Phyllocnistis perseafolia Davis and Wagner

Davis, Donald R. & Wagner, David L., 2011, Biology and systematics of the New World Phyllocnistis Zeller leafminers of the avocado genus Persea (Lepidoptera, Gracillariidae), ZooKeys 97, pp. 39-73 : 52-54

Phyllocnistis perseafolia Davis and Wagner sp. n. Figs 2D3C4 A–B14A15D19A–E.

Diagnosis:

Phyllocnistis perseafolia is the largest of the Persea -feeding species: forewing lengths typically exceed 2.6 mm, with that of intact specimens often reaching lengths of 2.9 or more mm. The well-developed black apical dot distinguishes Phyllocnistis perseafolia from all but Phyllocnistis hyperpersea . The forewing is the palest of the four Phyllocnistis described here: the black scaling--in the subbasal and tornal areas, as well as that which edges the longitudinal and transverse fascia--is reduced relative to the other species described here. The transverse fascia is often interrupted through the center of the forewing because the arms are so strongly angled outward that they may not meet; likewise the longitudinal fascia frequently does not join the transverse fascia in persaefolia for the same reason.

Adult

(Fig. 2D): Length of forewing: 2.6-3.2 mm.

Head: Frons shiny white, smooth glabrous. Flagellomeres with faint orange luster above but becoming smoky toward apex. Labial palpus white, long, slender, subequal to height of head, slightly upcurved; basal segment subequal to segments 2 + 3.

Thorax:Scaling of patagia and tegulae damaged. Longitudinal fascia ending before transverse fascia; anterior side ill-defined with orange scales often reaching to costa, especially towards base of wing; lower side straight and clearly delineated; fuscous scales, if present, only along lower edge. Transverse fascia edged inwardly and outwardly with black scales; upper arm leaving costal margin at 30-35° angle, with distal reach curving toward apical dot; often interrupted through cell; arm of transverse fasciae from inner margin more strongly edged with black along outer edge; proximal edge of fascia where it leaves the inner margin vague, with faint dark scaling. Second costal fascia ill-defined, with little black scaling, sometimes conjoined with transverse fascia. Three costal and three apical strigulae modestly differentiated. Apical spot well developed. Black fringe scales about tornus reduced in extent, many replaced with smoky orange fringe scales; none raised appreciably above plane of wing. Legs essentially silvery white and unmarked with exception of faint orange luster to dorsal and outer surfaces foretibiae and foretarsi and distal tarsomeres sometimes with smoky overscaling.

Abdomen: Silvery white and unmarked.

Male Genitalia (Figs 19 A–C): Similar to Phyllocnistis hyperpersea , with approximately straight valva, except valva relatively shorter, ~ 1.6 × length of vinculum; basal apodemes of valva more widely divergent than in other species, with ventral apodeme approximately straight (Fig. 19B).

Female Genitalia (Figs 19 D–E): Similar to Phyllocnistis longipalpa ,with ductus bursae joining corpus bursae near caudal end; corpus bursae elongate-ovoid, enlarged, ~ 0.5 × length of elongate ductus bursae; ductus seminalis ~ 2.25 × length of corpus bursae.

Larva:

Not examined.

Larval Mine

(Figs 3C, 4 A–B): Similar to that described for Phyllocnistis subpersea . A long, slender, serpentine gallery, containing a dark, narrow, median frass trail, present on either the underside or upperside of the leaf, with pupation occurring in a slightly enlarged, elliptical chamber at the mine terminus along the leaf edge. Serpentine mines of possibly this species have also been observed by Francisco Posada on avocado fruit at the type locality.

Pupa

(Figs 14A-15D): Similar to Phyllocnistis hyperpersea except: Length of largest pupa 3.4 mm. Vertex similar to that of Phyllocnistis vitegenella Clemens in possessing single, large apical spine (tip of spine broken in all 3 pupae examined) with minutely serrated, low ridge descending laterally from spine (Figs 14 A–B). Abdomen with apices of greatly lengthened SD1 seta on A2-7 spatulate; mid-dorsal cluster of spines on abdominal terga 2-7 (Figs 14 C–D) with median series of low, strongly recurved spines relatively larger than in hyperpersea and fewer in number, arranged instead in 2 short columns as in subpersea in about 2 ranks; 3-4 smaller, scattered spines immediately caudad to larger, median spine rows; pair of slightly larger, strongly recurved spines immediately lateral to caudal end of median cluster and nearly contiguous to D1 seta; sternum A6 with spinules arranged in ~ 20 longitudinal ridge-like rows (Fig. 15D); A10 with pair of relatively large, stout, caudal processes directed mostly laterally (Figs 15 A–C) as in subpersea.

Host:

Persea americana Mill., variety Hass.

Type Material:

Holotype: ♂, COLOMBIA: Caldas Department, Villamaria, April 2008, Francisco Posada, reared from Avocado, Persea americana , variety Hass, slide USNM 34075 (USNM). Paratypes: COLOMBIA: Same locality and data as holotype: 9 ♂, slides USNM 34078, 8 ♀, slides USNM 34076, 34077, BOLD ID: RDOPO393-10, RDOPO394-10; 5 pupae, USNM slide 34072 (UNCM, USNM).

Parasitoids:

Unknown.

Flight Period:

Adults have emerged in April in Colombia.

Distribution:

Currently reported only from the type locality in the Department of Caldas, west-central Colombia, but probably widespread over northern South America wherever avocado is cultivated.

Etymology:

The specific name is derived from the generic plant name of its host, Persea and the Latin, folium (leaf), in reference to its leafmining habit. The specific epithet is a noun in the nominative singular.

Remarks:

All adults examined were received unpinned, unspread, and slightly damaged to the extent that we are uncertain of some scaling characters. The apex of the large frontal process was broken in all 3 pupae available for study. A fragment of one spine remaining in a vial with a pupa of perseafolia was observed to be slightly recurved, but not to the extent observed in pupae of the North American Phyllocnistis vitegenella . The spatulate apex of abdominal SD1 setae of perseafolia (Fig. 14F) is notable in being the broadest of the three species examined.

One other species of Phyllocnistis , Phyllocnistis aurilinea (auriinea [sic]) Zeller, has been described from Colombia ( Bogotá). However, that species mines the leaves of a distinctly different host in the family Ericaceae , " Uva camarona " ( Zeller 1877), (probably Macleania rupestris A. C. Smith, according to W. and J. De Prins 2011), Because larvae of Phyllocnistis and related gracillariids are known to be stenophagous, Phyllocnistis aurilinea is believed to represent a different species from Phyllocnistis perseafolia , whose larvae are leafminers in Lauraceae .