Hymenoptera

Ward, Anna K. G., Busbee, Robert W., Chen, Rachel A., Davis, Charles K., Driscoe, Amanda L., Egan, Scott P., Goldberg, Bailey A. R., Hood, Glen Ray, Jones, Dylan G., Kranz, Adam J., Meadely-Dunphy, Shannon A., Milks, Alyson K., Ott, James R., Prior, Kirsten M., Sheikh, Sofia I., Shzu, Shih-An, Weinersmith, Kelly L., Zhang, Linyi, Zhang, Y. Miles & Forbes, Andrew A., 2022, Borneosa aspera, Zoological Studies 61 (57), pp. 1-30 : 15

( Hymenoptera : Chalcidoidea: Eurytomidae : Eurytominae )

16,712 individuals (mean = 253.2, range 1–9,934) reared from 66 gall types ( Table S1).

Summary of Natural History: Sycophila are known as parasitoids of endophytic insects, including gall wasps ( Balduf 1932; Askew et al. 2006 2013; Gómez et al. 2013). Some species are known from just a single host (e.g., Sycophila marylandica (Girault) ( Balduf 1932) , while the Palearctic species Sycophila buguttata (Swederus) has 80 recorded hosts ( Askew et al. 2013). Recent molecular work has shown considerable cryptic diversity and more limited host ranges among the Nearctic species, ( Zhang et al. 2022).

Relationship to galler phylogeny: Sycophila in our collections were broadly associated with almost all clades in the Nearctic gall wasp phylogeny ( Ward et al. 2022), including all Palearctic clades ( Fig. 6a ). Two clades from which no Sycophila were reared were a mixture of cluster galls on leaves and stems, early spring bud galls, and small unilocular leaf galls. Sycophila appear to be reared more often from large galls ( Fig. 6e ; Hall 2001; Zhang et al. 2022) such that this apparent absence may reflect a general favoring of larger galls, but could also or instead be related to phenology or a bias in survivorship from smaller galls when using our rearing methods.

Biogeography and oak tree section: Sycophila were reared from galls on oaks across all three floristic regions and in all three oak sections ( Fig. 6b c ). Nine of 10 galls reared from live oaks (section Virentes ) were host to Sycophila .

Tree organ and gall size: We reared Sycophila from all surveyed host tree organs ( Fig. 6d ). At least at this genus-level resolution, they were reared from a larger fraction (74%) of large galls than from medium (59%) or small (26%) galls ( Fig. 6e ). PCoA analyses of Sycophila from these and other collections also suggest that wasps in the genus generally favor medium and large galls ( Zhang et al. 2022).

Co-occurrence with other natural enemies: Sycophila did not co-occur significantly in a positive or negative direction with any of the other seven genera analyzed ( Fig. 6f ).

Figures

Fig. 6. Summary of data for Sycophila collected from Nearctic galls. For full explanation of figure details, refer to figure 1 legend. a) Associations of Sycophila with the Nearctic oak gall wasp phylogeny (Fig. S1). b) Gall types from which Sycophila were reared in the Californian (blue), Mexican and Central American (orange), and Eastern North American (green) floristic provinces. c) Associations of Sycophila with trees in sections Quercus (Q), Lobatae (L), and Virentes (V). d) Association of Sycophila with gall types on different oak tissues. e) proportion of gall types of three size categories (“small” <0.5 mm; “medium”, “large”> 20 mm) from which Sycophila were reared. f) Results of probabilistic co-occurrence analysis for Sycophila against seven other common associates. Yellow = significantly less likely to co-occur; blue = significantly more likely to co-occur; gray = no difference from probabilistic expectations. g) Sycophila lateral habitus.