Predatory potential of Alopecosa albofasciata (Araneae: Lycosidae) against Bactrocera oleae (Diptera: Tephritidae): laboratory functional response and field predation

• Alopecosa albofasciata is the dominant spider in olive groves during autumn/winter. • This period coincides with the overwintering soil stages of the olive fly B. oleae . • The wolf spider A. albofasciata efficiently preyed on third-instar B. oleae larvae. • PCR gut-content analysis confirmed field predation of B. oleae by A. albofasciata . • Conservation strategies for A. albofasciata should be promoted in olive groves. Spiders play a crucial role in the natural suppression of pests in agroecosystems. In olive groves, the olive fruit fly, Bactrocera oleae , is one of the major pests, increasing the need for sustainable management strategies based on naturally occurring enemies. This study evaluated the predatory potential of a ground-dwelling spider on the overwintering generation of B. oleae under laboratory and field conditions. Epigeic spiders were sampled using pitfall traps in an olive grove in northeastern Portugal over two consecutive years, from October to February. The functional response of the dominant species was assessed under laboratory conditions, and field predation was evaluated using PCR-based gut-content analysis. A total of 764 spiders were collected, representing 21 families, at least 38 species, and 10 guilds. The ground-hunting Alopecosa albofasciata was consistently the dominant and most active species across both sampling years. Due to its abundance and temporal stability, A. albofasciata was selected as the model species for laboratory functional response experiments and field assays. Laboratory trials showed that A. albofasciata efficiently consumed B. oleae third-instar larvae at low prey densities and exhibited a type-II functional response, whereas predation on pupae remained low across all prey densities. PCR analyses of field-collected specimens confirmed predation of B. oleae under natural conditions. Overall, these results indicate that A. albofasciata contributes to the natural mortality of B. oleae during the overwintering period and highlights its potential role in conservation biological control in the olive agroecosystems.