Wednesday 28 May 2014

A new species of Praying Mantis from southwestern Rwanda.

Praying Mantises (Mantodea) are large carnivorous Insects related to Cockroaches and Termites. They are easily recognised for their large, highly modified forelegs, which are no longer used for locomotion but instead used to strike rapidly and snatch prey. Mantises are well known in popular culture for the habit, seen in the females of some species, of consuming the males during mating, although as a group they show a wide range of behavioural and physical adaptations. The eggs of Mantises are laid in an ootheca, an egg case resembling a pea pod and containing several eggs. The larvae resemble smaller versions of the adults, and do not undergo a metamorphosis during growth. About 2500 species of Mantis are known from warm temperate, subtropical and tropical areas across the globe. The group is thought to have originated in the Cretaceous and diversified in the early Tertiary.

In a paper published in the journal ZooKeys on 20 May 2014, Riley Tedrow of the Department of Invertebrate Zoology at the Cleveland Museum of Natural History and the Department of Biology at Case Western Reserve University, Kabanguka Nathan and Nasasira Richard of the Kitabi College of Conservation and Environmental Management and Gavin Svenson, also of the Department of Invertebrate Zoology at the Cleveland Museum of Natural History and the Department of Biology at Case Western Reserve University describe a new species of Praying Mantis from the Nyungwe National Park in southwest Rwanda.

The new species is placed in the genus Dystacta, which currently contains a single morphologically variable species found across much of Africa, and given the specific name tigrifrutex, meaning ‘bush-tiger’, a reference for the female’s habit of stalking pray in undergrowth close to the ground. The species is described from two specimens, one male and one female, captured using a metal halide light trapping system, which involves shining a bright light onto a white sheet then capturing the insects attracted to this (a form of Moth-lamping).

The male specimen of Dystacta tigrifrutex is a 34.73 mm, elongate brown mantis with large wings that extend beyond the rear of the body; the forewings are 28.2 mm in length, the hindwings 27.16 mm. It has a large brown and white marking on its prosternum (the forepart of the abdomen).

The male specimen of Dystacta tigrifrutex. Tedrow et al. (2014).

The female specimen of Dystacta tigrifrutex is 19.82 mm in length, and considerably stouter than the male. It lacked any trace of wings and was highly active, stalking prey through vegetation.

The female specimen of Dystacta tigrifrutex. Tedrow et al. (2014).

After being captured the female laid an ootheca while in captivity. This was 11.42 mm in length and 6.40 mm wide and roughly elliptical in shape. It is brown in colour, and held several large eggs in a foamy matrix, and hatched to produce several 3.89 mm larvae.

The ootheca of Dystacta tigrifrutex, after hatching. Tedrow et al. (2014).

The specimens were captured in the Nyungwe National Park in southwest Rwanda in May 2013. The Nyungwe National Park covers about 970 km2 of mountain rainforest in the Albertine Rift, a series of mountain ranges running from the Rwenzori Mountains in western Uganda to the Lendu Plateau in eastern Congo. The ranges in altitude between 1600 and 2950 m above sea-level, and contains bamboo forest, flooded forests, marshes and open herbaceous areas. The park receives an average of 2000 mm of rain per year, with a rainy season between September and May and a dry season between June and August. Temperatures typically range from 10.9-19.6˚C.

The approximate location of the Nyungwe National Park. Google Maps.

See also…

Cockroaches (Blattida) are an ancient group of Insects which first appeared in the Carboniferous. They are closely related to Mantises (Mantodea) and Termites (Isoptera), with the latter group now generally being accepted to be specialized Cockroaches. Cockroaches are predominantly omnivorous detritivores. They breed rapidly, form large swarms and leave trails of pheromone-infused feces as a...

Stick Insects, Phasmida, are large insects noted for their camouflage abilities, frequently resembling sticks or leaves. They are related to...

Mantises are large predatory insects noted for their grasping spiked forelegs, which are used to grab and hold prey while it is eaten. They are related to Cockroaches and Termites, and do not undergo a full metamorphosis as with most insects, instead developing from a nymph which is essentially a smaller version of the adult, but unable to fly. Most species are stealth predators, though some will actively chase prey down and others have been shown to consume some plant matter...

Follow Sciency Thoughts on Facebook.