Sciency Thoughts: Curculionoidea

Showing posts with label Curculionoidea. Show all posts

Monday, 6 August 2018

Scolytoplatypus unipilus: A new species of Bark Beetle from Gabon.

Bark Beetles, Scolytinae, get their name from their habit of living underneath the bark of trees, Some species are generalists, living on a variety of trees, generally targeting weak or dying trees, though others target specific species and are often able to infect healthy members of their host species. Many Bark Beetles can carry Fungal infections and other Plant pathogens, making them a serious pest in areas where forests of single species are grown for commercial purposes. They were formerly considered to be a separate family of Beetles (the Scolytidae), but recent genetic studies have shown them to be members of the True Weevil Family (Curculionidae).

In a paper published in the journal ZooKeys on 10 April 2018, Bjarte Jordal of the University Museum at the University of Bergen describes a new species of Bark Beetle from the Ipassa National Park in Gabon.

The new species is described from three female specimens captured in baited traps in the Ipassa National Park. The species is placed in the widespread genus Scolytoplatypus, and given the specific name unipilus, meaning 'single hair' as the species is has single hairs on its body, where other species in the genus have clusters of hairs. All three specimens are dark brown in colour, and range from 1.6 to 1.7 mm in length, making this species the smallest known African member of the genus.

Habitus, head and elytral declivity of Scolytoplatypus unipilus. Jordal (2018).

Monday, 12 June 2017

Five new species of Broad-nosed Weevil from Dominican Amber.

Weevils, Curculionidae, are one of the largest and most diverse groups of Beetles. They first appeared in the Early Cretaceous, becoming common and diverse by the end of that period. Broad-nosed Weevils, Entiminae, first appear in Early Eocene Fushan Amber from China. They have larvae which infest the roots of plants, a novel innovation on this group, which has allowed them to exploit a range of new environments, enabling them to diversify rapidly and spread widely during the Eocene.

In a paper published in the journal Paleontologica Electronica in May 2017, George Poinar of the Department of Integrative Biology at Oregon State University and Andrei Legalov of the Institute of Systematics and Ecology of Animals of the Siberian Branch of the Russian Academy of Sciences describe five new species of Entimine Weevil from amber mines in the northern part of the Dominican Republic.

Amber from the Dominican Republic is generally thought to be 15-20 million years old (i.e. Miocene in age), and is obtained from mines in the Cordillera Septentrional mountain range, where it is found as inclusions in turbiditic sandstones (marine landslip deposits). This secondary deposition makes it possible that the Amber is much older than the deposits in which it is found, possibly as old as 40 million years (Early Eocene). It was produced by a Leguminous tree, Hymenaea protera, which, based upon the ecology of the organisms found in the amber, is interpreted as having lived in moist tropical forests.

The first new species described is placed in the genus Diaprepes, which is still found in the Caribbean today, and given the specific name squamula, meaning scaly, in reference to the dense scaly covering of the Weevil. The species is described from a single specimen, 9.0 mm in length with a 0.6 mm snout, black in colour, with a dense covering of light, rounded scales.

Ventral view of Diaprepes squamula, In Dominican amber. Scale bar is 1.0 mm. Poinar & Legalov (2017).

The second species described is placed in the genus Lachnopus, also still found in the Caribbean today, and given the specific name serraticrus, meaning ‘toothed-leg’, in reference to a pattern of prominent serrations on the Insect’s tibia. This species is also described from a single specimen, 7.4 mm in length with a 1.4 mm snout, black in colour with small, subcircular scales.

Lateral view of Lachnopus serraticrus in Dominican amber. Scale bar is 1.3 mm. Poinar & Legalov (2017).

The third new species described is placed in the genus Apodrosus, another modern Caribbean genus, and given the specific name tinctocorpus, meaning ‘dyed body’ in reference to the colour of the body, which brown-black and lacks any markings. The species is described from a single specimen, 5.0 mm in length with a 0.8 mm snout, and small oval scales.

Lateral view of Apodrosus tinctocorpus in Dominican amber. Scale bar is 1.2 mm. Poinar & Legalov (2017).

The fourth new species is also placed in the genus Apodrosus, and given the specific name canalinasus, meaning ‘grooved-nose’ in reference to a distinctive furrow on the snout. The species is described from a single specimen, 4.5 mm in length, with a 0.8 mm snout, and covered in small oval scales.

Lateral view of Apodrosus canalinasus in Dominican amber. Scale bar is 0.8 mm. Poinar & Legalov (2017).

The fifth new species described is placed in the genus Promecops, today found in the Caribbean, as well as in Central and South America, and given the specific name divarichela, meaning ‘spread-apart claws’, in reference to the free tarsal claws. The species is described from a single specimen 3.1 mm in length with a 0.4 mm snout, brown-black on colour and with curved, narrow scales.

Lateral view of Promecops divarichela in Dominican amber. Scale bar is 0.7 mm. Poinar & Legalov (2017).

Tuesday, 17 February 2015

A new species of Weevil from Jiangsu Province, China.

Weevils of the genus Orthotemnus were originally described from New Guinea, and have subsequently been recorded from Australia, the Seychelles, tropical Africa and the Russian Far East.

In a paper published in the journal ZooKeys on 19 January 2015, Youssef Mohamed Omar of the Faculty of Agriculture at Assiut University and the Institute of Zoology at the Chinese Academy of Sciences, Runzhi Zhang of the Institute of Zoology at the Chinese Academy of Sciences and Steven Davis of the Division ofEntomology at the Natural History Museum and Department of Ecology &Evolutionary Biology at the University of Kansas describe a new species of Orthotemnus from Jiangsu Province in China.

The new species is named Orthotemnus longitarsus, meaning ‘long tarsus’. The species is named from four male and four female specimens, all collected from under trees in a park in Zijingshan. The males are 3.29-3.40 mm in length, the females 2.58-2.80 mm. All are reddish brown in colour.

(Top) Female specimen of Orthotemnus longitarsus in lateral view. (Bottom) SEM image of male specimen of Orthotemnus longitarsus in lateral view. Omar et al. (2015).

Friday, 30 May 2014

A Pine Cone Weevil from Cretaceous Burmese amber.

Pince Cone Weevils (Nemonychidae) are thought likely to be the oldest group of surviving Weevils (Curculionoidea), making their understanding their evolution important for our understanding of Weevils as a whole. Modern Pine Cone Weevils feed on pollen of Pines and related Gymnosperms (non-flowering Seed Plants), and it is possible that they may have played a role in the origin of Insect-pollination in Flowering Plants.

In a paper published in the journal ZooKeys on 28 April 2014, Steven Davis and Michael Engle of the Division of Entomology at the Natural History Museum, and Department of Ecology & Evolutionary Biology at the University of Kansas describe a fossil Pine Weevil preserved in Cretaceous amber from the Hukawng Valley in Kachin State in northern Myanmar, thought to be about 99 million years old.

The new species is given the name Burmonyx zigrasi, where ‘Burmonyx’ means ‘Burmese night’ and ‘zigrasi’ honours James Zigras, from whose collection the specimen came. Burmonyx zigrasi is a 2.2 mm Pine Cone Weevil, which was apparently brown in life. Its dorsal surface has a dense covering of setae (hairs).

Photomicrograph and line drawing of Burmonyx zigrasi. (Top) Photomicrograph in dorso-lateral view of specimen inclusion, arrow pointing to antennal scape. (Bottom) Line drawing of specimen (scale bar only applies to this figure). Davis & Engle (2014).