Genome-wide SNPs of vegetable leafminer, Liriomyza sativae: insights into the recent Australian invasion

Liriomyza sativae, the vegetable leafminer, is a serious agricultural pest originally from the Americas which has now colonized all continents except Antarctica. In 2015, L. sativae arrived on the Australian mainland and established on the Cape York Peninsula in the northeast of the country. Here, we assessed genetic variation in L. sativae based on genome-wide single nucleotide polymorphisms (SNPs) generated by double-digest restriction-site associated DNA sequencing (ddRAD-seq) to uncover the potential origin(s) of this pest in Australia and contribute to reconstructing its global invasion history. Our principal component analyses (PCA) results suggested that Australian mainland populations were genetically close to populations from the Torres Strait and had connections to Bali and Papua New Guinea (PNG), whereas populations from Asia and Africa were more distantly related. Hawaii was genetically distinct from populations from Asia, Africa and Australia. Co-ancestry analyses pointed to signals of gene flow from the Torres Strait into the Australian mainland, while Indonesia/PNG were the likely sources of the initial invasion into the Torres Strait. Admixture analyses further revealed that L. sativae from the Torres Strait had genetic diversity originating from multiple sources, which has now spread to the Australian mainland. The L. sativae lineages from Asia/Africa appear closely related and may share co-ancestry. Isolation by distance (IBD) was found at a broad global scale, but not within small regions, suggesting human-mediated factors contribute to the local spread of this pest. Overall, our findings highlight the challenges in quarantine measures aimed at restricting the distribution of this global pest.

BIOLOGICAL INVASIONS: THE EUROPEAN SMELT OSMERUS EPERLANUS (L.) AND THE MICROSPORIDIAN GLUGEA HERTWIGI WEISSENBERG, 1911

The paper presents the phenomenology of the smelt Osmerus eperlanus and the microsporidian Glugea hertwigi invasion into a new habitat - Lake Syamozero (Karelia), where neither of the species occurred before. The invasion history falls into 4 phases. The first, latent phase started with a spontaneous invasion of the lake by smelt and lasted until the first fish showed up in catches (1968-1970). The second phase (1971 to 1980) was the invader number outbreak. The smelt became the dominant species in the fish community, while the native plankton-feeder, the vendace Coregonus albula, became an endangered species. The third phase (1980 to 1991) was the population outbreak of the microsporidian Glugea hertwigi, and development of an epizootic. The fourth phase (since 1991 until present) is the decreasing of the number of the invasive species - the smelt and the microsporidian Glugea hertwigi and the recovery of the native vendace population.

Tracing the invasion of a leaf-mining moth in the Palearctic through DNA barcoding of historical herbaria

Historical herbaria are valuable sources of data in invasion biology. Here we study the invasion history of the lime leafminer, Phyllonorycter issikii, by surveying over 15 thousand herbarium specimens of limes (Tilia spp.) collected in the Palearctic during last 253 years (1764-2016). The majority of herbarium specimens with the pest mines (89%) originated from East Asia (1859-2015), whereas remaining 11% of specimens with the mines came from Europe, European Russia and Western Siberia (1987-2015). These results support the hypothesis of a recent Ph. issikii invasion from Eastern to Western Palearctic. Single molecule real-time sequencing of the COI barcode region of 93 archival larvae and pupae (7-162 years old) dissected from the mines on historical herbaria allowed to distinguish between Ph. issikii and Ph. messaniella, a polyphagous species rarely feeding on Tilia, which mines were found in herbarium from Europe dated by 1915-1942. We discovered 25 haplotypes of Ph. issikii, of which 16 haplotypes were present solely in East Asia, and revealed wide distribution of the species in China. Six haplotypes shared between Eastern and Western Palearctic suggest the contribution of Ph. issikii populations from the Russian Far East, China and Japan to the westward invasion.

Population Genetic Structure of the Invasive Spotted Alfalfa Aphid Therioaphis trifolii (Hemiptera: Aphididae) in China Inferred From Complete Mitochondrial Genomes

Biological invasions represent a natural rapid evolutionary process in which invasive species may present a major threat to biodiversity and ecosystem integrity. Analyzing the genetic structure and demographic history of invaded populations is critical for the effective management of invasive species. The spotted alfalfa aphid (SAA) Therioaphis trifolii is indigenous in the Mediterranean region of Europe and Africa and has invaded China, causing severe damages to the alfalfa industry. However, little is known about its genetic structure and invasion history. In this study, we obtained 167 complete mitochondrial genome sequences from 23 SAA populations across China based on high-throughput sequencing and performed population genetic and phylogenomic analyses. High haplotype diversity and low nucleotide diversity were found in SAA populations in China with distinct genetic structures, i.e., all populations diverged into three phylogenetic lineages. Demographic history analyses showed a recent expansion of the SAA population, consistent with the recent invasion history. Our study indicated that SAA may have invaded through multiple introduction events during commercial trades of alfalfa, although this needs further validation by nuclear markers.

Biology, Ecology, and Management of the Invasive Longlegged Ant, Anoplolepis gracilipes

The longlegged ant ( Anoplolepis gracilipes) is one of the most damaging invasive tramp ants globally. It is generally found between latitudes 27°N and 27°S in Asia, although it has been introduced to other continents. Its native range remains debatable, but it is believed to be in Southeast Asia. Anoplolepis gracilipes invasion has many serious ecological consequences, especially for native invertebrate, vertebrate, and plant communities, altering ecosystem dynamics and functions. We examine and synthesize the literature about this species’ origin and distribution, impacts on biodiversity and ecosystems, biology and ecology, chemical control, and potential biocontrol agents. We highlight emerging research needs on the origin and invasion history of this species, its reproductive mode, its relationship with myrmecophiles, and its host–microbial interactions, and we discuss future research directions. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Predicting the Potential Distribution of Non-Native Mammalian Species Sold in the South African Pet Trade

The pet trade is one of the main pathways of introduction of several mammals worldwide. In South Africa, non-native mammalian species are traded as pets, and so far, only four of these species are considered invasive. We used a list of 24 companion mammalian species compiled from a previous study. We selected a subset of 14 species for species distribution modeling (SDM) based on their trade popularity, invasion history and potential economic and socio-economic impacts. We aimed to estimate their potential distribution using their distribution records. Our SDM indicated that climate in South Africa was suitable for most traded species. However, commonly and easily available species had the broadest areas of suitable climates, such as house mice (Mus musculus) and Norwegian rats (Rattus norvegicus). In addition, the model with a human footprint suggested a high risk of invasion for Norwegian rats but less for house mice distribution. This assessment suggests the need of strict trade regulations and management strategies for pet mammals with broader suitability, which are already invasive, and most available for sale. In addition, our results provide a baseline approach that can be used to identify mammalian pet species with a potential risk of invasion so that urgent preventive measures can be implemented.

ФИТОИНДИКАЦИОННАЯ ОЦЕНКА СОВРЕМЕННЫХ ЛАНДШАФТНО-ЭКОЛОГИЧЕСКИХ ТЕНДЕЦИЙ В ГЕОСИСТЕМАХ ЛОКАЛЬНОГО УРОВНЯ

Цель работы – оценка ландшафтно-экологических тенденций в геосистемах локального уровня на примере юго-востока Беларуси. Объекты исследования – природно-антропогенные ландшафты, представленные 5 тестовыми участками. Для оценки современных ландшафтно-экологических тенденций разработан комплекс показателей, получаемых на основе наземных и дистанционных исследований растительного покрова. Дается анализ и оценка экологической стабильности, фрагментации лесного покрова, процессов дигрессивной динамики растительности, восстановительных сукцессий на территории тестовых участков. Изучено влияние климатических факторов на биопродуктивность геосистем тестовых участков. Наиболее чувствительными к климатическим изменениями являются пахотные геосистемы. При потеплении климата в регионе наибольший рост напряженности ландшафтно-экологической тенденции прогнозируется на участке «Поколюбичи». Библиографические ссылки 1. Агроэкология / Под ред. В.А. Черникова, А.И. Чекереса. М.: Колос, 2000. 536 с.2. Виноградов Б.В. Основы ландшафтной экологии. М.: ГЕОС, 1998. 418 с.3. Гусев А.П. Потенциал самовосстановления геосистем и его оценка на основе фитоиндикации // Вестник Белорусского государственного университета. Сер. 2. 2010. №1. С. 77–81.4. Гусев А.П. Диагностика ландшафтно-экологических ситуаций на основе фитоиндикации // Вестник ВГУ. Серия: География. Геоэкология. 2016. №4. С. 77–83.5. Гусев А.П. Индикаторы ландшафтно-экологических тенденций (на примере Восточной части Белорусского Полесья) // Вестник ВГУ. Сер. География. Геоэкология. 2018. №2. С.28–33.6. Гусев А.П. Дистанционные индикаторы ландшафтно-экологических тенденций (на примере юго-востока Беларуси) // Ученые записки Крымского федерального университета им. В.И. Вернадского. География. Геология. 2019. Т. 5, №3. С. 127–135.7. Гусев А.П. Изменения NDVI как индикатор динамики экологического состояния ландшафтов (на примере восточной части Полесской провинции) // Вестник ВГУ. Сер. География. Геоэкология. 2020. №1. С. 101–107.8. Заиканов В.Г., Минакова Т.Б. Геоэкологическая оценка территорий. М.: Наука, 2005. 319 с.9. Коломыц Э.Г. Лесные экосистемы Волжского бассейна в условиях глобального потепления (локальный экологический прогноз) // Экология. 2009. №1. С. 9–21.10. Кочуров Б.И. Геоэкология: экодиагностика и эколого-хозяйственный баланс территорий. Смоленск: Маджента, 2003. 500 с.11. Логинов В.Ф. Климатические условия Беларуси за период инструментальных наблюдений // Наука и инновации. 2016. №9. С. 25–29.12. Шерстюков Б.Г., Шерстюков А.Б. Лесные пожары при потеплении климата в XXI веке // Проблемы экологического мониторинга и моделирования экосистем. 2013. Т. 25. С. 300–314.13. Mang T., Essl F., Moser D., Dullinger S. Climate warming drives invasion history of Ambrosia artemisiifolia in central Europe // Preslia. 2018. V. 90. P. 59–81.14. Yengoh G.T., Dent D., Olsson L., Tengberg A.E., Tucker C.J. The use of the Normalized Difference Vegetation Index (NDVI) to assess land degradation at multiple scales: a review of the current status, future trends, and practical considerations. Lund University Centre for Sustainability Studies – LUCSUS, 2014. 80 p.

Discovery of Novel Viruses Associated With the Invasive Cane Toad (Rhinella marina) in Its Native and Introduced Ranges

Cane toads (Rhinella marina) are notoriously successful invaders: from 101 individuals brought to Australia in 1935, poisonous toads now cover an area >1.2 million km2 with adverse effects on native fauna. Despite extensive research on the role of macroparasites in cane toad invasion, viral research is lagging. We compared viral prevalence and diversity between toads in their native range (French Guiana, n=25) and two introduced ranges: Australia (n=151) and Hawai’i (n=10) with a metatranscriptomic and metagenomic approach combined with PCR screening. Australian toads almost exclusively harbor one of seven viruses detected globally. Rhimavirus-A (Picornaviridae) exhibited low genetic diversity and likely actively infected 9% of sampled Australian toads extending across ~2,000km of Northern Australia and up to the current invasion front. In native range cane toads, we identified multiple phylogenetically distinct viruses (Iridoviridae, Picornaviridae, Papillomaviridae, and Nackedna-like virus). None of the same viruses was detected in both ranges, suggesting that Australian cane toads have largely escaped the viral infection experienced by their native range counterparts. The novel native range viruses described here are potential biocontrol agents, as Australian toads likely lack prior immunological exposure to these viruses. Overall, our evidence suggests that there may be differences between viruses infecting cane toads in their native vs. introduced ranges, which lays the groundwork for further studies on how these viruses have influenced the toads’ invasion history.