Mashpi walkingstick (Trychopeplus mashpiensis) from Chocó, Ecuador, based on males, females and eggs

NEWS - Researchers report Mashpi walkingstick (Trychopeplus mashpiensis Conle, Valero & Hennemann, sp. nov.) from the Chocó ecoregion of northwestern Ecuador is new to science based on its unique body ornamentation and egg structure morphology.

Trychopeplus Shelford 1909 is a genus of Neotropical stick insects (Phasmida Leach 1815) known for its remarkable morphological adaptations that allow it to blend in almost perfectly with epiphytic lichens in its habitat. These adaptations make Trychopeplus one of the most cryptic stick insect genera.

The genus was described to distinguish the Neotropical species from Pericentrus Redtenbacher 1908 based on morphological differences and distinct geographic distribution compared to the type species Pericentrus moewisi Redtenbacher 1908. Pericentrus is known to be restricted to East and South Asia, whereas Trychopeplus is endemic to the Neotropics.

Oskar Conle from the Bavarian State Collection of Zoology in Germany, Pablo Valero from the University of Murcia in Spain and Frank Hennemann from the Zoologische Staatssammlung München in Germany describe new species based on specimens collected from the Chocó forest in Ecuador through comprehensive morphological analysis of males, females and eggs.

The new species measures 3.6–4.2 mm in length including operculum, 2.9–3.4 in length, 2.5–2.8 in height, 2.2–2.4 in width and 1.9–2.1 in micropylar plate length. So far, the new species is only known from the type site, in the northwestern Pichincha Province of Ecuador. The epithet mashpiensis refers to the Mashpi Reserve.

The new species can be distinguished from T. laciniatus and T. thaumasius by the shape of the spiny ornamentation (vs. the irregular leaf lobes of T. laciniatus and T. thaumasius); the eggs have a tightly closed, smooth capsule (vs. a capsule with a long, hair-like yellowish margin). In addition, the distribution of T. laciniatus is restricted to Central America

Females of the new species can be distinguished from T. spinosolobatus by the pointed tips of the body spines (vs. rounded in T. spinosolobatus); the femoral ornamentation consists of two pairs of leaf-like lobes (vs. four pairs and larger); the subgenital plate is 1.2 times the combined length of the last three tergites (vs. 1.7 times the length of the last three tergites); known only from northwestern Ecuador (vs. Venezuela and Colombia).

The inclusion of Trychopeplus mashpiensis in Trychopeplus underscores the importance of taxonomic exploration and morphological revision in understanding the biodiversity of the Neotropics. This study not only increases the number to four species, but also provides new insights into the variability of egg morphology that has significant implications for identification and classification.

The close phylogenetic relationship between Trychopeplus and Phanocles highlights the need for further research to clarify the evolutionary relationships within the subfamily Diapheromerinae and to address the complexity of diversity within the genus.

Original research

Conle OV, Valero P, Hennemann FH (2024). A new Trychopeplus species (Phasmatodea, Diapheromerinae, Cladomorformia) discovered from Ecuador’s enigmatic Chocó ecoregion. ZooKeys 1217: 309-326, DOI:10.3897/zookeys.1217.130397

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