Groups. Those 30 species are left out of groups, and categorized as “unassigned”. Six groups each have nine or more species, jointly representing half of all described Mesoamerican species. The largest are the leucostigmus group (39 species parasitizing Hesperiidae) and the adelinamoralesae group (19 species attacking Elachistidae), both with many more Mesoamerican species awaiting description. A total of 15 species-groups (47 ) are represented by two species. This situation is mainly due to the fact that only the ACG fauna has been comprehensively studied. When the remainder of the Mesoamerican Apanteles fauna is revised, many of these groups are likely to have more species associated. We have seen in collections numerous undescribed species from the Neotropics other than ACG, species that fall into some of the new groups erected here (to encourage further study in the future we have noted those cases in the taxonomy treatment of species below). Most groups (79 ) are strongly supported by at least two of three sets of independent data: molecular (DNA barcodes), biology (host), and morphology (Table 2), and their component species can be clearly recognized and delimited. Others are defined mainly by shared morphological characters. In one case (A. joserasi), the group could only be defined by a unique combination of hosts and barcoding characters (see couplet 29 of the key to species-groups). Some groups partially overlap with others, e.g., the adrianachavarriae, javierobandoi, and joserasi groups, and future studies may reveal that they should be merged. However, without study of the whole Mesoamerican (or even Neotropical) fauna, we preferred to take a conservative approach in accommodating the perceived differences.Review of Apanteles sensu stricto (Hymenoptera, Braconidae, Microgastrinae)…Table 2. Species-groups of Apanteles in Mesoamerica, in alphabetical order. # of Spp: Total number of species currently within a group. Lepidoptera host families: “?” Unknown; for the carpatus group “??” refers to a mix of old and questionable references including nine different families (Gelechiidae, Lasiocampidae, Lecithoceridae, Lymantriidae, Pyralidae, Thaumetopoeidae, Tineidae, Tortricidae, Zygaenidae). Larvae: S asp larvae solitary; S? asp larvae strongly suspected to be solitary but not conclusive evidence; G asp larvae gregarious. ? nknown. In cases where a species-group has both solitary and gregarious larvae, the most common occurrence is indicated first. MOR, DNA, BIO: degree of group support by morphological (MOR), molecular (DNA), and biological (BIO) data. “+” Strong support, “-“No support, “P” Partial support, “?” Unknown.# of Spp Lepidoptera host families 19 Elachistidae, Pyralidae Attevidae, Crambidae, Elachistidae, adrianachavarriae 9 Tortricididae adrianaguilarae 3 Tortricidae alejandromorai 13 Elachistidae, Gelechiidae anabellecordobae 14 GLPG0187 web Hesperiidae anamarencoae 2 Elachistidae, Oecophoridae, Tortricidae arielopezi 2 Elachistidae, Tortricidae ater 9 Crambidae, Pyralidae Crambidae, Elachistidae, Gelechiidae, bernyapui 4 Noctuidae bienvenidachavarriae 3 Elachistidae calixtomoragai 3 Hesperiidae Choreutidae, Crambidae, Gelechiidae, carlosguadamuzi 6 Elachistidae carlosrodriguezi 3 Elachistidae, Choreutidae, Crambidae carloszunigai 2 ? carpatus 5 ?? AZD0865 chemical information coffeellae 4 Gracillariidae, Lyonetiidae diatraeae 3 Crambidae dickyui 2 ? erickduartei 5 Crambidae glenriverai 2 Pyralidae guadaluperodriguezae 2 Crambidae humbertolopezi 2 Elachisti.Groups. Those 30 species are left out of groups, and categorized as “unassigned”. Six groups each have nine or more species, jointly representing half of all described Mesoamerican species. The largest are the leucostigmus group (39 species parasitizing Hesperiidae) and the adelinamoralesae group (19 species attacking Elachistidae), both with many more Mesoamerican species awaiting description. A total of 15 species-groups (47 ) are represented by two species. This situation is mainly due to the fact that only the ACG fauna has been comprehensively studied. When the remainder of the Mesoamerican Apanteles fauna is revised, many of these groups are likely to have more species associated. We have seen in collections numerous undescribed species from the Neotropics other than ACG, species that fall into some of the new groups erected here (to encourage further study in the future we have noted those cases in the taxonomy treatment of species below). Most groups (79 ) are strongly supported by at least two of three sets of independent data: molecular (DNA barcodes), biology (host), and morphology (Table 2), and their component species can be clearly recognized and delimited. Others are defined mainly by shared morphological characters. In one case (A. joserasi), the group could only be defined by a unique combination of hosts and barcoding characters (see couplet 29 of the key to species-groups). Some groups partially overlap with others, e.g., the adrianachavarriae, javierobandoi, and joserasi groups, and future studies may reveal that they should be merged. However, without study of the whole Mesoamerican (or even Neotropical) fauna, we preferred to take a conservative approach in accommodating the perceived differences.Review of Apanteles sensu stricto (Hymenoptera, Braconidae, Microgastrinae)…Table 2. Species-groups of Apanteles in Mesoamerica, in alphabetical order. # of Spp: Total number of species currently within a group. Lepidoptera host families: “?” Unknown; for the carpatus group “??” refers to a mix of old and questionable references including nine different families (Gelechiidae, Lasiocampidae, Lecithoceridae, Lymantriidae, Pyralidae, Thaumetopoeidae, Tineidae, Tortricidae, Zygaenidae). Larvae: S asp larvae solitary; S? asp larvae strongly suspected to be solitary but not conclusive evidence; G asp larvae gregarious. ? nknown. In cases where a species-group has both solitary and gregarious larvae, the most common occurrence is indicated first. MOR, DNA, BIO: degree of group support by morphological (MOR), molecular (DNA), and biological (BIO) data. “+” Strong support, “-“No support, “P” Partial support, “?” Unknown.# of Spp Lepidoptera host families 19 Elachistidae, Pyralidae Attevidae, Crambidae, Elachistidae, adrianachavarriae 9 Tortricididae adrianaguilarae 3 Tortricidae alejandromorai 13 Elachistidae, Gelechiidae anabellecordobae 14 Hesperiidae anamarencoae 2 Elachistidae, Oecophoridae, Tortricidae arielopezi 2 Elachistidae, Tortricidae ater 9 Crambidae, Pyralidae Crambidae, Elachistidae, Gelechiidae, bernyapui 4 Noctuidae bienvenidachavarriae 3 Elachistidae calixtomoragai 3 Hesperiidae Choreutidae, Crambidae, Gelechiidae, carlosguadamuzi 6 Elachistidae carlosrodriguezi 3 Elachistidae, Choreutidae, Crambidae carloszunigai 2 ? carpatus 5 ?? coffeellae 4 Gracillariidae, Lyonetiidae diatraeae 3 Crambidae dickyui 2 ? erickduartei 5 Crambidae glenriverai 2 Pyralidae guadaluperodriguezae 2 Crambidae humbertolopezi 2 Elachisti.