Phantasca phantasma ( Westwood, 1859 )

Chiquetto-Machado, Pedro I., Hennemann, Frank H. & Conle, Oskar V., 2018, Description of the female and egg of Phantasca phantasma (Westwood, 1859) (Phasmatodea: Diapheromeridae: Diapheromerinae), Zootaxa 4486 (1), pp. 89-92 : 89-92

Phantasca phantasma ( Westwood, 1859) ( Figs. 1 –11 )

Material examined. 2♀ (MZSP 572, 573); 3♂ (MZSP 576, 577, 586); 9 eggs: Brasil, Pará, Parque Nacional da Amazônia, Base do Uruá. 04°32′58″S; 56°18′14″W. 4–6.I.2016. P. I. Chiquetto-Machado, A. Z. Ramin . 1♂ ( MZSP 581 ): Brasil, Pará, Floresta Nacional do Tapajós, Comunidade Jamaraquá. 02°48′31″S; 55°01′58″W. 30.XII.2015 – 2.I.2016. P. I. Chiquetto-Machado, A. Z. Ramin.

Diagnosis of female. The female of P. phantasma can be distinguished from most other females of the genus by its large size (body length> 100 mm). From P. quadrilobata ( Chopard, 1911) , which is the most similar species in various aspects including the size, it differs by the more elongate ventral lobes of the meso- and metatibiae (covering a larger extension on the ventral face of tibiae), smooth abdominal tergum VI (without a pair of swellings in the posterior portion as in P. quadrilobata ), and praeopercular organ corresponding to a larger swollen region (not restricted to a small median swelling at the posterior margin of sternum VII as in P. quadrilobata ). From the similarly sized female of P. guianensis Hennemann et al., 2018 it differs by the more convex vertex, more developed ventral lobes of meso- and metatibiae, smaller epiproct, shorter cerci which have a blunter apex, and praeopercular organ represented as a broad swollen region in the posterior portion of sternum VII (readily distinguishable from the organ of P. guianensis , composed of a pair of swellings positioned anteriorly to the scale-shaped posterior margin of sternum VII).

Description of female ( Figs. 1–8 ). Relatively large and slender for the genus. Body smooth. Apterous.

Color. Both specimens had most of the abdomen slightly darkened during the drying process. Generally light to dark brown, with diffuse but distinct dark markings on vertex of head ( Fig. 3 ), scapus, pedicellus, procoxa, basal region of profemur ( Fig. 4 ) and on ventral lobes of meso- and metatibia ( Fig. 5 ). Head with a somewhat paler region between the eyes ( Fig. 3 ).

Head. Distinctly ovoid; vertex strongly convex ( Figs 3–4 ). Eyes small, slightly elongate, approximately 0.2x length of head. Ocelli absent. Antennae filiform, extending approximately until posterior region of third abdominal segment; scapus subrectangular, compressed dorsoventrally; pedicellus subglobose, about half the length of scapus; first flagellomere approximately as long as scapus.

Thorax. Prothorax slightly shorter and distinctly narrower than head. Pronotum about 1.5x longer than wide, slightly constricted pre-medially ( Fig. 3 ); transverse sulcus conspicuous and curved; longitudinal median sulcus weakly marked. Mesothorax 6x longer than prothorax; as wide as prothorax anteriorly and slightly widening towards posterior region. Mesonotum with a very slight dorsomedian carina and a pair of more strongly marked lateral carinae; mesepisternum with a strong longitudinal carina near ventral margin; mesosternum with a pair of strong longitudinal lateral carinae. Metanotum and median segment similar in length, both combined approximately 0.6x length of mesothorax; metathorax parallel-sided, as wide as posterior region of mesothorax. Carinae in metathorax as in mesothorax, except for the absence of a dorsomedian carina.

Legs. Moderately long and slender for the genus ( Figs 1–2 ). Profemora similar in length to mesothorax; mesofemora about 0.7x length of profemora; metafemora slightly shorter than mesothorax. Tibiae slightly longer than corresponding femur and 2.5– 3x longer than corresponding tarsus. All basitarsi very elongate and longer than remaining tarsomeres combined. Femora and tibiae with edges distinctly carinate and with a distinct ventromedian carina; all carinae bearing a row of small setae. Profemur curved and compressed basally; anterodorsal carina distinctly raised sub-basally. Meso-, metafemora and all tibiae trapezoidal in cross-section. Ventromedian carina of meso- and metatibiae deflexed to produce a large elongate lobe in basal third ( Fig. 5 ).

Abdomen. Median segment with a pair of strong longitudinal carinae near lateral margins in anterior half. Combined length of segments II–XI as long as, or slightly longer than the combined length of head, thorax and median segment. Segments II–V similar in length, VI–X decreasing in length. Segments II–VII distinctly longer than wide, VIII– X approximately as long as wide. Tergites II–VII parallel-sided; VIII–X slightly widening towards the posterior. Tergum X with lateral margins rounded and posterior margin slightly emarginate. Epiproct very small, hardly visible under tergum X, rounded but very slightly emarginate. Cerci ( Figs. 6–8 ) small, straight, round in cross-section; distinctly shorter than tergum X; thicker in the basal half, slightly constricted subapically and with a blunt apex. Praeopercular organ represented as a relatively broad swollen region in the posterior portion of sternum VII, sparsely covered with fairly stout setae. Subgenital plate ( Figs. 7–8 ) boat-shaped, at best slightly surpassing mid of tergum X; posterior margin blunt, gently convex. Gonapophyses VIII filiform, slightly surpassing the posterior margin of subgenital plate; apex gently upcurving ( Fig. 7 ). Cerci and posterior region of subgenital plate densely covered with minute fine setae.

Measurements of females [lengths mm]. Body: 103.6–105.2; antenna: 61–63.7; head: 4.8; pronotum: 3.9–4.2; mesonotum: 24.7–25.8; metanotum: 7.8; median segment: 8.1; profemur: 26.2–26.5; mesofemur: 17–17.3; metafemur: 22.6–23.1; protibia: 27.4–28.3; mesotibia: 17.9–18.1; metatibia: 24.9–25.8; abdomen (excluding median segment): 52.8–56.1; subgenital plate: 7.2–7.7; cercus: 1.5–1.6.

Measurements of males [lengths mm]. Body: 61.7–67.7; antenna: 64.9–77.1; head: 2.2–2.6; pronotum: 1.7–2.3; mesonotum: 13.1–14.7; metanotum: 2.9–3.5; median segment: 7.9–8.2; tegmina: 3.4–3.7; hind wing: 26.2–29; profemur: 19.8–21.6; mesofemur: 14.1–15.2; metafemur: 18.5–20.9; protibia: 23.5–24.6; mesotibia: 14.6–16.2; metatibia: 21.7– 22.8; abdomen (excluding median segment): 32.5–36.3; cercus: 1.1–1.3.

Description of egg ( Figs. 9–11 ). Capsule strongly flattened laterally, 1.5x higher than wide in the median region,1.7x longer than wide, 1.1x longer than high; roughly circular in lateral view, with dorsal, ventral and posterior margins gently rounded; distinctly oval in cross-section. Micropylar plate ( Fig. 9 ) narrow and elongate, anterior margin approaching the opercular collar; almost parallel-sided but slightly wider in the posterior region; about 5x longer than wide and more than two-thirds length of capsule. Median line short and inconspicuous. Operculum ( Fig. 11 ) oval and flat, perpendicular in relation to capsule length; ornamented with an outer, distinct oval ridge near the margin, and a cluster of thin, sinuous ridges disposed irregularly in the center. Capsule distinctly smooth and shiny with relatively homogeneous brown coloration but slightly paler on the lateral surfaces and around the micropylar plate. The latter light brown. Operculum also light brown, with the outer ridge dark brown.

Egg measurements [mm]. Capsule length: 2.5; capsule width: 1.4; capsule height: 2.1–2.2; micropylar plate length: 1.6–1.8; micropylar plate width: 0.3–0.4; operculum diameter: 0.8 x 1.3.

Comments. As suggested by the comparison of males (see the diagnosis of P. phantasma in Hennemann et al. 2018 ), the morphologically closest species to P. phantasma seems to be P. quadrilobata . The remarkable similarity between females corroborates this hypothesis and a considerable similarity was also observed between the females of P. phantasma and P. guianensis . However, as described in the herein presented diagnosis of the female of P. phantasma , some characters enable a safe distinction between females of these three species.

Like other species in the genus, P. phantasma exhibits strong sexual dimorphism, with males having about 60% the body length of females. The body length range of the males available at the MZSP (61.7–67.7 mm) encompasses the length of the holotype of P. phantasma (62.6 mm) and suggests that males of the three species mentioned in the previous paragraph have rather overlapping size ranges (see Tables 4, 8 and 11 in Hennemann et al. 2018).

The similarity and presumed close relation of P. phantasma , P. guianensis and P. quadrilobata is also supported by comparison of the eggs (see descriptions of the eggs of P. guianensis and P. quadrilobata in Hennemann et al. 2018 ). All three species have rather similar general egg morphology, but the egg of P. phantasma described herein presents a remarkably smooth and shiny capsule which enables an easy differentiation from the rough egg capsule of P. guianensis and of “ type B” egg of P. quadrilobata . The “ type A” egg of P. quadrilobata , on the other hand, presents a very similar capsule texture and color to P. phantasma , but the egg of the latter differs by its more circular capsule in lateral view and its slightly less pronounced opercular ornamentation.

Figures

FIGURES 1–11. Phantasca phantasma (Westwood, 1859). 1.♀ habitus, dorsal view; 2.♀ habitus, ventral view; 3.♀ head and prothorax, dorsal view; 4.♀ head and prothorax, lateral view; 5.♀ mesotibia, lateral view; 6.♀ terminalia, dorsal view; 7.♀ terminalia, lateral view; 8.♀ terminalia, ventral view (arrow = praeopercular organ); 9. Egg, dorsal view; 10. Egg, lateral view; 11. Egg, anterior view.