Phyllocnistis hemera Brito & Fochezato, 2018

Fochezato, Júlia, Brito, Rosângela, Isaias, Rosy Mary dos Santos, Gonçalves, Gislene Lopes & Moreira, Gilson R. P., 2018, Phyllocnistis hemera sp. nov. (Lepidoptera: Gracillariidae): a new species of leaf-miner associated with Daphnopsis fasciculata (Thymelaeaceae) in the Atlantic Forest, Revista Brasileira de Entomologia 62 (1), pp. 57-65 : 58-59

Phyllocnistis hemera Brito & Fochezato sp. nov. ( Figs. 1–7 )

Type material. MALE HOLOTYPE: São Francisco de Paula municipality, Rio Grande do Sul ( RS), Brazil; preserved pinned and dried, reared from a mine associated with D. fasciculata , 22–24. VI.2016, G. R.P. Moreira, R. Brito and J. Fochezato colls. ( LMCI306-47 ). PARATYPES: Same locality, 28-30. VI.2017, G. R. P. Moreira and J. Fochezato coll., two males ( LMCI 319-30 and 319-36) and two females ( LMCI 319-35 and 319-45); 22–24. VI.2016, G. R.P. Moreira, R. Brito and J. Fochezato coll., one male ( LMCI 306-46 ) and one female ( LMCI 306-43 ) donated to MCTP (60251, 60252, respectively); 01–02.VII.2017, G. R. P. Moreira and J. Fochezato coll., one female ( LMCI 320-43 ), donated to MCTP (60253).

Additional specimens examined from the same locality and host plant, all preserved pinned and dried: 22–24.VI.2016, G. R. P. Moreira, R. Brito and J. Fochezato colls., four males ( LMCI 306-26 , 32 , 36 and 40) with genitalia on slides ( GRPM 50-144 to 147 , respectively); three females ( LMCI 306-34 , 35 and 49) with genitalia on slides ( GRPM 50-148 to 150 , respectively) ; 28–30.VI.2017, G. R. P. Moreira and J. Fochezato colls., one male ( LMCI 319-69 ).

Additional immature specimens of P. hemera were deposited at LMCI, all dissected from leaf mines of D. fasciculata collected at the type locality: 10–13.II.2015, G. R.P. Moreira and R. Brito coll., preserved in 100% ethanol at −10 ◦ C and used for DNA extraction ( LMCI 292-25 ); 28–30. VI.2017, G. R. P. Moreira and J. Fochezato coll. and preserved in 75% ethanol. Eight sap-feeding larvae ( LMCI 319-9 ), three spinning larvae ( LMCI 319-8 ) and three pupae ( LMCI 319-7 ) were used for microscopic studies. Additionally, nine leaf mine fragments containing sections of P. hemera mines ( LMCI 320-9 to 11 ) from the type locality were fixed and preserved in FAA as described above, and used in the histological sections, 01–02.VII.2017, G. R. P. Moreira and J. Fochezato coll.

Diagnosis. P. hemera adults are easily distinguished from the other Neotropical Phyllocnistis by a longitudinal fascia on the forewing with superior border enlarged, reaching the costal margin. Its pupal stage is similar to that of P. drimiphaga Kawahara, Nishida & Davis in having the cocoon-cutter divided into three processes, the central longer than the lateral ones, and by the similar arrangement of tergal spines on abdominal segments. However, P. hemera has lateral processes shorter and wider than P. drimiphaga , and two pairs of setae on the clypeus, while P. drimiphaga has only one pair. The spinning larva of P. hemera is similar to that of P. ourea Brito & Moreira , as both share ventral ambulatory, single callus on central meso- and metathorax. However, these species differ in the location of the ventral calli on the abdominal segments (Ab); P. hemera has ventral calli on abdominal segments 3 to 7 (Ab 3–7), while P. ourea has calli on Ab 3–6.

Description. Adult ( Fig. 1 ). Male and female similar in size and color. Forewing length 3.51–4.17 mm (n = 5). Head: antennae silver, ∼ the length of forewing. A pair of tufts formed by a set of scales emerging from the base of antenna are directed to the frons.

Labial palp slender, silver, ∼ 0.5 mm in length. Proboscis without scales. Thorax: Forewing ground color white silver, with light yellow fasciae bearing brown borders. Longitudinal fascia with well-marked border, which is much wider and convex on the basal half, reaching the costal margin; longitudinal fascia emerges from the wing base toward the median region, being completely connected to the first transverse fascia.The latter emerges on the costal margin and is slightly connected to the second transverse fascia. The second transverse fascia crosses the wing from the costal margin toward the inner margin; it is disconnected from the third and fourth fascia. Last two fasciae fused, forming a blotch on the distal region. Costal strigulae emerge from second, third and fourth transverse fasciae. Apical strigulae emerge from apical spot. Inner marginal fringes mostly light brown. Abdomen: covered with silver scales.

Male genitalia ( Fig. 2A–D ).One pair of coremata located between the intersegmentary membrane of Ab 8 and 9; the coremata are formed by a set of long, fine scales, reaching ∼0.4× the size of valvae ( Fig. 2B and C ). Uncus absent. Tegumen narrow at base, widening toward the apex, forming a dorsal sclerotized arch; small setae occur next to the lateral borders of the tegumen; tuba analis narrow and membranous, surpassing the distal margin of tegumen. Valvae digitiform, slightly narrower and finer on base, widening toward the apex. Setae vary in size from small to medium on ventral distal region, forming a line; along the valva, setae varying in size are randomly arranged ( Fig. 2A and C ). Saccus U-shaped. Phallus elongated, weakly sclerotized, cylindrical and partially wrinkled, with fine apex. Cornuti absent ( Fig. 2D ).

Female genitalia ( Fig. 2E–G ). Anterior and posterior apophyses similar in shape; the posterior half the size of the anterior; the posterior apophyses reach Ab 8 and the anterior ones the posterior portion of Ab 7. Anal papillae with medium-sized setae, randomly arranged. Ostium bursae located on median region of the eighth abdominal sternum; ductus bursae long, membranous and slender; corpus bursae ellipsoid and membranous; signum wide, slightly rectangular with two spines on the proximal margin; one acute, well developed, the other of reduced size ( Fig. 2E–G ). Variation in these structures was found, such as: (1) one of the signa with an acute spine, the other without spines; (2) both signa bearing well developed spines; (3) one single signum containing a spine with bifurcated apex.

Figures

Fig. 1. Adult of Phyllocnistis hemera, dorsal view:(A) wings spread,pinned and dried (LMCI 306-47); (B) wings folded,on Daphnopsis fasciculata leaf surface.Scale bars:1 mm.

Fig. 2. P. hemera genitalia under light microscopy: (A–D) male genitalia; (E–G) female genitalia. (A) apex of left valva, mesal view (LMCI 319-69); (B) left corema, ventral (LMCI 306-26); (C) male genitalia, ventral; (D) aedeagus, lateral (LMCI 306-36); (E) female genitalia, ventral; (F) female last abdominal segments, lateral (LMCI 306-49) with the ostium bursae indicated by arrow; (G) signum in detail, ventral (LMCI 306-49). Scale bars: 50 (A, B, D), 100 (C, F, G), 400 µm (E).

Fig. 3. Larval and pupal morphology of P. hemera under light microscopy: (A) sap-feeding larva, dorsal and ventral views; (B) spinning larva, dorsal and ventral; (C) pupa, dorsal, ventral and lateral, respectively. Scale bars: 500µm.

Fig. 4. Scanning electron micrographs of P. hemera sap-feeding larva: (A–D) head under dorsal, ventral, anterior and lateral views (arrow indicates stemma); (E) labrum, dorsal; (F) labium, ventral (arrow indicates spinneret aperture); (G) antenna, ventral;(H) stemma in detail (indicated by arrow in D),lateral;(I) prothoracic spiracle,dorsal; (J) segment A7, ventral; (K) segments A8-10, ventral; (L) detail of latero-ventral lobe indicated by arrow in K, ventral; (M, N) latero-dorsal lobe,highlighted by the red rectangle in K, lateral and dorsal; (O) last abdominal segment, ventral. Scale bars: 200 (A, B, D, K), 70 (C), 100 (E, F, O), 30 (G), 20 (H), 10 (I), 250 (J), 25 (L), 50 (M), 40 µm (N).

Fig. 5. Scanning electron micrographs of P. hemera spinning larva: (A, B) head, dorsal and ventral views; (C) spinneret, antero-lateral (arrow indicates functional aperture); (D) head, lateral; (E) detail of trophic lobe, dorsal; (F) prothoracic shield, dorsal; (G) prothoracic spiracle, lateral; (H) antenna, anterior; (I) meso- and metathoracic calli, ventral; (J) mesothoracic callus in detail (indicated by rectangle in I), ventral; (K) abdominal segments Ab 7-10, dorsal; (L) latero-sensillum indicated by arrow in K, dorsal; (M) abdominal segment Ab 7, ventral (arrow indicates one of the calli); (N) callus in detail, ventral (indicated by arrow in M); (O) last abdominal segment, ventral.Scale bars: 200 (A, B, D, E, K), 150 (C,F), 10 (G, N), 20 (H, L), 250 (I), 80 (J, O), 100µm (M).

Fig. 6. Scanning electron micrographs of P.hemera pupa:(A) head,lateral view;(B) setae over clypeus,ventral;(C,D) cocoon-cutter,ventral and dorsal; (E) terga of abdominal segments Ab 3-4, dorsal; (F) detail of segment Ab 3, dorsal; (G) lateral seta with fine apex, adjacent to spiracle on abdominal segment Ab 4, dorsal; (H) lateral seta of Ab 7 with clavate apex, dorsal; (I) detail of tergum of Ab 3, lateral; (J–L) last abdominal segments, lateral, dorsal and ventral.Scale bars: 200 (A), 80 (B), 100 (C, D, G, K, L), 400 (E), 150 µm (F, H, I, J).

Fig. 7. Natural history of P. hemera: (A) Host plant, Daphnopsis fasciculata at the type locality; (B) seedling of D. fasciculata with several mines; (C) leaf with a single P. hemera mine on adaxial surface (closed and open arrows indicate the beginning and final portions of the mine); (D) sap-feeding larva, latero-dorsal view; (E) spinning larva, latero-dorsal; (F) pupal cocoon, dorsal; (G) pupa, dorsal; (H) pupal exuvium protruded from cocoon after adult emergence.Scale bars: 40 (B), 3 (C), 1 (D, E, G, H), 0.3 mm (F).