Stigmella castanopsiella

Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Navickaitė, Asta & Rocienė, Agnė, 2013, Description of new species of oak leaf-miners (Lepidoptera: Nepticulidae), with notes on the species groups of Stigmella Schrank associated with Quercus as a host-plant, Zootaxa 3737 (3), pp. 201-222 : 219-220

The castanopsiella group

Diagnostic characters ( Fig. 44 ): forewing usually with fascia, androconial scales often developed; in male genitalia, uncus usually with two short and broad lateral lobes, gnathos always with two posterior processes, aedeagus always bulbous basally, numerous spine-like cornuti always aggregated into a band, vesica always coiled, manica always present; in female genitalia, accessory sac always long and with (usually coiled) band of long spines, no signa.

Host-plant preferences. Lithocarpus , Castanopsis and Quercus : subgenera Cyclobalanopsis and Quercus (section Mesolobatus) ( Fig. 37 ).

Distribution and taxonomic diversity. Comprises six species, all East Palaearctic: Stigmella castanopsiella (Kuroko, 1978) ; S. kurokoi Puplesis, 1984 ; S. dentatae Puplesis, 1984 ; S. circumargentea van Nieukerken & Liu, 2000; S. lithocarpella van Nieukerken & Liu, 2000; S. vandrieli van Nieukerken & Liu, 2000.

Note. S. dentatae and S. circumargentea are included in to the castanopsiella group here for the first time (previously they were placed in the ruficapitella group) (van Nieukerken & Liu 2000; Diškus & Puplesis 2003).

The hemargyrella group

Diagnostic characters ( Fig. 45 ): forewing often with fascia, androconial scales often developed (present); in male genitalia, uncus often with two short, distally divided lateral lobes (i.e. four small distal lobes), gnathos large, always with two posterior processes (M-shaped), valva often with slender and subcaudaly directed apical process, aedeagus always with numerous spine-like cornuti aggregated into a band, manica almost always present; in female genitalia, accessory sac often wrinkled, corpus bursae always without signa.

Host-plant preferences. Fagaceae ( Fagus and Quercus : section Quercus ), Sapindaceae (Acer) and Caprifoliaceae (Lonicera) ( Fig. 38 ).

Distribution and taxonomic diversity. Comprises six species, all in the Palaearctic Region.

West Palaearctic: Stigmella hemargyrella (Kollar, 1832) ; S. lonicerarum (Frey, 1857) ; S. speciosa (Frey, 1858) .

Central Palaearctic (Central Asia and Himalaya): S. kuznetzovi Puplesis, 1994 ; S. acuta Diškus, Navickaitė & Remeikis , sp. nov.

East Palaearctic: S. monticulella Puplesis, 1984 .

Note. S. motiekaitisi Puplesis, 1994 (Central Asia) is excluded from the hemargyrella group here for the first time but left assigned to any group).

Key to the species groups based on males (with a few additional data on females)

1. Gnathos with single caudal process; uncus semi-rounded, without lobes ( Fig. 39 )............... S. caerusifasciella group

- Gnathos with two caudal processes; uncus with lobes........................................................ 2

2. Male genitalia with cornuti extremely large, each approx. as long as half length of aedeagus............. S. cornuta group

- Male genitalia with cornuti small to large.................................................................. 3

3. Cornuti not aggregated into a band (“loose”); manica absent [female genitalia with prominent, strongly chitinized signa] ( Fig. 41 )................................................................................... S. saginella group

- Cornuti aggregated into a full or broken band; manica (except a few species) present [female genitalia without signa]..... 4

4. Gnathos broadly U-shaped ( Fig. 43 ); caudal lobes of uncus usually narrow and long (as it is shown in fig. 43); forewing usu- ally without fascia (occurrence 70%)..................................................... S. ruficapitella group

- Gnathos with central plate and two closely situated caudal processes; caudal lobes of uncus broad and (or) short; forewing usu- ally with fascia...................................................................................... 5

5. Aedeagus bulbous basally ( Fig. 44 ), vesica (and band of cornuti) coiled [female genitalia with coiled spinose structure]....................................................................................... S. castanopsiella group

- Aedeagus not bulbous basally, vesica (and band of cornuti) not coiled [female genitalia without coiled spinose structure].. 6

6. Gnathos with long anterior processes ( Fig. 42 ), uncus bilobed; host-plants exclusively from section Lobatae, genus Quercus ; North and Central America [female genitalia with enormously enlarged, markedly spiral (coiled) accessory sac]............................................................................................ S. quercipulchella group

- Gnathos without anterior processes ( Fig. 45 ), uncus usually with four small caudal lobes or papillae; host-plants: Lonicera , Acer , Fagus and Quercus (but not section Lobatae); distributed from Europe to Central and East Asia [female genitalia with short accessory sac or without it]........................................................ S. hemargyrella group

Figures

FIGURE 37. Feeding preferences of the species groups of Stigmella associated with Quercus as a host-plant. Some species of the ruficapitella group may feed on more than one host-plant, thus the total percentage of host use for the group exceeds 100 %.

FIGURE 38. Feeding preferences of the saginella, the cornuta and the hemargyrella groups. Some species of the saginella group may feed on more than one host-plant, thus the total percentage of host use for the group exceeds 100 %.

FIGURES 44, 45. Diagnostic characters of the castanopsiella and the hemargyrella species groups.

FIGURES 39 – 41. Diagnostic characters of the caesurifasciella, the cornuta and the saginella species groups.

FIGURES 42, 43. Diagnostic characters of the quercipulchella and the ruficapitella species groups.