Phyllocnistis subpersea 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 : 47-50

Phyllocnistis subpersea Davis and Wagner sp. n. Figs 2B3B5B8A13F17 A–E

Diagnosis:

Phyllocnistis subpersea is the phenotypicoutlier among the four Persea -feeding species that we treat here: the row of raised, broadened, black-tipped fringe scales along the tornal margin of the forewing is unique. The apical dot tends to be poorly developed. It is the only Persea feeder that consistently has a subbasal fuscous spot along the inner margin of the forewing ( Phyllocnistis hyperpersea sometimes has fuscous scales in the subbasal area of the forewing, but these do not form a spot but rather extend as a diffuse patch to the wing base). The hind tarsomeres (especially segments 2-3) often bear orange to fuscous scaling that is somewhat more pronounced than that of the species that follow. The ductus bursae is broadly joined to corpus bursae. The frontal process of the pupa consists of a pair of stout conical spines arising near the apex, and a single, more subapical, strongly curved spine from the upper frons (Figs 12 A–C).

Adult

(Fig. 2B): Length of forewing: 2.0 to 2.7 mm, although most measure between 2.4-2.6 mm.

Head: Frons shiny white, smooth glabrous, with subtle faint orange tints over vertex. Flagellomeres with faint orange luster above. Labial palpus white, short, roughened apically, length> height of eye; distal segment subequal to segment 2; segment 1 very short.

Thorax: Patagia and tegulae with stramineous to orange tints. Longitudinal fascia joining transverse fascia but weakened distad, edged with black scales above and below, with those below more consistently present distad. Transverse fascia leaves costal margin at 45° angle; lower arm where it leaves inner margin poorly defined, often fusing with diffuse subbasal patch of fuscous scales. Second costal fascia usually fusing with transverse fascia distally. Apical spot weakly developed, small, fuscous but not black in our material, composed of apices of a few to several scales. Apical strigulae vague and poorly differentiated. Black fringe scales about tornus broadened, conspicuously blackened apically, raised appreciably above plane of wing. Legs silvery white with exception of faint orange luster to dorsal and outer surfaces; foretibiae, foretarsi, and distal tarsomeres sometimes modestly darkened; hind tarsi with tarsomeres 2-4 with faint orange to fuscous tint.

Abdomen: Silvery white and unmarked.

Male Genitalia (Figs 17 A–C): Similar to Phyllocnistis hyperpersea except valva curved slightly dorsad; relatively shorter, ~ 1.6 × length of vinculum; basal apodeme of valva directed slightly caudad in repose.

Female Genitalia (Figs 17 D–E): Similar to Phyllocnistis hyperpersea except ductus bursae slightly shorter, ~ 2.2 × length of papillae anales and gradually enlarging to moderately slender, elliptical corpus bursae; ductus seminalis ~ 1.8 × length of corpus bursae.

Larva

(Figs 5B): Hypermetamorphic; early instars with highly modified, depressed body for sapfeeding. Final instar non-feeding, with all mouthparts reduced or absent except for functional spinneret.

Sapfeeding instar (Figs 5B, 8 A– 9D): Length of largest larva examined ~ 4.7 mm. Head prognathous, greatly depressed; primary setae either lost or reduced; two stemmata present laterally in a single, well-spaced horizontal alignment; antenna 3-segmented (Figs 9 A–B), second segment more slender than first, with 2 moderately stout and 1 short sensillae; third segment less that 1/3 the length of second, with single, apical sensillum basiconicum; labrum with well-developed, densely spinose, lateral lobes; anterior lateral margins rounded; posterior lateral margins extended caudally as triangular lobes; anterior ventral margin densely spinose. Labium also with well-developed lateral lobes; rugose band of cuticle extending across anterior ventral margin (Fig. 8D). Spinneret rudimentary, with narrow, acute extension of cuticle largely covering aperture (Fig. 8E). Legs and prolegs absent. Last (9+10th) segment of abdomen with pair of caudal processes ~ 0.75 × length of entire segment (Fig. 5B).

Spinning (last) instar (Figs 9E-11D): Body cylindrical, with all appendages and setae greatly reduced; integument finely tuberculate; length of largest larva examined ~ 4.1 mm. Head capsule weakly sclerotized, slightly broader than long; integument finely tuberculate; trophic region extended anteriorad as well-defined lobe; stemmata absent; antenna 2-segmented; first (basal) segment greatly reduced, nearly flush with head capsule, with 2 sensilla basiconica and 1 sensillum chaeticum; apical segment consisting of single sensillum basiconicum. Trophic lobe (Figs 10 A–E) with relatively broad but shortened spinneret with simple, terminal opening and rudimentary maxilla; maxilla flush with head capsule and represented by pair of moderately long and one very short sensilla chaetica. Thoracic legs absent, with only indistinct paired ventral callosities on T1-3. Abdomen without prolegs; paired ventral callosities present on A3-6 (Fig. 10F); seta SD1 much larger than other setae, relatively stout and short (Figs 11 A–B); A10 truncate, without caudal lobes or callosities (Fig. 11 C–D).

Larval Mine

(Figs 3B): Similar to that described for Phyllocnistis longipalpa . A long, slender, serpentine gallery, containing a dark, median frass trail, on the underside or occasionally the upperside of the leaf, with pupation occurring in a slightly enlarged, elliptical chamber at the mine terminus along a leaf edge. The egg is deposited away from the midrib, usually on the lower side of the leaf. Mine width increases from ~ 0.3 mm broad to a maximum width of ~ 2-2.5 mm; width of the frass trail is usually about half the mine width.

Pupa

(Figs 12 A– 13F): Similar to Phyllocnistis hyperpersea except: length of largest pupa 3.2 mm. Vertex with pair of stout conical, spines arising near apex, and single, slender, more subapical, strongly recurved spine from upper frons (Figs 12 A–C). Abdomen with 6 pairs of small, sclerotized, oval, median pits near anterior margins of terga 2-7; each sclerotized pit giving rise to 2 columns of low, strongly recurved spines, relatively larger than in hyperpersea and fewer in number, arranged in about 1-3 ranks (Figs 12 D–E); pair of slightly larger, strongly recurved spines immediately lateral to caudal end of median cluster and nearly contiguous to seta D1; A2-7 with SD1 setae greatly lengthened, apices spatulate (Fig. 13A); sternum A6 with spinules evenly scattered over surface as in hyperpersea (Fig. 13D); A10 with pair of relatively large, stout, caudal processes directed mostly laterally (Figs 13 E–F).

Host:

Persea borbonia (L.) Spreng.

Type Material:

Holotype: ♂, USA: FLORIDA: Dade Co: Everglades National Park, Long Pine Key, 26°24'N, 80°41'W, mine 21 Feb 1992, emerged 28 Feb 1992, D. and S. Davis, DRD 1061, host: Persea borbonia , (USNM). Paratypes: USA: FLORIDA: Dade Co: Everglades National Park: Long Pine Key, 26°24'N, 80°41'W, mines 21 Feb 1992, D. and S. Davis, DRD 1061, host: Persea borbonia , 1 ♀ emerged 22 Feb 1992, BOLD ID: RDOPO391-09, 1♂ emerged 26 Feb 1992, USNM slide 31632; 1♂ emerged 28 Feb 1992; 1♂ emerged 1 Mar 1992, USNM slide 31634; 2♂, 2♀ emerged 3 Mar 1992, 1♂, BOLD ID: RDOPO388-09, 2♀ emerged 6 Mar 1992, 1♀ emerged 10 Mar 1992 (USNM). Pa-hay-okee Overlook, 26°27'N, 80°47'W: mines 16 Apr 1995, D., M., and S. Davis, DRD 1624.1, host: Persea borbonia : 2♂, 4♀ emerged 28 Apr 1995, BOLD ID: RDOPO389-09. Monroe Co: Big Cypress National Preserve, Loop Road near Tamarind Hammock, 26°27'N, 80°31'30"W, mines 13 Mar 1991, D. L. Wagner and D. R. Davis, DLW Lot: 91C139, host: Persea borbonia : 8♂, 9♀, 2 unsexed emerged 15-25 Mar 1991 (UCMS); mines 21 Nov 1991, D. L. Wagner and D. R. Davis, DLW Lot: 91L35, host: Persea borbonia : 4♂, 8♀, 4 unsexed, emerged 25 Nov-4 Dec 1991 (UCMS); mines 22 Feb 1994, D. Davis, DRD 1490, host: Persea borbonia : 1♀ emerged 7 Mar 1994, BOLD ID: RDOPO392-09, 1♂ emerged 8 Mar 1994; 3♂, 2♀ emerged 4 Mar 1994; mines 25 Mar 1994, T. Dickel, DRD 1490.1, host: Persea borbonia : 2♀, emerged 4 Apr 1994, (USNM). Loop Road, Tamarind Hammock, 25°27'N, 81°16'W: 11 Apr 1995, D., M., and S. Davis, DRD 1624, host: Persea borbonia , 2 ♂, emerged 11 Apr, 1995, BOLD ID: RDOPO390-09 (USNM).

Parasitoids: Hymenoptera : Eulophidae : Cirrospilus sp., Galeopsomyia sp., Horismenus sp.

FlightPeriod: Adults (from recently collected mines) have emerged from February 22 to April 11 in Florida.

Distribution: At least Dade and Monroe Counties, Florida. We have found mines of what appear to be this species on Persea borbonia as far north as the Green Swamp in coastal South Carolina.

Etymology: The specific name is derived from the Greek, sub (under) and the generic plant name of its host, Persea , in reference to the characteristic leafmining habit of the larva usually on the underside of the leaf. The specific epithet is a noun in the nominative singular.