Brief Summary

Timorus sarcophagoides is a South American weevil (family Curculionidae) occurring between 1100-1300 m (3600-4300 feet) in elevation in Southeastern Brazil. Found and described as a new species, it is tentatively grouped with the six other species in genus Timorus (subfamily Conoderinae; Vanin and Guerra, 2012) though a revision of this genus and many other weevil genera is in order, which may considerably effect taxonomic placement. The coloration pattern and behavior of T. sarcophagoides is remarkable, as these two features have evolved to mimic dipteran flesh flies of family Sarcophagidae. This beetle is notable for two reasons:

• It is the first described South American weevil to mimic flies. UCLA biologist Henry Hespenheide has documented many Central American fly-mimicking conoderine weevils, and proposes that convergent fly mimicry (adaptive “mimetic” homoplasy; Hespenheide 1995) occurs frequently across many genera of tropical conoderine weevils. Hespenheide documents weevils mimicking fly families Tachinidae, Muscidae and Tabanidae, but not Sarcophagoidea. However, Vanin and Guerra (2012) uncovered several other genera of unidentified conoderine weevil species in the collections of the Museu de Zoologia, Universidade de Sao Paolo with coloration patterns very similar to those of T. sarcophagoides, and suggest that these too are flesh fly mimics. Clearly there are many unexplored avenues for future research on Neotropical conoderine weevil mimicry complexes, including the incidence of sarcophagid flies as models.

• Timorus sarcophagoides is the first fly-mimicking weevil found living in a Savanna habitat.

Rather than a species-specific mimicry, T. sarcophagoides appears to resemble flesh flies of several genera: Ravinia, Peckia, and Oxysarcodexia. The weevil mimics the flies’ large red eyes with red patches on the pronotum, variegated patterning on the thorax, and transparent wings. Behaviorally, T. sarcophagoides tends to perch on stems of its host plant, as do flesh flies. The weevils perform several leg movements stereotypical of flesh flies. Flesh flies are not distasteful or poisonous, however they are extremely agile and hard to catch. Although the idea is somewhat controversial (Brower 1995; Ruxton et al. 2004) and not yet tested, Hespenheide (1995) and Vanin and Guerra (2012) propose that mimicking flesh flies may confer adaptive benefit to weevils in that this makes potential predators believe the weevils are too fast to be easily captured: “evasive mimicry”.

Vanin and Guerra (2012) carried out year-round in vivo observations of T. sarcophagoides, finding that the species is host specific upon the woody mistletoe Psittacanthus robusta exclusively. Adults tend to sit on sit on the stems during the day, as do flesh flies. Adult weevils feed primarily on flower buds, pollen and stamens, between Nov-Feb., then oviposit onto haustorial roots. The rhizophagous larvae bore through the roots during the dry season (Feb-Sept) then pupate in October to emerge from the roots as adults in November.

Vanin, S.A., Guerra, T.J. 2012. A remarkable new species of flesh-fly mimicking weevil (Coleoptera: Curculionidae: Conoderinae) from Southeastern Brazil. Zootaxa; n. 3413, p. 55-63. ISSN: 1175-5334 PDF: http://www.producao.usp.br/bitstream/handle/BDPI/42335/wos2012-4510_en.pdf?sequence=1.

Brower, A.V.Z. 1995. Locomotor mimicry in butterflies? A critical review of the evidence. Phil. Trans. R. Soc. Lond. B. 347:413-425.

Hespenheide, H.A. (1973). A novel mimicry complex: beetles and flies, Journal of Entomology Series A, General Entomology, 48 (1) 55. DOI: 10.1111/j.1365-3032.1973.tb00034.x

Hespenheide, H.A. (1995) Mimicry in the Zygopinae (Coleoptera, Curculionidae). Memoirs of Entomological Society of Washington, 14,145–154.

Ruxton, G.D., Speed, M. & Sherratt, T.N. (2004) Evasive mimicry: when (if ever) could mimicry based on difficulty of capture evolve? Proceedings of Royal Society of London B, 271, 2135–2142.

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© Campbell, Dana

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