Phyllocnistis hyperpersea 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 : 42-46

Phyllocnistis hyperpersea Davis and Wagner sp. n. Figs 2A3A5A6A7D16 A–E

Diagnosis:

Phyllocnistis hyperpersea is the smallest of the species treated here with FW lengths <2.3 mm. The short labial palpi (less than height of eye) and prominent black apical spot, taken together, distinguish hyperpersea from the other Persea -feeding Phyllocnistis . The second costal fascia is weakly developed and does not fuse with the transverse fascia as in other Phyllocnistis treated here. Hind tarsomere 3 is more likely to be black than that of the other species. The black fringe scales about the tornus are less conspicuous: fewer in number, narrower, and less blackened relative to those of Phyllocnistis subpersea with which it commonly co-occurs. The frontal process of the pupa extends forward as a relatively large, broadly triangular, acute spine (Figs 6 A–B).

Adult

(Fig. 2A): Length of forewing: 1.9-2.2 mm.

Head: Frons shiny white, smooth glabrous, with subtle faint orange tints over vertex. Flagellomeres with orange-fuscous luster above. Labial palpus white, reduced, length less than height of eye.

Thorax: Patagia and tegulae with silvery stramineous to orange tints. Forewing with longitudinal fascia usually ending before joining transverse fascia, thinly edged with black scales above and below except distad. Transverse fascia usually complete, leaving costal margin at 45° angle; usually more thickly edged with black scales along proximal side; distal side somewhat rounded with black, edge-scaling weakened medially. Second costal fascia poorly differentiated, not fusing with transverse fascia. Apical spot of black scales well developed. Costal and apical strigulae modestly differentiated, often only two of latter evident. Black fringe scales about tornus only modestly differentiated: few in number, not strongly raised, and not appreciably broadened. Dorsal and outer surfaces of foretibiae and foretarsi, and to lesser extent those of mesothoracic legs, with fuscous metallic orange; third tarsomere of hindleg often darkened; otherwise legs mostly silvery white and unmarked.

Abdomen: Silvery white and unmarked.

Male Genitalia (Figs 16 A–C): Uncus absent. Tegumen complex, consisting of narrow, sclerotized dorsal arch, continuing caudally as far as apex of valva as an elongate, mostly membranous, basally spinose cylinder which encloses anal tube. Vinculum well developed, ~ 0.5 × length of valva, U- to V-shaped with relatively narrow anterior end. Valva simple, relatively long, ~ 2.0 × length of vinculum, very slender and straight; broad at extreme base, then narrowing along middle, becoming slightly broader over apical third; apex of valva evenly rounded; basal apodeme of valva directed mesad at nearly right angle to valva. Transtilla arising from mesal base of valva as an elongate, acute process, and continuing mesally to articulate at midline with process from opposite valva. Aedeagus slender, weakly sclerotized, externally finely wrinkled cylinder ~ half length of valva; cornuti absent; phallobase greatly extended as membranous tube ~ 6 × length of aedeagus; terminal hood of phallobase abruptly inflated and curved at ~ right angle to phallobase.

Female Genitalia (Figs 16 D–E): Oviscapt greatly reduced; anterior and posterior apophyses of about equal lengths, very short, ~ 0.4 × length of papillae anales. Ostium bursae opening in membrane between sterna 7 and 8; ductus bursae completely membranous, slender, moderately long, ~ 2.7 × length of papillae anales and terminating near caudal third of corpus bursae; corpus bursae greatly enlarged, ~ 1.5 × length of ductus bursae; walls of corpus bursae membranous except for pair of approximately identical, fusiform signa, with each bearing single inward-projecting, acute, blade-like process; length of process ~ 0. 2 × length of signum; ductus seminalis extremely slender, elongate, ~ 1.3 × length of corpus bursae, arising from cephalic end of corpus bursae.

Larva:

Sapfeeding instar (Fig. 5A): Similar to Phyllocnistis subpersea except: length of largest larva examined ~ 4.4 mm; labrum well developed, with lateral margins evenly rounded, not produced caudally as in subpersea; caudal processes of last (9+10th) abdominal segment ~ half length of entire segment.

Last instar larva not examined, but probably similar to that of Phyllocnistis subpersea .

Larval Mine

(Fig. 3A): A long, slender, serpentine gallery, with a relatively broad, dark brownish, median frass trail, almost always located on the upper (adaxial) side of the leaf (only 1 under (abaxial) side mine found). The egg is deposited on the upper leaf surface away from the midrib. Mine begins on one side of the blade, but after much of one side is consumed, crosses over near the leaf apex to the other side. The median frass line is unusually broad for a species of Phyllocnistis , resembling more that of the Chilean genus Prophyllocnistis ( Davis 1994). As previously noted ( Davis 1994), the mines of hyperpersea are also similar in general morphology to early Cenomanian phyllocnistine leafmines ( Labandeira et al. 1994). Pupation occurs in the lamina, away from the leaf edge (~ 5-7 mm in diameter) in a circular nidus, similar to that fashioned by Prophyllocnistis . The serpentine portion of the mine begins as a narrow tract ~ 0.3 mm wide and gradually enlarges before the pupation chamber to a width of ~ 2-2.5 mm. The median frass line is ¼ of the mine width in the early instars and gradually broadens to more than half the mine width.

Pupa (Figs 6 A– 7D): Length of largest pupa 2.8 mm, maximum diameter 0.7 mm. Vertex with relatively large, broadly triangular, acute frontal process (cocoon-cutter) similar to that of Metriochroa psychotriella Busck, but with base constricted slightly on each side (Fig. 6A); lower frons with 2 pairs of short frontal setae. Antenna long and straight, extending almost to 7th abdominal segment (A7); forewing extending almost to A6. Abdominal setae generally short except for greatly lengthened SD1 on A2-7; apex of SD1 on A2-7 slightly enlarged, but not spatulate; abdomen with 6 mid-dorsal pairs of spine clusters (Figs 6 C–D) beginning near anterior margins of terga 2-7; each cluster with series of similar, low, strongly recurved spines arranged in 4 irregular columns of about 4-6 ranks; pair of much larger, strongly recurved spines immediately lateral to central cluster and adjacent to seta D1 on A4-7; sternum A6 with spinules evenly scattered over surface (Fig. 6F); A10 with pair of relatively large, stout, caudal projections arising laterally and directed ventrally (Figs 7 A–D).

Host: Persea americana Mill., variety Blair, Persea borbonia (L.) Spreng.

TypeMaterial: Holotype: ♂, USA: FLORIDA: Dade Co: Everglades National Park, Pa-hay-okee Overlook, 26°27'N, 80°47'W, 24 Nov 1991, emerged 2 Dec 1991, D. Davis, DRD 1020.1, host: Persea borbonia , USNM slide 316 35 (USNM). Paratypes: USA: FLORIDA: Dade Co: Everglades National Park, Pa-hay-okee Overlook, 26°27'N, 80°47'W, mine 24 Jun 1990, DRD 724, host: Persea borbonia : 1♀ emerged 26 Jun 1990, USNM slide 31637; mines 25 Nov 1991, D. L. Wagner and D. R. Davis, DLW Lot: 91L121, host: Persea borbonia : 4♂, 2♀ emerged 27 Nov to 4 Dec 1991 (UCMS); mines 16 Apr 1995, D. Davis, DRD 1626.1, host: Persea borbonia : 7♂, 2♀ emerged 26 Apr 1995, BOLD ID: RDOPO396-09, 2♂ emerged 27 Apr 1995, 3♂, 2♀ emerged 28 Apr 1995, DRD 724, BOLD ID: RDOPO395-09, host: Persea borbonia (BMNH, NMNH). Dade Co: Everglades National Park, Long Pine Key, 26°24'N, 80°41'W, mines 21 Feb 1992, D. and S. Davis, DRD 1060, host: Persea borbonia : 1♀, emerged 27 Feb 1992, slide USNM 31636 (USNM). Homestead: 1♂, 1♀ 1 Sep 1993, R. E. Duncan, J. E. Pena, M. Biondo, host: Persea americana , (USNM); 1♂, 1 May 2008, J. E. Pena, 08-2811, 4 upperside leafmines, 2 pupae, host: avocado (FSCA). Highlands Co: Archbold Biological Station, 11 km S. Lake Placid: 8 leafmines, 14 Jun 1992, DRD 1097, host: Persea borbonia (USNM); Highland Hammock State Park: 7 leafmines, 15 Jun 1992, DRD 1097.1, host: Persea borbonia (USNM). Liberty Co: Appalachicola National Forest: 2 leafmines, 18 Jun 1992, DRD 1097.2, host: Persea borbonia (USNM). 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: 91C138, host: Persea borbonia : 1♀ emerged 18 Mar 1991 (UCMS); mines 22 Feb 1994, T. Dickel, DRD 1489, host: Persea borbonia : 1♂, 1♀ emerged 27 Feb 1994, 4♂, 2♀ emerged 4 Mar 1994, 1♂ emerged 7 Mar 1994, 1♂ emerged 8 Mar 1994 (USNM); 1 km W. Tamarind Hammock, 29 April 1992, T. Dickel, DRD 1088, host: Persea borbonia : 28 leaf mines, 1♂ emerged 7 May 1992, 1♂, 5♀ emerged 10-11 May 1992, 1♂ emerged 14 May 1992, (USNM); DRD 1020, 5 leafmines, 21 Nov 1991, D. Davis, host: Persea borbonia ;DRD 1060.1, host: Persea borbonia , 17 Feb 1992, D. and S. Davis: 1♂ emerged (DOA) 12 Mar 1992, 1♂ emerged 24 Mar 1992 (USNM). VIRGINIA: Nansemond Co: Dismal Swamp near Lake Drummond: 1 leafmine, 7-8 Jul 1962, D. Davis, DRD 187, host: Persea borbonia ; 1♂ with pupal exuvium, 8-10 June 1974, emerged 16 Jun 1974, D. and M. Davis, DRD 187.2, host: Persea borbonia ; Virginia Beach Co: Seashore State Park [First Landing State Park]: 7 leafmines, 9 July 1962, D. Davis, DRD 187, host: Persea borbonia (USNM).

Parasitoids: Hymenoptera : Eulophidae : Chrysocharis sp., Cirrospilus sp., Closterocerus sp., Elasmus sp., Horismenus sp., Sympiesis sp.

FlightPeriod: We have had adults issue from our mine collections from southern Florida during September, December, February, March, April, May, and June; and in southern Virginia during June.

Distribution: This species has been found from Nansemond and Virginia Beach Counties, Virginia, USA, south along the lowland Atlantic coastal region to the Florida Everglades. Adults in the collections of the USNM, from avocado, some with associated mines and collected at various localities in Honduras, may also represent this species. No pupae were available for study and attempts to barcode two specimens were unsuccessful. Mines with associated pupae of what appear to be hyperpersea have also been intercepted on shipments of avocado within the United States from unspecified localities in Mexico. Some fluctuation in the northern limits of this leafminer may have occurred in recent years. As late as June 8-11, 1974, DRD and Mignon Davis found mines of Phyllocnistis hypersersea common on leaves of Persea borbonia within First Landing State Park and Dismal Swamp, Virginia. On March 14, 1992 and during August 1993 no mines could be found at First Landing State Park (Dismal Swamp was not visited in 1993). These localities have not been surveyed for leafminers since 1993.

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