The geographic distribution of the 2 phytotelmatous chironomids Monopelopia caraguata and Phytotelmatocladius delarosai is found to extend southward into Argentina, and the occurrence of parthenogenesis in the latter species is corroborated under laboratory conditions.
Phytotelmata are structures present in terrestrial plants such as modified leaves, leafaxils, flowers, stem holes or depressions, open fruits and fallen leaves. These structures allow water to impound and are more common in tropical areas where plant diversity and rainfall are higher (Fish 1983). The phytotelmata provide a suitable habitat where immature chironomids are common inhabitants.
In this contribution, the occurrence of the chironomid species Monopelopia caraguata Mendes et al. (Chironomidae: Tanypodinae: Pentaneurini) and Phytotelmatocladius delarosai Epler (Chironomidae: Orthocladiinae) are reported in Argentina for the first time. A list of the American phytotelmatous chironomids (except for species inhabiting tree holes and bamboo internodes) with the host plant and references is presented in Table 1.
Immatures stages of Monopelopia Fittkau (Chironomidae: Tanypodinae) have been found living in small bodies of water such as ponds, marshes and streams or phytotelmata. Of the phytotelmatous species, M. tillandsia Beck et Beck, M. mikeschwartzi Epler, M. gesta (Roback), M. caraguata Mendez et al. and an undescribed Monopelopia species were reported living in the impounded water of bromeliads (Poales: Bromeliaceae) (Cranston 2007; Cranston & Epler 2013). Monopelopia tillandsia was reported living in Tillandsia, Catopsis and Hohenbergia in Florida and Cuba (Beck & Beck 1966; Roback 1987; Bello et al. 2011). Monopelopia mikeschwartzi and M. gesta were reported living in Aechmea paniculigera (Swartz) Grisebach (Bromeliaceae) in Jamaica (Epler & Janetzky 1999; Cranston & Epler 2013), whereas the undescribed species of Cranston (2007) was reported living in Guzmania in Puerto Rico. Monopelopia caraguata was reported developing in species of Vriesea, Nidularium, Hohenbergia and Aechmea in southern Brazil (Mendez et al. 2003) and in solution holes in the Everglades National Park, Florida, USA (Jacobsen 2008). Up to present, this species was not found developing in bromeliads in Florida (R. Jacobsen, J. H. Epler and J. H. Frank, personal communication).
The cosmopolitan Eryngium L. (Apiales: Apiaceae) includes more than 200 species distributed in temperate and tropical areas, but these species develop phytotelmata only in southern Brazil and Argentina (Campos 2010). Plants of this genus grow on the ground and have a simple structure and are annuals, differing from bromeliads, which comprise mainly perennial epiphytic plants with a complex structure.
Larvae of Monopelopia caraguata were collected from Eryngium plants and reared in the laboratory. This is the first report of this chironomid species associated with the terrestrial Eryngium plants in a temperate region. Monopelopia caraguata co-occurred in some Eryngium plants with Polypedilum parthenogeneticum Donato et Paggi (Chironomidae: Chironominae) and Metriocnemus eryngiotelmatus Donato et Paggi (Chironomidae: Orthocladiinae), which are common inhabitants of Eryngium in Argentina.
Phytotelmatocladius (Chironomidae: Orthocladiinae) is a monospecific genus described from bromeliad phytotelmata in southern Florida and Brazil (Epler 2010). Because only female adults and pupae have been collected or reared, this author postulated that this taxon could be parthenogenetic. Immatures of P. delarosai were recently collected from the impounded water of Bromelia balansae Mez (Bromeliaceae) in a botanical garden at FCAyFUNLP (Facultad de Ciencias Agrarias y Forestales-Universidad Nacional de La Plata, Buenos Aires, Argentina). This bromeliad species is exotic to this region, being native to Paraguay, Brazil and the northeast of Argentina (Zuloaga et al. 2008). Of the reared P. delarosai, only female adults emerged, which were maintained in separate vials containing little water. The females laid their eggs which hatched 7 days later; therefore, we confirm the assumption of Epler (2010) that P. delarosai could be parthenogenetic.
In the sampling of Eryngium plants in FCAyFUNLP close to B. balansae plants, P. delarosai was not collected. Besides, Monopelopia caraguata, Metriocnemus eryngiotelmatus and Polypedilum parthenogeneticum were not collected from B. balansae, suggesting a possible specificity or preference of those chironomids for each plant species.
Monopelopia caraguata: ARGENTINA, Buenos Aires Province, Punta Lara, ex Eryngium sp. S 34° 51′ 10″ W 57° 57′ 33″, 7 m asl, adult male reared from larva, 4-VIII-2004, Donato col.; Adult female reared from larva, same data except for Jan 2008; ARGENTINA, Buenos Aires province, Punta Lara, ex Eryngium sp. S 34° 54′ 37″ W 57° 55′ 34″, 14 m asl, adult male reared from larva, 10-IX-2013, Donato & Siri cols.
Phytotelmatocladius delarosai: ARGENTINA, Buenos Aires province, La Plata, ex Bromelia balansae Mez at the Jardín Botánico y Arboretum, Facultad de Ciencias Agrarias y Forestales (FCAyF) (UNLP), S 34.912881° W 57.9332227°, adult female reared from larva, collected 9-VIII-2012, emerged 18-VIII-2012, laid their eggs which hatched on 25/26-VIII-2012, Donato & Siri cols.