Herpetology Notes, volume 12: 913-914 (2019) (published online on 01 September 2019)

Predation on the lesser treefrog minutus (Peters, 1872) (Anura: ) by Lethocerus sp. water bugs (Hemiptera: Belostomatidae) in São Paulo,

Filipe Serrano1,*, Juan C. Diaz-Ricaurte1,2, and Estefany Caroline Guevara-Molina3,4

Information on predation can be of importance to canopy ephemeral , with fallen Pinus sp. trunks understand predator-prey interactions (Toledo, 2005) and areas of submerged aquatic vegetation. and it is fundamental to elucidate the trophic networks On 7 February 2018, during nocturnal active searches, of ecosystems (Hero et al., 2001). Predation pressure we observed adult water bugs (Lethocerus sp.) feeding on on one species can impact the species composition Dendropsophus minutus, a small-sized hylid widespread (Morin, 1981) and respective patterns of distribution throughout open biomes in cis-Andean South America. (Smith, 1983). Anurans are important components of At 2217 h, a water bug was preying on a tadpole freshwater ecosystems, eating invertebrates and detritus of D. minutus while perched on a submerged trunk while simultaneously being vulnerable to aquatic approximately 2 m from the pond’s margin (Fig. 1A). predators (Toledo, 2003). Anurans have been reported as At 2224 h, 10 m away from the previous observation, a prey of several arthropod species (Toledo et al., 2007). second water bug was found preying on another tadpole Water bugs (Belostomatidae: Hemiptera) are one of the (Fig. 1B). Both tadpoles were motionless and we could most important invertebrate predators, preying on all not determine if the tadpole was still alive at the time of life stages of anuran species (Toledo, 2005). Here, we predation or observation. report two observations of giant water bugs (Lethocerus At 2234 h, while capturing a Lethocerus sp. for sp.) preying upon on tadpoles and a post-metamorphic experimental set-ups, a recently-metamorphosed D. individual of Dendropsophus minutus (Peters, 1872) minutus fell into the net. While the frog stayed floating, at Estação Ecológica de Santa Bárbara (22.9488°S, the water bug inadvertently made contact with it and 43.2862°W; WGS84, elevation 590 m), one of the most promptly grabbed the frog by its inguinal region (Fig. important remnants of Cerrado savannas in São Paulo 1C). We were unable to identify the water bugs to State, Brazil. The consists of a shallow open- species-level but due to their typical three-segment antennae, two large claws on the tarsi of the first pair, and widely dilated anterior and posterior femurs, we could identify them as members of the genus Lethocerus (De Carlo, 1962). 1 Laboratório de Ecologia, Evolução e Conservação de Despite multiple observations of predation by water Vertebrados, Departamento de Ecologia, Instituto bugs on anurans (Toledo, 2003; Batista et al., 2013; de Biociências, Universidade de São Paulo, Cidade Rocha et al., 2014), information on invertebrate diet Universitária, São Paulo, SP 05508-090, Brazil. 2 Grupo de Investigación en Biodiversidad y Desarrollo is still scarce due to the difficulty of stomach content Amazónico, Programa de Biología, Facultad de Ciencias analysis and thus its incidence and impact might be still Básicas, Universidad de la Amazonía, Florencia, Caquetá, under-reported (Pombal, 2007). Kwet (2001) reported . that predation by water bugs resulted in up to 10% of 3 Laboratório de Comportamento e Fisiologia Evolutiva, the annual mortality rates for D. minutus in Rio Grande Departamento de Fisiologia, Instituto de Biociências, do Sul, Brazil. The reproductive season of D. minutus Universidade de São Paulo, São Paulo, SP 05508-090, Brazil. occurs from November–May, with both tadpoles and 4 Grupo de Evolución, Ecología y Comportamiento (EECO). Programa de Biología. Universidad del Quindío, Armenia, post-metamorphic individuals emerging in January Quindío, Colombia. (Kopp and Eterovick, 2006), which is consistent with * Corresponding author. E-mail: [email protected] our reported predation events. 914 Filipe Serrano et al.

Figure 1. Adult water bugs (Lethocerus sp.) preying on two tadpoles of Dendropsophus minutus by the ventral fin (A) or the tail muscle (B), and on a recently-metamorphosed individual (C).

Although Dendropsophus minutus was the most Kwet, A. (2001): Frösche im brasilianischen Araukarienwald - abundant species in the pond, several other species were Anurengemeinschaft des Araukarienwaldes von Rio Grande seen or heard vocalizing (e.g., Dendropsophus jimi, D. do Sul: Diversität, Reproduktion und Ressourcenaufteilung. Münster, Germany, Natur und Tier-Verlag. elianae, Scinax fuscomarginatus), but no predation on McCormick, S., Polis, G.A. (1982): Arthropods that prey on these species was observed. vertebrates. Biological Reviews 57: 29–58. Morin, P.J. (1981): Predatory salamanders reverse the outcome of Acknowledgments. This study was financed in part by the competition among three species of anuran tadpoles. Science Coordenação de Aperfeiçoamento de Pessoal de Nível Superior 212: 1284–1286. – Brasil under Finance Code 001. We thank Matheus Januário for Pombal, J.P., Jr. (2007): Notas sobre predação em uma taxocenose the field assistance and we thank Cristiano de Campos Nogueira de anfíbios anuros no sudeste do Brasil. Revista Brasileira de for his review and comments. Furthermore, we acknowledge Zoologia 24: 841–843. the review by Angelica Crottini on an earlier version of the Rocha, R., Almeida, T., López-Baucells, A. (2014): Field manuscript. observation of an adult Lesser treefrog Dendropsophus minutus (Anura: Hylidae) being consumed by a neotropical Lethocerus References sp. (Hemiptera: Belostomatidae) nymph. Alytes 31: 37–39. Smith, D.C. (1983): Factors controlling tadpole populations of the Batista, V.G., Affonso, I.P., Hanisch, R.F., Oda, F.H. (2013): chorus frog (Pseudacris triseriata) on Isle Royale, Michigan. Predation on Eupemphix nattereri Steindachner, 1863 (Anura, Ecology 64: 501–510. Leiuperidae) by giant water bugs, Lethocerus delpontei Toledo, L.F. (2003): Predation on seven South American anuran De Carlo, 1930 and L. annulipes (Herrich-Schäffer, 1845) species by water bugs (Belostomatidae). Phyllomedusa 2: 105– (Hemiptera, Belostomatidae). Pan-American Journal of Aquatic 108. Sciences 8: 364–368. Toledo, L.F. (2005): Predation of juvenile and adult anurans De Carlo, J.M. (1962): Consideraciones sobre la biologia de by invertebrates: current knowledge and perspectives. Lethocerus mazzai De Carlo (Hemiptera: Belostomatidae). Herpetological Review 36: 395–399. Physis 23:143–151. Toledo, L.F., Ribeiro, R.S., Haddad, C.F. (2007): Anurans as prey: Hero, J.M., Magnusson, W.E., Rocha, C.F., Catterall, C.P. (2001): an exploratory analysis and size relationships between predators Antipredator defenses influence the distribution of and their prey. Journal of Zoology 271: 170–177. prey species in the central Amazon rain . Biotropica 33: 131–141. Kopp, K., Eterovick, P.C. (2006): Factors influencing spatial and temporal structure of frog assemblages at in southeastern Brazil. Journal of Natural History 40: 1813–1830. Kopp, K., Wachlevski, M., Eterovick, P.C. (2006): Environmental Accepted by Angelica Crottini complexity reduces tadpole predation by water bugs. Canadian Journal of Zoology 84: 136–140.