Anacampsis rhoifructella ( Clemens, 1861 )

Harrison, Terry L. & Berenbaum, May R., 2014, Anacampsis rhoifructella (Clemens): clarification of its identity and larval biology, and differentiation from a similar species, Anacampsis consonella (Zeller), revised status (Lepidoptera: Gelechiidae), Zootaxa 3794 (4), pp. 545-555 : 547-553

Anacampsis rhoifructella ( Clemens, 1861) , redescription

Gelechia rhoifructella Clemens 1861: 163

Diagnosis. In A. rhoifructella ( Fig. 1 A), the forewing from base to fascia appears pale brown with a few mediumbrown scales, and the medium-brown spots contrast markedly, whereas in A. consonella ( Fig. 2 A), this area of the wing is heavily suffused with medium-brown scales so that it appears darker with the spots less contrasting, as was mentioned by Chambers (1874) in the original description of Gelechia quadrimaculella . This difference, however, is slight and subtle, and it is readily obliterated in specimens with even moderate wear. Sight identification therefore should be based only on comparison of fully scaled specimens with pristine, accurately determined moths of both species. Characters that provide reliable differentiation between the two species include phenology, coloration of the mature larva, and differences in morphology of the vinculum, valva, gnathos and phallus in the male, and in the 8th abdominal tergite, base of ductus bursae and surface texture of corpus bursae in the female ( Table 1 ).

Adult ( Fig. 1 A). Head. Vertex, frons, and scaling on haustellum brown; labial palpus brown laterally, pale yellowish brown medially; antenna brown dorsally, yellowish brown ventrally, flagellum of alternating brown and yellow flagellomeres.

Thorax. Brown dorsally, shining pale brown ventrally; forewing length, 7.2–8.4 mm (n=14). Ground color light brown, with a few darker, medium-brown scales in basal two-thirds of wing; costal margin somewhat contrastingly ochreous; four small blotches of brown, darker than the ground color, two lying on CuP fold at 0.20 and 0.45, two lying anterad of the fold at 0.48 and 0.60; a narrow ochreous fascia at 0.80, expanded into small blotch at costa; at least four small, dark-brown spots on apical margin; fringe nearly concolorous with wing, with five alternating bands of pale and dark; hindwing uniformly brown, slightly darker than forewing; fringe slightly paler than wing, with three alternating bands of pale and dark along outer margin; legs brown laterally, coxae and medial surfaces of free segments pale shining brown; apices of basal four tarsomeres yellowish brown; dorsal margin of hind tibia with brushlike row of long yellow hairlike scales.

Abdomen. Brown dorsally, pale shining brown ventrally. Male genitalia ( Fig.5 ). Valva a straight simple lobe, broadening slightly from base to apex; vinculum asymmetrical, anterior part appearing as a loop in lateral aspect; left margin straight, with broad ventral keel in posterior half; right margin curved laterad at midlength, without ventral keel; a narrow diagonal keel from midlength of right margin to posterior end of left margin; juxta with posterior margin medially emarginate, slightly asymmetrical; gnathos a transverse band with small, pointed medial lobe bearing thornlike subapical projection; phallus narrow with acuminate apex, doubly curved in ventral view ( Fig. 5 G). Female genitalia ( Fig. 7 ). Papillae anales membranous, with setae of varying length; posterior apophysis slender, rodlike; anterior apophysis broadly triangular at base, narrowing to become rodlike; posterior margin of tergite 8 narrowest laterally, broadening gradually to widest point at midline; ostium bursae in transverse invagination, indistinct, with dense scales on either side; ductus bursae slender, not enlarged at base; corpus bursae ovate, smooth, sparsely covered with long microtrichia except in area of signum; signum a transverse band with one large and two or more small, thornlike projections on posterior margin; ductus seminalis originating near signum at anterior margin of unspined area of corpus; appendix bursae small, membranous.

Final-instar larva ( Fig. 1 B). Length, approximately 11 mm. Color reddish brown; head and prothoracic shield blackish, the latter sometimes with anterior margin yellowish brown; pinacula of most primary setae large, but brown and inconspicuous. Chaetotaxy as shown in Fig. 3 .

Pupa ( Fig. 4 ). Length, 8.5 mm; densely covered with short seta-like projections; texture at junctions of abdominal segments IV/V, V/VI, and VI/VII as shown; cremaster with eight hooklike cuticular projections at the caudal extremity.

Larval damage ( Fig. 1 C). Leaf of host plant sewn together at lateral margins to form a distinctive pouchlike shelter within which the larva feeds.

Phenology. Univoltine, overwintering as adult. Larvae have been collected in central Illinois from 14 April to 7 May, with adult emergence occurring from 5 May to 24 May. This phenology averages about three weeks earlier than A. consonella .

Food plants. Not known to have been reared from Rhus typhina since Clemens’ (1861) original record. We observed that in no-choice feeding trials, penultimate and ultimate-instar larvae of A. rhoifructella refused overwintered sumac fruits. Apparently monophagous on Viburnum prunifolium in central Illinois. Schaffner (1959) reported rearing A. rhoifructella from Viburnum dentatum Linnaeus in Massachusetts. This certainly seems possible; however, in Illinois, we have not observed either of the Anacampsis species to feed on V. dentatum , even at a site where it occurs in physical contact with V. prunifolium on which Anacampsis larvae of both species are seen to feed. In Canada, A. rhoifructella has been reared from Viburnum lentago Linnaeus in Ontario and from Viburnum sp. in Ontario and Nova Scotia (J.-F. Landry, in litt.). Occasional literature references (e.g., Coquillett 1883) to A. rhoifructella feeding on Populus Linnaeus (Salicaceae) refer to the native Anacampsis innocuella (Zeller) and/or a similar, Palearctic species, Anacampsis populella (Clerck) , which has been recorded in North America ( Hodges 1983). Both of these Salicaceae-feeding species are highly variable in appearance, and individuals of indistinctly marked phenotypes can somewhat resemble A. rhoifructella , but they usually can be differentiated in that, in A. innocuella and A. populella , the forewing area that is distal to the pale transverse line at 0.75 the length of the wing is partially or entirely darker than the general ground color, whereas in the two Viburnum -feeding species this area is concolorous with or paler than the rest of the wing.

Distribution. Type locality, Pennsylvania; known with certainty from Illinois; also confirmed from Quebec, Nova Scotia and Ontario (J.-F. Landry, in litt.). In published literature, “ Anacampsis rhoifructella ” has been reported from New Jersey ( Smith 1910), Massachusetts ( Schaffner 1959), New York, Missouri, California ( Walsingham 1882), and Texas ( Walsingham 1882, Tucker 1911), and from the Canadian provinces of New Brunswick, Manitoba ( Prentice 1965) and Quebec ( Handfield et al. 1997). The confusion of this species with the sympatric A. consonella renders it impossible to assess which of the two species is represented in any of these records without evaluation of the relevant specimens (if they have been preserved) on basis of the characters given in the present paper.

Material examined. Pennsylvania: holotype ( ANSP type #7345); abdomen, most of right antennal flagellum, and right wings missing; otherwise in good condition; labels: (1) Type Gelechia rhoifructella B. Clemens 7345; (2) Gelechia (Anacampsis) rhoifructella Type! Clemens AB 1902. Texas: syntype of Gelechia consonella ( MCZ type # MCZT _2982); abdomen and metathorax missing, otherwise in good condition; labels: (1) “Dallas Tex. Boll”; (2) “Zeller”; (3) “ Gelechia / (Tachyptilia) consonella Z.”; (4) “ Type 2982”; (5) “ Anacampsis rhoifructella Clem = consonella Zel. AB 1902”; (6) “ Anacampsis rhoifructella (Clemens) Det. T. Harrison, 2013 ”; Illinois, reared on Viburnum prunifolium : 7 miles south of Charleston: (2) 20-IV-1991, em. 5/ 12-V-1991; (1) 22-IV-1991, em. 10-V- 1991; (4) 1-V-1993, em. 18/ 19-V-1993; (2) 22-IV-1995, em. 9/ 12-V-1995; (1) 27-IV-2001, em. 11-V-2001; Charleston Lake View Park: (2) 7-V-1995, em. 23/ 24-V-1995; (4) 26-IV-1997, em. 15/ 17-V-1997; 3 miles east of Charleston: (7) 14-IV-2001, em. 7/ 12-V-2001.

Figures

FIGURE 3. Larva, Anacampsis rhoifructella. A, head, frontal and left-lateral aspects; B, right mandible, medial aspect; C-H, chaetotaxy of body segments, left-lateral aspect, all at same scale; C, T 1; D, T 2 - 3; E, A 1, 2, 7, 8, showing differences in the association of seta SD 1 with the spiracle; F, A 3 - 6; G, A 9; H, A 10.

FIGURE 4. Pupa, Anacampsis rhoifructella. A, dorsal and ventral aspects; B, short, dense, hairlike vestiture of entire surface of pupa; C, texture of cuticle, as seen at junctions of abdominal segments 4 / 5, 5 / 6, and 6 / 7.

FIGURES 1 – 2. 1, Anacampsis rhoifructella, and 2, A. consonella. A, adults, reared from Viburnum prunifolium, Illinois; B, larvae; C, larval feeding evidence; A rhoifructella on Viburnum prunifolium, Illinois, A. consonella on V. nudum var. crassinoides, Wisconsin. Photos in Figs. 2 B and 2 C by Ilona Loser; used with permission.

FIGURES 5 – 6. Male genitalia. 5, Anacampsis rhoifructella; 6, Anacampsis consonella. Each structure shown at same scale in Figure 6 as in Figure 5; A, B, D and F, left lateral aspect; C, E and G, ventral aspect. A, intact genitalia; B and C, valvae, vinculum and juxta (left valva removed in lateral aspect of A. rhoifructella); D and E, tegumen, gnathos and socii; F and G, phallus.

FIGURES 7 – 8. Female genitalia. 7, Anacampsis rhoifructella; 8, Anacampsis consonella. Each structure at same scale in Fig. 8 as in Fig. 7; B – E at same scale. A, overview, ventral aspect; B and C, segments 7 and 8, left lateral and dorsal aspects, respectively, showing posterior margin of tergite 8; D, base of ductus bursae (sternite 7 reflected caudad; scale patches removed in A. consonella); E, corpus bursae, left lateral aspect; F, detail of texture and microtrichia of wall of corpus bursae; G, signum.

Tables

TABLE 1. Characters differentiating Anacampsis rhoifructella from A. consonella.

	A. rhoifructella	A. consonella
Life history/immatures
Phenology (central Illinois)	Early (larva from 14 April to 7 May, adult from 5 May to 24 May)	Late (larva from 13 May to 7 June, adult from 30 May to 21 June)
Color of final-instar larva (Figs. 1B, 2B)	Reddish brown with blackish head; pinacula of most primary setae brown, inconspicuous	Dull green with orange head; pinacula of most primary setae black, conspicuous
Male genitalia
Vinculum (Figs. 5A–C, 6A–C)	Asymmetrical, with broad ventral keel on left margin, no keel on right margin; a narrow independent keel running diagonally between the two margins; free anterior part in lateral aspect appearing as a loop	Symmetrical, with narrow ventral keel on left margin identical to that on right margin; no independent keel between margins; free anterior part in lateral aspect appearing as a single slightly curved line
Valva (Figs. 5B–C, 6B–C)	Relatively broad, width 0.13X to 0.24X length	Relatively narrow, width 0.06X to 0.15X length
Gnathos (Figs. 5D–E, 6D–E)	Medial region relatively small, pointed; subapical sharp projection visible in lateral aspect	Medial region relatively large, rounded; no subapical projection visible in lateral aspect
Phallus (Figs. 5F–G, 6F–G)	Relatively narrow, apex acuminate; strongly doubly curved in ventral aspect	Relatively broad, apex truncate; straight in ventral aspect
Female genitalia
Posterior margin, tergum 8 (Figs. 7B–C, 8B–C)	Narrowest laterally, broadening gradually to widest point at midline	A narrow transverse band laterally, broadening abruptly into large rounded medial projection
Ductus bursae (Figs. 7D, 8D)	Not enlarged at base	Bulbously enlarged at base
Corpus bursae (Figs. 7E–F, 8E–F)	Wall smooth; microtrichia relatively long and sparsely distributed	Wall foveolate; microtrichia relatively short and densely distributed