Palaeomystella fernandesi Moreira & Becker

Luz, Fernando A., Goncalves, Gislene L., Moreira, Gilson R. P. & Becker, Vitor O., 2014, Three new cecidogenous species of Palaeomystella Fletcher (Lepidoptera, Momphidae) from the Brazilian Atlantic Rain Forest, ZooKeys 433, pp. 97-127 : 100-104

Taxon classification Animalia Lepidoptera Momphidae

Palaeomystella fernandesi Moreira & Becker sp. n. Figs 1 A–B, 2-4, 11 A–C, 12 A–C

Diagnosis.

Although showing congeneric affinity, Palaeomystella fernandesi has morphological features that in conjunction distinguish it from all known Palaeomystella species, as follows: 1) male genitalia with upper section of valve narrowing distally, forming a single process that bends medially; 2) pupa with cremaster short and apically rounded, with four pairs of setae; 3) galls of fusiform type, external surface without conspicuous ornament, bearing a few longitudinal carinae, induced on stem of Tibouchina sellowiana apical branches.

Description.

Adult (Figs 1 A–B). Sexes similar in size and color; Forewing length 4.68 to 6.11 mm (n = 7). Head (Fig. 1B): Frons and vertex creamy white; labial palpus mostly dark brown, basal segments angled laterally, terminal segment slightly angled upward; antennae dark brown; proboscis yellowish brown. Thorax: Tegula and mesonotum whitish creamy white with pale-brown scales; legs dark brown. Forewing (Figs 1A, 2A): lanceolate, with 13 veins; L/W index ~ 5.1; dorsally covered mostly by dark-brown scales; with three interconnected white areas that form a longitudinal S-like band; one proximal, rounded, in the anal area, made of pale-creamy white scales, followed by a short stripe aligned in the cubital area, made of creamy white scales, and a third, also rounded and faint, in the cell, made of pale-creamy white scales; a tenuous, U-shaped band of pale-gray scales following the contours of the tornus; three raised tufts of pale-gray scales, located posteriorly to cubitus, in anal area, in line with mid-cell, and near tornal area respectively; fringes dark brown; ventrally mostly covered by dark-brown scales; retinaculum subcostal; discal cell closed, ~ 0.8 × length of forewing, ending near 1/5 of wing margin; Sc ending ca. middle of anterior margin; R 5-branched; R1 ending near 1/3 of wing margin; R4 and R5 stalked ca. 1/2 distance from the cell apex; M 3-branched; CuA 2-branched; CuP weak proximally and not stalked, with well-developed 1A+2A extending more than 1/2 posterior margin. Hindwing (Figs 1A, 2A): strongly lanceolate, with nine veins; L/W index ~ 7.2, ~ 0.8 forewing in length; scales dark brown on both sides; fringes dark brown; frenulum a single acanthus in male, with two distally directed acanthi in female; Sc+R1 ending ca. 1/2 anterior margin; Rs ending ca. 1/5 anterior margin; M 3-branched, M1 and M2 stalked from remnant chorda of cell, from point beyond base of Rs; CuA 2-branched, with CuA1 stalked to M3; CuP weakly sclerotized, ending 1/3 posterior margin; 1A+2A well developed, ending near basis of posterior margin. Abdomen (not illustrated): pale brown, intermixed with gray scales, with transverse irregular rows of spiniform setae on terga 2-7 in both sexes; eighth sternum (Fig. 2C) anteriorly expanded medially into a short lobe, associated with a subtriangular sternite.

Male genitalia (Figs 2B, D–H). Uncus narrow, separated from tegumen by a narrow membranous area, distally roof like and laterally setose (Figs 2F, H); tegumen narrow; vinculum widened ventrally; transtilla a flat, rounded fig; aedeagus cylindrical, moderately long, slightly wider basally (Fig. 2G); vesica bearing a few short stout cornuti; juxta (Fig. 2D) attached to distal portion of aedeagus (Fig. 2G), longer than wide, with two small, parallel pointed projections mid-anteriorly and deeply concave distally; valva (Figs 2B, F, H) covered with several long setae, divided near 1/3 from the basis, with a long, finger-like sacculus and a wide spatulate costa, bearing a thin ventral finger-like projection near apex, and several stout, medium-sized spines meso-ventrally (Fig. 2E).

Female genitalia (Figs 2 I–J). Papillae anales connected dorsally, narrowed distally, setose; anterior apophyses with arms slightly curved, similar in length to posterior apophyses; sterigma divided into a bandlike tergum and a distally bilobed sternum, shallowly and widely emarginate medially; ostium bursae small, wider than long; ductus bursae membranous, shorter than corpus bursae; ductus seminalis inserted distally; corpus bursae an elongate sac, with no sclerotizations on inner wall.

Type material.

Holotype ♂ Brazil: Centro de Pesquisas e Conservação da Natureza Pró-Mata (CPCN Pró-Mata; 29°29'16"S, 50°10'60"W; 925 m), São Francisco de Paula, RS, Brazil. Dry preserved pinned adults, reared from galls induced on Tibouchina sellowiana (Cham.) Cogn. ( Melastomataceae ), LMCI 210-56, 7-9.III.2013, by G.R.P. Moreira, F.A. Luz and L.T. Pereira, donated to DZUP (29.409). Paratypes: same data, 26.III.2012, by G.R.P. Moreira, F.A. Luz and P. Pollo; 2♀ (LMCI 174-161 and 162), donated to DZUP (29.410 and 29.411); 1♂ (LMCI 174-157) with genitalia in glycerin (GRPM 50-51) and 1♀ (LMCI 174-158), donated to MCTP (36.225 and 36.226, respectively).

Other specimens examined.

With the same collection data, deposited in LMCI. Adults, dried and pinned: 2♂ (LMCI 174-159 and 210-49), 1♀ (LMCI 174-160), 1♀ (LMCI 174-163) with genitalia in glycerin (GRPM 50-52). Adults, fixed in Kahle-Dietrich’s fluid and preserved in 70% EtOH: 1♂ (LMCI 174-165), 3♀ (LMCI 174-164, 166 and 167). Slide preparations, mounted in Canada balsam: genitalia, 3♂ (GRPM 50-29, 47 and 48), 1♀ (GRPM 50-28); wings, 2 ♂ (GRPM 50-45 and 50), 1♀ (GRPM 50-46); larvae, 2 last instars (GRPM 50-49). Immature stages, fixed in Kahle-Dietrich’s fluid and preserved in 70% EtOH: 8 last-instar larvae (LCMI 174-52); 7 pupae (LMCI 174-168, 169 and 223; and 210-16); 10 galls (LMCI 174-47 to 49, 174-217 to 222, and 210-15). In tissue collection, 9 larvae (LMCI 174-50 and 56) fixed and preserved in 100% EtOH, at -20°C.

Immature stages.

Last instar larva (Figs 3 A–D), 3.51 to 7.01 mm (n = 6). Cecidogenous, endophyllous, semiprognathous, and tissue-feeder. Body with setae well developed. Head (Figs 3A, C–D): brown, with two paler mid-dorsal areas; smooth, with shallow ridges; labrum shallowly notched; frons higher than wide, extending ca. 3/4 epicranial notch; six stemmata arranged in C-shape. Chaetotaxy (Fig. 3A): A-group trisetose; L-group unisetose; P-group bisetose; MD trisetose; C-group bisetose; F-group unisetose; AF-group bisetose; S-group trisetose; SS-group trisetose. A1, A3, P1 and S2 about equal in length, longest setae on head; C1, C2, F1, A2, AF2, L1 intermediate in length; AF1 shorter; MD1-3 very reduced and aligned with each other. Antenna two-segmented. Mandibles broad with four teeth, and one seta on outer surface; labium broad, with two-segmented palpus and spinneret parallel-sided; maxilla prominent. Thorax and abdomen (Figs 3 B–D): Prothoracic shield light brown, divided longitudinally by indistinctly marked, unpigmented area; anal fig brown. Thoracic legs slightly pigmented. Prolegs on A3-A6 and A10 of equal size; crochets in a circle, uniserial and uniordinal. Thorax chaetotaxy: T1 with D-group bisetose, both located on the dorsal shield, D1 shorter than D2; XD-group bisetose, setae similar in length and both on the dorsal shield; SD bisetose, laterally on the dorsal shield; L-group bisetose, L1 longer than L2; SV-group bisetose, posteroventral to L2, SV1 slightly longer than SV2; V-group unisetose. T2 and T3 with D- and SD-groups bisetose, median-transversely aligned; D2 and SD1 similar in length, and longer than D1 and SD2 respectively; L trisetose, L3 posterior to L1-L2, similar in length to L1; SV unisetose; V unisetose. Abdomen chaetotaxy: D-group bisetose; A1-9 with D2 slightly longer than D1, and A10 with D1 longer than D2; SD-group bisetose, A1-7 with SD1 slightly longer than SD2 and A10 with SD2 longer than SD1, SD2 absent in A9; A1-8 with L-group bisetose, L1 longer than L2, L2 absent in A9; A1-8 with SV-group bisetose, SV1 slightly shorter than SV2, SV1 absent in A9; V-group unisetose.

Pupa (Figs 4 A–C, 11 A–C), 4.42 to 6.11 mm long (n = 5). Body elongate-oval in dorsal and ventral views, widest and dorsally raised in mesothoracic region. Integument weakly melanized, mostly smooth, with a few scattered microsetae dorsally. Frontoclypeal suture not evident. Labrum U-shaped. Labial palpi long; antennae arched anteriorly and separate, approximate and parallel posteriorly to distal margins of maxillae, surpassing apical margin of forewings; maxillae extending distally between sclerites of mid-legs; femora of midleg not fused distally; femora of foreleg extending beyond widest part of labial palpi. Cremaster (Figs 11 A–C) short and apically rounded, with four pairs of setae; one latero-basally, another latero-dorsally and two latero-distally.

Distribution.

Known only from the type locality, in the Dense Umbrophilous Forest (= Brazilian Atlantic Rain Forest sensu stricto) portions of the CPCN Pró-Mata, São Francisco de Paula, RS, Brazil.

Host Plant.

Tibouchina sellowiana (Cham.) Cogn. ( Melastomataceae ). A small tree (3 to 6 m), endemic to the coastal montane forests of southern Brazil, ranging from Minas Gerais to Rio Grande do Sul, usually flowering in April–May ( Souza 1986, Guimarães 2014).

Life history

(Figs 12 A–C). Galls induced by Palaeomystella fernandesi are common on Tibouchina sellowiana at the type locality, during spring (October) and summer (February). They are prosoplasmatic histioid ( Küster, in Meyer 1987); fusiform, 6.0 to 18 mm long (n = 12); induced on stem apex (Fig. 12A); without conspicuous projections, bearing a few longitudinal carinae on surface and changing gradually from green to violet as ages; fleshy, without uniformly defined internal chamber; unilocular, unilarval. Most of them house a specialized kleptoparasitic gelechiid moth, whose complex natural history is described in detail elsewhere ( Luz et al. 2014). Those that are free from the kleptoparasite fall to the ground in late larval ontogeny and larva complete development on the ground. Pupation occurs inside the gall, within a cylindrical, longitudinally arranged cocoon made of woven white silk (Fig. 12C). The adult emerges presumably after the winter (September), through a circular operculum (with plant epidermis and penellipse white silk frill) on upper half of gall wall (Fig. 12B) constructed by the last instar larva prior to its pupation.

Etymology.

Named in honor of Prof. Dr. Geraldo Wilson Fernandes, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, for his great contributions to the development of cecidology in the Neotropics.