Revision of Agathacrista new genus ( Hymenoptera , Braconidae , Agathidinae , Agathidini )

Based on a cladistic analysis, a new genus of Agathidini, Agathacrista Sharkey, is proposed and its phylogenetic position hypothesized. Two previously described (Agathacrista cancellata, Agathacrista depressifera) and three new species (Agathacrista sailomi, Agathacrista winloni, Agathacrista krataeii) are included. The distribution of Agathacrista is limited to the Oriental region and southern portion of the eastern Palearctic.


Introduction
Agathacrista, as proposed here, includes two previously described species, both of which were included in the paraphyletic concepts of Bassus s.l. and Therophilus s.l. This paper is part of a series that investigates these non-monophyletic taxa, while describing taxa from Thailand, Costa Rica, or more inclusive areas of the world.
tion is monophyly and this is why the polyphyletic concept of Bassus s.l. was rejected (Sharkey et al. 2009). The following criteria are in no particular order and may be more or less important depending on the genus.
Identifiability: Agathacrista is a good example of the utility of this criterion. Agathacrista, Bassus s.s. and a new genus to be described in a forthcoming paper, form a monophyletic group (Fig. 2). The only morphological synapomorphy to aid in the recognition of the group is the presence of small spines or pegs on the fore tibia; convergent in some members of Earinus and many other non-agathidines. If there was an easily observed character it might be best to expand the concept of Bassus to include Agathacrista and the new genus. Conversely, all three genera as here proposed have distinguishing characteristics. Bassus s.s. has long, simple claws that lack a basal lobe; Agathacrista has a crest between the antennae and the undescribed new genus has a distinct longitudinal carina on the hind trochanter, a character formerly thought to be restricted to some members of the Cremnoptini and Disophrini.
Biological information content: Typically the more that is known about organisms the more finely split the higher ranks are. This criterion has little application to any agathidines since we know so little about their natural history. Undoubtedly the morphological autapomorphies of the three genera referred to above will be shown to relate to unique behaviours.
Stability: This is somewhat tied to most other criteria and Bassus s.l. is a good example of an unstable concept. Over the years it has been included in the genus Agathis s.l. and numerous genera like Camptothlipsis and Therophilus have been included, or not. This instability has made information retrieval on any particular species rather cumbersome, as the number of different combinations they have been referred to is a minimum of three, i.e., Microdus, Bassus, Agathis, the foremost being a junior objective synonym of Bassus. Thus, generic concepts should be accompanied by solid phylogenetic evidence when such is available. Phylogenetic evidence: This is directly related to stability. If new, but weak evidence suggests the non-monophyly of a well-recognized genus, it is usually best to wait for more data before making formal changes. In the case presented here, there is strong molecular phylogenetic evidence suggesting that the broad concept of Bassus (Bassus s.l.) is polyphyletic and there is significant morphological and molecular evidence for the monophyly of Agathacrista.
Specimen collection: As part of the inventory of Thai insects, 3 Malaise traps at each of 30 different localities throughout Thailand were operated from 2007-2010, comprising approximately 90 trap-years. The specimens dealt with here are primarily from these traps.
Phylogenetic methods: Regions D2-D3 of 28S rDNA (roughly 560 base pairs) were sequenced using the following primers: 28SD2hymF 5' -AGAGAGAGTTCAA-GAGTACGTG -3' and 28SD3hymR 5' -TAGTTCACCATCTTTCGGGTC -3'. Sequences were edited using Geneious Pro v4.7.5 (Drummond et al. 2009) and aligned based on a secondary structure model for Ichneumonoidea developed by Yoder and Gillespie (2004) and Gillespie et al. (2005). Regions of expansion and contraction (RECs), regions of slipped-strand compensation (RSCs), and short regions of alignment ambiguity were further aligned/corrected by eye. Three of these regions (~30 base pairs) were deleted because they could not be aligned with confidence, i.e., there were multiple equally supported alignment options.
The NJ analysis ( Fig. 1) was conducted with PAUP* (Swofford 2003) using default settings. The parsimony analysis (Fig. 2) was performed using TNT (Goloboff et al. 2008) [traditional search with 100 random addition sequences followed by branchswapping, saving 100 trees per replication; 1000 bootstrap replications were used to estimate branch reliability].
Morphological terms used in this revision were matched to the Hymenoptera Anatomy Ontology (HAO; Yoder et al. 2010) (Appendix 4). Identifiers (URIs) in the format http://purl.obolibrary.org/obo/HAO_XXXXXXX represent anatomical concepts in HAO version http://purl.obolibrary.org/obo/hao/2011-05-18/hao.owl. They are provided to enable readers to confirm their understanding of the anatomical structures being referenced. To find out more about a given structure, including images, references and other metadata, use the identifier as a web-link, or use the HAO:XXXXXXX (note colon replaces underscore) as a search term at http://glossary. hymao.org.
All species are treated with a diagnosis and distributional data. They are illustrated with color photos using a JVC digital camera mounted on a Leica MZ16 microscope and Automontage® stacking software. Distributional data are listed for all species and a link to a Google map is included for all species. The descriptions are of holotypes and variation is given in parentheses. Sharkey et al. (2006) showed that the entities formerly referred to as Bassus s.l. fall into two widely disparate clades. One associated with the genus Mesocoelus, Therophilus and allies and the other with Bassus s.s., Agathis, Alabagrus, Braunsia and allies. Agathacrista falls into the latter lineage. It is sister to Bassus s.s. + a new genus to be described in another paper. All three genera are restricted to the Old World, and except for one species of Bassus s.s, B. calculator Fabricius, 1798, the type species, which is widely distributed throughout the Palearctic, all are restricted to the Oriental region, the northern, tropical parts of the Australian region, and the far eastern Palearctic.

Phylogenetic considerations
Members of all three genera have distinct pegs on the anterior surface of the fore tibia (Fig. 3a), a synapomorphy. This character state is convergent in some members of the distantly related genus Earinus (Agathidinae), some Braconinae, most Doryctinae, and has rare and scattered appearances in other braconid subfamilies. Members of Agathacrista and Bassus have similar and rather unique color patterns (see Figs 4-8). The thin, acute, interantennal crest (Fig. 3b) is an autapomorphy for Agathacrista that is found convergently though rarely in a few other agathidine genera, e.g., a few members of Therophilus. taxonomy Agathacrista Sharkey, gen. n. http://zoobank.org/0E5C3C07-22D0-45B8-8B9A-4BA142EE1731 http://species-id.net/wiki/Agathacrista Type species. Agathacrista winloni Sharkey, sp. n.
Diagnosis. Interantennal space with longitudinal keel that is sharply declivous posteriorly (Figs 3b, 7d); ocelli elevated above surface of vertex; fore tibia with pegs ( Fig. 3a); third metasomal median tergite lacking sculpture; basal lobe of tarsal claws large and right angled or slightly acute (Fig. 7a); fore wing partly or completely pigmented; hind wing vein CUb absent. Some members of a few other genera of Agathidini have a sharp keel between the antennae, but none of these have pegs on the fore tibia.
Description. Head. Lateral carina on frons (as in members of Alabagrus) absent; interantennal space with longitudinal keel that is sharply declivous posteriorly (Figs 3b, 7d); ocelli elevated above surface of vertex; gena not extended ventroposteriorly into sharp prominence (Fig. 6a); gena lacking sharp angle posteriad of eye; labial palpus with 4 segments, third segment less than ½ as long as apical segment; apical antennomere acute but lacking nipple-like process. Mesosoma. Propleuron convex ventrally but lacking a sharp bump; notauli impressed and pitted, at least in part (Fig. 6c); posteroscutellar depression absent but sculpture usually present in this area; propodeum rugose to areolate-rugose (Fig. 7g); sclerite between hind coxal cavities and metasomal foramen complete, its ventral margin situated ventral to dorsal margin of hind coxal cavities. Legs. Fore tibia with pegs (Fig. 3a); all tarsal claws with strong basal lobe and with right-angled or slightly acute angle (Fig. 7a). Wings. (Figs 6d, 8b). Fore wing RS+M vein mostly absent; second submarginal cell triangular; fore wing 3RSb straight and strong throughout; hind wing r and r-m cross veins absent; hind wing vein CUb absent; fore wing partially or completely pigmented, with yellow or melanic color. Metasoma. First median tergite longitudinally striate, with a slightly stronger pair of lateral striae and a medial stria (Fig. 7h, 8e), rarely striae reduced and sculpture mostly weakly rugose (see couplet 1 in the identification key); second median tergite with an elevated semi-circular area separated from the remainder of the tergite by a shallow groove (Fig. 8e); second median tergite from smooth to striate, usually smooth anteriorly with a few longitudinal striae in posterior half; median tergite 3 smooth; length of ovipositor rather uniform, as long as (Fig. 5) or slightly longer than body (Fig. 8c).
Biology. Unknown Distribution. Restricted to the eastern Palearctic (Taiwan) and the Oriental region. For a distribution map, click here.
Etymology: From the Greek agathis, meaning "ball of thread", and the Latin crista, meaning "crest". Crest is in reference to the ridge between the antennal insertions. The gender is feminine. Agathis cancellata Enderlein, 1920 Diagnosis. This species has the northern-most distribution and appears to be restricted to Taiwan where it is the only species present. Members come in two color morphs; one with the mesosoma bicolored and the other with the mesosoma entirely melanic.
Etymology. Named after Winlon Kongnaka a collector for the TIGER project at Phuphan National Park.