Colocasiomyia (Diptera: Drosophilidae) revised phylogenetically, with a new species group having peculiar lifecycles on monsteroid (Araceae) host plants

Abstract

The phylogeny of Colocasiomyia (Drosophilidae) is analysed using data for 70 morphological characters, many of which are re‐evaluated from or added to those used previously, for an expanded taxon sample of 24 Colocasiomyia ingroup species. A special focus is put on three species, of which two have remained unresolved for their relationships to other Colocasiomyia species, and the other is a newly discovered species. The analysis results in a single, most parsimonious cladogram, in which a clade comprising the three focal species is recognized along with other clades recovered for the known species groups of Colocasiomyia. Based on this, a new species group—the gigantea group—is established, including Colocasiomyia gigantea (Okada), C. rhaphidophorae Gao & Toda, n.sp. and C. scindapsae Fartyal & Toda, n.sp. These species of the gigantea group breed on inflorescences/infructescences of the subfamily Monsteroideae (Araceae) exceptionally among Colocasiomyia species, most of which use plants of the subfamily Aroideae as their hosts. Colocasiomyia gigantea uses Epipremnum pinnatum (L.) Engler, C. rhaphidophorae uses Rhaphidophora hookeri Schott and C. scindapsae uses Scindapsus coriaceus Engler as their hosts. The host plants of the gigantea group are epiphytes and differ in the structure of spadix and the fruiting process from those of the Aroideae. To understand how the species of the gigantea group adapt to properties of their host plants, their reproductive ecology—most intensively that of C. gigantea—is investigated. The lifecycle of C. gigantea is characterized by its relatively slow embryonic development (taking approximately 6 days), the very long duration of the full‐grown first instar within the egg capsule (approximately three months) until dehiscence of host infructescence, and its relatively fast larval and pupal development (taking approximately 11 or 12 days). Some morphological adaptations and the reproductive strategy in terms of ‘egg size vs. number’ trade‐off are discussed in relation to their reproductive habits and peculiar lifecycles.

Floral diversity and pollination strategies of three rheophytic Schismatoglottideae (Araceae)

“…; Fartyal et al . ). Further investigation is needed to determine mutualistic relationships between Colocasiomyia and host plants.…”

“…Colocasiomyia were observed to consume the stigmatic secretions and pollen droplets (and pollen powder), and oviposit in the pistillate zone. Utilisation by Colocasiomyia of aroid inflorescences as brood sites has been reported (Miyake & Yafuso 2003, 2005Takenaka et al 2006;Takenaka-Takano et al 2012;Fartyal et al 2013). Further investigation is needed to determine mutualistic relationships between Colocasiomyia and host plants.…”

Taxonomy of the Colocasiomyia gigantea species group (Diptera, Drosophilidae), with descriptions of four new species from Yunnan, China

“…Fartyal et al (2013) have revealed that, in single-host/single-user systems, the gigantea -group species have evolved peculiar lifecycles, ecological traits and morphological features adaptive to characteristics of the monsteroid host plants. According to our preliminary observations, similar adaptations are also seen in the species cohabiting on Rhaphidophora decursiva (Li et al unpubl.…”

A review of taxonomy and flower-breeding ecology of the Colocasiomyia toshiokai species group (Diptera: Drosophilidae), with description of a new species from Indonesia

“…The genus Colocasiomyia de Meijere is one such group that obligatorily breeds in fl owers. Currently there are 29 formally described species in this genus, mostly from the Asian tropics (Toda, 2018), which are classifi ed into six species groups (Sultana et al, 2006;Fartyal et al, 2013). Each species group specialises on host plants A review of taxonomy and fl ower-breeding ecology of the Colocasiomyia toshiokai species group (Diptera: Drosophilidae), with description of a new species from Indonesia TAO SHI 1, 8 , MASANORI J. TODA 2 , KOHEI TAKENAKA TAKANO 3, 4 , MASAKO YAFUSO 5 , AWIT SUWITO 6 , SIN YENG WONG 7 , SU-QIN SHANG 8, * and JIAN-JUN GAO 1, 9, * of a particular taxon (Yafuso & Okada, 1990;Yafuso et al, 2000;Sultana et al, 2002Sultana et al, , 2006Toda & Lakim, 2011;Fartyal et al, 2013;Li et al, 2014): crassipes group (Sultana et al, 2006) the family Magnoliaceae, zylanica group (Sultana et al, 2006) the family Arecaceae (genus Pinanga Blume), gigantea group (Fartyal et al, 2013) the subfamily Monsteroideae (Araceae), baechlii group (Okada, 1990) the tribe Schismatoglottideae (subfamily Aroideae, Ara ceae), cristata group (Okada, 1990) the Colocasia clade and genera Alocasia (Schott) G. Don and Leucocasia (sensu Cusimano et al, 2011;Aroideae, Araceae), and toshiokai group (Sultana et al, 2002) the genera Homalomena Schott (Philodendron clade) and Aglaonema Schott (tribe Aglaonemateae) of Aroideae (Araceae).…”

“…Colocasiomyia fl ies depend on specifi c host plants throughout their entire life cycle; their life histories from oviposition to adult eclosion are adapted to the fl owering/ fruiting of specifi c host plants, and vary depending on the number and combination of cohabiting fl y species (Carson & Okada, 1980;Honda-Yafuso, 1983;Toda & Okada, 1983;Yafuso, 1994;Takenaka, 2006;Takenaka et al, 2006;Takano et al, 2012;Fartyal et al, 2013). In turn, the fl ies serve as specifi c, obligate pollinators of their host plants (Yafuso, 1993;Miyake & Yafuso, 2003;Takenaka, 2006;Takenaka et al, 2006;Takano et al, 2012).…”