Promicrogaster Brues & Richardson, 1913

Fernandez-Triana, Jose, Boudreault, Caroline, Dapkey, Tanya, Smith, M. Alex, Rodriguez, J., Hallwachs, Winnie & Janzen, Daniel H., 2016, Revision of the genus Promicrogaster (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservacion Guanacaste, Costa Rica, with a key to all species previously described from Mesoamerica, Journal of Hymenoptera Research 50, pp. 25-79 : 27-28

Taxon classification Animalia Hymenoptera Braconidae

Promicrogaster Brues & Richardson, 1913

Promicrogaster : Brues and Richardson 1913: 499.

Diagnosis.

Glossa elongate and bilobate (Figs 4, 10, 16, 22, 28, 34, 40, 46, 70, 76, 82, 101, 107, 118, 130, 149). Lateral face of scutellum with polished area (=lunules) occupying most of the lateral face (Figs 12, 18, 24, 32, 36, 42, 62, 66, 72, 78, 84, 110, 114, 120, 126, 138, 147, 151). Propodeum clearly sculptured and usually with some carination (Figs 12, 18, 36, 42, 66, 90, 99, 114, 120, 132, 133, 157). Metacoxa very long, 0.8-1.0 × metafemur length and 0.6-0.8 × metatibia length (Figs 7, 15, 38, 45, 51, 57, 63, 74, 87, 106, 117, 129, 135, 146, 148, 154). Mediotergite 1 parallel-sided (Figs 8, 13, 19, 32, 60, 140) to slightly narrowing towards posterior margin (Figs 38, 44, 55, 67, 73, 85, 91, 105, 127, 132, 147). Mediotergite 2 transverse, its width at posterior margin 3.0-4.5 × (rarely 2.0 ×) its length medially. Ovipositor very long for a microgastrine wasp (approximately two times longer than metatibia length), strongly curved and with its apex sinuate (Figs 1, 5, 14, 15, 20, 26, 30, 37, 43, 50, 51, 56, 61, 63, 68, 69, 74, 86, 87, 92, 98, 104, 108, 116, 121, 123, 128, 139, 140, 144, 148, 154, 159). Fore wing usually with a small areolet, which is sometimes poorly defined (Figs 3, 17, 23, 29, 35, 47, 59, 65, 71, 77, 83, 89, 95, 108, 113, 119, 131, 137, 156); but some small species have no trace of areolet whatsoever (Figs 41, 102, 125, 150). Body and fore wing lengths ranging from 1.8-2.0 mm in the smallest species up to 4.9-5.3 mm in the largest species. Body length varying from slightly longer to slightly shorter than fore wing length.

Promicrogaster is a very distinctive genus as defined by the combination of elongate and bilobate glossa, large polished areas on lateral face of scutellum, and ovipositor shape and length. Within Microgastrinae, it can only be confused with Sendaphne , but the later has a much less transverse mediotergite 2, the apex of ovipositor is not sinuate, the propodeum is entirely or mostly smooth, and the first discal cell is much wider (e.g., Fernandez-Triana et al. 2014d).

We consider the described ' Promicrogaster ' from India as incertae sedis (see below for a detailed discussion on that species). Thus, Promicrogaster as defined here is restricted to the New World, with the vast majority of the species found in the Neotropics and a few extending north to the Nearctic ( Mason 1981, and unpublished data from the CNC collection). This pattern of distribution is remarkably similar to that found in other genera recently revised in the New World, such as Pseudapanteles and Venanus ( Fernandez-Triana et al. 2013, 2014b, 2014c). A total of 21 new species are described below, increasing the total known Mesoamerican species from 4 to 25, and the total number of described species for the genus from 11 to 32 (Table 1). We are aware of many additional undescribed species in collections, from North America (Canada/US) and South America, which will be dealt with in future papers.

As for habitat preference, 82% of the ACG species were collected in rain forests and cloud forests (with almost 60% restricted to cloud forests), while only 18% were found in dry forests. Around 40% of the species were found at low-mid elevation (0-500 m) whereas almost 60% of the species were collected at altitudes over 1,000 m. This strongly contrasts with the closely related genus Sendaphne , which has been mostly found at altitudes between 100-900 m with just a few species found in cloud forests ( Fernandez-Triana et al. 2014d).

All of the verified and authenticated host records for Promicrogaster are from caterpillars living more deeply inside more or less woody plant material than simply in rolled leaf structures. It is possible that the sinuate ovipositor tip in all known species of Promicrogaster is an adaptation allowing the ovipositor to be steered through fissures in harder/more woody structures than mere leaf rolls (e.g., Quicke 2015).

Muesebeck (1958) described Promicrogaster polyporicola as reared from unidentified Lepidoptera larvae infesting a bracket fungus ( Fomes sp.) in Panama. Davis (1996) reared an unidentified species of Promicrogaster from caterpillars of Prosetomorpha falcata ( Tineidae ) in Colombia; the larvae of this small moth are scavengers feeding on frass within the burrows made by larval Curculionidae in the stems of Solanum quitoensis ( Solanaceae : ‘Naranjilla’). Garcia and Montilla (2010) reared Promicrogaster as a parasitoid of cocoa fruit borers, Carmenta spp. ( Sessidae) in Venezuela; Carmenta larvae mine through the pericarp of cocoa ( Malvaceae : Theobroma cacao ) fruit, and their damage leads to secondary phytopathogenic fungal infections (such as Phytophthora sp.) that cause the fruit to rot (e.g., Morrilo et al. 2009). The 21 species of Promicrogaster found in ACG have only been collected in Malaise traps. It is likely that those wasp species have not been reared yet because they are parasitizing small moth larvae concealed inside more or less woody plant or fungal tissues - the ACG inventory, while being the most comprehensive effort ever done to rear tropical caterpillars, has only focused on exposed feeders and rollers of green leaves.