Sympherobius sp.

ENGEL, MICHAEL S. & GRIMALDI, DAVID A., 2007, The Neuropterid Fauna of Dominican and Mexican Amber (Neuropterida: Megaloptera, Neuroptera), American Museum Novitates 3587, pp. 1-60 : 22-24

Sympherobius sp.

DIAGNOSIS: The species is unique within the genus for the plesiomorphic retention of crossvein 4m-cu (absent in all Recent Sympherobius ), the presence of the distal radial crossvein (r 2+3 –r 4+5), and the unpatterened wings.

DESCRIPTION: Total body length 2.52 mm; forewing length 2.53 mm. Integument light brown; flagellum concolorous; 42 flagellomeres (observed for left antenna; right antenna damaged slightly beyond midpoint). Wing membrane hyaline; longitudinal veins and crossveins light brown. Forewing with proximal humeral trace strongly recurrent, trichosores present on humeral margin, humeral veinlets simple; costal space broad; Sc widely separated from R along its entire length; 2sc-r absent; two prestigmal radial sectors, posteri- or radial sector with a single branch proximad midpoint; four interradial crossveins comprising outer gradate series, outer gradates alternating in position (not stepped in a single direction); proximal radial crossvein (r 1+2+3 – r 4+5) absent; distal radial crossvein (r 2+3 –r 4+5) present; two r-m crossveins (i.e., 2r-m and 3rm), 4r-m absent; 3im present, 4im absent; 4mcu present; CuA branching distad 2m-cu, next branch confluent with 3m-cu; CuP simple, not forked proximad 2cua-cup. Setae generally pale brown, minute, and sparse except on wings setae more elongate and numerous and at abdominal apex setae elongate. Terminalia not visible.

MATERIAL: Private collection of J.M. Pérez, Miocene amber of the Dominican Republic.

COMMENTS: Owing to the uncertain final repository of the only known specimen (which resides in the collection of a dealer who intends to sell it), we have avoided describing this species as new until such time as new material is discovered or the specimen is deposited in a more permanent collection, preferably that of a museum.

The fossil can be easily assigned to the Sympherobiinae based on the following combination of characters in the forewing: proximal humeral trace recurrent (strongly so in the fossil), trichosores present on humeral margin, broad costal space, 2sc-r absent, two prestigmal radial sectors, posterior radial sector branching proximad its midpoint, 4r-m absent, and CuP simple, not forked proximad 2cua-cup. Within the sympherobiines, the fossil is apparently sister to living Sympherobius and is placed basal within this genus. Although the fossil lacks one of the four synapomorphies of the genus (i.e., apomorphic loss of forewing 4m-cu), we have placed the species here rather than erect a monotypic genus sister to Sympherobius based upon a single character (moreover, a single plesiomorphic character!). Both Nomerobius and Neosympherobius plesiomorphically retain 4m-cu (as well as 4im in the forewing, which is absent in the fossil). The fossil can be immediately excluded from both of these genera as follows: absence of 4im in forewing (present in Nomerobius and Neosympherobius ), presence of outer gradates (absent in Neosympherobius ), four outer gradates alternating in position (stepped in a single direction in Nomerobius ). Until a cladistic study of the world Sympherobius fauna is completed, it is not possible to definitively determine whether the fossil is indeed sister to the remainder of the genus, but the loss of 4m-cu would apparently be a good synapomorphy of Recent Sympherobius , as it was originally hypothesized by Oswald (1993). However, note that the fossil is not without some similarity to the principally eastern United States species S. amiculus (Fitch) and S. umbratus (Banks) , all of which are unique among Sympherobius for the presence of a distal radial crossvein, this being either a plesiomorphy or the secondary reacquisition of this feature (as hypothesized by Oswald [1988] for the two living species). It is certainly plausible that this character is a plesiomorphy for the fossil and a synapomorphy for the two living species rather than a character uniting all three taxa (i.e., if the fossil is indeed basal while S. amiculus and S. umbratus are more derived, as other characters would suggest). Such determination will await a cladistic analysis for all Sympherobius .

FAMILY CHRYSOPIDAE SCHNEIDER

Larvae are active, generalist predators. Some species rapidly cover themselves with debris (held in place by long, curved setae), which may include remains of their prey. Most species are arboreal. Adults are commonly predators although some lineages are specialized to feed on honeydew and harbor symbiotic yeasts, presumably to facilitate digestion.

Although a veritable plethora of chrysopid fossils have been previously described or reported on (e.g., Adams, 1967; Carpenter, 1935; Cockerell, 1909, 1914; Handlirsch, 1908; Handschin, 1937; Makarkin, 1991, 1994; Martins-Neto and Vulcano, 1989c; Martynov, 1927; Nel and Henrotay, 1994; Nel and Séméria, 1986; Panfilov, 1980; Peñalver et al., 1995; Ren and Guo, 1996; Schlüter, 1982; Scudder, 1890; Séméria and Nel, 1990; Statz, 1936; Willmann and Brooks, 1991), none has been discovered in amber until now. Fossils recognizable as Chrysopidae (albeit of an extinct, plesiomorphic subfamily) are known as far back as the Late Jurassic. The wing terminology of Brooks and Barnard (1990) is used for the three chrysopine fossils described herein to facilitate comparison with their monograph on the world fauna of living Chrysopidae .

The genera Chrysopa and Chrysoperla are separated mostly by behavior and minutiae of the terminalia. However, there are some minor differences of wing venation that distinguish these two genera. Both of the fossils considered below fall within the Chrysopa class of wing venation and are therefore considered to be of this genus.