Advisor(s)
Abstract(s)
Spiders are successful natural enemies of pests occurring throughout the different
strata of an agroecosystem. The study of their functional responses can provide
information related to the potential effectiveness of different species and guilds on
reducing a pest population. However, multiple prey availability may change the functional
response of a predator. In this study, the functional responses of three species
of spiders in single-prey and multiple-prey experiments were modelled. The spider
species Haplodrassus rufipes, Araniella cucurbitina and Synema globosum were chosen
as being representatives of ground runners, orb-weavers and ambushers, respectively.
Three prey species were selected: a target prey, the Mediterranean fruit fly
Ceratitis capitata and two alternate prey species, the flour moth Ephestia kuehniella
and the house cricket Acheta domesticus. When the selected target prey C. capitata
was supplied in the single-prey experiments, the most and the least efficient spider
species were H. rufipes and S. globosum, respectively. However, opposite results were
obtained when alternative preys were supplied. Also, A. cucurbitina significantly changed
its functional response with the presence of alternative prey species. Considering
the prey preference during the multiple-prey experiments, A. domesticus, used as representative
of a heavy, long-sized and highly motile prey, was avoided whereas
C. capitata, the target pest used as representative of light, small-sized and moderately
motile prey was preferred by the three species of spiders. Ephestia kuehniella, used as
representative of light, medium-sized and low motile prey was occasionally consumed.
Each guild could include efficient predators against pests according to its
hunting strategies and the ecological exploited niches. Orb-weavers could be efficient
predators against flying pests; ambushers such as S. globosum could contribute
to the reduction of the populations of flower-visiting pests, whereas active ground
hunters may also play an important role preying on pests that develop a part or all of
its life cycle in the ground. However, further research on feeding behaviour such as
prey switching is needed for a better understanding of the effectiveness of spiders as
natural enemies.
Description
Keywords
Biological control Ceratitis capitata Electivity Functional groups Overkilling
Citation
Benhadi-Marín, Jacinto; Pereira, José A.; Sousa, José P.; Santos, Sónia A.P. (2019). Functional responses of three guilds of spiders: Comparing single- and multiprey approaches. Annals of Applied Biology. ISSN 0003-4746. 175, p. 202-214