Research Article |
Corresponding author: David N. Honsberger ( dnh8@hawaii.edu ) Academic editor: Petr Janšta
© 2022 David N. Honsberger, John T. Huber, Mark G. Wright.
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:
Honsberger DN, Huber JT, Wright MG (2022) A new Mymaromma sp. (Mymarommatoidea, Mymarommatidae) in Hawai‘i and first host record for the superfamily. Journal of Hymenoptera Research 89: 73-87. https://doi.org/10.3897/jhr.89.77931
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A new species of Mymaromma, M. menehune sp. nov., is described from the Hawaiian Islands. It was found emerging as a solitary endoparasitoid from eggs of a Lepidopsocus sp. (Psocodea: Lepidopsocidae) on branches of Ficus microcarpa (Moraceae) on the island of O‘ahu. This the first host record for the superfamily Mymarommatoidea, coming almost exactly 100 years after the first extant species of Mymarommatidae was described.
barklice, egg parasitoid, Lepidopsocus sp., Psocoptera
Mymarommatoidea are a superfamily of beautiful but minuscule wasps with a two segmented petiole, a bellows-like expandable structure forming the back of the head, exodont mandibles, fore wings with long fringe setae and a reticulate pattern on the membrane, and hind wings reduced to a bifuracted haltere-like structure with no wing membrane (
Here we confirm, through rearing of psocopteran eggs taken from wood from which a species of mymarommatoid has been observed to emerge, that this suspicion was accurate for at least one species and we describe it. It is the same undescribed species previously reported by
In a separate study (D. Honsberger, unpublished), specimens of the mymarommatid were observed to emerge from branches of a large Ficus microcarpa L.f. tree (Fig.
A Ficus microcarpa tree on which the Mymaromma sp. was found and from which branches were obtained for collection of potential host eggs B the lengths of structures measured as shown. See text for more explanation C, D Mymaromma menehune sp. nov. wings C allotype wing on left showing ventral microtrichia only, wing on right showing dorsal microtrichia only D holotype wing on left showing dorsal microtrichia only, wing on right showing ventral microtrichia only. Scale bars: 250 µm (C, D).
In the present study, approximately 8 branches 2–8 cm in diameter and 30–60 cm long were cut from the same tree and suspended from it in the same position as in the previous study. After 5 weeks, the branches were taken to a laboratory and their surface inspected under a Leica MZ16 stereomicroscope. All arthropod eggs found on the surface of the wood were either picked off the bark or carefully cut from the bark together with a small piece of the surrounding wood and placed individually in gelatin capsules. The branches were then placed again in the tree. Inspection of the branches and collection of eggs was repeated approximately once per week, and new branches were added after the previous branches had been exposed for 6 weeks. Branches were removed after they had been exposed for 12 weeks. The capsules were periodically inspected under the microscope for emergence of parasitoids from the eggs. After mymarommatoids had been observed to emerge from eggs in the capsules, morphologically identical eggs were collected from the surface of the branches and reared to adulthood for host identification. Eggs putatively belonging to other species of psocopterans found on the branches were also reared to associate the adult stage of the psocopterans known to occur on that tree with their egg morphology, and thereby determine whether any of their eggs could be confused with eggs of the species reared for host identification. Photographs and videos of psocopterans, their eggs, and parasitoids were also opportunistically recorded during inspection of the wood.
Wasps that emerged from host eggs were point mounted, with the egg from which the individual emerged also glued to the point, and both were photographed using a Macropod Pro imaging system. Other specimens were slide mounted and photographed under an Olympus CX31 compound microscope, or point mounted and examined under a stereomicroscope. Morphological terms follow
UHIM University of Hawai‘i Insect Museum, Honolulu, Hawai‘i, USA
Holotype
: female (Fig.
1 female, 5 males, all slide mounted. Moloka‘i • Mapulehu Valley near Ili‘ili‘opae heiau, 10–40’, viii.1995, 29.ix–13.x.1995, 1–15.iii.1996, W.D. Perreira, yellow sticky board traps (3♂,
Mymaromma menehune is most similar to M. goethei Girault, 1920 and M. longipterus Ayyamperrumal & Manickavasagam, 2017. All are distinguished from other described species of Mymaromma by the sculpture of the propodeum: obliquely striate in anterior half and transversely striate in posterior half (Figs
Female (Figs
Head. Eye with about 35 ommatidia. Ocelli absent. Vertex, temple and gena faintly and finely transversely striate, with a few scattered white setae (Fig.
Mesosoma. Mesosoma length 2.22–2.42× propodeum length (n = 5). Mesoscutum with raised isodiametric reticulate sculpture and four thick setae in a transverse line near posterior margin (Fig.
Metasoma. Length range of P1/length range of P2 (ratio range) = 49–55/31–37 (1.42–1.58); P1 with small spicules ventrobasally, otherwise smooth; segment P2 slightly rougher especially ventrobasally. Cercus with four long setae. Ovipositor length 0.55–0.59× metatibia length (n = 5).
Male (Figs
Because of its size and elusivity, this species is named after the Menehune, in Hawaiian legend a people who were small and not often seen, that live in the forests and are known for being industrious craftspeople who emerge during the night and build structures.
Three M. menehune individuals emerged from the eggs in the capsules, all from morphologically identical eggs, and each M. menehune individual from a single egg in a single capsule (Fig.
Lepidopsocus sp., host of Mymaromma menehune sp. nov. A–D Lepidopsocus sp. eggs, found on F. microcarpa branches, in C two eggs visible, oviposited into a fissure in the wood presumably chewed by an ovipositing cerambycid, and secondarily inhabited by Cryphalus brasiliensis (Coleoptera: Scolytinae) E, F Lepidopsocus sp. adult reared from morphologically identical eggs.
Eggs and adults of two other species of bark lice found to emerge from F. microcarpa branches from the same tree A Psocidae sp. adult B–C eggs of Psocidae sp. (B unhatched C hatched) D Ectopsocus ? pilosus adult E–F eggs, frass, and web of E. ? pilosus (E a patch of eggs visible near bottom left F the eggs are the white ovoids).
Three mymarommatoids were observed on the surface of the branches inspected under the microscope (Fig.
We provide the first host record for the superfamily Mymarommatoidea, thus confirming the hypothesis by
Only one described species of Mymarommatidae, M. longipterus, has a striated propodeum exactly as in M. menehune but it differs in number of funicle segments. Most Mymaromma females appear to have a 7-segmented funicle but a few, e.g., M. goethei, have a 6-segmented funicle. Two slide-mounted females and 1 male from Thailand, and 2 males from Taiwan (
We thank Maya Honsberger for her observations, support, and help examining branches for eggs. We also thank Keith Arakaki, Lisha Jasper, and Neil Evenhuis of the Bernice Pauahi Bishop Museum for supporting visits to the museum, and their help locating and imaging specimens; and Whit Farnum, Crystal Maier, and Brian Farrell of the Museum of Comparative Zoology for locating and imaging specimens. We are very grateful to Hawai‘i Department of Agriculture, USDA-APHIS, USDA-ARS, and NIFA Hatch project HAW09041-H, administered by CTAHR, for their funding.
Video 1. Mymaromma menehune sp. nov. ♀ exploring a F. microcarpa branch and grooming
Data type: Mp4 file.
Explanation note: https://vimeo.com/666102893