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 from this blog

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

Lolot (Piper sarmentosum)

Lolot pepper ( Piper sarmentosum ) is a species of plant in Piperaceae, perennial herb, erect or lodging, creeping rhizome, up to 120 cm long, branched, enlarged branches, cylindrical stems, brown or green, often grooved, growing on the forest floor and shade. P. sarmentosum has leaf stalks up to 15 cm long, up to 13 cm wide, green, alternately arranged, heart-shaped, pointed tips and flat margins. The leaves have 5 main veins from the base of the blade, linear and slightly curved to the tip, glands on the upper surface and many fine pinnate veins. The upper side is shiny green, the lower side is pale green. The flowers are white. The fruit grows in the upper armpit of the leaf, is slightly oval and green. The leaves are used as a medicine for asthma, malaria, stomach ache, tinea versicolor, toothache, difficulty urinating, aches and pains, maintaining stamina, antibacterial, antimicrobial, antioxidant, and so on. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiosperma...
Read more

Cogon grass (Imperata cylindrica)

Cogon grass ( Imperata cylindrica ) is a species of plant in the Poaceae, an annual grass, sharp leaves, long and scaly shoots, creeping underground, white or purplish flowers, very adaptive and grows in all climates. I. cylindrica has sharply pointed shoot tips that emerge from the ground, up to 3 meters high, short stems, rising above the ground surface. Leaves are long ribbon-shaped, pointed tip, narrow base, up to 100 cm long, very rough and sharply serrated edges, long hairs at the base and wide veins. Inflorescences in panicles, up to 28 cm long, spikes long-haired and white to 1 cm. The seeds spread quickly with the wind or via rhizomes that quickly penetrate the soil. This species grows in tropical to subtropical areas, elevation up to 2000 meters, temperature 20-40C, rainfall 500-3500 mm/year, pH 4-7.5, lots of sunlight to a bit of shade. This plant dominates open land, former forests, dry rice fields, roadsides and so on. This plant contains mannitol, glucose, sacharose...
Read more