Atomacera josefernandezi Smith, 2013

Smith, David R., Janzen, Daniel H. & Hallwachs, Winnie, 2013, Food plants and life histories of sawflies of the families Argidae and Tenthredinidae (Hymenoptera) in Costa Rica, a supplement, Journal of Hymenoptera Research 35, pp. 17-31 : 17-20

Atomacera josefernandezi Smith sp. n. Figs 1-3 , 12 , 16

Description.

Female ( Figs 1-3 ). Length, 4.0 mm. Head black, labrum and mandible whitish. Antenna black with first and second antennomeres dark orange. Thorax black with pronotum, tegula, mesoprescutum, and mesonotal lateral lobes red; mesosternum dark orange. Legs mostly white; tarsi black, tibiae with apex black and spot of black near base, black more distinct on hind tibia. Abdomen black. Wings darkly infuscated, slightly lighter toward apex; veins and stigma black.

Head smooth and shining, without punctures or other sculpture. Antennal length 1.3 × head width. Lower interocular distance about 1.2 × eye height. Distances between eye and hind ocellus, between hind ocelli, and between hind ocellus and posterior margin of head as 1.0:1.2:0.5. Clypeus with shallow central emargination. Interantennal area rounded, without carina. Malar space about 1.3 × diameter of front ocellus. Postocellar area very short, almost non-existent, sloping downward just behind lateral ocelli; without lateral postocellar grooves. Forewing with 4 cubital cells, first cubital crossvein may be weak. Hind basitarsomere 0.9 × length of remaining tarsomeres combined. Sheath uniformly slender in dorsal view, straight above and rounded below in lateral view. Lancet ( Fig. 12 ) with serrulae moderately deep, with 1 or 2 anterior and 4-5 posterior subbasal teeth; annuli slightly curved in basal half, straighter in apical half; short hairs on annuli.

Male. Unknown.

Type material.

Holotype female, labeled "Voucher: D. H. Janzen & W. Hallwachs, DB: http://Janzen.sas.upenn.edu, Area de Conservación Guanacaste, Costa Rica, 11-SRNP-20098," "legs away for DNA" (USNM). Paratypes: Same data except for voucher numbers, 10-SRNP-22258 (♀), 10-SRNP-22259 (1 ♀), 10- SRNP-22260 (1 ♀), 10- SRNP-22263 (1 ♀), 10- SRNP-22264 (1 ♀), 10- SRNP-22265 (1 ♀), 10- SRNP-22266 (1 ♀), 10- SRNP-22269 (1 ♀), 10- SRNP-22272 (1 ♀), 10- SRNP-22273 (1 ♀), 10- SRNP-22274 (1 ♀), 11- SRNP-20096 (1 ♀), 11- SRNP-20099 (1 ♀), 11- SRNP-20104 (1 ♀), 11- SRNP-20105 (1 ♀), 11- SRNP-20109 (1 ♀), 11- SRNP-20110 (1 ♀) (USNM, INBio).

Etymology.

This species is named in honor of Jose Fernandez-Triana of Ottawa, Canada, in recognition of his outstanding efforts to describe and otherwise clarify the taxonomy of the many hundreds of species of microgastrine braconid wasps being reared by the same inventory that discovered this new sawfly.

Food plant and biology.

All specimens of Atomacera josefernandezi were found as tiny spun cocoons on the leaves of Hampea appendiculata (Donn. Sm.) Standl. ( Malvaceae ). While the cocoons of all other species of sawflies reared by the ACG inventory have been ovoid in shape, the cocoons of Atomacera josefernandezi are conspicuously squared off at both ends, making them look like small bricks ( Fig. 16 ). The larvae were not seen, and this may not be the food plant. However, we suspect that it is the food plant because the many cocoons were all on one individual of Hampea appendiculata and not scattered over other individual plants, and were accompanied by large areas of strongly skeletonized leaves. There were two sets, apparently broods, of wild-caught cocoons (2010 and 2011) in the same area on the same species of plant, again suggesting that this really is the food plant.

Remarks.

The combination of the following characters will distinguish Atomacera josefernandezi from other species of Atomacera : tegula, pronotum, and mesonotum (except mesoscutellum) red; mesosternum dark orange; tibiae mostly white with some black at base and apex; interantennal area rounded, without a carina; clypeus, supraclypeal area, and areas surrounding antennae smooth, shiny, without sculpture; very short postocellar area, lacking lateral furrows; and lancet ( Fig. 12 ) with distinct serrulae and short hairs on the annuli. With the red pronotum, tegula, and most of the mesonotum and mostly white tibiae, this species will run to couplet 10, Atomacera ebena Smith, in the key to Atomacera ( Smith 1992). Atomacera ebena is separated from Atomacera josefernandezi by the presence of a short interantennal carina, the clypeus, supraclypeal area, and interantennal area punctate, the postocellar area defined by lateral furrows, a red mesoscutellum, most of the hind tarsi white, and the lancet with very low serrulae and lacking annular hairs ( Fig. 13 ). This species is also similar to Atomacera nama Smith, but Atomacera nama has the legs black, metascutellum and metascutellum orange, and flatter serrulae on the lancet ( Smith 1992: fig. 113).

Atomacera josefernandezi DNA barcodes ( Janzen and Hallwachs 2011) are very distinctively different from all other species of Argidae and Tenthredinidae reared to date in ACG. However, it is noteworthy that the 2010 rearing consistently differed by what appears to be 1 basepair from the 2011 rearing, a very shallow split that needs to be analyzed with a larger sample size. All the specimens found within a year, to date, are likely to be sibs, and therefore in one sense we have DNA barcoded only two specimens (= two broods).

The New World genus Atomacera includes about 32 species, 30 of which are Neotropical and were keyed by Smith (1992). It occurs from Canada to Argentina. Only five species apart from the one recorded here have been associated with food plants. Atomacera pubicornis (Fabricius) from northern South America feeds on Ipomoea sp. ( Convolvulaceae ) ( Smith 1992), Atomacera petroa Smith has been reared from Miconia calvescens DC ( Melastomataceae ) in Costa Rica ( Badenes-Perez and Johnson 2007), and Atomacera raza (99-SRNP-4547), also reared by the ACG inventory ( Smith and Janzen 2003a), was feeding on leaves of Malvaviscus palmanus ( Malvaceae ). The Nearctic species Atomacera debilis Say feeds on Desmodium sp. ( Fabaceae ), and Atomacera decepta Rohwer feeds on Hibiscus sp. ( Malvaceae ) ( Smith 1969).

Figures

Figures 1 - 3. Atomacera josefernandezi. 1 Lateral 2 Dorsum of head and thorax 3 Face, front.

Figures 12 - 15. Lancets. 12 Atomacera josefernandezi 13 Atomacera ebena 14 Waldheimia lucianocapellii 15 Waldheimia fascipennis.

Figures 16 - 22. 16 Adult of Eriglenum tristum 17 Cocoon of Atomacera josefernandezi on leaf 18 Cocoon of Eriglenum tristum on leaf 19 cocoon of Scobina lepida 20 Larva of Scobina notaticollis 21, 22 Larvae of Waldheimia lucianocapellii.