Fig 1.
a) Female wasp introducing a captured orb-weaving spider into her nest (i.e. an abandoned beetle bored stem). b) Brood cell provisioned with paralyzed spiders.
Table 1.
Sampled localities along the Baja California peninsula.
SA = Santiago, EP = El Pilar, LP = La Purísima, ES = El Sauzal, SB = San Borja, SF = San Fernando. Temperature (°C), precipitation (mm), and relative humidity (Rh) were obtained from SMN [38]. Size was extracted from maps from INEGI [39].
Fig 2.
Studied Trypoxylon species and their most common preyed spiders.
a) T. bridwelli and b) Sassacus vitis, c) T. dubium and d) Eustala sp., e) T. tridentatum and f) Metepeira arizonica. Photographs by A. Falcón-Brindis and Luis E. Robledo Ospina.
Table 2.
List of spider species and their guild category captured by each mud-daubing wasp.
AH = ambush hunter, OW = orb web, SW = spatial web, ST = stalker, GH = ground hunter, SP = specialist. Spiders within the nest in oasis = ●, desert = ○, and both habitats = Δ. Guild categories from Cardoso et al. [33] and Uetz et al. [46].
Fig 3.
Spiders captured by the Trypoxylon wasps throughout the localities.
a) Life cycle stage of captured spiders; abundance was counted as adults (male, female) and juvenile individuals; b) monthly variation of total spider abundance c) nest length and d) cell length. Whiskers represent the standard error. Blue bars = males, orange = females, green = juveniles.
Fig 4.
a) Total species richness and abundance per spider guild. Bars represent the richness (q = 0) and the line the abundance (right axis). b) Abundance of spider guilds in the diet of each wasp species. AH = ambush hunter, OW = orb web, SW = spatial web, ST = stalker, GH = ground hunter, SP = specialist.
Fig 5.
Bipartite interaction between wasps and spider guilds.
Each guild contains the total number of spider species (right bars) preyed upon by each wasp species (left bars). The thickness of bars indicate the abundance of predators and prey, respectively. The line thickness represents the abundance of individuals captured by each wasp species.
Fig 6.
Non-metric multidimensional scaling of the spider prey composition.
See the high dissimilarity between wasp species.
Fig 7.
Species accumulation curve of captured spiders among the wasp species.
The abscissa values represent the number of spiders that occurred within the wasps´ nests. The curves were extrapolated with 95% confidence intervals. Values of Hill numbers of order q = 0 (species richness), q = 1 (effective number of common species) and q = 2 (effective number of dominant species) are shown for each wasp species.
Table 3.
Summary of diversity and functional parameters between the three wasp species and their prey.
The habitat indicates where the nests of each wasp species were found. The wasp body length is the measurement from the frons to the last segment of metasoma (only females). All estimators and diversity indices were calculated for the total number of spider species each wasp captured.
Table 4.
Pairwise comparison of niche overlap using Pianka´s measure.
Values of quantitative Sorensen index are in bold.
Fig 8.
Morphological differences associated to prey selection.
a) Differences in body size between the three wasp species, b) differences in spider prey size and c) range of prey size chosen by each Trypoxylon species. Dashed lines indicate the median.