Fig 4. Host preference, colonies exclusively occupied by a single Tetradonia species, and relative co-occurrence of Tetradonia species at La Selva Biological Station, Costa Rica.

(a) White numbers in cells depict host preference (or beetle prevalence) evaluated as the proportion of colonies of a given host species in which a given Tetradonia species was collected. (b) Species exclusivity in colonies reflects the proportion of colonies of a given host species in which we found only a single Tetradonia species, relative to the total number of sampled colonies of that host, but excluding those colonies in which no Tetradonia specimens were found at all (see Table 1). For example, we exclusively found T. laticeps in 5 colonies out of 8 E. vagans angustatum colonies sampled, and 6 sampled E. vagans angustatum colonies contained some Tetradonia beetles (i.e., 5/6 = 0.83). (c) To quantify the level of relative co-occurrence of different Tetradonia species, we first counted the number of host colonies that were simultaneously parasitized by a given species pair (for absolute number of co-occurrence events see S2 Fig). To account for differences in species prevalence, we divided the total number of co-occurrence events for a given species pair either by the number of host colonies in which the more prevalent partner (lower left) or the less prevalent partner (upper right) was found. For instance, out of the 5 colonies in which T. tikalensis was found, it co-occurred in 4 of them with T. cf. marginalis, the latter of which was found in a total of 28 colonies (i.e., standardized for more prevalent partner: 4/28 = 0.14; standardized for less prevalent partner: 4/5 = 0.80). Differential shading corresponds to the white numbers in cells ranging from white (value 0) to black (value 1). Photographs depict frontal head views of Eciton soldier workers and dorsal views of Tetradonia beetles for the different species. Abbreviations: E. ham. = Eciton hamatum, E. bur. f. = Eciton burchellii foreli, E. luc. c. = Eciton lucanoides conquistador, E. vag. a. = Eciton vagans angustatum, E. mex. = Eciton mexicanum s. str., E. dul.c. = Eciton dulcium crassinode, T. lat. = Tetradonia laticeps, T. mar. = Tetradonia cf. marginalis, T. tik. = Tetradonia tikalensis, T. las. = Tetradonia laselvensis, T. liz. = Tetradonia lizonae.