Research Article |
Corresponding author: Norman F. Johnson ( baeus2@yahoo.com ) Academic editor: Jose Fernandez-Triana
© 2018 Norman F. Johnson, Huayan Chen, Bernhard Huber.
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:
Johnson NF, Chen H, Huber BA (2018) New species of Idris Förster (Hymenoptera, Platygastroidea) from southeast Asia, parasitoids of the eggs of pholcid spiders (Araneae, Pholcidae). ZooKeys 811: 65-80. https://doi.org/10.3897/zookeys.811.29725
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Four new species of the genus Idris Förster (Hymenoptera: Platygastroidea), reared from the eggs of pholcid spiders (Araneae: Pholcidae) in southeast Asia are described on the basis of external morphology and the barcode region of the mitochondrial COI gene. The new species and their hosts are: I. badius Johnson & Chen, sp. n. (ex Nipisa phyllicola (Deeleman-Reinhold), Panjange hamiguitan Huber), I. balteus Johnson & Chen, sp. n. (ex Panjange camiguin Huber), I. curtus Johnson & Chen, sp. n. (ex Calapnita nunezae Huber, Panjange camiguin Huber, Tissahamia bukittimah (Huber), Uthina luzonica Simon), and I. fusciceps (ex Belisana khaosok Huber).
Araneomorphae , Baeini , Scelioninae , taxonomy, wasps
Egg parasitoid wasps of the tribe Baeini (Hymenoptera: Platygastridae) are one of the major biotic sources of mortality among their spider hosts (
The use of the eggs of spiders as hosts among platygastroids is characteristic of baeines, but not limited to them. The genera Echthrodesis Masner, Mirobaeoides Dodd, and Neobaeus Austin also attack these hosts and form a small, separate clade together with Emibodobia Ashmead in the analysis of
The spider hosts in the present paper are all members of Pholcidae, but this is primarily a result of collection trips focused on pholcid spiders and does not imply host specificity of the wasps. Pholcid spider females carry their egg-sacs with their mouthparts until the spiderlings hatch. It is possibly for this direct protection by the female that in most species the eggs are not densely covered by a protective layer of silk but held together by a few turns of silk. This is in contrast to most other spider families where dense and often complex layers of silk are thought to have coevolved with specialized parasitoids and predators (
Approximately sixty species of the genera Idris and Ceratobaeus have been described from tropical Asia, almost entirely from either India or Vietnam (
The problem is that we are dealing with (1) a richly speciose genus, (2) a group without any solid, comprehensive treatment for the region, and (3) a group containing numerous described species many of which are more or less unidentifiable. Would the addition of more isolated species descriptions be a contribution toward progress, or would it simply make the problem larger and more intractable?
If the ultimate goal is a complete documentation of the diversity in such a group, then one can imagine various strategies to achieve that aim. The ideal might be a comprehensive monographic treatment based on the totality of specimens existing in collections, the addition of targeted, newly collected material, a review of all existing primary types, and data sets that incorporate as many independent character sources as possible. For many reasons, this standard may be difficult or impossible to achieve, especially when dealing with a genus comprised of hundreds of species. An alternative could be to work gradually toward that same goal by incrementally planting signposts in the terrain, signposts that are well-defined points of reference to guide for future work. This is our goal here: each species description has host records and COI barcode data to supplement the morphological characters.
Pholcid spiders were collected manually and egg sacs were checked with a hand-held lens in search of parasitized eggs. Females with parasitized eggs were kept alive in small plastic containers until the wasps emerged. Adult specimens emerged from eight samples. Specimens from these samples were used in both the morphological and molecular analyses:
In an additional five samples the parasitoids grew to the pupal stage, but failed to emerge as adults. Pupae from these samples were used in the molecular analyses.
The wasp specimens are deposited in the C.A. Triplehorn Insect Collection, Ohio State University, Columbus, OH (OSUC). The host spiders are deposited at the Zoological Research Museum Alexander Koenig, Bonn, Germany (ZFMK).
Abbreviations and morphological terms used in text: A1, A2, A3: antennomere 1, 2, 3; T1, T2, ... T5: metasomal tergite 1, 2, ... 5. Morphological terminology otherwise generally follows
Genomic DNA was extracted from ethanol-preserved specimens using the DNeasy Blood & Tissue Kit (Qiagen, Germantown, MD; cat. num. 69506) and following the protocol used by
The nucleotide alignment file and GenBank accession numbers are included in Suppl. materials
1) Mal305
2) PSt84 + PSt461
3) Mal331 (Idris fusciceps sp. n.)
4) Phi286
5) Mal276 + PSt1226 (Idris badius sp. n.)
6) Phi 291 (Idris balteus sp. n.)
7) Mal228 + Mal256 + PSt1564 + Mal226 + Phi271 (Idris curtus sp. n.)
Within each grouping of more than one sequenced sample the average pairwise percentage identity of the sequences was 99.443% (99.142–100%). The average between-group pairwise percentage identity was 88.154% (87.016–90.207%). The average percent identity with the outgroup, Trissolcus basalis, was 79.2%. In one egg sac, Phi271, the two specimens sequenced were identical in only 91.3% of the sequence, suggesting either two different species or a relatively high level of intraspecific variation. Unfortunately, no adults emerged from these eggs so it was impossible to distinguish between the two possibilities on the basis of morphological characters.
Five of the seven groupings of molecular samples were represented by adults, and all but one of these are described below as new species. The one not described could not be distinguished on the basis of morphology alone from I. badius. The low level of sequence identity (86.5%) strongly suggests that they are not conspecific, but in lieu of finding any morphological distinction, we decided to refrain from describing it. None of these new species were identifiable on the basis of the key in
Body length: 0.81 mm. Head color: brown. Mesosoma color: brown. Metasoma color: brown.
Head shape in frontal view: ovoid, distinctly wider than high. Head width/mesosomal width: 1.34–1.44. Sculpture of upper frons, vertex: finely coriaceous reticulate. Position of lateral ocellus: contiguous with inner orbit of compound eye. Central keel of frons: present. Length of central keel of frons: extending dorsally half distance to median ocellus. Speculum: present. Striae on lower frons: absent. Setation of compound eyes: eyes distinctly setose.
Size of A3: subequal in length, width to A2. Shape of A3: length greater than width.
Length/width mesoscutum: 0.74–0.83. Sculpture of mesoscutum: finely reticulate, setal bases pustulate. Notauli: absent. Sculpture of mesoscutellum: finely reticulate, setal bases pustulate. Sculpture of metascutellum: smooth. Propodeal armature: lateral propodeal area produced dorsomedially into small tooth.
Wing development: fully developed, macropterous. Fore wing patterning: fore wing hyaline throughout. Marginal fringe of fore wing: present, short. Length of bristles on submarginal vein: short, barely reaching beyond costal margin of wing. Basal vein: well-defined, straight, lightly pigmented. Length of stigmal vein: elongate, extending nearly to middle of fore wing. Length of postmarginal vein: extremely short, subequal in length to marginal vein.
Metasoma length/body length: 0.47–0.48. Sculpture of T1: longitudinally costate. Sculpture of T2: longitudinally costate in medial third, finely reticulate along lateral margin, elsewhere smooth. Length T3/length T2: 2.21. Sculpture of T4–T5: finely reticulate basally, smooth apically. Setation of T3: lateral thirds of tergite moderately setose through, median third nearly glabrous, with sparse apical transverse band of setae.
This species runs to I. nautalis Kozlov & Lê in the keys of
Eggs of Nipisa phyllicola (Deeleman-Reinhold) (ZFMK, Mal 276) (Fig.
The specific epithet badius refers the rich brown color of the body and is intended as an adjective.
Holotypefemale: MALAYSIA: Perak, Gunung Liang, forest along river, 250 m a.s.l., 3°47.7'N 101°32.0'E, 22.ii.2015, B. A. Huber, A.R.M. Ghazali & K. A. Braima, ex: egg of Nipisa phyllicola (Deeleman-Reinhold), OSUC270822. Paratypes: MALAYSIA: 3 females, 1 male with same data as holotype, OSUC270823, 420837–420838, 627622. PHILIPPINES: Mindanao, Davao Oriental, 580 m a.s.l., 6.6805N, 126.1591E, site 3, Mount Hamiguitan Wildlife Sanctuary (access Governor Generoso), 13.ii.2015, M. A. Responte, ex egg of Panjange hamiguitan Huber (1 female, OSUC627625).
Body length: 0.85–0.99 mm. Head color: dark brown. Mesosoma color: dark brown. Metasoma color: first segment yellow, second segment brownish yellow, otherwise brown.
Head shape in frontal view: ovoid, distinctly wider than high. Head width/mesosomal width: 1.24–1.31. Sculpture of upper frons, vertex: finely coriaceous reticulate. Position of lateral ocellus: contiguous with inner orbit of compound eye. Central keel of frons: present. Length of central keel of frons: extending dorsally half distance to median ocellus. Speculum: present. Striae on lower frons: with short striae flanking speculum. Setation of compound eyes: eyes distinctly setose.
Size of A3: distinctly smaller than A2. Shape of A3: length greater than width.
Length/width mesoscutum: 0.72. Sculpture of mesoscutum: finely reticulate, setal bases pustulate. Notauli: absent. Sculpture of mesoscutellum: finely reticulate, setal bases pustulate. Sculpture of metascutellum: smooth. Propodeal armature: lateral propodeal area produced dorsomedially into small tooth.
Wing development: fully developed, macropterous. Fore wing patterning: fore wing hyaline throughout. Marginal fringe of fore wing: present, short. Length of bristles on submarginal vein: short, barely reaching beyond costal margin of wing. Basal vein: well-defined, straight, lightly pigmented. Length of stigmal vein: elongate, extending nearly to middle of fore wing. Length of postmarginal vein: extremely short, subequal in length to marginal vein.
Metasoma length/body length: 0.45–0.48.Sculpture of T1: longitudinally costate. Sculpture of T2: longitudinally costate in medial third, finely reticulate along lateral margin, elsewhere smooth. Sculpture of T3: finely reticulate, with weak irregularly longitudinal rugulae medially. Length T3/length T2: 1.81–2.17. Sculpture of T4–T5: finely reticulate basally, smooth apically. Setation of T3: lateral thirds of tergite moderately setose through, median third nearly glabrous, with sparse apical transverse band of setae.
In the keys of
Panjange camiguin Huber (ZFMK, Phi291) (Araneae: Pholcidae) (Fig.
The specific epithet balteus, a Latin word for belt, refers to the golden base of the metasoma. It is intended as a noun in apposition.
Holotypefemale: PHILIPPINES: Bohol, near Loboc, above Loboc River, forest near caves, ~250 m a.s.l., ~9.655N, 124.015E, 5.iii.2014, B. A. Huber, ex egg of Panjange camiguin Huber, OSUC270828. Paratypes: PHILIPPINES: 3 females, 1 male with same data as holotype, OSUC270829, 420844–420845, 627631). Other material: 1 broken female with same data as holotype, OSUC270830.
Body length: 0.83–0.89 mm. Head color: brown. Mesosoma color: brown. Metasoma color: brown
Head shape in frontal view: ovoid, distinctly wider than high. Head width/mesosomal width: 1.20–1.27. Sculpture of upper frons, vertex: finely coriaceous reticulate. Position of lateral ocellus: contiguous with inner orbit of compound eye. Central keel of frons: present. Length of central keel of frons: extending dorsally half distance to median ocellus. Speculum: present. Striae on lower frons: with short striae flanking speculum. Setation of compound eyes: eyes distinctly setose.
Size of A3: distinctly smaller than A2. Shape of A3: length greater than width.
Length/width mesoscutum: 0.65–0.79. Sculpture of mesoscutum: finely reticulate, setal bases pustulate. Notauli: absent. Sculpture of mesoscutellum: finely reticulate, setal bases pustulate. Sculpture of metascutellum: smooth. Propodeal armature: lateral propodeal area produced dorsomedially into small tooth.
Wing development: fully developed, macropterous. Fore wing patterning: fore wing hyaline throughout. Marginal fringe of fore wing: present, short. Length of bristles on submarginal vein: short, barely reaching beyond costal margin of wing. Basal vein: well-defined, straight, lightly pigmented. Length of stigmal vein: elongate, extending nearly to middle of fore wing. Length of postmarginal vein: extremely short, subequal in length to marginal vein.
Metasoma length/body length: 0.52–0.57. Sculpture of T1: longitudinally costate. Sculpture of T2: longitudinally costate in medial third, finely reticulate along lateral margin, elsewhere smooth. Length T3/length T2: 1.87–2.33. Sculpture of T4–T5: finely reticulate basally, smooth apically. Setation of T3: lateral thirds of tergite moderately setose through, median third nearly glabrous, with sparse apical transverse band of setae.
Very similar to I. badius, distinguished by the distinctly shorter third antennomere (compared with A2). As with I. badius, this species runs to I. nautalis Kozlov & Lê in the keys of
Calapnita nunezae Huber (ZFMK, Phi271), Panjange camiguin Huber (ZFMK, PSt1564 = Ar 15064), Tissahamia bukittimah (Huber) (ZFMK, Mal 256) (Fig.
The name curtus, Latin for short, refers to relative length of the first flagellomere of the female antenna. It is intended to be used as an adjective.
Holotypefemale: SINGAPORE: 50 m a.s.l., 1°21.6'N 103°46.7'E, Dairy Farm Nature Park, 15.ii.2015, B. A. Huber & J. Koh, reared ex egg of Tissahamia bukittimah (Huber), OSUC270831. Paratypes: SINGAPORE: 6 females, 2 males, with same data as holotype, OSUC270832, 270833, 420829–420831, 420833, 627623, 627624. 1 female, 2 males with same data as holotype except reared ex egg of Uthina luzonica Simon, OSUC420836, 6217633, 627634. PHILIPPINES: Visayas, Bohol, Bilar, Barangay Riverside, 440 m a.s.l., 9.7052N, 124.1253E, 15.vi.2015, M.R.B. Dacar; reared ex egg of Panjange camiguin Huber, 1 female, 1 male, OSUC420834, 627632. Other material: SINGAPORE: 50 m a.s.l., 1°21.6'N 103°46.7'E, Dairy Farm Nature Park, 15.ii.2015, reared, B. A. Huber & J. Koh, ex egg of Tissahamia bukittimah (Huber), female, OSUC420832 (broken specimen); ex egg of Uthina luzonica Simon, male, OSUC420835 (broken). The remaining material is based on DNA sequences from pupae. SINGAPORE: Upper Selatar Reservoir Park (1°21.3'N, 103°48.4'E), 20 m a.s.l., 15.ii.2015 (B.A. Huber, D. Court). Host: Uthina luzonica Simon. PHILIPPINES: Mindanao, Mt. Matutum, Kawit Forest, ‘site 1’, (6.338N, 125.104E), 950 m a.s.l., along brook, on leaves, 13.ii.2014, B. A. Huber, ex egg of Calapnita nunezae Huber.
Body length: 0.58–0.66 mm.
Head color: light brown. Mesosoma color: brownish yellow, contrasting with darker color of head. Metasoma color: brownish yellow.
Head shape in frontal view: ovoid, distinctly wider than high. Head width/mesosomal width: 1.17–1.24. Sculpture of upper frons, vertex: pustulate. Position of lateral ocellus: separated from inner orbit of compound eye by approximately 1 ocellar diameter. Central keel of frons: present. Length of central keel of frons: extending dorsally one-third distance to median ocellus. Speculum: present. Striae on lower frons: absent. Setation of compound eyes: eyes distinctly setose.
Size of A3: distinctly smaller than A2. Shape of A3: width greater than length.
Length/width mesoscutum: 0.64–0.72. Sculpture of mesoscutum: finely reticulate, setal bases pustulate. Notauli: present, short. Sculpture of mesoscutellum: finely reticulate, setal bases pustulate. Sculpture of metascutellum: rugulose. Propodeal armature: lateral propodeal area produced dorsomedially into small tooth.
Wing development: fully developed, macropterous. Fore wing patterning: fore wing hyaline throughout. Marginal fringe of fore wing: present, short. Length of bristles on submarginal vein: elongate, extending beyond costal margin by distance more than half their length. Basal vein: well-defined, straight, lightly pigmented. Length of stigmal vein: elongate, extending nearly to middle of fore wing. Length of postmarginal vein: extremely short, subequal in length to marginal vein.
Metasoma length/body length: 0.44–53. Sculpture of T1: longitudinally costate. Sculpture of T2: longitudinally costate in medial third, finely reticulate along lateral margin, elsewhere smooth. Sculpture of T3: finely reticulate, with weak irregularly longitudinal rugulae medially. Length T3/length T2: 1.56–1.60. Sculpture of T4–T5: finely reticulate basally, smooth apically. Setation of T3: lateral thirds of tergite moderately setose through, median third nearly glabrous, with sparse apical transverse band of setae.
In the keys of
Belisana khaosok Huber (ZFMK, Mal331= Ar 19649) (Araneae: Pholcidae) (Fig.
The specific epithet refers to the darker color of the head in comparison with the mesosoma and metasoma. It is to be treated as a noun in apposition.
Holotype, female: THAILAND: Krabi, ~9 km N Krabi town, degraded forest between plantation and rocks, 75 m a.s.l., 8°09.9'N 98°51.7'E, 7.III.2015, B. A. Huber & B. Petcharad, ex egg of Belisana khaosok Huber. OSUC270824. Paratypes: THAILAND: 8 females, 1 male with same data as holotype (OSUC270825–270827, 420839–420843, 627626).
Host spiders with parasitized egg-sacs. 14 Nipisa phyllicola (Mal276); note that two eggs are not parasitized 15 Panjange camiguin (Phi291) 16 Tissahamia bukittimah (Mal256); note that only some of the eggs are parasitized 17–19 Tissahamia gombak (Mal305) at different stages of wasp development (6 days lie between 17 and 18 1 day between 18 and 19); arrow points at eclosed wasp 20 Belisana khaosok (Mal331); arrow points at eclosed wasp.
BAH thanks Booppa Petcharad, Venus Saksongmuang, Olga M. Nuñeza, Eddie P. Mondejar, Joseph K.H. Koh, David Court, Mustakiza Muslimin, Amir R.M. Ghazali, and Kamil A. Braima for assistance in the field; Mae A. Responte, Maria R.B. Dacar, and Noraya U. Elias for contributing specimens from their own research; Sara Bumrungsri for supporting permit requests in Thailand; Noraishah Mydin Abdul Aziz for facilitating field work in Malaysia; the National Research Council of Thailand (NRCT), the Singapore National Parks Board (Permit No. NP/RP15-003a), and the Philippine Department of Environment and Natural Resources (DENR) CARAGA, DENR Region X, and DENR Region XI, for issuing permits; and the German Research Foundation for financial support (DFG Project HU 980/11-1). NFJ thanks Luciana Musetti for constant support and inspiration.
Fasta file: pholcid Idris
Data type: Fasta file
GenBank accessions: pholcid Idris
Data type: Microsoft Excel Worksheet (.xlsx)
Explanation note: GenBank Accession numbers for DNA sequences..