Population dynamics of the bark-dwelling spider Eustala perfida Mello-Leitão, 1947 (Araneidae)

ABSTRACT

Population dynamics of spiders may vary according to biotic and abiotic factors. We studied the phenology of the bark-dwelling spider Eustala perfida over a two-year period and investigated how temperature, precipitation, and prey availability were associated with the population of this species. The population of E. perfida presented a well-defined fluctuation, with one reproductive cycle per year. The recruitment of spiders occurred in summer, followed by successive phenological peaks at all stages of development. The species is protogynic, and the population of adult males peaks in the cold/dry season, indicating a winter mature phenological pattern. The diet of E. perfida is composed mainly of medium-sized homopterans, complemented by small dipterans and hymenopterans. We found that the higher abundance of spiders occurred two months after the highest values of precipitation and temperature, and three months after the higher abundance of potential prey items. These results indicate that spiders require time to respond to changes in environmental conditions. The species’ natural history and the structure of the trunks in which it lives may also affect the number of individuals in a particular area and over time.

KEYWORDS:

• Population density
• phenology
• prey availability
• Serra do Japi
• sex ratio

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (process: 11/15457-0) and Instituto Nacional de Ciência e Tecnologia dos Hymenoptera Parasitoides da Região Sudeste (INCT-HYMPAR/SUDESTE) (CNPq, FAPESP, CAPES).