Oliera saizi Moreira & Vargas

Silva, Gabriela T., Moreira, Gilson R. P., argas, Hector A., Gislene L. Goncalves,, Mainardi, Marina D., las, German San & Davis, Donald, 2018, Overlooked gall-inducing moths revisited, with the description of Andescecidiumparrai gen. et sp. n. and Olierasaizi sp. n. from Chile (Lepidoptera, Cecidosidae), ZooKeys 795, pp. 127-157 : 127

Oliera saizi Moreira & Vargas sp. n. Figs 2, 9, 10, 11, 12, 13, 14

Diagnosis.

A typical member of Oliera , having two-segmented labial palpi, pupa with five-pointed frontal process and galls enclosed within swollen terminal branches of Schinus plants (for a generic review, see Moreira et al. 2012). It differs from O. argentinana by characteristics present on the adults, pupae, larvae, and galls. Contrary to adults of O. argentinana that vary from shiny copper to reddish brown, those of O. saizi are brownish gray in color. Adults of O. saizi (forewing length 5.5-6.3) are slightly larger than O. argentinana (forewing length 4.3 mm). Pupae of O. saizi have the two lateral units of the anterior row of the gall cutter short, ca. 1/3 the central one in length; in O. argentinana such processes are much longer, reaching ca. 3/4 the central in length. Furthermore, pupae of O. saizi bear long, conspicuous setae on the last abdominal segment, which are absent in O. argentinana . Larvae of O. saizi have the head with long, continuous and rectilinear, pigmented adfrontal sutures more or less parallel to the unpigmented ecdysial lines. Together they delimit two long adfrontal areas, which extend from the posterior margin of the labrum to the epicranial notch; in O. argentinana , the adfrontal sutures are marked only distally, delimiting two smaller, semicircular, posteriorly located adfrontal areas. In addition, the integument of O. saizi is covered by a greater number of rounded microtrichia that are finer and more regular in size compared to the less dense, larger in size and more irregular-shaped ones in O. argentinana . Galls of O. saizi are larger, and generally found on subterminal branches of S. polygamus plants, contrary to those of O. argentinana that occur commonly on narrower, terminal branches.

Description of adults.

Male. Forewing length varying from 5.5 to 6.3 mm (n = 3). Head: Vertex and frons covered with smooth, narrow, brownish gray scales. Compound eyes black. Antennae filiform, about half the length of forewing, with brownish gray scales dorsally, ventral half with short sensilla. Labrum semicircular, short. Mandibles poorly developed, as small stubs. Pilifers absent. Maxillae with galeae reduced to small lobes; maxillary palpi tri-segmented (ratios of segments from base ~1.0:0.9:0.6). Labial palpi tri-segmented (ratios of segments from base ~1.0:0.8:0.7). Maxillary and labial palpi with brownish gray scales. Thorax: Mostly with brownish gray scales. Wing venation (Figure 9A) as in O. argentinana ( Moreira et al. 2012). Prothoracic legs with coxa, trochanter and femur dark gray (occasionally brownish gray); tibia and tarsus brownish gray; apex of tibial epiphysis reaching the apex of tibia. Mesothoracic leg brownish gray; one pair of tibial spurs. Metathoracic legs brownish gray; two pairs of tibial spurs; tibia with longitudinal band of narrow, elongated hair-like scales. Tibial length proportion (anterior / medium / posterior legs) ~ 0.5:0.6:1.0. Fore- and hindwings lanceolate, brownish gray. Abdomen: Brownish gray. Genitalia (Figure 9D) with narrow tegumen; uncus bilobed; socii as two small setigerous lobes. Saccus with dorsal arms narrow, U-shaped, with anterior projection prominent, slightly widened close to apex. Valva narrow, about 3/4 the length of the anterior projection of the saccus; dorsal and ventral margins sub-parallel, and distal portion dorsally dilated. Pectinifer (Figure 9E) as a straight band on the ventral part of the medial surface of the valva. Transtilla as an inverted “V”, with ventral arms straight, slightly widened close the vertex. Juxta (Figure 9G) narrow, elongated, slightly spatulate distally. Phallus (Figure 9F) narrow, somewhat sinuous, with similar length to valva, with anterior apex laterally widened forming a semicircle; vesica without cornuti.

Female. Forewing length varying from 5.2 to 5.9mm (n = 7). Similar to male in general, but with abdominal sternumVII showing a ring of stout setae on caudal margin. Genitalia (Figure 9B) bearing an oviscapt cone (sensu Kristensen 2003, San Blas and Davis 2013), with weak internal dorsal crest, reaching the anterior portion of tergum seven. Posterior apophyses fused posteriorly, forming distally the laterally compressed, serrated apex of the ovipositor (Figure 9C). Anterior apex of posterior apophyses extend to abdominal segment VI; anterior apophyses project into the segment V. Internal reproductive system not represented, apparently as in O. argentinana ( Moreira et al. 2012).

Type material.

Chile: Holotype ♂, Cuesta Barriga roadside, Padre Hurtado, Metropolitan Region, emerged December 2013, ex gall on Schinus polygamus collected 25 November 2013, HA Vargas & GRP Moreira leg. (MNNC). Paratypes: 1♂, 2♀, same data as holotype (MNNC); 7♀, same data as holotype (IDEA); 1♂, roadside near Til-Til, Rungue, Metropolitan Region, emerged December 2013, ex gall on Schinus polygamus , collected 26 November 2013, HA Vargas & GRP Moreira leg. (IDEA).

Non-type material.

Immature specimens used for descriptions: 33°31'24"S, 70°54'35"W, Cuesta Barriga roadside, Padre Hurtado, Metropolitan Region, HA Vargas & GRP Moreira leg., 6 larvae (25.XI.2013, LMCI 231-3, 4); 33°3'42"S, 71°0'35"W, roadside on Cuesta La Dormida, near border Til-Til/Valparaiso, Metropolitan Region, HA Vargas & GRP Moreira leg., 8 larvae (20.V.2013, LMCI 216-14), 2 pupae (28.XI.2013, LMCI 233-3); 33°00'31"S, 70°53'52"W, roadside near Til-Til, Rungue, Metropolitan Region, HA Vargas & GRP Moreira leg., 4 larvae (26.XI.2013, LMCI 232-4); 36°48'22"S, 71°44'36"W, roadside near Recinto, Bio-Bio Region, HA Vargas, LE Parra & GR. Moreira leg., 30.V.2013, 12 larvae (LMCI 222-2 to 6) and 2 pupal exuviae (LMCI 222-1).

Additional larvae.

Data as above, fixed and preserved in 100% EtOH at -20 °C for DNA extraction (n = 2, LMCI 232-4; n = 2, LMCI 233-2).

Additional pinned-dried adults examined.

Puente El Yeso, Cajón del Maipo, Metropolitan Region, R. Charling C. leg., 4 males, with one genitalia (DRD 16536) and one wing (DRD 29925) preparations; 2 females, with one wing and genitalia preparation (DRD 16537), USNM.

Etymology.

Named in honor of Prof. Dr. Francisco Sáiz, from the Universidad Católica de Valparaiso, who first noticed the existence of these galls, for his great contribution to the development of Cecidology in Chile.

Descriptions of immature stages.

Last instar larva (Figs 10, 11). Body length = 3.99 ± 0.41 mm; head capsule width = 0.97 ± 0.02 mm (n = 3). Head (Figs 10B, C; 11A) creamy to light brown, ~ 2 × broader than high, with convex lateral margins. Frontoclypeus triangular, marked by pigmented adfontral sutures extending to apex of epicranial notch that is paralleled by unpigmented ecdysial lines. Adfrontal sutures and ecdysial lines delimit two long adfrontal areas. Hypostomal ridges well marked and divergent; hypostomal lobes trapezoidal. Integument densely covered by rounded microtrichia (Figure 11F). Stemmata absent; antennae (Figure 11C) reduced, with five sensilla, two stout and three filiform; labrum (Figure 11B) slightly bilobed, with three pairs of small setae on distal margin; mandible well developed with four cusps along distal margin and one small seta basally on external surface; maxilla (Figure 11D) with poorly developed palpus and galea; spinneret tubular; labial palpus one-segmented with well-developed apical seta (Figure 11E). Chaetotaxy consisting of 9 pairs of setae: F group unisetose, C group unisetose, AF group unisetose, A group unisetose, L group bisetose, S group trisetose.

Thorax (T) and abdomen (A) creamy white, mostly covered with rounded microtrichia; prothoracic shield weakly defined by a pair of slightly differentiate areas, with reduced microtrichia. A1-7 with well-developed callus (Figure 11H), mesally, close to posterior margin of terga. Thoracic legs (Figure 11G) reduced to circular, unsegmented tubercles; prolegs absent. Spiracles circular, without elevated peritreme, laterally on T1 and A1-8. Abdominal segment 10 composed of three lobes, one dorsal, wider and two ventral (Figure 11I). Chaetotaxy of thorax and abdomen composed of setae reduced in size. T1 with eight pairs of setae; XD group bisetose, SD group unisetose outside prothoracic shield, L group trisetose, SV group unisetose, V group unisetose. T2-3 with four pairs of setae; D group bisetose, L and V groups unisetose. A1-5 with two pairs of setae; D group bisetose. A6-7 with three pairs of setae, D group bisetose and V group unisetose. A8 with four pairs of setae; D group bisetose, L group unisetose and SV group unisetose. A9 with five pairs of setae; SD group unisetose and L group tetrasetose. A10 with four pairs of setae; SD unisetose, SV unisetose and V bisetose.

Pupa (Figs 12, 13). Length = 6.1 + 0.2mm; n = 3. Orange brown, becoming dark brown near adult emergence. Head with frontal process (= gall-cutter; Figure 13 A–C) formed by five spines that are grouped into two parallel rows; the anterior row with three processes; middle process with a blunt apex, ca. 3/4 longer than lateral ones; posterior pair consists of two minute, pointed processes. Vertex with two pairs of setae laterally. Antennae narrow, long, with apex slightly surpassing forewing apex. Prothorax as a narrow transverse band between head and mesothorax; forewings reaching sternum A7; hindwings concealed by forewings; metathoracic legs reaching segment A9. Terga T2-3 with two pairs of latero-dorsal setae. Abdominal segments covered with microtrichia; A2-8 with a transverse band of spines (Figure 13E, F) near anterior margin of terga; tergum A9 with acute process (Figure 13H, I) on posterior margin. Setae relatively small, arranged in three rows, from A1 to A8 (dorsal, supra- and subspiracular): one dorsal pair on segments A1-8; one supra-spiracular pair on segments A2-8; two subspiracular pairs on segments A3-7 and one pair on A8. Six pairs of long and stout setaeon last segment (Figure 13J). Spiracles (Figure 13D) circular, without elevated peritreme, laterally on A2-8, and on A8, reduced.

Life history.

Oliera saizi develops spindle-shaped galls enclosed within swollen stems of S. polygamus subterminal branches (Figure 14A, B). The larval chamber is elliptical in shape and transversally located in relation to the stem axis, and as in O. argentinana , the gall lacks an operculum. A progressive necrosis extends up the gall wall with the advent of pupation; meanwhile the pupa opens an orifice on the wall with the aid of its frontal process and through body contortions. The abdominal spines help the pupa during these movements to anchor itself on the wall; it pushes part of its body out of the gall, when the exuvia splits and the adult emerges (Figure 14B, D). The outer wall eventually collapses, leaving the empty galls appearing as small holes on the host plant branches (Figure 14E, F).

Little is also known about the biology of O. saizi . Similar to what has been found for O. argentinana ( Moreira et al. 2012), their galls have been collected occasionally, either on isolated plants or in groups. They may occur at high densities per branch, sometimes adjacent to those of A. parrai . Our field collection data indicate that the species is univoltine, with adult emergence occurring from late spring to early summer (November / December). Schinus polygamus branches bearing galls with full-grown pupae were field-collected during November, from which a few adults used for description emerged under laboratory conditions ca. 25 days later.

Host plant and distribution of both species.

Galls of both A. parrai and O. saizi have been found only on branches of Schinus polygamus (Cav.) Cabrera ( Anacardiaceae ), a small tree with single and glabrous leaves and slender spiny branches ( Barkley 1957, Fleig 1989), commonly known in Chile as Huingan. The taxonomy of Schinus L. in southern South America is rather complex, as its wide geographic distribution and phenotypic plasticity have lead historically to a confused taxonomy. In fact, the genus is currently under review (CLS Luz, USP, pers. comm.), and S. polygamus (sensu lato; Cabrera 1938, Fleig 1987, 1989) may be split into several species, as already proposed by Barkley (1957). Nevertheless, according to this author in this case the true S. polygamus would be restricted in distribution to Chile. Andescecidium parrai and O. saizi galls were found on populations of S. polygamus on the central area, also known as the Mediterranean portion of the country ( Quintanilla et al. 2012), which extends from 32°45'N to 37°30'S, abridging the V, VI, VII, VIII and Metropolitan (RM) regions (Figure 15). The main characteristics of this area are the presence of two mountainous ranges, the Andes on the east and the Coastal Range on the west, as well as the central valley located in between them. Plants bearing galls of both cecidosid species were found mainly in the Coastal Range (Figs 8A, 14A). The climate in these valleys is typically austral Mediterranean; the vegetation is autochthonous, composed of sclerophyllous forests, palm communities and coniferous forests and steppe at higher altitudes ( Quintanilla et al. 2012, Valencia et al. 2015).