Melville Hatch

Insects are the most diverse group of organisms, but their large number of species and the lack of specialists to study them have made this group particularly vulnerable to the main limitations in biological diversity, such as the Wallacean deficit. This study will contribute to the geographical knowledge of an insect trophic guild that has been widely used as an indicator group, the Scarabaeoidea and Silphidae copro-necrophagous beetles, emphasizing their geographical distribution in two Mexican national parks (Iztaccíhuatl-Popocatepetl and La Malinche) and the intermediate region, which includes sky-island ecosystems in central Mexico. Geographic records of the 32 species that have been previously recorded in the study region were compiled and used to generate potential distribution models aiming to generate potential alpha (species richness) and beta (total beta diversity, nestedness and replacement) diversity maps. The greatest predicted species richness was found between 3,000 and 3,500 m a.s.l. in the study region. Potential species richness ranged from 2 to 24 species. Total beta diversity was low in the study region (mean 0.1), while nestedness was the most important component of beta diversity (0.8). The maximum alpha and beta diversity values were predicted outside the national parks. Consequently, we consider that the studied national parks are not able to protect completely the regional alpha and beta diversities by themselves. Implications for insect conservation: Our results show that the highest alfa and beta diversity values of copro-necrophagous beetles might occur outside the national parks, and a suitable way to protect them could be the Archipelago reserve model as an alternative to protect the regional diversity.

AbstractEstablished alien land snail species that were introduced into the Western Palaearctic Region from other regions and their spread in the Western Palaearctic are reviewed. Thirteen of the 22 species came from North America, three from Sub-Saharan Africa, two from the Australian region, three probably from the Oriental Region and one from South America. The establishment of outdoor populations of these species was usually first seen at the western or southern rims of the Western Palearctic. Within Europe, the alien species usually spread from south to north and from west to east. The latitudinal ranges of the alien species significantly increased with increasing time since the first record of introduction to the Western Palearctic. The latitudinal mid-points of the Western Palaearctic and native ranges of the species are significantly correlated when one outlier is omitted. There is a general trend of poleward shifts of the ranges of the species in the Western Palaearctic compared to their native ranges. There are three reasons for these shifts: (1) the northward expansion of some species in Western Europe facilitated by the oceanic climate, (2) the impediment to the colonisation of southern latitudes in the Western Palaearctic due to their aridity and (3) the establishment of tropical species in the Mediterranean and the Middle East. Most of the species are small, not carnivorous and unlikely to cause serious ecological or economic damage. In contrast, the recently introduced large veronicellid slugs from Sub-Saharan Africa and the giant African snail Lissachatinafulica could cause economic damage in irrigated agricultural areas or greenhouses in the Mediterranean and the Middle East.

Agricultural intensification is a key suspect among putative drivers of recent insect declines, but an explicit link between historical change in agricultural land cover and insect occurrence is lacking. Determining whether agriculture impacts beneficial insects (e.g. pollinators), is crucial to enh…

Insects are the focus of many recent studies suggesting population declines, but even invaluable pollination service providers such as bees lack a modern distributional synthesis. Here, we combine a uniquely comprehensive checklist of bee species distributions and >5,800,000 public bee occurrence re…

Well-preserved beetle elytra from the fossil and subfossil record are used by palaeoclimatologists to estimate past temperatures. Beetle-derived estimates of temperature across the Pliocene Arctic are consistently lower than those derived from other palaeoclimate proxies. Here we test if that patter…

Müllerian mimicry theory states that frequency-dependent selection should favour geographical convergence of harmful species onto a shared colour pattern. As such, mimetic patterns are commonly circumscribed into discrete mimicry complexes, each containing a predominant phenotype. Outside a few exam…

Aim: The aim of this study was to test the hypothesis that the global latitudinal diversity gradient pattern in spiders is pear‐shaped, with maximum species diversity shifted south of the Equator, rather than egg‐shaped, centred on the equator, this study infers the gradient using two large datasets…

The American tropics (the Neotropics) are the most species-rich realm on Earth, and for centuries, scientists have attempted to understand the origins and evolution of their biodiversity. It is now clear that different regions and taxonomic groups have responded differently to geological and climati…