Helianthecis capitum Gagné, 2016

Gagné, Raymond J., 2016, Three new genera and three new species of Nearctic Lasiopteridi (Diptera: Cecidomyiidae: Cecidomyiinae) from Asteraceae and Caprifoliaceae, and the tribe Rhopalomyiini subsumed under Oligotrophini, Zootaxa 4158 (3), pp. 403-418 : 409

Helianthecis capitum Gagné , new species

Figs 4 , 7–18 .

Description. Adult: Wing ( Fig. 4 ) length: male 2.3–2.9 mm (n = 6, avg. = 2.6); female 2.3–2.7 mm (n=6, avg.=2.5). Head as in Fig. 7 , palpus 4-segmented, antennal flagellomeres as in Figs 8–9 . Anepimeron with 12–17 setae (n=10). Acropods as in Fig. 10 . Male terminalia and postabdomen as in Figs 11–13 . Female postabdomen as in Fig. 15 .

Pupa. Anterior segments as in Fig. 16 .

Larva, third instar: Length, 2.1–2.5 mm (n=10). Spatula and associated papillae as in Fig. 17 . Eighth and terminal abdominal segments as in Fig. 18 .

Material examined. HOLOTYPE, male, ex Helianthus petiolaris , 20.ix.1973, Wilbarger Co., Texas, C.E. Rogers . Paratypes: male, 3 females, pupa, 6 pupal exuviae, same data as holotype; female, H. petiolaris , 5.viii.1977, Ulysses, Kansas, C.E. Rogers ; 5 larvae, Helianthus sp., 11.x.1972, Munday, Texas, C.E. Rogers ; 5 larvae, Helianthus annuus , 4.x.1978, Bushland, Texas ; 3 males, female, H. annuus , 6 to 13.viii.1971, Fargo, North Dakota, K. Kamali, emerged 9 to 18.viii.1971 ; 2 males, 1 female, 1 pupa, H. grosseserratus , 30.vii to 23.viii.1979, West Okoboji , Dickinson Co., Iowa, B.W. Minor, emerged 5.viii to 23.viii.1979 .

Etymology. The name capitum , genitive plural of caput (Latin for head), refers to the species' niche in the flower heads of its hosts.

Distribution. The new species was collected in North Dakota, Iowa, Kansas and Texas from heads of Helianthus annuus L., H. grosseserratus M. Martens , and H. petiolaris Nutt.

Remarks. Larvae of this species from Helianthus annuus in Wilbarger Co. , Texas were first reported as Dasineura sp., and adults from Helianthus petiolaris , also in Wilbarger Co., were reported as Rhopalomyia sp. ( Rogers 1977). Rogers et al. (1979) later reported both those larvae and adults as Mayetiola sp. The determinations for both reports were provided by me and reflect my evolving concept for the taxonomic placement of this new gall midge. By the time of the report by Rogers et al. (1979), I had realized that the larvae and adults were the same species due to additional material I had seen from Texas and specimens obtained separately from North Dakota. The exact niche of or damage made by H. capitum is still uncertain. Rogers et al. (1979) stated that, “Although the larvae are thought to feed primarily in the corolla tubes, specimens from North Dakota were reared from floral ovaries.” Specimens were subsequently received from Iowa, reared from "galled inflorescences." That the adults were in all cases reared directly from inflorescences allows us to assume that pupation occurred in the heads, typical of species that live inside galled plant tissue.

Figures

FIGURES 4 – 6. Wings. 1, Helianthecis capitum. 2, Lonicerae russoi. 3, Chiosperma turgidum. Line = 1 mm.

FIGURES 7 – 14. Helianthecis capitum. 7, Head (frontal, flagella removed). 8, Male third flagellomere (ventral). 9, Female third flagellomere (ventral). 10, Acropod (lateral). 11, Male terminalia (lateral). 12, Same, one gonopod removed (dorsal). 13, Same (ventral). 14, Male sixth (on left) through eighth abdominal tergites.

FIGURES 15 – 18. Helianthecis capitum. 15, Female abdomen, sixth segment to cerci (dorsolateral), with details of eighth tergite, fused cerci and seventh sternite. 16, Pupal anterior parts (ventral). 17, Larval spatula and associated papillae. 18, Larval eighth and terminal segments (dorsal).