Amasa parviseta: A new and highly invasive species of Ambrosia Beetle from Australia, South America, and Europe.

Ambrosia Beetles are one of the most diverse groups of Bark Beetles, with over 1300 described species in 43 genera, found throughout the world's tropical and temperate regions. The biology of these Beetles enables them to colonise new areas rapidly, with many species considered to be highly invasive pests, causing significant economic and ecological damage in forests, orchards, nurseries as well as urban and suburban gardens. This is because the Beetles bore into the wood of trees and cultivate gardens of Fungus, feeding on an ambrosia produced by the Fungus rather than the wood of the tree. This means that, unlike most wood-boring Insects, they are not tied to a single species of tree, although some species and genera are restricted to a single family of hosts. The reproductive cycle of the Beetles also favours dispersal, with diploid females mating with haploid males within their birth tree before dispersing to new trees to lay eggs. 

The taxonomy of Ambrosia Beetles can be challenging, due to the small size of these Insects, and their wood boring lifestyle, which means both that they are out of sight and that they are not under any evolutionary pressure to become visually distinct. Members of the genus Amasa can be distinguished from other genera by their truncated abdomens and elytra (wing cases) which have a distinct declivity (downward fold) at the rear. However, telling species apart can be difficult, particularly as most species are known only from a single, or very small number of, specimen(s) held in widely distributed collections. There are currently 47 species of Amasa, from across tropical Asia and Oceania; two species from Madagascar have been assigned to the species, but this is probably erroneous. 

In 2011 a species of Amasa found infesting a Eucalyptus grandis plantation in São Paulo State,  Brazil, was provisionally identified as Amasa truncata, a widespread invasive species, although further investigation led to the conclusion that this was a morphologically similar, but unknown, species. This new Beetle was reported from Minas Gerais State in Brazil as well as in neighbouring Uruguay in 2015. In 2016 it was reported from Valparaíso in Chile, and by 2018 it had reached Argentina.

Similar specimens found in Cádiz, Spain, in 2009, were initially identified as Amasa  resecta, but again were later shown not to belong to this species. In 2018 the same species was found in Antibes,  France, and in 2019 in Lisbon,  Portugal. A genetic analysis of specimens collected in France found them to be 100% identical to members of an unknown species from New South Wales.

In a paper published in the journal Zootaxa on 12 January 2024, Miloš Knížek of the Forest Protection Service at the Forestry and Game Management Research Institute, and Sarah Smith of the Department of Entomology at Michigan State University, formally describe the unknown Amasa species based upon specimens from Australia, South America, and Europe.

The new species is named Amasa parviseta, where 'parviseta' means 'small hairs' as the hairs on the elytral  declivity is almost hairless, with only a few microscopic hairs. The new species is described on the basis of specimens from New South Wales, the Australian Capital Territory, and Queensland in Australia, Alpes-Maritimes Department in France, Galicia in Spain, São Paulo State in Brazil, and Tacuarembó Department in Uraguay. It is also thought to be present in Corsica, Portugal, Minas Gerais, Argentina, and Chile.

Amasa parviseta paratype female from Ponteverda Spain (Miloš Knížek collection) (1) habitus dorsal view; (2) habitus lateral view; (3) elytral declivity part; (4) elytral declivital face; (5) lateral detail of elytral declivity with microscopic hair-like setae visible on the lateral edge of the declivity and on the apices of tubercles on the declivital face. Antonín Knížek in Knížek & Smith (2024).

Females of Amasa parviseta are 2.38–3.00 mm long and light brown in colour, with slightly darker elytra. Males are unknown. The species was found on Eucalyptus trees and in Eucalyptus leaf litter; some were captured in traps in mixed Eucalyptus and Pine woodland. 

See also...

The survival of wild Grassland Birds on Cattle ranches and Soybean plantations in Uruguay and Brazil.

The temperate Grasslands of South America are home to a unique assemblage of Bird species, which are increasingly being affected by habitat modification as wild Grasslands are converted to agricultural usage. As a consequence many South American Grassland Bird species are now at risk, with 50 species considered to be threatened in Brazil and 24 in Uruguay. While conservation in South American tropical forests has become a matter of international interest in recent years, very little attention has been paid to the fate of South American grasslands, with a consequence that they have received relatively little protection; only 2.2% of all protected areas in Brazil cover temperate Grasslands and only 1.7% in Uruguay.

Wild Grasslands are being converted to a variety of usages in South America, including arable monoculture, particularly Soy (Glycine max), but also corn (Zea mays), Oats (Avena sativa), Ryegrass (Lolium multiflorum), Wheat (Triticum vulgare), Barley (Hordeum vulgare), Sunflower (Helianthus annuus) and Rice (Oryza spp.). Many areas have also been converted to Cattle pasture; these areas are considered to be more natural and likely to provide a better environment for Grassland Bird species, but are also seeded with introduced Grass species to improve the pasture, particularly Ryegrass (Lolium multiflorum) and Lovegrass (Eragrostis plana). Significant areas of Grasslands have also been converted to forestry, particularly of Eucalyptus and Pine (Pinus spp.).

Previous studies of these environments have suggested that natural grasslands are better environments for native Birds than Barley or Sunflower fields or Cattle pasture in Uruguay and that Cattle ranches were better habitats for Birds than croplands in Argentina.

In a paper published in The Condor on 14 January 2015, Thaiane Weinert da Silva of the Laboratório de Ornitologia at the Museu de Ciências e Tecnologia and Programa de Pós-Graduação em Zoologia at the Pontifícia Universidade Católica do Rio Grande do Sul, Graziela Dotta of the Laboratório de Ornitologia at the Museu de Ciências e Tecnologia and Programa de Pós-Graduação em Zoologia at the Pontifícia Universidade Católica do Rio Grande do Sul and of the Conservation Science Group at the Department of Zoology at the University of Cambridge, and Carla Suertegaray Fontana, also of the Laboratório de Ornitologia at the Museu de Ciências e Tecnologia and Programa de Pós-Graduação em Zoologia at the Pontifícia Universidade Católica do Rio Grande do Sul describe the result of a study of Bird abundances and species diversity on Cattle ranchlands and Soybean farms in Uruguay and Brazil.

All of the sites chosen were areas with deep soil layers with essentially flat topographies and occasional undulating hills (coxilhas). These sites were chosen for their similarity, in order to exclude variations in Bird populations caused by topography rather than land-use. The Cattle ranchlands were considered to be semi-natural, with a range of native Grasses. The Soybean sites were all former Cattle ranchlands in their second and third years of arable cultivation. At these sites genetically modified Soybeans were grown as a monoculture with treatment with glyphosate (N-(phosphonomethyl)glycine); a systemic herbicide which kills non-immune plants by inhibiting amino acid synthesis, and which is widely criticized by environmentalists for its environmental persistence and ability to enter water systems, particularly since the advent of resistant crops which can encourage heavy use. 

Soybeans were grown in the spring and summer at these sites, with Wheat being grown at the two Uruguayan sites during the autumn and winter, while Ryegrass was grown out of season at the Brazilian sites. None of these sites was ploughed, and the Soybean sites contained variable amounts of uncultivated Grassland deemed unsuitable for Soybean production and standing fallow; this ranged from 8% Grassland at a site in Santana do Livramento county in Rio Grande do Sul, Brazil, to 17% grassland at a site at Vichadero in Uruguay.

Da Silva et al. found 75 species of Birds living at Cattle ranch sites, of which 38 species are considered to be South American Grassland species (the remainder being more generalist species able to survive in a variety of environments). The Soybean sites were found to host 57 species, including 30 South American Grassland species. Where more than 30 individuals were present it was deemed possible to measure the comparative population densities between the two environments; of the 56 species for which this was done 50 species showed no preference, while five, the Rufous Hornero (Furnarius rufus), Firewood-gatherer (Anumbius annumbi), Great Kiskadee (Pitangus sulphuratus), Grassland Yellow-finch (Sicalis luteola) and Rufous-collared Sparrow (Zonotrichia capensis) favoured Cattle ranchland while one species, the Eared Dove (Zenaida auriculata), was present at higher densities in Soybean cultivation sites.

Only five species classified as Threatened or Near Threatened were observed during the study. The Greater Rhea (Rhea americana), Burrowing Owl (Athene cunicularia) and Black-and-white Monjita (Xolmis dominicanus), were observed on both Cattle ranches and Soybean plantations, whereas the Sedge Wren (Cistothorus platensis) and Saffron-cowled Blackbird (Xanthopsar flavus) were seen only on Cattle ranches.

Sedge Wren (Cistothorus platensis). Graziela Dotta in da Silva et al. (2015).

The species composition in the two environments was essentially similar, but the Cattle ranches had a greater number of Bird species, higher population densities of more species and more Threatened species than the Soybean plantations, suggesting that this environment was more favourable. Da Silva et al. note that this was the first such study of Birdlife in Soybean plantations in South America, despite the fact that this is the fastest growing form of cultivation on the continent. They suggest that future studies should seek to incorporate areas of Soybean cultivation which lack natural Grassland areas, in order to determine how Birds fare in these areas.

See also…

The diet of breeding Grass Owls in Thailand.

Grass Owls are members of the Barn Owl family, Tytonidae, distinguished by their habit of roosting and nesting in tall grasses or other ground-cover plants, rather than trees. Until fairly recently all Grass Owls were thought to belong to a single species, but there...

Establishing Vulture Safe Zones across South Asia.

In the late 1990s and early 2000s it became apparent that the Oriental White-backed Vulture, Gyps bengalensis, Long-billed Vulture, Gyps indicus, and Slender-billed Vulture, Gyps tenuirostris, were undergoing rapid population declines across Bangladesh, India, Nepal and Pakistan, losing...

Hand rearing African Penguin chicks in the Western Cape.

African Penguins, Spheniscus demersus, breed at a number of sites along the coasts of South Africa and Namibia. The species is considered to be...

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A Chacoan Peccary from the Late Pleistocene of northern Uruguay.

The Chacoan Peccary (Catagonus wagneri) was first recorded from pre-Columbian archaeological sites in northern Argentina in 1930, and subsequently found to be still living in the dry Chacos thorny forests of northern Argentina, western Paraguay and southeastern Bolivia in the 1970s. The Chacos Forests are hot and dry, with average annual temperatures over 24˚C and average annual rainfall between 80 and 800 mm. The two archaeological sites in northern Argentina where Catagonus wagneri has been recorded are outside the Chacos Forests, but are relatively close and still within areas with a hot dry climate; both are about a thousand years old.

In a paper published in the journal Historical Biology on 18 December 2012, Germán Mariano Gasparini of the División Paleontología Vertebrados at the Museo de La Plata, Martín Ubilla of the Facultad de Ciencias at the Universidad de la República and Eduardo Pedro Tonni, also of the División Paleontología Vertebrados at the Museo de La Plata, describe the skull of a Choacan Peccary from the Late Pleistocene Sopas Formation in Artigas Department in northern Uruguay. 

The specimen comprises a partial skull covered in carbonaceous material (limestone) with most of its teeth intact. The skulls of Catagonus wagneri are quite distict, and there is no doubt about the assignation of this specimen to the species.

Specimen assigned to Catagonus wagneri: (a) Lateral view. (b) Palatal view. (c) Occlusal view of right P2-M3 series. Gasparini et al. (2012).

The Sopas Formation outcrops along streams and rivers in northern Uruguay. It is about 15 m thick and comprises brownish mudstones, siltstones, sandstones and occasionally conglomerates. It has not been dated precisely, but based upon biostratigraphical evidence it is Late Pleistocene, and probably predates the last Glacial Maximum. It has previously yielded other fossils associated with dry climates, such as Camelids and Guinea Pigs, but also species associated with much wetter environments, such as Otters, Tapirs and Capybaras, suggesting that the climate varied considerably during the time period when it was laid down.

Archaeological and paleontological sites where fossil remains of Catagonus wagneri were found and current range. (1) Llajta Maüca archaeological site, 15 km north-west of Melero, Santiago del Estero Province. (2) Tulip-Loman archaeological site, near Icano, Santiago del Estero Province, 45 km south of Llajta Maüca. (3) Paleontological site in the Cuareim river, Artigas Department, Uruguay. (a) Mariscal Estigarribia, Boquerón Department, Paraguay. (b) Las Lomitas, Formosa Province, Argentina. Grey area: current range of Catagonus wagneri. Gasparini et al. (2012).

See also

 A new species of Musk Ox from the Late Miocene of Gansu Province, China.

A diverse fauna of Musk Oxen (Ovibovines) is known from the Late Miocene of China, each showing distinct and specialized horn cores (the bone core upon which the keratin horn is supported; the diversity of horn core shapes can be used to infer a diversity of horn shapes, even in the absence of horns), but otherwise quite similar. One of...

 A new species of fossil Pig from the early Pleistocene of Ethiopia.

Pigs (Suidae) are found throughout the Old World. They are members of the Artiodactyla, the group that also includes Cattle, Deer and Antelopes (and, curiously, Whales), though they are considered less highly derived than other members of the group, lacking a rumen (additional stomach compartment) and retaining four toes on each foot (though two of these are...

 How fencing the Tibetan prairies is effecting the endangered Przewalski’s Gazelle.

The Przewalski’s Gazelle (Procapra przewalskii) is a species of high altitude adapted Antelope, which formerly ranged across much of...

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New species of Daisy from Brazil.

Daisies of the genus Trichocline are found across southern South America, with a single species from Australia. They are small perennial herbs with red, yellow, orange, or rarely white flowers found on sandy or rocky grasslands, shrublands, or human-modified areas such as roadsides with exposed soil, mostly at high altitudes.

In a paper published in the journal Phytotaxa on 23 January 2012, Eduardo Pasini of the Programa de Pós-Graduação em Botânica at the Universidade Federal do Rio Grande do Sul and Mara Rejane Ritter of the Departamento de Botânica at the Universidade Federal do Rio Grande do Sul describe a new species of Trichocline  from southern Brazil and adjacent areas of Uruguay.

The new species is named Trichocline cisplatina, with cisplatina meaning beside the Platina, referring to the Río de la Plata. The plants were found in the Brazilian State of Rio Grande do Sul and Rocha Province, Uruguay. They grew on rocky or sandy soils on grasslands, shrublands and disturbed soils, on coastal plains up to an altitude of 400 m.

Map showing the known distribution of Trichocline cisplatina (black circles), and the closely related Trichocline catharinensis (black squares). Pasini & Ritter (2012).

Trichocline cisplatina is a herbaceous plant reaching 23 cm in total height when flowering. It is considered to by Vulnerable under the terms of the International Union for the Conservation of Nature's Red List, due to introduced commercial Pines and European Gorse in its range.

(Top) Photograph of Trichocline cisplatina in the wild. (Bottom) Line drawing of Trichocline cisplatina. Pasini & Ritter (2012).

Environments colonized by Trichocline cisplatina. (Top) Sandy grassland. (Bottom) Hillside with shrubland vegetation. Pasini & Ritter (2012).

See also A new, diploid, Pincushion Plant, from the Rocky Mountains, New species of Ox-eye Bean from Costa Rica and Panama, New species of Pipewort from Brazil, A new species of Orchid from Bahia State, Brazil and New species of parasitic Broomrape from South Korea. 

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