Neurostigma willkeniae, Reategui & Rafael & da Silva-Neto, 2025

Reategui, Natália S., Rafael, José A. & da Silva-Neto, Alberto M., 2025, Neurostigma Enderlein, 1900 (Psocodea: ‘ Psocoptera’: Epipsocidae) from Brazilian Amazon Rainforest: new species and variations in forewings, European Journal of Taxonomy 976, pp. 1-32 : 20-26

publication ID	https://doi.org/ 10.5852/ejt.2025.976.2771
publication LSID	lsid:zoobank.org:pub:4E810C5C-B478-4CDC-8AD3-9B4E65B518C4
persistent identifier	https://treatment.plazi.org/id/03AE802C-FFF8-FFB9-FDBB-FA1BA763F877
treatment provided by	Plazi
scientific name	Neurostigma willkeniae
status	sp. nov.

Treatment

Neurostigma willkeniae sp. nov.

urn:lsid:zoobank.org:act:2F344899-1DF5-45AB-9887-025DF52C9BEA

Figs 18–22 View Fig View Fig View Fig View Fig View Fig

Diagnosis

The new species belongs in species group II, of Mendivil-Nieto et al. (2020). It is similar to Neurostigma thorntoni , N. lienhardi , and N. spinosum sp. nov., in having anchor-shaped spines in the endophallus. It is closer to Neurostigma spinosum in the venation of the forewing, but it differs from it by having a spot between the base of the pterostigma and the Rs vein ( Fig. 20A–B View Fig ), and by having a robust posterior process of the aedeagal arch, with a slight indentation of the inner margin, and an abrupt relief on the external margin ( Fig. 21C View Fig ). The anterior region of the endophallus has a slight central indentation, and a field of spines close to the posterolateral margins with numerous small spines on the posterior edges, separated by a large membranous area ( Fig. 21C View Fig ).

Etymology

This species is dedicated to Dr Dayse Willkenia Almeida Marques, from the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA), in recognition of her enthusiasm in deciphering the female genitalia of Neurostigma .

Type material

Holotype

BRAZIL • ♂; Amazonas , Presidente Figueiredo; 02°57′48.0″ S, 59°55′22.2″ W; 9 Apr. 2013; J.A. Rafael leg.; light trap; INPA, INPA-PSO 000038 . GoogleMaps

Description

Male

COLORATION. Head uniformly pale yellow; lateral areas of head light yellow; compound eyes black, ocelli hyaline with ochre centripetal crescents ( Fig. 18A–E View Fig ). Scape, pedicels and flagellomeres hyaline. Clypeus light yellow ( Fig. 18D View Fig ), labrum hyaline with dark brown labral sclerites ( Fig. 19A View Fig ), labium with light brown prementum, with labial palpi, paraglossas and glossas light brown ( Fig. 19B View Fig ), mandibles hyaline with yellowish and brownish ends ( Fig. 19D–E View Fig ), laciniae hyaline with yellowish distal region ( Fig. 19F–G View Fig ). Tergal lobes of mesothorax hyaline, tergal lobes of metathorax dark brown ( Fig. 18C View Fig ), thoracic pleura hyaline ( Fig.18B View Fig ). Forewings with three light brown spots, first in medial region between CuP and M+Cu veins, second in basal region of bifurcation of M+Cu veins, third in basal region between base of pterostigma and Rs vein ( Fig. 20A–B View Fig ); hindwings with brownish spots in basal region from vein A to CuP ( Fig. 20C–D View Fig ). Legs thighs yellowish, trochanters light brown, femurs with blackish spots basally, and rounded black spots medially and distally ( Fig. 20E View Fig ), tibiae with two rounded black spots distally, tarsomeres 1 dark brown, tarsomeres 2 dark brown ( Fig. 20E View Fig ). Abdomen hyaline ( Fig. 18A View Fig ).

MORPHOLOGY. Head with macrosetae, more concentrated on vertex ( Fig. 18D–E View Fig ), compound eyes large, widely separated, laterally rounded in shape ( Fig. 18D–E View Fig ), vertex bilobed, approximately at same level as upper border of compound eyes ( Fig. 18D View Fig ). Labium with prementum narrow, labial palpi with round shape, paraglossa with round shape, glossa slender ( Fig. 19B View Fig ). Mandibles asymmetrical, elongate and with outer margin angled ( Fig. 19D–E View Fig ), outer cusp of lacinial tip broad, with eight to nine denticles ( Fig. 19F–G View Fig ). Tergal lobes with setae ( Fig. 18C View Fig ). Forewings with many setae, especially on margins; right forewing pterostigma with four crossveins ( Fig. 20A View Fig ); left forewing pterostigma with six crossveins ( Fig. 20B View Fig ); M vein before its first bifurcation abruptly concave U-shape ( Fig. 20A–B View Fig ). Hindwing with R 2+3 and R 4+5 almost straight, M sinuous ( Fig. 20C–D View Fig ). Hypandrium with abundant setae, distally rounded, gently concave, wirh sides not angled, more sclerotized on sides ( Fig. 21A View Fig ). Posterior process of aedeagal arch with slight indentation of inner margin, with abrupt relief on external margin ( Fig. 21C View Fig ); anterior region of endophallus with slight central indentation, with a field of spines, close to posterolateral margins with numerous small spines on posterior edges, separated by large membranous area ( Fig. 21C View Fig ). Epiproct with concave posterior margin, with field of microsetae in distal region ( Fig. 21B View Fig ). Paraproct with narrow base, widening distally, with straight distal region, with microsetae field towards outer margin, sensory fields with 38–39 basal rosettes ( Fig. 21B View Fig ).

MEASUREMENTS (in μm). FW: 3658, HW: 2661, F: 627, T: 788, t1: 284, t2: 145, MX 2: 113, MX 4: 226, IO: 503, D: 245, d: 184, PO: 0.751.

Key to males of Neurostigma

Neurostigma furcivenula and N. chaetocephalum are excluded from the key as their male genitalia remain unknown..

1. Forewing with areola postica fused with M; M vein concave with a V-shape before bifurcation ( Fig. 23H–K View Fig ) ..................................................................................................................................... 2

– Forewing with areola postica free, not fused with M; M vein concave with a U-shape before bifurcation ( Figs 3A–B View Fig , 8A–B View Fig , 12A–B View Fig , 16A–B View Fig , 20A–B View Fig , 23A–G View Fig ) .................................................. 4

2. Proximal half of forewing homogeneously pigmented ( Fig. 23K View Fig ) .............. N. enderleini New, 1980 View in CoL

– Proximal half of forewing not homogeneously pigmented, with some areas having lighter pigmentation and other areas having distinctly darker pigmentation ( Fig. 23H–J View Fig ) ......................... 3

3. Large irregular dark brown spots from base of pterostigma to CuP ( Fig. 23I View Fig ) or only from M+CuA to CuP ( Fig. 23H View Fig ); small dark brown spot at pterostigma base transverse veins pigmented along its entire length ( Fig. 23H–I View Fig ) ..................................................................... N. xanthopterum New, 1980 View in CoL

– Almost continuous spot from base of areola postica to CuP, with central discontinuity; no irregular spot between half of anal vein and wing margin strongly pigmented spot along M+Cu ( Fig. 23J View Fig ) ... ........................................................................... N. atlanticum Reategui, Rafael & Silva-Neto, 2022 View in CoL

4. Forewing completely hyaline ( Fig. 23E–G View Fig ) ..................................................................................... 5 – Forewing not hyaline ( Figs 3A–B View Fig , 8A–B View Fig , 12A–B View Fig , 16A–B View Fig , 20A–B View Fig , 23A–D View Fig ) ................................. 7

5. M with three primary branches and third branch unforked ( Fig. 23E View Fig ); phallosome not as below ..... ........................................................................................................................................................... 6

– M with three primary branches, M 3 forked into M 3a and M 3b ( Fig. 23F View Fig ); posterior process of aedeagus short and straight distally; endophallus with two groups of small spines separated by reticulated area ( Fig. 24A View Fig ) ........................................................................................................................................... .............. N. lienhardi González-Obando, Carrejo-Gironza, Mendivil-Nieto & García Aldrete, 2021

6. Areola postica narrow, with Cua 1 touching wing margin at a point parallel to the second bifurcation of M ( Fig. 23E View Fig ); distal process of aedeagal arch wide and short; endophallus with two sclerites with numerous small spines, directed antero-laterally ( Fig. 24E View Fig ) .............................................................. ..................... N. newi González-Obando, Carrejo-Gironza, Mendivil-Nieto & García Aldrete, 2021 – Areola postica wide, with Cua 1 touching wing margin at a parallel point after the first bifurcation of M vein ( Fig. 23G View Fig ); posterior process of edeagal arch long and narrow with slight indentation of outer margin; endophallus with sharp spines directed antero-mesally, with long spicules on outer margin and dense field of short spines and spicules latero-posteriorly ( Fig. 24H View Fig ) ......................................... .......................................................................................................................... N. roesleri New, 1980

7. M+Cu has with slight concavity before bifurcation that gives rise to Cu A and M ( Fig. 8A–B View Fig ) ....... 8 – M+Cu straight, without concave region ( Figs 3A–B View Fig , 16A–B View Fig , 20A–B View Fig , 24A–D View Fig ) ............................. 9

8. Posterior process of aedeagal arch long and wide, with slight indentation of external and internal margins; anterior margin of endophallus with U-shaped indentation, originating two areas similar to ‘angels’ wings, extremely membranous, ending posteriorly with six strongly sclerotized and acuminate projections ( Fig. 9C View Fig ) ...................................................................... N. angelicum sp. nov. – Posterior process of aedeagal arch long, wide, with long indentation of external margin, and slight indentation of internal margin; endophallus with two distinctly sclerotized areas, with separate endophallic sclerites touching anteriorly, separated posteriorly by membranous area, each sclerite with denticulated posterior margin with numerous small acuminate projections coiled anteriorly, giving rise to spiral area ( Fig. 13C View Fig ) .................................................................... N. patriciae sp. nov.

9. Pterostigma with spot on distal half, M gently concave before first bifurcation ( Fig. 23D View Fig ); endophallus subquadrate with recess, originating two symmetrical regions composed of two lobes with numerous rows of vertical spines ( Fig. 24G View Fig ) ........................................................ N. paucivenosum New, 1980

– Pterostigma without spots or with spot only along crossveins; M vein gently concave with U-shaped before its bifurcation ( Figs 3A–B View Fig , 16A–B View Fig , 20A–B View Fig , 23A–C View Fig ) ......................................................... 10

10. R 2+3 four times as long as section Rs ( Fig. 23B View Fig ); endophallus region without sclerites or spines ..... ..........................................................................................................................................................11 – R

2+3

two times as long as section Rs ( Fig. 24I View Fig ); endophallus region with sclerites or spines ........ 12

11. M 3 unbifurcated; areola postica rounded distally ( Fig. 23B View Fig ); edeagal arch posterior process robust, rounded apically ( Fig. 24C View Fig ) ................................................................................................................ ............ N. mockfordi González-Obando, Carrejo-Gironza, Mendivil-Nieto & García Aldrete, 2021

– M 3 bifurcated into M 3a and M 3b; areola postica almost triangular distally ( Fig. 23A View Fig ); aedeagal arch distal process narrow, almost truncate apically ( Fig. 24B View Fig ) ................................................................. ........ N. valderramae González-Obando, Carrejo-Gironza, Mendivil-Nieto & García Aldrete, 2021

12. Aedeagal arch posterior process short and wide, apically U-shaped; endophallus with pair of golf club-shaped sclerites separated by membranes ( Fig. 24I View Fig ) ..................... N. dispositum Roesler, 1940

– Aedeagal arch posterior process robust and long; endophallus with sclerites sepated by membranes ( Figs 4C View Fig , 17B View Fig , 21C View Fig , 24A–F View Fig ) ........................................................................................................... 13

13. Endophallus with sclerites and spines V-shaped ( Figs 4C View Fig , 24F View Fig ) .................................................... 14 – Endophallus without sclerites and with anchor-shaped spines ( Figs 17B View Fig , 21C View Fig , 24D View Fig ) ................... 15

14. Areola postica wide, with Cua 1 touching wing margin at parallel point, after second bifurcation of M ( Fig. 23C View Fig ); endophallus with two distinctly long, sclerotized and acuminate sclerites directed antero-laterally, arising from dense field of small spines ( Fig. 24F View Fig ) .............. N. radiatum Mockford, 1991

– Areola postica narrower basally, with Cua 1 touching wing margin at point parallel between first and second bifurcation of M ( Fig. 3A–B View Fig ); endophallus with numerous V-shaped small spines, radula with two sclerites, these almost together in middle of endophallus, basally almost triangular and weakly sclerotized, posteriorly strongly sclerotized, with numerous acuminate projections, with two medially detached projections ( Fig. 4C View Fig ) .............................................................. N. alfonsoi sp. nov.

15. Endophallus with indentation in anterior region, laterally with rows of spines ( Fig. 24D View Fig ) ............... ............. N. thorntoni González-Obando, Carrejo-Gironza, Mendivil-Niero & García Aldrete, 2021 – Endophallus not as above ( Figs 17B View Fig , 21C View Fig ) .................................................................................... 16

16. Endophallus with slight central indentation, with field of spines close to posterolateral margins with numerous small spines on posterior edges, separated by large membranous area ( Fig. 21C View Fig ) ............ .......................................................................................................................... N. willkeniae sp. nov.

– Endophallus with median region deeply septate with V-shaped indentation, laterally membranous with seven distinct rows of spines, separated by membranous area ( Fig. 17B View Fig ) ................................. ........................................................................................................................... N. spinosum sp. nov.