Morphology of the antennal sensilla of two species of Hoplopyga Thomson, 1880 (Coleoptera, Scarabaeidae, Cetoniinae)

Cleicimar Gomes Costa,Juares Fuhrmann,Sérgio Roberto Rodrigues

doi:10.1590/1806-9665-rbent-2020-0078

Abstract

Antennal sensilla are important functional elements of sensory systems in insects. This study aimed to determine the morphology and structure of the sensilla of two species of the genus Hoplopyga. Adults of Hoplopyga liturata (Olivier, 1789) were collected in traps with sugarcane juice as an attractant. Thereafter, larvae of Hoplopyga albiventris (Gory and Percheron, 1833) were collected in mounds of termites (Cornitermes cumulans (Kollar, 1832) Isoptera). Then, they were reared in the laboratory for adult observations. Antennae of H. liturata and H. albiventris have sensilla chaetica, trichodea, placodea (type I and II), coeloconica (type I and II), and ampullacea (or pore). Females of H. liturata have a total of about 10657 sensilla and males have about 12512, whereas females of H. albiventris have about 16490 sensilla and the males 24565 sensilla. Sensilla placodea are predominant in the antenna of males and females of both species.

Highlights

Antennal sensilla are responsible for reception of semiochemicals, such as sexual or aggregative pheromones, and of other volatiles, helping insects to locate plants used as food and mating sites (Visser, 1986; Tegoni et al, 2004; Wee et al, 2016)
The present paper aimed to describe the morphology of antennal sensilla of males and females of two species of phytophagous scarab beetles included in the genus Hoplopyga: H. albiventris and H. liturata
Adults of H. liturata and H. albiventris have similar antennae structure, shape, and size, but the amount of sensilla is quite different between both species

Summary

Introduction

The genus Hoplopyga Thomson, 1880 (Coleoptera, Scarabaeidae, Cetoniinae, Gymnetini) includes 20 species distributed from Mexico to Argentina, of which 11 were registered in Brazil (Shaughney and Ratcliffe, 2015), namely: H. albiventris (Gory and Percheron, 1833), H. brasiliensis (Gory and Percheron, 1833), H. cerdani Antoine, 1998, H. liturata (Olivier, 1789), H. marginesignata (Gory and Percheron, 1833), H. miliaris (Gory and Percheron, 1833), H. multipunctata (Gory and Percheron, 1833), H. ocellata (Gory and Percheron, 1833), H. ravida (Janson, 1881), H. riparia Shaughney and Ratcliffe, 2015, and H. singularis (Gory and Percheron, 1833).Adults of Hoplopyga have been noticed feeding on leaves, flowers, fruits, and plant sap (Ballou, 1937; Solís, 2004; Gonçalves and Louzada, 2005; Puker et al, 2012; Rodrigues et al, 2013, Shaughney and Ratcliffe, 2015; Kirmse and Ratcliffe, 2019), while larvae feed on mounds of termites (Isoptera) and decaying woods trunks (Luederwaldt, 1911; Vanin and Costa, 1984; Micó et al, 2001; Garcia et al, 2013; Puker et al, 2012, 2014; Shaughney and Ratcliffe, 2015).Insect antennae are important sensory structures involved in the detection of odorants, and temperature, besides being tactile and gustative organs (Schneider, 1964; Hansson and Stensmyr, 2011). Adults of Hoplopyga have been noticed feeding on leaves, flowers, fruits, and plant sap (Ballou, 1937; Solís, 2004; Gonçalves and Louzada, 2005; Puker et al, 2012; Rodrigues et al, 2013, Shaughney and Ratcliffe, 2015; Kirmse and Ratcliffe, 2019), while larvae feed on mounds of termites (Isoptera) and decaying woods trunks (Luederwaldt, 1911; Vanin and Costa, 1984; Micó et al, 2001; Garcia et al, 2013; Puker et al, 2012, 2014; Shaughney and Ratcliffe, 2015). Adults of scarab beetles (Coleoptera, Scarabaeidae) use to swarm to find partners to copulate (Rodrigues et al, 2014, 2016). During the couple formation, these beetles usually use chemical communication detecting released odors using their antennal sensilla (Meinecke, 1975; Leal, 1998). Sensilla types and number vary with species and between males and females within a species, especially for Scarabaeidae (Ochieng et al, 2002; Romero-López et al, 2004, 2010; Tanaka et al, 2006; Handique et al, 2017; Rodrigues et al, 2019)

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