the holes occupied by females , or wander- 

 ing about in the neighborhood of these 

 holes. The mating season extends 

 through most of the months of September 

 and October. All the males that have 

 been brought into the laboratory died 

 soon after the mating season was over, 

 usually during the month of November. 

 One male lived through the winter and 

 till the following July. 



This account of the life cycle is based 



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