Myronides Stal 1875
Creators: name: Hennemann, Frank H.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Phasmida
Phasmatidae
Myronides

description: Genus Myronides Stål, 1875
(Figs. 19–23)
Type-species: Lonchodes pfeifferae Westwood, 1859: 44, pl. 5: 6, by subsequent designation of Rehn, 1904: 38.
Description: ♀, ♂. Moderately sized (body length ♂♂ 60.0–85.0 mm, ♀♀ 88.0– 125.5 mm) and slender to fairly stocky Lonchodinae. Distinct sexual dimorphism with ♂♂ much smaller, more slender and less sculptured than ♀♀. Colouration various shades of brown, ochre, grey and green; variable intraspecifically in ♀♀, which often have the femora with a conspicuous pale transverse band in apical half of femora. In ♀♀ dorsal body surface with a ± defined longitudinal median carina or weakly tectinate longitudinally. Body surface of ♀♀ densely granulose and/or tuberculose, in ♂♂ smooth with only a few scattered granules on thorax. Head slightly longer than wide with genae ± parallel-sided; vertex flattened and between eyes with a pair of ± distinct spines. Antennae elongate, consisting of about 60 antennomeres and reaching at least to median segment (♀♀) or abdominal segment V–VI (♂♂). Prothorax about equal in length to head, rectangular and with a distinct median sulcus. Mesothorax 5.5–7.0x longer than prothorax; very slender in ♂♂. Meso- and metasternum ± distinctly tectinate longitudinally (very weak in ♂♂); in ♀♀ keel often granulose. Abdomen equal in length or a little longer than head and thorax combined. Median segment of moderate length, less than ½ the length of metanotum. Segments II–VI in ♀♀ very indistinctly increasing in length, all longer than wide and ± parallel-sided. At least terga V–VI with a posteromedian tubercle or swelling. Sternum VII with a distinct Preopercular organ formed by a pair of swellings, spines or lobes close to posterior margin. Terminalia of ♀♀: Terga VIII–X much shorter than previous and decreasing in length. Anal segment tectinate with anterolateral angles rounded and ± deflexed; posterior margin deeply excavated. Epiproct fairly large, rounded, scale-shaped and slightly projecting over apex of anal segment. Cerci very small and hidden under anal segment. Subgenital plate strongly keeled longitudinally, convex and bulgy. Terminalia of ♂♂: Segments II–VI considerably longer than VII and roughly uniform in width and length; VII–X much shorter than previous. Anal segment tectiform and split over entire length to form two hemi-terga that have the anterior margins roundly excavated in apical portion and are apically protruded into a ± long, slender and straight digitiform process. Cerci small, cylindrical and hidden under anal segment. Poculum small, convex, cup-shaped with posterior margin rounded and hardly reaching to posterior of tergum IX. Legs long and slender, profemora longer than mesothorax, mesofemora longer than mesothorax and hind legs slightly (♀♀) to distinctly (♂♂) projecting beyond apex of abdomen. In both sexes entirely unarmed, except for minute sub-apical lobe and/or spine on two outer ventral carinae of meso- and metafemora. In ♀♀ anterodorsal carina of profemora sometimes weakly undulate, occasionally deflexed and slight-ly lobate sub-basally just behind basal constriction of femur. Tarsi slender and simple in both sexes; probasitarsus in ♀♀ not lobed.
Egg: Small (overall length 2.5–3.5 mm), capsule ovoid to barrel-shaped,> 1.5x longer than wide, notably higher than wide and oval cross-section; polar area simple, without mound. Capsule surface coriaceous, granulose or minutely rugulose. Micopylar plate positioned centrally on dorsal egg surface, fairly small, elongately drop-, or pear-shaped with anterior portion progressively narrowing; ± half the length of capsule. Micropylar cup distinct, median line short. Operculum oval and inserted at in capsule at a positive angle of ± 10°. Capitulum irregularly shaped and on a short stalk. Colour of capsule shiny and often with a variable number of dark markings.
Differential diagnosis: Morphology suggests close relation to the Sulawesian endemic Neomyronides n. gen., Chondrostethus Kirby, 1896 (type-species: C. woodfordi Kirby, 1896) from the Solomon islands and New Britain as well as the Philippine Mithrenes Stål, 1877 (type-species: M. asperulus Stål, 1877).
From Neomyronides n. gen. it differs by the averaging larger size and more slender shape with relatively longer and more slender legs and longer tarsi as well as having a distinct medioventral keel on the mesosternum. Females are readily distinguished by the simple front and mid legs, slender probasitarsus and lacking tubercles in the posterior portion of the subgenital plate. Also, ♀♀ never have the struma or lobe-like posteromedian swelling on abdominal tergum VI occasionally seen in Myronides. Males differ by the more slender hemi-terga of the anal segment, which have a narrowed postero-apical protrusion, as well as the larger cerci. Eggs at once differ from those of Neomyronides n. gen. by the flat operculum (Figs. 20D–E).
From Chondrostethus both sexes differ by the shorter median segment of both sexes (more than half the length of metanotum in Chondrostethus), slender probasitarsus of ♀♀ (with a dorsal lobe in Chondrostethus) and lacking the conspicuous and typical node-like remnants of alae seen in ♂♂ of Chondrostethus. Eggs of Myronides are on average much paler in colour, have the capsule considerably less distinctly sculptured and a relatively shorter and broader micropylar plate.
Mithrenes was redescribed by Hennemann & Conle (2007: 7) and shares with Myronides the longitudinal median keel of the meso- and metasternum. From this genus Myronides however differs by the longer median segment, which is about half as long as the metanotum (at best 2/5 the length of metanotum in Mithrenes), more globose head and more distinctly laterally compressed meso- and metafemora of both sexes. Males have the posteroventral projection of the hemi-terga of the anal segment straight and ± horizontal, whereas they are finger-like and angled downward by at least 60° in Mithrenes. The eggs of Myronides differ significantly from those of Mithrenes by being simply ovoid or barrel-shaped.
The monotypical New Guinean Echinothorax Günther, 1932 is only known from a unique ♀ specimen, which seems to differ from Myronides only by the dorsally spinose head and thorax and paired spines on the abdominal terga.
Comments: A re-description of Myronides is presented here to properly define the genus and to provide a basis for removing species that are currently attributed but not congeneric. As previously defined (see Otte & Brock, 2005: 207) Myronides is apparently polyphyletic. All Indochinese species previously attributed to Myronides belong elsewhere and are here transferred to other genera. Myronides ashmeadi (Rehn, 1904) from Trong, Thailand, is a member of the genus Lopaphus Westwood, 1859 (subfamily Necrosciinae), which is seen in the median segment being considerably longer than the metanotum und genital morphology of the ♂ (n. comb.). The same is the case for Myronides baucis (Westwood, 1859) from Nepal, whose ♀ is a fairly typical representative of the Necrosciinae genus Lopaphus; e.g. the mesosternum is entirely smooth and there is no Preopercular organ on abdominal sternum VII (n. comb.). Myronides magnificus Brunner v. Wattenwyl, 1907 from Vietnam is of somewhat questionable generic affiliation and a more detailed treatment of this and a few apparently closely related species is necessary for any broader discussion and confirmed generic affiliation. Several characters, such as the unsplit anal segment and presence of a vomer (small and notably reduced although) in ♂♂, trapezoidal cross-section of the profemora, which have the medioventral carina midways on the ventral surface of the femur and lack of a stalked capitulum in the eggs place it in the subfamily Necrosciinae and in close relation the Lopaphus. Hence, it appears best to provisionally place M. magnificus and the very similar and closely related Lonchodes elegans (Brunner v. Wattenwyl, 1907) in the genus Lopaphus (n. comb.). Myronides curvithorax Brunner v. Wattenwyl, 1907 from Sikkim in NE-India is a member of the subfamily Lonchodinae but is for now best placed in Phraortes Stål, 1875 (n. comb.). Finally, Myronides kaupii Stål, 1875 is here transferred to the genus Leprocaulinus Uvarov, 1940 (see above, n. comb.).
Distribution: Wallacea (Seram, Ambon, Kelang, Ambelau, Buru, Peleng).
Species included:
description: Published as part of Hennemann, Frank H., 2021, Stick insects of Sulawesi, Peleng and the Sula Islands, Indonesia- a review including checklists of species and descriptions of new taxa (Insecta: Phasmatodea), pp. 1-189 in Zootaxa 5073 (1) on pages 47-48, DOI: 10.11646/zootaxa.5073.1.1, http://zenodo.org/record/5760636