Family RHOPALIDAE

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Family RHOPALIDAE

Compiler and date details

15 February 2002

Introduction

The Rhopalidae or scentless plantbugs are a cosmopolitan family of coreoid bugs comprising 21 genera and 209 species (Chopra 1967, Schaefer & Chopra 1982, Schuh & Slater 1995, Schaefer & Kotulski 2000, Zoological Record 1982–2001, Henry 2009). The Australian fauna is represented by two genera and seven species.

Amyot & Serville (1843) first recognised rhopalids as a family. Stål (1873) established the basis of the modern classification, recognising four divisions (Harmostaria, Corizaria, Myrmaria and Serinetharia). Chopra (1967) reviewed the history of the group and proposed the following classification: Rhopalinae (Niesthreini, Rhopalini, Chorosomini, Harmostini, Maccevethini, Corizomorphini) and Serinethinae. Göllner-Scheiding (1983) followed this arrangement.

Chopra (1967) also provided a phylogeny of rhopalids and reviewed their morphology. Schaefer & Chopra (1982) gave a phylogeny of the suprageneric groups of the Rhopalidae, recognising the Rhopalinae as a paraphyletic group, and establishing a sister-group relationship between the Rhopalinae: Maccevethini and Serinethinae. Schaefer (1993, 1994) maintained these arrangements in subsequent works. Li & Zheng (1994) also conducted a phylogenetic analysis of the Rhopalidae and proposed the following classification: Rhopalini and Serinethini. In the Catalogue, we recognise these two taxa at subfamilial rank as follows: Rhopalinae and Serinethinae. No tribal classification is used in the Catalogue.

Göllner-Scheiding (1983) catalogued the rhopalids of the world. Lethierry & Severin (1894) and Stål (1870, 1873) are important early references to the world fauna. Regional catalogues include: Froeschner (1981—Ecuador, 2000—Panama) and Henry (1988—Nearctic Region). Stonedahl & Dolling (1991) listed key taxonomic works. Gross (1960) revised the Australian and Indo-Pacific species of Leptocoris Hahn. Moulet (1995) revised the Mediterranean fauna and provides species descriptions, ecological notes and host associations. Linnavuori (1987) reviewed the distribution of rhopalids from west and central Africa. Göllner-Scheiding (1975, 1976, 1980, 1984) revised several rhopalid genera.

Both subfamilies are found in the Eastern and Western Hemispheres. Schaefer & Kotulski (2000) reported that Rhopalinae are most diverse in the Palaearctic Region and Serinethinae are more tropical in distribution. Some of the suprageneric groups exhibit unusual disjunct distributions that are not consistent with vicariant explanations (Schaefer 1994; Schuh & Slater 1995).

Liorhyssus Stål (1 species) and Leptocoris Hahn (6 species) are the only known genera in Australia. Gross (1960) revised Leptocoris and recognised five species from Australia, three of which are also known from the Oriental Region, Micronesia and Melanesia. Leptocoris subrufescens (Kirby) is known only from Christmas Island. The tramp species Liorhyssus hyalinus has a cosmopolitan distribution and the nominotypical subspecies is found in eastern and southern Australia.

Schaefer & Kotulski (2000) reviewed the biology of rhopalids. They are known to feed on ripe and unripe seeds, but are not known to be economic pests of any significance. Kumar (1966) discussed the biology of the Australian species, Leptocoris mitellatus Bergroth. He found it feeding on the ripe seeds of Geijera parviflora Lindl. (Rutaceae) and Alectryon tomentosus (F.Muell.)Radlk (Sapindaceae). He also described the immature stages. Carroll et al. (2005) published a paper on the ecology of Leptocoris and recorded Leptocoris isolates from Australia for the first time.

Schaefer & Chopra (1982) listed the host plants of Rhopalidae and concluded that rhopalids prefer plants of the angiosperm subclasses Rosidae and Asteridae. They suggested that Rhopalinae feed on a wider variety of plants than Serinethinae which are commonly associated with Sapindaceae.

The Australian rhopalid species are known from several host plant families. Most of the Australian serinethines are known from sapindaceous plants but have also been recorded from plants belonging to the Mimosaceae, Moraceae, Polygonaceae, Solanaceae and Rutaceae. Liorhyssus hyalinus hyalinus (Rhopalinae) has been recorded from plant species in the Asteraceae, Euphorbiaceae and Malvaceae.

Diagnosis

Rhopalids are medium-sized to large bugs, usually robust, and elongate in shape. The head has the clypeus surpassing the jugae. Two ocelli are present on raised tubercles. The external efferent system of the metathoracic glands is usually obsolete or reduced. The hemelytral membrane has numerous veins. Abdominal trichobothria are present in a straight line on sterna IV, V and VI, and obliquely placed on sterna VII. The ovipositor is plate-like. (Chopra 1967; Schaefer & Chopra 1982; Slater 1982; Schuh & Slater 1995)