Eosalpingogaster and Salpingogaster are readily distinguished from all other syrphine groups by the presence of distinct black spinose bristles on the metafemur combined with the petiolate abdomen and sinuate vein R4+5. Both genera have petiolate abdomens, but Salpingogaster is distinguished from Eosalpingogaster by the much more greatly sinuate vein R4+5; other syrphines with sinuate vein R4+5 have oval abdomens. Eosalpingogaster has 1st tergum not produced into a spur, vein R4+5 only slightly sinuate and occipital cilia in 3–4 rows dorsally. In contrast, Salpingogaster has 1st tergum produced laterally into a strong spur and occipital cilia reduced to a single row dorsally.
Species only known from Venezuela, very distinct without any yellow marking on abdomen, except first tergum yellow on very basolateral corners. Male and female with different wing pattern as described (Mengual & Thompson 2011).
Holotype and paratypes were found preying on Dactylopius sp. Paratype from Falcón was found feeding on Aspidiotus destructor Signoret on Cocos nucifera L., and the male paratype from Boquerón was reared from a larva feeding on Coccus viridis on Citrus sinensis (L.) Osbeck (Mengual & Thompson 2011).
Mengual, X. and Thompson, F.C. (2011). Carmine cochineal killers: the flower fly genus Eosalpingogaster Hull (Diptera: Syrphidae) revised. Systematic Entomology 36, 713–731. doi: 10.1111/j.1365-3113.2011.00588.x
From original description (Mengual & Thompson 2011).
MALE.
Head. Face with facial tubercle, yellow with medial broad dark vitta, yellow pilose, white pollinose laterally; gena dark brown; lunule dark brown; holoptic; frontal triangle yellow with a medial dark brown joining facial vitta ventrally; vertical triangle black; antenna light brown; occiput black, silver pollinose, withish-yellow pilose on ventral two third, golden pilose dorsally with some black pile dorsolaterally.
Thorax. Scutum black with dorsomedial broad white polli- nose vitta; postpronotum yellow; notopleuron mostly yellow, brown laterally. Pleuron mostly brown, except posterior anepisternum with yellow vitta and katepisternum with dorsal yellow macula. Wing. Wing membrane mostly hyaline, dark brown in basal costal cell, subcostal cell (sc), stigma and area around furcation of RS; apically microtrichose, cells CuP, CuA1, DM, R4+5 and R2+3 bare basally, cell R1 bare except apically and medially in the brown area, cells BM and R entirely bare; second costal cell mostly bare, microtrichose on apical quarter. Alula bare. Legs. Entirely black except tibiae yellow on basal two fifths and femora yellow very apically.
Abdomen. Strongly petiolate, dorsum black, except first tergum yellow basolaterally, black pilose; sterna black.
Female. Similar to male except for normal sexual dimor- phism and as follows: abdomen black with bluish metallic iridescence; second costal cell dark, entirely microtrichose; cell R1 medially dark.
GenBank accession number for this species are: protein-coding COI gene (HQ845759), rRNA 28S gene (HQ845762) and 18S gene (HQ845767).
Length (5): body, 10.9–13.0 (12.1) mm; wing, 8.0–9.5 (8.7) mm (Mengual and Thompson 2011).
Eosalpingogaster was proposed by Hull (1949: 299) as a new subgenus of Salpingogaster Schiner. Hull based his decision on the absence of a sharp hook on anterior corners of the first abdominal segment and on the slight curvature of vein R4+5. In contrast, the species of the genus Salpingogaster have the first abdominal tergum produced laterally into a strong spur and vein R4+5 strongly sinuate.
Eosalpingogaster larvae are predators of scale insects (Coccoidea), in contrast with the larvae of Salpingogaster, which feed on spittlebugs (family Cercopidae).
The results from the molecular analysis by Mengual (Mengual and Thompson 2011) resolved Eosalpingogaster and Salpingogaster in two different clades, independent of the method used to infer the phylogeny, and they considered Eosalpingogaster as a valid genus.
A similar result was obtained by Mengual et al. (2008, 2012).
Species only found in Venezuela (Mérida, Falcoón, Lara).
Eosalpingogaster is an important factor in the international trade of the cochineal for producing carminic acid. In countries where cochineal scales are used to produce carminic acid, such as Mexico, Guatemala or Argentina, or in countries where cochineal scales are used as biological control agents of cactus weeds (e.g. South Africa, Australia and Mauritius), Eosalpingogaster might be considered a pest and it could decrease populations of Dactylopius.
On the other hand, in countries where Dactylopius may be considered a pest because cacti are cultivated for fodder, for prickly pear production or to obtain raw materials for medicaments and cosmetics, the genus Eosalpingogaster might be considered a biological control agent because its larvae feed on Dactylopius species (Mengual & Thompson 2011).
unless otherwise stated