Liriomyza phloxiphaga, Eiseman & Lonsdale, 2019

Eiseman, Charles S. & Lonsdale, Owen, 2019, New State and Host Records for Agromyzidae (Diptera) in the United States, with the Description of Ten New Species, Zootaxa 4661 (1), pp. 1-39 : 14-15

publication ID	https://doi.org/ 10.11646/zootaxa.4661.1.1
publication LSID	lsid:zoobank.org:pub:8DF7EC6E-ECF2-4819-979E-0E26BDDC2B21
persistent identifier	https://treatment.plazi.org/id/2A7A4D79-3520-FFA1-14C5-FF3BFB3FFD4F
treatment provided by	Plazi
scientific name	Liriomyza phloxiphaga
status	sp. nov.

Treatment

Liriomyza phloxiphaga spec. nov.

( Figs. 18, 19 View FIGURES 14–26 , 48 View FIGURES 46–56 , 101–104 View FIGURES 101–104 )

Holotype. MASSACHUSETTS: Hampshire Co., Pelham, 88 Arnold Rd. , 11.vii.2017, em. by 31.vii.2017, C.S. Eiseman, ex Phlox paniculata , #CSE4016, CNC939692 View Materials (1³).

Etymology. The specific epithet refers to the host plant, Phlox L. (combined with Gr. phago, to eat).

Host. Polemoniaceae : Phlox paniculata L. We have found similar leaf mines on P. divaricata L.

Leaf mine. ( Fig. 48 View FIGURES 46–56 ) Narrow, entirely linear; greenish, with the dark brown frass partly in minute scattered grains and partly in fine strips along the sides. The larva exits the upper-surface mine through a crescent-shaped slit in the lower epidermis. Mines are inconspicuous until they are vacated and turn whitish.

Puparium. ( Fig. 19 View FIGURES 14–26 ) Yellow; formed outside the mine.

Distribution. USA: MA. We have found similar leaf mines in KS, MO, OH, and TN (see Comments).

Adult description. Wing length 1.9 mm (³). Female unknown. Length of ultimate section of vein CuA 1 divid- ed by penultimate section: 3.1. Eye height divided by gena height: 5.6. First flagellomere small, rounded. Clypeus glossy with medial bridge upcurved and visible anteriorly. Thorax glossy.

Chaetotaxy: Two ors, two ori on left side and three on right; anterior one or two ori slightly shorter. Postvertical and ocellar setae subequal to ors. Four dorsocentral setae, decreasing in length anteriorly. Acrostichal seta absent. Acrostichal setulae in four scattered rows.

Coloration: ( Fig. 18 View FIGURES 14–26 ) Setae black. Head mostly light yellow with slight orange tint; ocellar tubercle within dark brown spot that expands to vertex where it is confluent with dark marking in posterolateral corner of frons that encloses base of both vertical setae; orbital plate to level of posterior ori with narrow dark brown line along outer margin, medially with faint brownish mottling; back of head and clypeus dark brown. Notum dark brown with complete lateral yellow stripe that is brownish postsuturally and whitish medially on notopleuron; lateral corner of scutellum dark brown. Mediotergite dark brown, anatergite slightly paler with posterodorsal corner yellowish, katatergite brown with posteroventral corner darker. Anepisternum yellow with large floating oblique anteroventral brown spot that narrows posteriorly, and with narrow brown line on posteromedial margin; anepimeron with extensive brown markings; katepisternum dark brown with dorsal margin (not including base of seta) yellow; meron dark brown with dorsal margin yellow. Calypter margin and hairs brown, with hairs half as long as those typically seen in genus. Legs mostly light yellow; fore coxa brown on basal third of dorsolateral margin, mid and hind coxae brown; apical margin of mid and hind femora very narrowly dark brown; tibiae brown dorsally, faintly brownish laterally and yellow ventrally, being palest on fore leg and darkest on hind; tarsi with distal three segments becoming browner to apex. Abdomen dark brown.

Genitalia: ( Figs. 101–104 View FIGURES 101–104 ) Epandrium with large spine produced from posteroventral margin; inner surface with partially differentiated sclerotized bar with inner-posterior spine. Surstylus dark, narrow, curved inwards and with one apical spine. Cercus narrow. Phallophorus short and cylindrical. Basiphallus nearly symmetrical, with one pair of short, narrow dorsomedial processes attached to broad apical sclerotized plate that extends laterally to fuse to sides of broad, lightly sclerotized hypophallus; hypophallus with very long, curved, pigmented distomedial flagellum. Paraphallus absent. Mesophallus dark, three times longer than wide, slightly expanded apically (viewed ventrally); one pair of flat anterodorsal extensions fused to distiphallus, which is suspended from mesophallus; mesophallus and distiphallus with ventral suture that widens on distiphallus. Distiphallus pigmented, not much longer than high, as long as wide, narrowed basally and cup-shaped; seen ventrally, with several ring-like bands and wrinkles along surface; seen laterally, with two strong dorsal folds; distal margin of cup embedded with minute sclerotized balls laterally and dorsally. Ejaculatory apodeme with pale stem and large sclerotized blade with distal and medial striations; base not much wider than stem; sperm pump with irregular transverse sclerotized base.

Comments. Liriomyza phloxiphaga can be differentiated from many congeners by having a glossy notum with four rows of acrostichal setulae, a clypeus that is glossy and upcurved anteriorly, a strong dark spot in the posterolateral corner of the frons to the level of the inner vertical that extends anteriorly as a thin line along the eye to the level of the ori that is accompanied by some very faint additional brown mottling medially on the orbital plate, a yellow anepisternum with a large anteroventral spot, a katepisternum that is only yellow dorsally above the level of the seta, a dark distal line at the apex of the mid and hind femora, and ventrally yellow tibiae.

Similar to other members of the Liriomyza taraxaci group of species to which it belongs, the surstylus is more darkly pigmented, the posteroventral spine on the epandrium is produced, the inner-distal margin of the epandrium has a dark bar with a posterior spine, the paraphallus is reduced (here perhaps fused to the lateral margin of the enlarged hypophallus), the mesophallus is dark and cylindrical and the distiphallus is small and cup-shaped. Unlike other group members, however, L. phloxiphaga has a much broader and more sclerotized hypophallus with a larger, darker flagellate process, the mesophallus is three times longer than wide with the basal 2/3 slightly compressed laterally, there is a strong dorsal plate connecting the mesophallus and distiphallus, and the distiphallus is unique. The key in Lonsdale (2017) will identify L. phloxiphaga as one member of this species group— L. lathryi Sehgal—al-though the terminal couplet does not match precisely.

No species of Phlox is native to New England (where the holotype of L. phloxiphaga was reared) with the exception of P. pilosa L., which is found only in southern Connecticut ( Haines 2011). Phlox paniculata is a common garden plant north into eastern Canada, and its cultivation has presumably allowed this fly to expand its range. We have found likely mines of L. phloxiphaga on P. paniculata in Tennessee, and mines on P. divaricata (often with the frass in more distinct strips than is typical on P. paniculata ) in Kansas, Missouri, and Ohio. With the possible exception of L. sativae Blanchard , which Spencer (1990) stated has “colonized” Phlox in Arkansas, this is the first rearing of any agromyzid from Polemoniaceae in North America. Two other polyphagous species that occur on this continent, L. huidobrensis (Blanchard) and L. trifolii (Burgess) , are recorded from Phlox elsewhere.