Abstract:
More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their
parasitoids, identified, and DNA barcoded over a period of 34 years (and ongoing) from Area de Conservación
de Guanacaste (ACG), northwestern Costa Rica. This provides the world’s best location-based
dataset for studying the taxonomy and host relationships of caterpillar parasitoids. Among Hymenoptera,
Microgastrinae (Braconidae) is the most diverse and commonly encountered parasitoid subfamily, with
many hundreds of species delineated to date, almost all undescribed. Here, we reassess the limits of the
genus Apanteles sensu stricto, describe 186 new species from 3,200+ parasitized caterpillars of hundreds of
ACG Lepidoptera species, and provide keys to all 205 described Apanteles from Mesoamerica –including
19 previously described species in addition to the new species. The Mesoamerican Apanteles are assigned
to 32 species-groups, all but two of which are newly defined. Taxonomic keys are presented in two formats:
traditional dichotomous print versions and links to electronic interactive versions (software Lucid
3.5). Numerous illustrations, computer-generated descriptions, distributional information, wasp biology,
and DNA barcodes (where available) are presented for every species. All morphological terms are detailed
and linked to the Hymenoptera Anatomy Ontology website. DNA barcodes (a standard fragment of the
cytochrome c oxidase I (COI) mitochondrial gene), information on wasp biology (host records, solitary/
gregariousness of wasp larvae), ratios of morphological features, and wasp microecological distributions
were used to help clarify boundaries between morphologically cryptic species within species-complexes.
Because of the high accuracy of host identification for about 80% of the wasp species studied, it was possible
to analyze host relationships at a regional level. The ACG species of Apanteles attack mainly species
of Hesperiidae, Elachistidae and Crambidae (Lepidoptera). About 90% of the wasp species with known
host records seem to be monophagous or oligophagous at some level, parasitizing just one host family and
commonly, just one species of caterpillar. Only 15 species (9%) parasitize species in more than one family,
and some of these cases are likely to be found to be species complexes. We have used several information
sources and techniques (traditional taxonomy, molecular, software-based, biology, and geography) to accelerate
the process of finding and describing these new species in a hyperdiverse group such as Apanteles.
