Rhyzobius, Stephens, 1829

Gonzalez, Guillermo, Cotoras, Darko D. & Grez, Audrey A., 2020, Annotated list of island lady beetles from Chile (Coleoptera: Coccinellidae), Zootaxa 4852 (5), pp. 501-526 : 513

Rhyzobius sp. ( Fig 4n ).

Examined material: 1 ex. (hembra) “ Ba. Cumberland, J. Fernández, 22.12.195 4. col. Kuschel ( MNHN) .

Original reference: First record of this species for Juan Fernández archipelago.

Comments: The genus Rhyzobius Stephens , with more than a hundred species, is distributed mainly in Australia and New Guinea, with few more species in Europa and Africa (Tomaszewska 2010). The examined specimen was identified as Coccidulini based on the dorsal pubescence, the antenna with 11 antennomeres, with basal two not enlarged and with loose club (discarding Chnoodini , Azyini ), the tarsal claws with only a triangular basal tooth (discarding Poorini) and the abdominal postcoxal line complete and recurved. The pronotum not concealing head, the oval body not dorsoventrally flattened, and the prosternum carinate discard all native South American genera of Coccidulini (keys after Gordon 1995). In Eastern Hemisphere genera, the specimen fits well with Rhyzobius , considering additional characters as the head normally exposed and normal sized eyes, the pronotum not grooved, hypomera not excavated, the cryptotetramerous tarsi, anterior margin of prosternum normal and tibiae not angulate externally ( Ślipiński 2007; Tomaszewska 2010). It was not possible to identify the specimen to the species level, but the simple pubescence discard an immature of Rhyzobius lophantae . It could correspond to an exotic introduced species or a new one.

Summary: The Coccinellidae fauna of the Juan Fernández archipelago is composed by ten species with at least one endemic. Among the other species, four are cosmopolitan (also present in Rapa Nui and mainland Chile); three are introduced from mainland Chile; and two with uncertain origin. The Coccinellidae fauna of the archipelago is rather poor, due to most of the species being introduced for commercial or touristic activities. The presence of Harmonia axyridis is worrisome, a species known for its negative effects on the local Coccinellidae of many countries ( Grez et al. 2016; Roy et al. 2016). González (2008) cited wrongly Eriopis chilensis for Juan Fernández, but later genital dissection discarded that identification.

Figures

FIGURE 4. Island Coccinellidae from Chile, Coccinellini part II and Coccidulini. a: Hippodamia convergens; b: H. variegata; c: Olla v-nigrum; d: Cranoryssus variegatus; e: Paracranoryssus chilianus; f: Orynipus chilensis; g: O. darwini; h: O. kuscheli; i: O. ultimensis; j: Eupaleoides Chiloénsis; k: Nothocolus sicardi; l: Nothocolus sp.; m: Rhyzobius lophantae; n: Rhyzobius sp.; o: Stenadalia nigrodorsata.