Revision of Zosteragathis Sharkey of Thailand (Hymenoptera, Braconidae, Agathidinae, Agathidini)

Michael J. Sharkey; Eric G. Chapman

doi:10.3897/dez.65.25772

Research Article

Revision of Zosteragathis Sharkey of Thailand (Hymenoptera, Braconidae, Agathidinae, Agathidini)

Michael J. Sharkey^‡, Eric G. Chapman^‡

‡ Limestone University of Kentucky, Lexington, United States of America

Corresponding author: Michael J. Sharkey ( msharkey@uky.edu )

Academic editor: Ralph Peters

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Sharkey MJ, Chapman EG (2018) Revision of Zosteragathis Sharkey of Thailand (Hymenoptera, Braconidae, Agathidinae, Agathidini). Deutsche Entomologische Zeitschrift 65(2): 225-253. https://doi.org/10.3897/dez.65.25772

ZooBank: urn:lsid:zoobank.org:pub:5A043F9D-93FA-4DD7-873A-1A0101C849FE

Abstract

Based on cladistic analyses recently conducted by Sharkey and Chapman, the genus Zosteragathis Sharkey is revised. Twenty-two species are reported from Thailand, three previously described species, Z. samensis, Z. contrasta and Z. nuichuaensis, and 19 new species, i.e., Z. chaiyaphumensis, Z. eukos, Z. hinensis, Z. hongensis, Z. inthanonensis, Z. krachanensis, Z. lampangensis, Z. lampooensis, Z. luangensis, Z. ngamensis, Z. perknos, Z. petchaburiensis, Z. phahompokensis, Z. phuphanensis, Z. sakaeratensis, Z. sakonensis, Z. samensis, Z. surinensis, Z. taemensis, Z. tonensis. Members of Zosteragathis are known from the Australian, Ethiopian, Oceania, Oriental, and eastern Palaearctic regions.

Key Words

Insecta , identification key, taxonomy, systematics

Introduction

Agathidinae is a moderately large subfamily the members of which are koinobiont endoparasitoids of lepidopterous larvae. For more general information on Agathidinae see Sharkey et al. (2006). As of 2005, roughly 1,000 species were described (Yu et al. 2005). The senior author (MJS), based on the number of new species in recent revisions (see below), believes that there are a magnitude more undescribed species. Zosteragathis is restricted to the Old World. It is very diverse with species richness in the hundreds, but most of these are undescribed. This paper is part of a series that investigates members of the massively paraphyletic genus Bassus s.l.. (Sharkey and Clutts 2011, Sharkey et al. 2011a and b, Sharkey and Stoelb 2012 and 2013, Sharkey and Chapman 2017a, b). The generic concept Bassus is now confined to a small clade restricted to The Palearctic and Oriental realms, Zosteragathis Sharkey (Sharkey and Chapman 2017a), includes 25 previously described species (24 currently recognized as valid), all of which were previously included in the polyphyletic concepts of Agathiss.l., Bassuss.l. and Therophiluss.l. i.e.:

Z. annuliferus (Achterberg & Long, 2010), comb. n., from Therophilus

Z. annulus (Chou & Sharkey, 1989), from Bassus

Z. asper (Chou & Sharkey, 1989), from Bassus

Z. conformis (Bhat & Gupta, 1977), from Agathis

Z. contrasta (Achterberg & Long, 2010), from Therophilus (as contrastus)

Z. coryphe (Nixon, 1950), from Agathis

Z. depressa (Chou & Sharkey, 1989), from Bassus (as depressus)

Z. dravida (Bhat & Gupta, 1977), from Agathis

Z. elongator (Achterberg & Long, 2010), from Therophilus

Z. festiva (Muesebeck, 1953), from Agathis

Z. festivoides (Sharkey, 1996), from Bassus

Z. fujianicus (Chen & Yang, 2006), from Bassus

Z. gracilis (Bhat & Gupta, 1977), from Agathis

Z. lienhuachihensis (Chou & Sharkey, 1989), from Bassus

Z. lini (Chou & Sharkey, 1989), from Bassus

Z. masoni (Bhat & Gupta, 1977), from Agathis

Z. nigrolineatus (Achterberg & Long, 2010), from Therophilus

Z. nuichuaensis (Achterberg & Long, 2010), from Therophilus

Z. oranae (Watanabe, 1970), (syn. of Agathis festiva, by Sharkey 1996)

Z. parasper (Achterberg & Long, 2010), from Therophilus

Z. punctiscutum (Achterberg & Long, 2010), from Therophilus

Z. robusta (Achterberg & Long, 2010), from Therophilus (as robustus)

Z. scutellatus (Achterberg & Long, 2010), from Therophilus

Z. sungkangensis (Chou & Sharkey, 1989), from Bassus

Z. tanycoleosus (Chen & Yang, 2006), from Bassus

Methods

Morphological terms: The length of the first metasomal median tergite is measured from the apex of the tendon emanating from the propodeum to the posterior border of the tergite. Metasomal median tergites are abbreviated as follows, T1 = metasomal median tergite 1, T2 = metasomal median tergite 2. T2–3 = metasomal median syntergite 2 + 3. Other terms are from Sharkey and Wharton (1997). Morphological terms used in this revision can be found in the Hymenoptera Anatomy Ontology (HAO; Yoder et al. 2010). To find definitions for any structure search for the term at http://glossary.hymao.org.

Museum acronyms

HICHymenoptera Institute Collection, University of Kentucky, Department of Entomology, Lexington, Kentucky, USA.

QSBG Queen Sirikit Botanic Gardens, Chiang Mai, Thailand.

Species description format: Descriptions are of the holotype; variation is given in parentheses. Color is not extensively described because the images serve this purpose; however color characters that are variable or of diagnostic significance are detailed. 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 AutomontageR stacking software.

Species delimitation: We used evidence from molecular data (COI and 28S) and morphology to arrive at species concepts. Details are given in Sharkey and Stoelb (2013). Table 1 gives details on the COI distances within species of Zosteragathis as well as distances to the nearest species.

Table 1.

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COI divergence data COI data for each species. If a species has more than one terminal, both intra- and interspecific uncorrected p-distances are reported. Interspecific p-distances are to the nearest OTU in the COI tree (not shown). Values are averaged if two or more comparisons are made.

Species	Intraspecific variation	Interspecific variation	Nearest species
Z. contrasta	0.318%	3.899%	Z. taemensis
Z. eukos	–	5.234%	Z. ngamensis
Z. hongensis	–	1.414%	Z. sakonensis
Z. inthanonensis	–	5.801%	Z. ngamensis
Z. krachanensis	–	4.683%	Z. nuichuaensis
Z. lampangensis	0.491%	5.2365%	Z. inthanonensis
Z. lampooensis	0%	1.514%	Z. taemensis
Z. lunagensis	–	0%	Zosteragathis sp. n. 2
Z. ngamensis	–	5.801%	Z. inthanonensis
Z. nuichuaensis	0%	3.038%	Zosteragathis sp. n. 2
Z. perknos	–	5.221%	Z. ngamensis
Z. petchaburiensis	–	6.428%	Z. contrastus
Z. phahompokensis	–	1.972%	Z. tonensis
Z. sakonensis	–	1.414%	Z. hongensis
Z. samensis	0.920%	4.074%	Z. surinensis
Zosteragathis sp. n. 2	–	0%	Z. lunagensis
Z. surinensis	–	4.074%	Z. samensis
Z. taemensis	–	1.514%	Z. lampooensis
Z. tonensis	–	1.972%	Z. phahompokensis

Specimen collection: As part of the inventory of Thai insects, three 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. Two numbers, beginning with the letters “H” and “T” are listed for each specimen collected by our collaborators in Thailand. The H-number is the specimen number. Specimen information is stored in the Symbiota database (Gries et al. 2014) under the Hymenoptera Institute Collection (HIC). (Symbiota Collections of Arthropods Network; http://symbiota4.acis.ufl.edu/scan/portal/). To search for a specimen in the database, do the following: Under the Search tab (upper left of the screen), select Search Collections. Deselect all collections, and scroll down the Southeast section, put a check in the box next to Hymenoptera Institute Collection, scroll back up and hit the Search > button (right side of screen). H-numbered specimens are stored with a 4- letter prefix (HICH) followed by a 6-digit number. Therefore, H660, as it appears in this publication, is stored as HICH000660. To search for this specimen, scroll down to the Specimen Criteria section, type this number in the box next to Catalog Number and hit the search button. This displays a page with a summary of the specimen information. Clicking on Full Record Details opens a new window with the full specimen record, including all available images. The T-number is the number associated with a single Malaise trap for a single trapping period (usually one week). A complete list of these numbers and associated collection events is available from the authors upon request.

Links to species maps in this paper were generated from the Symbiota database. These are not static maps and as georeferenced specimens are added to the database, the maps will update in real time such that a reader following a map link will see a map of all of the specimens of the taxon at hand in the database, including those that may have been added after this paper is published. Clicking on the dots on these maps links to the specimen record in the database.

Phylogenetic methods: The data set and analyses presented herein is from Sharkey and Chapman (2017a). In that paper, the Zosteragathis terminals were largely unnamed, leaving species descriptions for this paper. In short, we conducted maximum likelihood (ML) phylogenetic analyses on a concatenated COI + 28S dataset (1,313 total characters) using Garli (v. 2.01; Zwickl 2006). The 28S multiple alignment was assembled using the default settings on the MAFFT server (http://mafft.cbrc.jp/alignment/server/; v. 7; Katoh et al. 2006), and employing the Q-INS-i strategy which takes secondary RNA structure into account. All 28S bases were included in subsequent phylogenetic analyses. The data were partitioned by gene region and codon position (COI: 3 partitions; 28S: un-partitioned, total of 4 partitions). The most complex model available (GTR+I+G; Rodriguez et al. 1990) was applied to each partition as per recommendations of Huelsenbeck and Rannala (2004). A 20-replicate ML search for the tree of highest log-likelihood and a 500-replicate ML bootstrap analysis (Felsenstein 1985) were conducted using the default settings. Outgroup genera (Alabagrus, Braunsia, Aerophilus, Camptothlipsis and Neothlipsis) were selected based on two criteria: (1) they comprise genera that are members of three clades that are successively sister to the ingroup clade in the phylogeny in Sharkey and Chapman (2017b), and (2) full length sequences of COI and 28S were available for most of these OTUs. The data set analyzed herein is available from the authors upon request. All of the specimens for which we have DNA sequences are listed in Appendix I, including their accession numbers.

Phylogenetic considerations: Sharkey and Chapman (2017b) revised the agathidine tribes and showed that Zosteragathis falls within the Agathidini. They could not demonstrate the monophyly of Zosteragathis, but confounded with the choice of erecting four genera for morphologically uniform clades, or one genus for the lot, they opted for the latter. The cladogram in Figure 1 shows that none of basal clades that separate the four Zosteragathis clades have support, therefore it is entirely possible that the genus is monophyletic.

Figure 1.

Tree of highest log-likelihood from 20 ML search reps of a combined COI+28S data set with bootstrap values ≥50% (500 search replicates) plotted at the nodes. Tree modified from Sharkey and Chapman (2017a).

Results and discussion

Below is a discussion of the taxonomy of Zosteragathis, a key to the Thai species of this genus, and descriptions of each species.

Taxonomy

Zosteragathis Sharkey, 2017

Type species

Zosteragathis samensis Sharkey, 2017

Diagnosis

Most species can be recognized as members of this genus by the combination of finely microsculptured striae on T2 that end abruptly just anterior to the posterior margin of the tergite; this in combination with a pale colored band in the anterior half of T2, or T2 entirely black. Some species have reduced striae on T2 and are recognized by the lack of apomorphic structures that distinguish other closely related genera, e.g., claws not simple; interantennal space without a sharply declivous keel; T1 without prominent lateral carinae or medial carina; fore tarsus without spines or pegs.

Description

See Sharkey and Chapman 2017a.

Biology

Hosts are unknown for all Thai species however there are records for three extra-Thailand species. These appear to suggest that the host range is wide. The records are: Zosteragathis coryphe was reared from Phycodes radiata (Sesioidea: Brachodidae) (Nixon 1950). Zosteragathis festiva (Muesebeck) was reared from Grapholitha molesta, oriental fruit moth, (Tortricoidea: Tortricidae) and many other Lepidoptera from a wide range of families, i.e., Blastobasidae, Gelechiidae, Cossidae, Carposinidae, Noctuidae, and Pyralidae. See Yu (2012) for a complete list. Zosteragathis robusta (Achterberg and Long) from Vietnam was reared from “Omiodes indicata (Lepidoptera: Pyralidae: Pyraustinae) on soybean (Glycine max (Linnaeus)), according to the label data”, (van Achterberg and Long 2010).

Distribution

Australian, Ethiopian, Oceania, Oriental, and eastern Palearctic regions.

Etymology

From the Greek zoster, meaning “belt or girdle” and agathis the type genus of the subfamily. Zoster is a reference to the diagnostic pale colored transverse band that is usually present on T2. The gender is feminine.

Key to Thai species of Zosteragathis

1	A. Mesoscutum pale, yellow to orange	2
–	B. Mesoscutum melanic, black	4

2	A. Scutellum rugose; T2 distinctly longer than wide; head mostly or entirely yellow to orange	Z. ngamensis
–	B. Scutellum smooth with punctures; T2 as wide as long or wider; head mostly or entirely black; pale color, if present restricted to the gena	3

3	A.T1 mostly or entirely pale (white to yellow)	Z. hongensis
–	B.T1 mostly or entirely melanic (brown to black)	Z. contrasta

4	A. Scutellum rugose	5
–	B. Scutellum smooth with punctures	7

5	A.T2 as wide as long or wider	Z. nuichuaensis
–	B.T2 distinctly longer than wide	6

6	A.T2 entirely or almost entirely (80%) pale (white to yellow)	Z. krachanensis
–	B.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	Z. luangensis

7	A.T2 as wide as long or wider	18
–	B.T2 distinctly longer than wide	8

8	A. Pronotum melanic dorsomedially, concolorous with lateral surfaces of pronotum	9
–	B. Pronotum pale dorsomedially (yellow to orange), contrasting with melanic lateral surfaces of pronotum	11

9	A.T2 entirely or almost entirely (>70%) pale (white to yellow)	Z. lampangensis
–	B.T2 entirely or almost entirely (>70%) melanic (dark brown to black)	10
–	C.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	Z. inthanonensis

10	A. Fore wing with a small infuscate area posterior to stigma; apex of T1 yellow	Z. inthanonensis
–	B. Fore wing without a small infuscate area posterior to stigma; apex of T1 melanic (brown to black)	Z. perknos

11	A. Hind femur mostly or entirely pale, yellow to orange	12
–	B. Hind femur mostly or entirely melanic, brown to black	13

12	A.T2 entirely or almost entirely (80%) pale (white to yellow)	Z. lampangensis
–	B.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	Z. surinensis

13	A. Striae of T2 curving towards the midline	14
–	B. Striae of T2 relatively straight	15

14	A.T2 entirely or almost entirely (>70%) pale (white to yellow)	Z. lampangensis
–	B.T2 entirely or almost entirely (>70%) melanic (dark brown to black); or C.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	Z. phuphanensis

15	A.T2 entirely or almost entirely (>70%) pale (white to yellow)	Z. lampangensis
–	B.T2 entirely or almost entirely (>70%) melanic (dark brown to black)	Z. lampooensis
–	C.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	16

16	A. Exposed portion of ovipositor longer than body length	Z. tonensis
–	B. Exposed portion of ovipositor equal to or shorter than body length	17

17	A. Fore coxa mostly or entirely yellow	Z. lampooensis
–	B. Fore coxa mostly or entirely melanic	Z. hinensis

18	A.T2 entirely or almost entirely (>70%) pale (white to yellow)	Z. sakonensis
–	B.T2 entirely or almost entirely (>70%) melanic (dark brown to black)	19
–	C.T2 mostly pale (white to yellow) in anterior half and mostly melanic (brown to black) in posterior half	22

19	A. Hind femur mostly or entirely pale, yellow to orange	Z. sakaeratensis
–	B. Hind femur mostly or entirely melanic, brown to black	20

20	A. Fore wing with a small infuscate area posterior to stigma	Z. chaiyaphumensis
–	B. Fore wing without a small infuscate area posterior to stigma	21

21	A.T2 almost entirely melanic	Z. eukos
–	B.T2 mostly melanic, but pale, yellow to orange, anteriorly and anterolaterally	Z. petchaburiensis

22	A.T1 extensively pale, white to yellow, basally	Z. phahompokensis
–	B.T1 mostly or entirely melanic basally	23

23	A. Scutellar groove pale, yellowish brown, significantly lighter than remainder of mesonotum	Z. taemensis
–	B. Scutellar groove melanic, concolorous with remainder of mesonotum	Z. samensis

Species descriptions