# Tisamenus (insect)

The genus Tisamenus native to the Philippines combines small to medium-sized species of stick insects.
Tisamenus
Tisamenus sp. 'Cebu'
Tisamenus clotho 'Camarines'
Tisamenus cervicornis 'Pocdol'
Tisamenus sp. 'Camiguan'
Tisamenus hystrix 'Sibuyan'?
Tisamenus deplanatus 'Ilocos'
Tisamenus sp. 'Palaui'
Tisamenus sp. 'San Pablo'
Tisamenus hebardi
Tisamenus lachesis
Tisamenus sp. 'Mt. Binangonan'
Tisamenus sp. 'Quezon' = Tisamenus sp. 'Nueva Vizcaya'
Tisamenus sp. 'Macatel Falls'
Tisamenus draconinus 'Cagayan' = Tisamenus sp. 'Callao Cave' :
Relationships of the examined Tisamenus species by Sarah Bank et al. (2021)Species classification according to Hennemann (2024) :

## Taxonomy

In 1875 Carl Stål established the genus Tisamenus in addition to the genus Hoploclonia. In this he described the type species determined by William Forsell Kirby in 1904 Tisamenus serratorius. He also transferred two species described by John Obadiah Westwood in 1848 to this genus, namely Phasma (Pachymorpha) deplanatum (today's name Tisamenus deplanatus) and Phasma (Pachymorpha) draconinum (current name Tisamenus draconina). James Abram Garfield Rehn and his son John William Holman Rehn mention in 1939 the special position of the two Hoploclonia species Hoploclonia gecko and Hoploclonia cuspidata, which are already known from Borneo, but synonymized Tisamenus with Hoploclonia. They transferred all previously known Tisamenus species to the genus Hoploclonia, in which they described a further eight species. They created an identification key for the Philippine species and divided them into four subgroups according to morphological aspects. They also described the genus Ilocano for Ilocano hebardi and transferred the species listed as Heterocopus ranarius (current name Tisamenus ranarius) to this genus. In 2004 the two genera were separated again and the Filipino species were transferred back to the genus Tisamenus. Only those occurring on Borneo were left in the genus Hoploclonia. In 2021, a study based on genetic analysis shows that Ilocano hebardi, the only remaining species of this genus at that time, belongs to Tisamenus, whereby Ilocano became a synonym for it. The division into subgroups made in 1939 could not be confirmed for four investigated species known by name. The name "Tisamenus" is the Latinisation of the Greek Tisamenos (Τισαμενός), an ancient, male given name.
Valid species are:
* Tisamenus alviolanus Lit & Eusebio, 2010
* Tisamenus armadillo Redtenbacher, 1906
* Tisamenus asper Bolívar, 1890
* Tisamenus atropos (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus cervicornis Bolívar, 1890
* Tisamenus clotho (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus deplanatus (Westwood, 1848)
* Tisamenus draconinus (Westwood, 1848)
* Tisamenus fratercula (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus hebardi (Rehn, J.A.G. & Rehn, J.W.H., 1939) (Syn. = Ilocano hebardi Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus hystrix (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus kalahani Lit & Eusebio, 2005
* Tisamenus lachesis (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus polillo (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus ranarius (Westwood, 1859)
* Tisamenus serratorius Stål, 1875
* Tisamenus spadix (Rehn, J.A.G. & Rehn, J.W.H., 1939)
* Tisamenus summaleonilae Lit & Eusebio, 2005
* Tisamenus tagalog (Rehn, J.A.G. & Rehn, J.W.H., 1939)

## Description

The representatives of this genus are consistently small to medium-sized with 2.5 to 4.5 centimetres (0.98 to 1.77 in) in the male and 3.0 to 6.7 centimetres (1.2 to 2.6 in) in the female sex. Both sexes are wingless. The often very similar species differ mainly in their species-specific spines. There are also species that have no or barely recognizable spines. A triangular structure on the mesonotum is characteristic of all representatives. The short side of this isosceles triangle runs parallel to the leading margin of the mesonotum. The other two sides are longer and meet more or less after a third of the mesonotum length, depending on the species. From there a mostly clear keel runs in the middle. In some species this begins at the front margin of the mesonotum and can therefore also be recognized on the triangle. Sometimes it extends to the abdomen or even to the end. Spines are often found on the lateral margins of the thorax, in pairs on the pronotum, and in the middle of the meso- and metanotum. Many representatives also have additional paired and/or centrally arranged spines on the abdomen. The color is mostly dominated by light brown tones. Often, black, light brown to beige patterns can be found, less often even almost white patterns. Males are usually less patterned. When looking at them from above, they often notice their abdomen, which is apparently much too narrow. This is especially true for species whose thorax becomes wider and wider towards the metanotum. The proportions of the females appear more symmetrical, as the abdomen is always wider than that of the males. As is typical for the representatives of the Obriminae, they have a secondary ovipositor at the end of the abdomen for laying the eggs in the ground, which is rather short in Tisamenus females. It surrounds the actual ovipositor and is ventral formed from the eighth sternite, here called subgenital plate or operculum and dorsally from the eleventh tergum, which is referred to here as the supraanal plate or epiproct.

## Way of life and reproduction

The nocturnal animals hide near the ground during the day. Even at night they hardly climb higher than 20 centimetres (7.9 in) on the food plants. The eggs are laid in the ground by the females with the ovipositor. They are 4 to 5 millimetres (0.16 to 0.20 in) long and 2.5 to 3.0 millimetres (0.098 to 0.118 in) wide and usually covered with more or less clear lines of hairs. The micropylar plate has three arms and resembles an upside-down "Y". The arm pointing to the lid (operculum) is significantly longer than the arms pointing to the lower pole. The nymphs hatch after 4 to 6 months and need 5 to 7 months to become adult.

## In terraristics

Many of the breeding stocks found in the terrariums of enthusiasts initially came into circulation under different names. The first animals of the genus to be bred in Europe were collected in 2009 by Joachim Bresseel and Thierry Heitzmann in the province of Quezon on the island of Luzon. Locations are the Sierra Madre mountains near Real and Real itself. Bresseel, Rob Krijns and Tim Bollens found more animals in 2010. The animals initially came to Europe as Tisamenus sp. 'Sierra Madre' or Tisamenus sp. 'Real'. The species was later referred to as Tisamenus serratorius before being identified as Tisamenus lachesis by Frank H. Hennemann in 2024. The Phasmid Study Group lists it as Tisamenus serratorius under the PSG number 314.
At the end of November 2008, Heitzmann collected a female in the Quezon National Park, from which another breeding stock can be traced back. Specimens of this stock were initially referred to as Tisamenus sp. 'Quezon National Park' after their location, but according to Hennemann they also belong to Tisamenus lachesis. Bressell, Bollens and Mark Bushell also found other animals on Luzon in the province Aurora near the city of San Luis in Cunayan. Although these have more or more pronounced spines, particularly along the middle of the body, they are also classified as the very variable Tisamenus lachesis. They were also initially referred to as Tisamenus sp. 'Cunayan' after their location. The Phasmid Study Group lists them under this name as PSG number 359.
In October and November 2010, Heitzmann found animals in the southern Luzon in the Pocdol Mountains on Mount Pulog (not to be confused with Mount Pulag in the north of Luzon) and on Mount Osiao that were initially identified as Tisamenus deplanatus. The resulting breeding strain was long referred to as Tisamenus deplanatus 'Pocdol' and was given the PSG number 399 by the Phasmid Study Group. It was not until 2024 that Hennemann clarified that the animals in this breeding strain were Tisamenus cervicornis.
In 2014, Heitzmann collected further, similar animals in the Ilocos region. They were named Tisamenus sp. 'Ilocos' after their place of discovery and were recorded under this name as PSG number 391. Following an initial identification, they were assigned to Tisamenus fratercula. Hennemann identified them in 2024 as the real Tisamenus deplanatus.
At the beginning of June 2014, Albert Kang brought animals from the island of Sibuyan that were initially named and distributed as Tisamenus sp. 'Sibuyan'. Hennemann identified these as Tisamenus hystrix in 2023. Another breeding stock goes back to two very differently colored females that Heitzmann and Kang collected on November 5, 2014 in a protected area near the Callao Cave in the province of Cagayan. A sexual breeding stock was established from the eggs laid by these females, which was initially distributed as Tisamenus sp. 'Cagayan'. It is one of the most widespreaded species of the genus. The species was identified as Tisamenus draconinus by Hennemann in 2024, so the stock must be fully referred to as Tisamenus draconinus 'Cagayan'.
A species called Tisamenus sp. 'Palaui' was collected by Kang in June 2016 on the island of Palaui, which also belongs to the province of Cagayan. Heitzmann was able to breed the species successfully and sent eggs from the offspring to Europe. The species is similarly spiny to Tisamenus draconinus, but has a much more contrasting and intense coloration. The adult females are characterized by a longitudinal orange stripe and the males have an almost orange-red body coloration.
Heitzmann found specimens on July 22nd at Mount Bagacay and on August 4th, 2015 at Mananap Waterfall in the province of Camarines Norte that were initially bred as Tisamenus cf. clotho 'Camarines'. Bressell confirmed that these animals belonged to Tisamenus clotho.
No longer in breeding are Tisamenus sp. 'Ifugao', which was collected in October 2013 by Heitzmann and Kang, and Tisamenus hebardi, which was collected in April 2014 by Heitzmann, Bresseel and Jérôme Constant in the cloud forest on Mount Polis and was initially called Ilocano hebardi 'Sagada'. Both species were only kept for a short time and could not be successfully bred.
The keeping and breeding of most of the species mentioned is considered easy. They willingly feed on various forage plants such as bramble, hazel, firethorn, ivy and Hypericum. They only need small, moderately moist terrariums with a substrate for laying eggs.

## Gallery

* Pair of Tisamenus cervicornis 'Pocdol'
* Pair of Tisamenus deplanatus 'Ilocos'
* Pair of Tisamenus draconinus 'Cagayan'
* Pair of Tisamenus hystrix 'Sibuyan'
* Female of Tisamenus lachesis 'Sierra Madre'
* Pair of Tisamenus lachesis 'Cunayan'
* Pair of Tisamenus lachesis 'Quezon National Park'
* Pair of Tisamenus sp. 'Palaui'