Life History And Social Behavior Of Anelosimus Jabaquara And Anelosimus Dubiosus (araneae, Theridiidae)

The life history and social behavior of two sympatric spider species, Anelosimus jabaquara and A. dublosus (family Theridiidae), were examined to provide comparative data of intermediate social behaviors in this genus of social spiders. Both species occur in sympatry in a subtropical humid lowland forest in Brazil and shared very similar life history traits such as univoltinism and slightly biased subadult sex ratios with more females per colony than males. Reproduction in A. jabaquara took place in early summer (December) and the brood developed during winter (April to October) under the care of females. But the reproductive periods in A. dubiosus and A. jabaquara were desynchronized by one month with A. dubiosus reaching maturity and mating in November. Both species showed cooperation in spinning and repairing the colonial web, in capturing prey and caring for the brood. When compared to A. jabaquara, in A. dubiosus there were 2.6× more individual spiders per colony, 1.4× more females than males, the colonial webs were 0.4× larger and the females showed greater cooperation in caring for the brood. We believe that A. dubiosus showed a more complex array of social behaviors when compared to A. jabaquara probably due to the greater tolerance of other conspecific individuals. We placed A. jabaquara in the same level of sociality as another non-territorial periodic-social species, A. jucundus. Anelosimus dubiosus would be a non-territorial permanent-social species in the same level of sociality as A. domingo, A. rupununi and A. eximus, but with less complex social behaviors than any of the former species.262227237Avilés, L., Causes and consequences of cooperation and permanent-sociality in spiders (1997) The Evolution of Social Behavior in Insects and Arachnids, pp. 476-498. , (J.C. Choe & B.J. Crespi, eds.). Cambridge Univ. PressBrach, V., The biology of the social spider Anelosimus eximus (Araneae, Theridiidae) (1975) Bull. Southern California Acad. Sci., 74, pp. 37-41Christenson, T.E., Behaviour of the colonial and solitary spiders of the Theridiidae species Anelosimus eximus (1984) Anim. Behav., 32, pp. 725-734D'Andrea, M., Social behaviour in spiders (Arachnida, Araneae) (1987) Italian J. Zool. N.S. Monogr., p. 3Fowler, H.G., Levi, H.W., A new quasisocial Anelosimus spider (Araneae, Theridiidae) from Paraguay (1979) Psyche, 86, pp. 11-18Kullman, E.J., Evolution of social behavior in spiders (Araneae, Eresidae, Theridiidae) (1972) American Zool., 12, pp. 419-426Levi, H.W., The spider genera Neottiura and Anelosimus in America (1957) Trans. American Micros. Soc., 75, pp. 407-421Levi, H.W., The american spiders of the genus Anelosimus (Araneae, Theridiidae) (1963) Trans. American Micros. Soc., 32, pp. 30-48Levi, H.W., Smith, D., A new colonial Anelosimus spider from Suriname (Araneae, Theridiidae) (1982) Psyche, 89, pp. 275-278Marques, E.S.A., (1991) Historia Natural e Comportamento Social de Anelosimus Jabaquara e Anelosimus Dubiosus (AraneaeTheridiidae), , Master's thesis, Univ. of Campinas, BrazilNentwig, W., Christenson, T.E., Natural history of the non-solitary sheet weaving spiders Anelosimus jucundus (Araneae, Theridiidae) (1986) Zool. J. Linn. Soc., 87, pp. 27-35Shear, F., The evolution of social phenomena in spiders (1970) Bull. British Arachnol. Soc., 1, pp. 65-76Rypstra, A.L., Tirey, L., Observations on the social spider Anelosimus domingo (Araneae, Theridiidae) in southwestern Peru (1989) J. Arachnol., 17, pp. 368-370Vollrath, F., Colony foundation in a social spider (1982) Z. Tierpsychol., 60, pp. 313-324Vollrath, F., Eusociality and extraordinary sex ratios in the spider Anelosimus eximus (Araneae, Theridiidae) (1986) Behav. Ecol. Sociobiol., 18, pp. 283-28