Marie-Claude Larivière

Aim Many invasive plant species benefit from enemy release resulting from the absence of insect herbivores in their invaded range. However, over time, specialized herbivores may ‘catch up’ with such invasive plants. Black locust is a tree species with a relatively limited native range in North America but has invaded large areas in virtually every temperate continent including North America. We hypothesize that both intra- and intercontinental spread of black locust leads to a parallel, though delayed pattern of intra- and intercontinental spread of insect herbivores. Location Global. Taxon Black locust, Robinia pseudoacacia, and its insect herbivores. Methods We compiled historical records of the occurrence of insect herbivore species associated with R. pseudoacacia from all world regions. Based on this list, we describe taxonomic patterns and investigate associations between environmental features and numbers of non-native specialist herbivores in the portion of North America invaded by R. pseudoacacia. Results A total of 454 herbivorous species are recorded feeding on R. pseudoacacia across the world, with 23 of these being specialized on Robinia. From this group, seven species have successfully expanded their range beyond North America. Within North America, the richness of specialists is explained by a combination of road density, R. pseudoacacia density, distance from the R. pseudoacacia native range, and climate. Main Conclusion Non-native herbivore species have accumulated on invasive R. pseudoacacia in both North America and in other continents. The steady build-up of invasions likely has diminished the enemy release that this invasive tree species has benefited from – a trend that will likely continue in the future. These findings support the hypothesis that invasive plants promote parallel though delayed invasions of specialist insect herbivores.

The superfamily Cercopoidea is commonly named as “spittlebugs”, as its nymphs produce a spittle mass to protect themselves. Cosmoscartini (Cercopoidea: Cercopidae) is a large and brightly colored Old World tropical tribe, including 11 genera. A new genus Nangamostethos gen. nov. (type species: Nangamostethostibetense sp. nov.) of Cosmoscartini is described from Niubao Formation, the late Eocene of central Tibetan Plateau (TP), China. Its placement is ensured by comparison with all the extant genera of the tribe Cosmoscartini. The new fossil represents one of few fossil Cercopidae species described from Asia. It is likely that Nangamostethos was extinct from the TP due to the regional aridification and an overturn of plant taxa in the late Paleogene.

Insect phenological lability is key for determining which species will adapt under environmental change. However, little is known about when adult insect activity terminates and overall activity duration. We used community‐science and museum specimen data to investigate the effects of climate and urbanisation on timing of adult insect activity for 101 species varying in life history traits. We found detritivores and species with aquatic larval stages extend activity periods most rapidly in response to increasing regional temperature. Conversely, species with subterranean larval stages have relatively constant durations regardless of regional temperature. Species extended their period of adult activity similarly in warmer conditions regardless of voltinism classification. Longer adult durations may represent a general response to warming, but voltinism data in subtropical environments are likely underreported. This effort provides a framework to address the drivers of adult insect phenology at continental scales and a basis for predicting species response to environmental change.

Climate change will cause drastic fluctuations in agricultural ecosystems, which in turn may affect global food security. We used ecological niche modeling to predict the potential distribution for four cereal aphids (i.e., Sitobion avenae, Rhopalosiphum padi, Schizaphis graminum, and Diurphis noxia…

Plant pest invasions cost billions of Euros each year in Europe. Prediction of likely places of pest introduction could greatly help focus efforts on prevention and control and thus reduce societal costs of pest invasions. Here, we test whether generic data-driven risk maps of pest introduction, val…

Hotspots are priority marine or terrestrial areas with high biodiversity where delineation is essential for conservation, but equally important is their linkage to the environmental policies of the overall region. In this study, fish diversity presences were linked to abiotic conditions and differen…

随机森林(Random forest)模型在2001年发表后得到广泛的关注。由于随机森林可以进行回归和判别等多种统计分析,而且不受正态性、方差齐性和自变量独立性等参数检验的前提条件的制约,其应用日益普遍,有被看作万能模型的趋势。实际上,随机森林是一种特点鲜明的模型,应用局部优化拟合观察值,在分析有偏效应关系的数据时,其结果往往不准确。本文以蝉科(Cicadidea)物种的分布数据为例,比较了随机森林在回归分析时与多元线性回归、广义可加模型和人工神经网络模型的差别,在判别分析时与线性判别分析的差别,强调了随机森林预测时的碎片化特点。结果显示随机森林在处理有多元共线性和交互作用的数据时,以及在判别…

In multiple regression Y ~ β0 + β1X1 + β2X2 + β3X1 X2 + ɛ., the interaction term is quantified as the product of X1 and X2. We developed fractional-power interaction regression (FPIR), using βX1M X2N as the interaction term. The rationale of FPIR is that the slopes of Y-X1 regression along the X2 gr…

We provide an annotated checklist of species recorded from caves and other subterranean habitats in the state of Georgia, USA. We report 281 species (228 invertebrates and 53 vertebrates), including 51 troglobionts (cave-obligate species), from more than 150 sites (caves, springs, and wells). Endemi…