Skip to main content

Taiwanese ambrosia beetle (Eccoptopterus formosanus) and midst ambrosia beetle (Eccoptopterus intermedius)

Taiwanese ambrosia beetle (Eccoptopterus formosanus) and midst ambrosia beetle (Eccoptopterus intermedius)

NEWS - Two xyleborine ambrosia beetles, Taiwanese ambrosia beetle (Eccoptopterus formosanus Lin, Sittichaya & Smith, sp. nov.) and midst ambrosia beetle (Eccoptopterus intermedius Sittichaya, Lin & Smith, sp. nov.) described from Taiwan and Thailand based on DNA sequences (COI and CAD) and morphological characteristics.

Eccoptopterus Motschulsky 1863 is the earliest described xyleborine ambrosia beetle (Coleoptera: Curculionidae: Scolytinae). Victor Ivanovich Motschulsky assigned the name to the monotypic genus and a new species, E. sexspinosus Motschulsky 1863, described from Burma.

Currently 14 species and subspecies have been described of which 4 are: E. drescheri Eggers 1940, E. limbus Sampson 1911, E. spinosus (Olivier, 1800) and E. tarsalis Schedl 1936. Eccoptopterus is easily distinguished by its autapomorphically enlarged metatibiae and metatarsi.

Based on specimens collected as part of a survey of xyleborine ambrosia beetles in Thailand and Taiwan, researchers have found variations in Eccoptopterus specimens that suggest the potential for a new species.

E. formosanus female, 2.56−2.64 mm long (mean = 2.61 mm; N = 4), 2.13−2.17× as long as wide (mean = 2.14×; N = 4). Medium body size, declivital armature composed of a pair of major spines on declivital summit and 2–4 minor denticles unevenly spaced on each lateral margin; protibiae slender, broadest at apical 1/3, outer margin armed with six or seven moderated socketed denticles; scutellum broadly linguiform; elytra tapering laterally.

Bred from Elaeocarpus sylvestris (Lour.) Poir. (Elaeocarpaceae), Lithocarpus hancei (Benth.) Rehder, Quercus glauca Thunb. ex Murray (Fagaceae), Sapium discolor Muell.-Arg. (Euphorbiaceae), Trema orientale (L.) Blume (Cannabaceae) with a diameter of about 4.8–6.2 cm in Taiwan. The radial entrance gallery leads to several branches in various planes without enlarged brood chambers.

E. intermedius female, 1.70−1.90 mm long (mean = 1.80 mm; N = 6), 2.03−2.38× as long as wide (mean = 2.13×; N = 6). Small body size, declivital armature composed of a pair of major spines at interstriae 3 on declivital summit and four minor spines unevenly spaced on each lateral margin, declivity covered with flattened scale-like setae; protibiae slender, broadest at apical 1/3, outer margin armed with four or five moderated socketed denticles, elytra tapering laterally.

Formosa is the old name of the island of Taiwan, referring to the location of the type collection with a distribution in Nantou County). L. inter + medius = in the middle. The name refers to the morphological character of the species which is intermediate between E. limbus and E. spinosus. Distribution in Chiang Mai, Lamphun, Tak, Ubon Ratchathani provinces (Thailand).

The differences in COI and CAD sequences between the new species (E. formosanus, E. intermedius) and E. limbus, E. spinosus sensu lato and the junior synonym E. gracilipes are greater than the suggested species boundaries for these genera. Geographically separated morphological characters also show variation in the degree of elytral constriction and density of declivital setals.

E. intermedius is more similar to E. limbus than to E. spinosus but some characters are intermediate. E. intermedius differs from E. limbus by its smaller size, shorter elytra (elytra: pronotum), only four minor spines on the declivital margin, and more slender protibiae. It differs from E. spinosus by its hair-like declivital seta and only one pair of major spines and more slender protibiae.

E. formosanus is more similar to E. spinosus than to E. limbus. E. formosanus differs from E. spinosus in lacking the second and third major spines on the declivital margin and the declivital surface is densely covered with long, thick setae. It differs from E. limbus in having a smaller body size, tapering elytra and a declivital margin with 2–4 minor denticles.

Original research

Sittichaya W, Lin C-S, Smith SM, Pornsuriya C, Cognato AI (2024). Two new species of Eccoptopterus Motschulsky, 1863 ambrosia beetle from Taiwan and Thailand (Coleoptera, Curculionidae, Scolytinae, Xyleborini). ZooKeys 1217: 247-262, DOI:10.3897/zookeys.1217.129707

Dlium theDlium
Labels:

Popular Posts

Humpback whales (Megaptera novaeangliae) manufacture bubble-nets as tools to increase prey intake

NEWS - Humpback whales ( Megaptera novaeangliae ) create bubble net tools while foraging, consisting of internal tangential rings, and actively control the number of rings, their size, depth and horizontal spacing between the surrounding bubbles. These structural elements of the net increase prey intake sevenfold. Researchers have known that humpback whales create “bubble nets” for hunting, but the new report shows that the animals also manipulate them in a variety of ways to maximize catches. The behavior places humpbacks among the rare animals that make and use their own tools. “Many animals use tools to help them find food, but very few actually make or modify these tools themselves,” said Lars Bejder, director of the Marine Mammal Research Program (MMRP), University of Hawaii at Manoa. “Humpback whales in southeast Alaska create elaborate bubble nets to catch krill. They skillfully blow bubbles in patterns that form a web with internal rings. They actively control details such ...
Read more

Javanese grasshopper (Valanga nigricornis)

Wooden grasshopper or Javanese grasshopper ( Valanga nigricornis ) is an animal species of Acrididae, grasshoppers that have at least 18 subspecies, insects with very wide diversity in color and size, sexual dimorphism in which females are larger in size and paler in color. V. nigricornis in males has a length of 45-55 millimeters and females 15-75 mm. The head is square and green or yellow or brown or black in color. A pair of antennas has a black color. The eyes are large and gray or white or brownish. The hind legs are very large and have a green or yellow or brown or black color, plain or brindle. The limbs have two rows of large and long spines with black tips facing backward. The wings have a length exceeding the belly, a rough surface and are brown or green or yellow or black in color with pulse lines forming spaces filled with black color. The hind wings are rose red which will be visible when flying. Nymphs are pale green or yellow or brown or blackish in color. Javanese gr...
Read more

Sojiwan Temple

Sojiwan Temple or Candi Sojiwan or Candi Sajiwan is a Buddhist monument in the Kewu Plain , village of Kebon Dalem Kidul, Prambanan District, Klaten Regency, Central Java Province, Indonesia. This temple has a characteristic that is 20 reliefs at the foot of the temple associated with the stories of Pancatantra or Jataka. Sojiwan temple was completely restored in 2011. Some inscriptions say that was built between 842 and 850 AD. The Rukam inscription in 829 Saka (907 AD) mentions the ceremony of the inauguration of the improvement of Rukam Village by Nini Haji Rakryan Sanjiwana which was destroyed by a volcanic eruption. The residents of Rukam Village were given the obligation to maintain a sacred building located in Limwung. The sacred building was later attributed to the Sojiwan Temple, while Nini Haji Rakryan Sanjiwana was associated as Queen Pramodhawardhani. Sojiwan Temple was first reported in 1813 by Colonel Colin Mackenzie, a messenger of Raffles, who was collecting arch...
Read more