<I>Pharaxonotha</I> (Coleoptera: Erotylidae)
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University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Center for Systematic Entomology, Gainesville, Insecta Mundi Florida September 2005 A new species of Pharaxonotha (Coleoptera: Erotylidae), probable pollinator of the endangered Cuban cycad, Microcycas calocoma (Zamiaceae) Ramiro Chavez Museo Nacional de Historia Natural, Cuba Julio A. Genaro York University, Department of Biology, Toronto ON, M3J 1P3, Canada Follow this and additional works at: https://digitalcommons.unl.edu/insectamundi Part of the Entomology Commons Chavez, Ramiro and Genaro, Julio A., "A new species of Pharaxonotha (Coleoptera: Erotylidae), probable pollinator of the endangered Cuban cycad, Microcycas calocoma (Zamiaceae)" (2005). Insecta Mundi. 70. https://digitalcommons.unl.edu/insectamundi/70 This Article is brought to you for free and open access by the Center for Systematic Entomology, Gainesville, Florida at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Insecta Mundi by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. INSECTA MUNDI, Vol. 19, No. 3, September, 2005 143 A new species of Pharaxonotha (Coleoptera: Erotylidae), probable pollinator of the endangered Cuban cycad, Microcycas calocoma (Zamiaceae) Ramiro Chaves Museo Nacional de Historia Natural Obispo no. 61, Habana Vieja 10100, Cuba [email protected] Julio A. Genaro York University, Department of Biology 4700 Keele St., Toronto ON, M3J 1P3, Canada [email protected] Abstract: The new species Pharaxonotha esperanzae (Coleoptera: Cucujoidea: Erotylidae: Pharaxonothinae) is described. It feeds on the pollen of the endangered Cuban cycad Microcycas calocoma (Miq.) A. DC. and breeds in its male cones. Its potential role as a pollinator of Microcycas is discussed. Resumen: Se describe la especie nueva: Pharaxonotha esperanzae (Coleoptera: Cucujoidea: Erotylidae: Pharaxonothinae). Ésta se alimenta del polen del cicadal cubano amenazado Microcycas calocoma (Miq.) A.DC y se reproduce en su cono masculino. Se discute su papel potencial como agente polinizador. Key words: Pharaxonotha, Erotylidae, Languriidae, new species, Cycadales, pollination. Palabras claves: Pharaxonotha, Erotylidae, Languriidae, especie nueva, Cycadales, polinización. Introduction et al. 1995, Tang et al. 1999, Wilson 2002, Hall et al. 2004, Tang 2004). Cycadales (cycads) are the oldest group of in- Within Erotylidae (which now includes taxa sect-pollinated plants (Norstog and Nicholls 1997). previously in Languriidae) is the genus Pharaxono- Many insects have developed mutualistic interac- tha Reitter 1875 (= Planismus Casey 1890) belong- tions that can be host-specific (Donaldson 2003). ing to the subfamily Pharaxonothinae, which is one There are different hypotheses on the antiquity of the most primitive in the family (Leschen 2003). and original association (whether with gymno- Of all insect genera known to pollinate cycads, sperms or angiosperms) of the insects known to Pharaxonotha is the most important based on the pollinate cycads. Some of these interactions appar- fact it has been associated with three of eleven ently have recent origins (Crowson 1991, Oberpri- cycad genera: Zamia, Dioon, and Ceratozamia (Tang eler 1995a, 1995b). Nevertheless, the fossil record, 1987, Vovides 1991). This genus of little beetles was phylogenetic studies and biogeography support the taxonomically redefined by Sen Gupta and Crow- existence of Coleoptera feeding on gymnosperms son (1971). At present, there are 11 described since the Jurassic, and those associated with cones species for the world (Leschen 2003). Pakaluk (1988) are considered precursors of important families of described two new species from Costa Rica and phytophagous beetles (Crowson 1991, Farrell 1998). presented a key including the four New World Primitive beetles of the family Erotylidae are among species. These are: P. kirschii Reitter (= Thalisella the oldest extant pollinators of cycads. Their bioge- conradti Gorham), P. floridana (Casey) [= P. zami- ography supports the hypothesis that they pollinat- ae Blake], P. clarkorum Pakaluk, and P. confusa ed cycads before the Cretaceous diversification of Pakaluk. angiosperms (Hall et al. 2004, Tang 2004). Erotyl- Pharaxonotha kirschii, the type species, is na- ids are known to pollinate species in six of the tive to Mexico and Central America, but as a stored eleven cycad genera, but only eight of these genera product pest, it now has a much wider distribution had been surveyed up to now (Tang 1987, Vovides that includes North America, South America and 1991, Ornduff 1991, Forster et al. 1994, Donaldson Europe (Pakaluk 1988). Pharaxonotha floridana, 144 Volume 19, No. 3, September, 2005, INSECTA MUNDI from the southeastern United States (Leschen and Materials and Methods Skelley 2002), is hosted by Zamia integrifolia [= Z. floridana (Jones 1993)] and was the first erotylid Both adult beetles and larvae were collected cited as a mutualistic pollinator of a cycad (Tang from male cones of M. calocoma, in an area of 1987). Pharaxonotha clarkorum and P. confusa, Parque Nacional Viñales, Viñales Township, Pinar from Costa Rica, feed on pollen and breed in male del Río Province, Cuba. This is a well-preserved cones as P. floridana, but in Zamia skinneri and Z. area where pollination and seed production occurs fairchildeana, respectively (Pakaluk 1988). annually. There are Pharaxonotha species yet to be de- Measurements were made with a stereo micro- scribed. All of which are considered mutualistic scope from 25 adult Pharaxonotha esperanzae sp. pollinators and are apparently host specific with nov., mounted or taken from alcohol: total body other New World Zamiaceae of the genera Zamia, length from anterior head edge to elytral apex; Dioon and Ceratozamia (Vovides 1991, Norstog et maximum body width; pronotum, length along its al. 1992, Cruz 1999, Pérez-Farrera et al. 2000, midline from anterior to posterior edge, and at its González 2004, P. Skelley and M. Thomas, pers. widest point; elytral length from base adjacent to comm. 2004). The genera Zamia and Dioon also scutellum to its apical edge; head width; dorsal have mutualistic pollinators among curculionoids interocular distance; and ventral interocular dis- in the family Belidae (Tang 1987, Vovides 1991, tance (following Pakaluk 1988). Other measure- Norstog et al. 1992). The New World Zamiaceae ments taken were antennal length and width of genera: Chigua (endemic from Colombia) and Mi- antennomeres VIII and IX. crocycas (monotypical endemic from Cuba) have no Genitalia were studied from five specimens. previously reported insect pollinator (Tang 2004). Genitalia were dissected, cleared 1 hour in 10% Prior to this study, there were no reported mem- KOH and preserved in 70% alcohol or slide mount- bers of Pharaxonotha from the West Indies. ed with euparol. Two specimens were dissected to The endemic Cuban cycad, Microcycas caloco- study mouthparts and wing venation. Drawings ma (Miq.) A.DC., is a threatened plant listed as were made from photographs taken by digital cam- Critically Endangered (CR), according to IUCN era through a microscope, and corrected or detailed criteria (Peña et al. 1998, Stevenson et al. 2003). A after additional observations were made. very important factor contributing to this status is its scarce reproduction, fundamentally due to lim- Taxonomy ited pollination (Cendrero 1940, Foster and Ro- dríguez 1942, Peña et al. 1997a, 1997b, Vovides et Order Coleoptera: Superfamily Cucujoidea al. 1997, Peña et al. 1998). This has been attributed Family Erotylidae: Subfamily Pharaxonothinae to the supposed extirpation or population decline of the yet unknown pollinator in most of its localities Pharaxonotha esperanzae, n. sp. (Norstog et al. 1986, Peña et al. 1997a and b; Vovides et al. 1997). Nevertheless, some preserved Description. There were no observable external localities showed a habitual seed production (Risco sexual dimorphism. Body oblong, oval (Fig. 1B), et al. 1984, Peña et al. 1988, Peña et al. 1997a), length 3.49-4.21mm (x =3.91mm), 2.50-3.06 times which proved the existence of a pollinator. It was maximum width (Table 1), and approximately 4.0 believed the unknown pollinator could be a curcu- times maximum body height. Body finely pubes- lionoid of the family Belidae. The discovery and cent, cuticle between punctures on frons and prono- identification of this pollinator was an urgent pri- tum minutely granulate, dull; general colour red- ority for the development of a conservation strategy dish brown, elytra generally uniform in colour, (Vovides et al. 1997). some structures with dark stains of variable inten- The objective of this work is to present the first sity and form, generally without fixed pattern. record for the genus Pharaxonotha in Cuba, de- Head: Eyes prominent, coarsely faceted (9 facets in scribe Pharaxonontha esperanzae and discuss the longitudinal axis), wide ventrally in relation to potential function of this species as the pollinator of dorsal width (Figs. 1B, 1C, and Table 1), with short, Microcycas. inconspicuous setae of variable density. Antennae relatively short, length less than pronotal width and slightly more than head width (Table 1); anten- nomere relative lengths approximately INSECTA MUNDI, Vol. 19, No. 3, September, 2005 145 Fig. 1. Pharaxonotha esperanzae, n. sp. A) Head, dorsal view; B) Habitus, dorsal view; C) Habitus, ventral view, without left legs; D) Coarse and fine punctations on elytra; E) Posterior