**3. Results**

Successful plant sequences were recovered from the stomach contents of 71 insects representing 17 Neotropical forest katydid species. These katydid species consumed a wide variety of plant families, with each katydid species consuming multiple families of plants (Figure 1), and multiple katydid species consuming the same plant species. Comparing 2016 to 2017, katydids sampled from the same locations were often eating different plant families in different years (Figure 2).

In total 27 species of host plants were determined from the gu<sup>t</sup> contents of the sampled katydids by DNA barcodes (Table 1 and Table S3). These 27 species were distributed across 22 genera in 16 families and 12 orders and were phylogenetically spread across the 23 orders of flowering trees on Barro Colorado Island (Figure 3 and Figure S1). The largest numbers of species were found in the Fabales (six species), Sapindales (six species), and Laurales (three species). The remaining nine orders each had one or two species of host plants. Relatively few or no host species were detected in the speciose orders Gentianales, Rosales, Malpighiales, and Myrtales.

**Figure 1.** Plant families recovered from the stomach contents of six common katydid species on Barro

> different primer sets show different plant species

**Figure 2.** Map of katydid collection localities on Barro Colorado Island, with pie charts representing the plant families that were recovered from katydid stomachs by location and year. Each black dot represents a light capture location, with lights divided into three spatially and elevationally clustered zones. The inset pie charts represent the plant families that were sequenced in a given zone and year. "Conflict" indicates that different primer sets show different plant species identifications for a given individual katydid.

Colorado Island, Panama. "Conflict" indicates thatforindividual


**Table 1.** Plant species identified by DNA barcoding from the digestive tracts of Neotropical katydids.


**Table 1.** *Cont.*

Plant species listed are supported by two or more primer sets. Plant species with \* are supported by a single primer. The paranthetical number indicates the number of individual katydids associated with the identified plant.

**Figure 3.** The phylogenetic distribution of plant species in the diets of katydids on BCI. The evolutionary relationships of the 23 orders of flowering plants found on BCI are represented in the branching diagram (modified from Figure 1 in [39]; see Figure S1 for a full representation of the species diversity of trees in the 50-ha forest dynamics plot). Circled numbers indicate the number of host plant species per order detected in the gu<sup>t</sup> contents of katydids, as determined by DNA barcoding.

Most katydid species were consuming plant species that could grow into the canopy layer (Figure 4). However, some katydid species were foraging on plants that never grow higher than the understory.

**Figure 4.** Maximum published growth height for the plants contained in the katydid diet, shown by katydid species. In the case of repeated plant height values, points are jittered slightly to show all data. Plants that could not be identified to species or genus level are not included due to variability of family-level maximum growth height. Katydid species abbreviations (*Aw: Anaulacomera* "wallace"; *Af: Anaulacomera furcata; As: Anaulacomera spatulata; Afe: Arota festae; Cm: Ceraia mytra; Dg: Docidocercus gigliotosi; Dl: Dolichocercus latipennis; Ei: Euceraia insignis; Im: Idiarthron major; Lm: Lamprophyllum micans; Mc: Microcentrum championi; Mb: Montezumina bradleyi; Pd: Phylloptera dimidiata;* Ws: Waxy sp.).
