Research Article |
Corresponding author: Jose Fernandez-Triana ( cnc.braconidae@gmail.com ) Academic editor: Kees van Achterberg
© 2016 Jose Fernandez-Triana, Caroline Boudreault.
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:
Fernández-Triana J, Boudreault C (2016) Keylimepie peckorum gen. n. and sp. n., (Hymenoptera, Braconidae) from southern Florida, U.S., the first known brachypterous member of the subfamily Microgastrinae. ZooKeys 584: 95-107. https://doi.org/10.3897/zookeys.584.8319
|
Keylimepie peckorum Fernandez-Triana, gen. n. and sp. n., are described from southern Florida, U.S. Females have the shortest wings (0.6–0.7 × body length) of any known microgastrine wasp. The genus can also be recognized on features of the head, propodeum and first three metasomal tergites. All specimens were collected in hammock forests of the Florida Keys and Everglades National Park, but their host caterpillar is unknown. Because its morphology is unique and it is the first new microgastrine genus discovered in North America since 1985, the potential for future conservation of the species is discussed.
Microgastrinae , new genus, North America, southern Florida, Keylimepie , brachyptery, conservation
Microgastrinae (Hymenoptera, Braconidae) is a hyperdiverse and challenging group of parasitoid wasps, with almost 2,700 described species (
All 60 specimens studied for this paper were found among unsorted Microgastrinae in the Canadian National Collection of Insects (
Morphological terms and measurements of structures are mostly as in
Photos were taken using a Canon EOS 60D with MPE-65 lenses (aperture: 4.0, ISO: 100, CR2 format images) and a 600EX-RT Speedlight (manual) flash. Multiple images through the focal plane were taken of a structure, and these were combined to produce a single in-focus image with Zerene Stacker (http://zerenesystems.com/cms/stacker). Plates for the illustrations were prepared using Adobe Photoshop CS4.
A map with the distribution of all species was generated using SimpleMappr (
Keylimepie peckorum Fernandez-Triana new species, by present designation.
Female. Fore wings (0.6–0.7 × body length), shorter than any other species of Microgastrinae (where fore wings are 0.9–1.2 × body length); malar distance more than 2.0 × mandibular width; eye and ocelli small. Both sexes. Propodeum sculpture with a complex pattern that includes partial transverse and longitudinal carinae and a posteriorly defined areola; T1 without median sulcus; T1–T3 with strong longitudinal sculpture.
Female. Head heavily punctured, in lateral view strongly projecting forward below the antennal sockets. Malar distance more than 2.0 × mandibular width. Anterior tentorial pits very large compared to clypeus width. Eyes and ocelli small. Pronotum with one broad, transverse pronotal sulcus. Propleuron flange sharply defined by carina. Notauli faint, almost invisible. Propodeum with complex sculpture pattern, including partial median longitudinal carina (sometimes obscured by other sculpture), traces of transverse carina, and partial areola with only the posterior carina defined. Fore wing short and narrow, brachypterous (fore wing length 0.6-0.7 × body length, and 1.1–1.3 × metasoma length), with small to almost obliterated quadrangular areolet. Metacoxa of moderate size, not surpassing posterior margin of T2. Inner and outer spurs of metatibia subequal and less than half length of metatarsal segment 1. T1 relatively short, more or less parallel-sided in anterior 0.5, then narrowing towards posterior margin, without median sulcus, with anterior 0.5 rather depressed and concave, and posterior 0.5 with strong transversal striation. T2 trapezoidal. T2 and T3 with strong longitudinal striations, T4–T8 smooth. Hypopygium small, inflexible and unfolded. Ovipositor sheaths mostly smooth, with a few, short setae posteriorly. Ovipositor very short, 0.2 × as long as metatibia. Male as in female but not brachypterous, antenna uniformly brown and body color much darker.
Southern Florida: four Florida Keys and a single locality in Everglades National Park (Fig.
Hosts are unknown. All specimens were collected in hammock forests from February to November.
Propodeum carination pattern, shape and sculpture of T1 (without median sulcus), sculpture of T2 and T3, reduced eyes, long malar space, and, in females, short fore wing are treated tentatively as apomorphies.
Named after the Key Lime Pie, a typical dessert originated in the Florida Keys –the same area where the new genus was collected. The name not only honors a significant component of the culinary culture in southern Florida, but is also intended to bring attention to and promote conservation efforts for the habitats where the wasps occur. The gender of the genus name is neuter.
The relationships of Keylimepie with other genera of Microgastrinae are hard to assess at present, especially because there are no molecular data available, and nothing is known about potential hosts. Several morphological characters, e.g., head shape and sculpture, mesosoma sculpture, shape and sculpture of T2, and ovipositor, suggest it is related to some species-groups of Diolcogaster, part of the Cotesini tribe (sensu
The reduced wings in females, relatively small eyes and long malar space present interesting evolutionary questions. More study of additional species of Microgastrinae worldwide would be needed before it can be established if those characters truly are autapomorphies of Keylimepie or just an adaptation to local conditions (see Discussion below).
Female,
3 ♀, 56 ♂ (
Female.Color. Body mostly orange yellow, with mediotergites 4–8, laterotergites 4–8, sternites 4–8 and hypopygium darker, mostly brown. Antenna with anterior 6–7 flagellomeres yellow, and posterior 9–10 flagellomeres dark brown. Metatibia and metafemur mostly to completely brown. Anteromesoscutum, propodeum and metapleuron varying from entirely orange-yellow to partially dark brown. Wings mostly infumated, except for small central white band; veins mostly brown, pterostigma with a pale spot anteriorly or mostly brown.
Head. Coarsely sculptured, in lateral view strongly projecting forward below antennal sockets. Head in frontal view with maximum width right below the eyes (due to bulging gena). Gena in lateral view wider than eye width. Anterior tentorial pits large, 0.3 × as wide as clypeus width. Malar line long, more than 2.8 × mandibular width. Eye small, its height 0.6 × head height. Ocelli relatively small, diameter of posterior ocelli about half of both OOL and POL. Anatomical line tangent to posterior margin of anterior ocellus, crossing well above the anatomical line tangent to anterior margin of posterior ocelli. Antenna about same length as body.
Mesosoma. Pronotum rather narrow, with one broad, transverse pronotal sulcus. Propleuron flange sharply defined by carina. Notauli very faintly marked by slightly coarser sculpture than rest of anteromesoscutum. Scutoscutellar sulcus with seven carinae. Mesoscutellum with lateral face mostly strongly striated, with polished area (mesoscutellum lunula) very narrow, 0.1 × lateral face height. Scutellum with posteromedian band weakly rugose. Mesopleuron sculptured on anterior half, smooth posteriorly. Mesopleural scrobe extending to almost 0.5 of mesopleuron width. Metapleuron mostly smooth anterior to metapleural scrobe but with strong transverse striation posterior to scrobe. Propodeum with complex sculpture pattern, including partial median longitudinal carina (sometimes obscured by other sculpture), traces of transverse carina and partial areola with only the posterior carinae of areola defined.
Metasoma. T1 relatively short, its medial length 1.2 × its width at anterior margin. T1 more or less parallel-sided for anterior 0.5, then narrowing towards posterior margin (width at anterior margin 2.0 × width at posterior margin). T1 without median sulcus, with anterior 0.5 rather depressed and concave, and posterior 0.5 with strong transversal striation. T2 trapezoidal, its width at posterior margin 1.5 × its medial length. T2 and T3 with strong longitudinal striation; T4–T8 smooth. Hypopygium small, inflexible and unfolded. Ovipositor sheaths mostly smooth, with few, short setae on posterior 0.2–0.3. Ovipositor short, 0.2 × as long as metatibia.
Legs. Metacoxa of moderate size, not surpassing posterior margin of T2; metafemur 5.0 × as long as wide. Metatibia with inner and outer spurs subequal (inner 1.1 × as long as outer) and 0.35–0.40 as long as metatarsal segment 1.
Wings. Fore wing relatively short (0.6–0.7 × body length and 1.1–1.3 × metasoma length), with small to almost obliterated, 4-sided areolet, and with vein R1 shorter than pterostigma length and only 2.0–2.5 × as long as the distance between its posterior end and posterior end of vein M.
Holotype measurements (some measurements of female paratypes between parentheses). Body length: 2.2 mm (1.9– 2.1, 2.4–2.5 mm). Fore wing length: 1.3 mm (1.2, 1.6–1.8 mm). Metasoma length: 1.1 mm (0.9–1.0, 1.2–1.3 mm). Mandible width: 0.06 mm. Malar line: 0.17 mm. Clypeus length/ width: 0.15 mm/0.045 mm. Tentorial pit width: 0.05 mm. Head maximum width: 0.58 mm. Head height: 0.48 mm. Eye height: 0.27 mm. Eye maximum width (lateral view): 0.15 mm. Gena maximum width (lateral view): 0.20 mm. OOL: 0.09 mm; POL: 0.09 mm; diameter of posterior ocellus: 0.05 mm. Flagellomere 2 lenght/width: 0.20 mm/0.065 mm. Flagellomere 14 length/width: 0.14/0.07. T1 width at anterior margin/width at posterior margin: 0.39 mm/0.19 mm. T2 length/width at posterior margin: 0.34 mm/0.52 mm. Metacoxa length: 0.42 mm. Metafemur length/width: 0.75/0.15. Metatibia length: 0.82 mm. Metatibial spurs length, inner/outer: 0.17 mm/0.15 mm. First segment of metatarsus length: 0.40 mm. Ovipositor length: 0.15 mm.
Male. As in female except for uniformly brown antenna, longer fore wing, lighter-coloured wings (hyaline or slightly infumated), and darker body color which in some cases becomes dark brown to black in areas of the head and mesosoma.
Unknown. All specimens were collected in hammock forests from February to November. Based on the labels, the species would seem to be more abundant in April–June and November. However, the collecting device, a Malaise trap, was not emptied regularly (at times running for months), and so the actual flight dates for the species cannot be considered as very precise.
Named after Stewart and Jarmila Peck, tireless insect collectors over the last 30+ years and the ones finding the species back in 1985 and1986. Also in recognition of their great knowledge as entomologists and as an appreciation for the important papers published by Stewart on the insect fauna of southern Florida.
In females, smaller specimens tend to have shorter wings, a smaller areolet and pterostigma in the fore wing, and lighter color than larger specimens. Males also show variation in the extent of darker areas, but are always darker than females. Although numerous specimens (60) were found and are included as part of the type series, it should be noted that all of them were collected during two collecting trips made in 1985 and 1986 (see
Belokobylskij and Kula (2012) analyzed the species of Braconidae that could be considered as apterous, micropterous and brachypterous and listed over one hundred species worldwide.
According to Belokobylskij and Kula (2012: 6) the following parameters characterize specimens of Braconidae as brachypterous: fore wing length greater than 0.25 mesosoma length but less than metasoma length, venation distinct but incomplete, tegula present and usually not reduced in size. Females of Keylimepie peckorum have fore wings just slightly longer than metasoma length (1.1–1.3×), but they do not actually extend beyond T4, i.e., well before the metasoma apex (Fig.
The phenomenon of wing size reduction in Braconidae has been related to penetration of parasitoids into the microhabitats of their hosts, temporal (seasonal) abundance of preferred hosts in limited space, or unknown causes (see Belokobylskij and Kula 2012). There may also be a tendency for short wings to evolve more on islands and in relatively harsh environments such as arid, arctic or high mountains where it is windy, hosts may be distributed in an exceedingly patchy manner, and/or due to the need to conserve energy (
Because of the geographic location of the Florida Keys, its biota includes species that a) arrived naturally from nearby mainland Florida, b) arrived naturally from the nearby West Indies, c) were introduced by humans, or d) are endemic (
Conservation efforts in the Florida Keys are mainly focused on marine life, plants such as the Key tree cactus (Pilosocereus robinii), and charismatic fauna such as the Key deer (Odocoileus virginianus clavium) and the Key Largo woodrat (Neotoma floridana smalli). Among insects butterflies and ants have also been studied from a conservation perspective (
A recent assessment on vulnerability of 300 species in Florida found a number of species from the Keys as of high priority (
We believe that Keylimepie peckorum fits the above scenario perfectly. It is not only the first new genus of Microgastrinae discovered in North America in more than 30 years, but it also represents a distinctive and arguably unique lineage among microgastrine parasitoid wasps, and the species is likely to be endemic to the Florida Keys and Everglades areas. The poor ability to fly may also make K. peckorum less adaptable to changes in habitat distribution due to human disturbance, climate change, etc. Based on what is already known, it could easily be considered as a high priority species. However, the lack of basic biological information (host unknown) and the uncertainty of its current presence in the Keys (the only known specimens were collected 30 years ago) is a serious obstacle towards any conservation effort. This paper has only filled the first gap, giving a name to the species and summarizing what is known to date about it. More research is needed, including collecting of fresh specimens (to prove that the species is not extinct) as well as trying to find the host caterpillars of this amazing parasitoid wasp.
We are grateful to John Huber, Henri Goulet (