Major Evenhuis, 2005

Evenhuis, Neal L., 2005, A review of the genera comprising species of the genus Eurynogaster sensu Hardy & Kohn, 1964 in Hawai‘i (Diptera: Dolichopodidae), Zootaxa 1017, pp. 39-60 : 51-53

Genus Major Evenhuis , gen. n.

( Figs. 8, 12a, 17, 25)

Type species: Paraliancalus minor Parent, 1938 , by present designation.

Diagnosis: The genus is easily recognized among Hawaiian dolichopodids by its conspicuously large tarsal claws (present in both males and females) combined with the long, thin,

recurved and fused cerci of the hypopygium, and large unilobed surstyli without conspicuous setation ( Fig. 25).

Description: Male. Body length: 3.5–4.5 mm. Wing length: 3.5–5.2 mm. Head. Generally shining metallic; face equal to distance between lateral edges of antennal sockets (cf. Fig. 1), parallel to clypeus; ventral margin of clypeus ending just above lower margin of eyes; palpi extending below eyes. Antennae with first flagellomere long, rounded apically, length ca. 3 x width; arista dorsal, bare, with micropubescence only at tip. Ocellars large, 1/4–1/3 head height; verticals absent. Thorax. Generally shining metallic dorsally, pleura subpollinose. Chaetotaxy as follows: 5 dc; 2 np; 1 ph; 1 pa; 1 sc; 2 sa; ac absent. Legs. Coxae I–III predominantly bare, short fine hairs apically. All femora with ventral bristles, strongest on FII and FIII. Tibia II and TIII with a few strong setae. Claws large ( Fig. 12a). Wing ( Fig. 17). With dense brown microtrichia giving wing a smoky brown appearance. CuAx ratio about 2. Abdomen. Shining metallic dorsally, pollinose on sternites. Segments I–V subequal in length; abdominal hairs generally short, longer on posterior margins of tergites, sternite IV bilobed to accommodate terminalia. Hypopygium ( Fig. 25). Ovate­elliptical; extending forward to posterior margin of 4th segment; cerci fused basally, sclerotized along entire length, recurved on apical 1/4, tip slightly swollen with dark sclerotization; surstylus unilobed, robust, without strong setation; basiventral epandrial lobe long, thin, with apical setae; hypandrium broad basally, then tapering to recurved pointed apex.

Female. As in male except for genitalic features; legs normal, without modifications.

Discussion: Only one species, Major minor (Parent) , is known. Parent (1938) originally described the species in Paraliancalus with which it does have certain similarities; however, the cerci are differently modified and the claws are extremely large (relatively normal sized in Paraliancalus ). He later ( Parent 1940) transferred the species to Eurynogaster with the following caveat: “J’ai été amené à ranger dans le genre Eurynogaster , la forme que j’avais décrite sous le nom Paraliancalus minor , bien que cette dernière espèce soit un peu aberrante dans ce genre.” Parent was correct in his assumption of it being an aberrant species in that genus; yet subsequent workers kept the species in Eurynogaster , possibly without having properly studied the male genitalia. Examination in this study confirms that the species does not fit the generic limits of Eurynogaster or any other known genus and is here transferred to the new genus Major .

Williams (1940) conducted biological observations on the species and found it commonly at seeps near Mt. Ka‘ala in the Wai‘anae range on O‘ahu. Its large claws are similar to the size found in species of the Marquesan sympycnine genus Humongochela Evenhuis ( Evenhuis 2004) , which are also found clinging to wet vertical seeps; and in Sigmatineurum , many species of which can also be found clinging to the wet vertical faces of boulders in the middle of fast moving streams. Williams (1940) related the following concerning his observations near Gunnera Springs near Mt. Ka‘ala: “[The genus] appears to favor the steep banks with patchy lights (water, etc., reflections)” ... Though brilliant, it is not conspicuous as it rests head upwards and high on its legs on a dripping wet bank.”

Included species: Major minor (Parent) *, comb. n.

Etymology: The genus­group name derives from the Latin major (= large); referring to the extremely large tarsal claws of species in this genus used for clinging to steep, wet, rocky seeps.