Distribution and biology of the ectoparasitic beaver beetle Platypsyllus castoris Ritsema in North America (Coleoptera: Leiodidae: Platypsyllinae)

The distribution and biology of the beaver beetle, Platypsyllus castoris Ritsema, are summarized for North America. In light of the fact that the beetle uses two beaver species as hosts which have seemingly been separated for some five million years on two continents, it is asked if the Nearctic and Palearctic beetle populations are really the same species

New distributional records of the flightless primitive carrion beetle Necrophilus pettitii Horn in eastern North America (Coleoptera: Agyrtidae)

New distribution records significantly expand the known range of flightless Necrophilus pettitii Horn in the eastern United States

The inter-related dynamics of unemployment and low-wage employment

This paper examines the extent of state dependence in unemployment and the role played in this by intervening low-wage employment. A range of dynamic random and fixed effects estimators are compared. Low-wage employment is found to have almost as large an adverse effect as unemployment on future prospects and the difference in their effects is found to be insignificant. Evidence is presented that low-wage jobs act as the main conduit for repeat unemployment and considerably increases its probability. Obtaining a higher-wage job reduces the increased risk of repeat unemployment to insignificance

The beetle fauna of Dominica, Lesser Antilles (Insecta: Coleoptera) : diversity and distribution

The beetle fauna of the island of Dominica is summarized. It is presently known to contain 269 genera, and 361 species (in 42 families), of which 347 are named at a species level. Of these, 62 species are endemic to the island. The other naturally occurring species number 262, and another 23 species are of such wide distribution that they have probably been accidentally introduced and distributed, at least in part, by human activities. Undoubtedly, the actual numbers of species on Dominica are many times higher than now reported. This highlights the poor level of knowledge of the beetles of Dominica and the Lesser Antilles in general. Of the species known to occur elsewhere, the largest numbers are shared with neighboring Guadeloupe (201), and then with South America (126), Puerto Rico (113), Cuba (107), and Mexico-Central America (108). The Antillean island chain probably represents the main avenue of natural overwater dispersal via intermediate stepping-stone islands. The distributional patterns of the species shared with Dominica and elsewhere in the Caribbean suggest stages in a dynamic taxon cycle of species origin, range expansion, distribution contraction, and re-speciation

Analytical drafting curves provide exact equations for plotted data

Analytical drafting curves provide explicit mathematical expressions for any numerical data that appears in the form of graphical plots. The curves each have a reference coordinate axis system indicated on the curve as well as the mathematical equation from which the curve was generated

The beetles of St. Lucia, Lesser Antilles (Insecta: Coleoptera): diversity and distributions

The published beetle fauna of the island of St. Lucia is summarized. It contains 135 genera, and 175 species in 25 families. Four species are accidentally introduced by human activities. Twenty three species are endemic (restricted) to the island. Twenty seven species on St. Lucia are shared only with other islands of the Lesser Antilles, and 22 species are widespread Antilles endemics. The remaining 56.6% of the fauna is otherwise mostly one which is widely distributed in the Antilles and the Neotropics. This suggests that it is mostly an immigrant fauna originating in the continental Neotropics. Undoubtedly, the actual numbers of species on St. Lucia are many times higher than now reported and may originally have been as high as around 1400 species. Of the St. Lucia species known to occur on other islands, the largest numbers are shared with Guadeloupe (102), St. Vincent (79), and Martinique (55)

The beetles of Martinique, Lesser Antilles (Insecta: Coleoptera); diversity and distributions

This paper summarizes the published information on the beetle fauna of the island of Martinique, in the Lesser Antilles. The fauna is known to contain 42 families, with 201 genera, and 270 species. The families with the largest numbers of species are Cerambycidae (57), Curculionidae (43), Scarabaeidae (42), Tenebrionidae (18), and Staphylinidae (17). At least 15species (5.5%) were probably accidentally introduced to the island by human activities. Forty six species (17.0%) are endemic (restricted) to the island and likely speciated on the island. Sixty seven species (24.8%) are shared only with other islands of the Lesser Antilles (Lesser Antillean endemics), and 26 species (9.6%) are more widespread Antilles endemics. The remaining 116 species (42.8%) in the fauna are otherwise mostly widely distributed in the Antilles and the Neotropical Region. The Martinique beetle fauna has mostly originated elsewhere than on Martinique and is largely an immigrant fauna from other islands of the West Indies or the continental Neotropics. The numbers of Martinique species shared with other larger islands of the Lesser Antilles are (north to south) Montserrat (73), Guadeloupe (175), Dominica (98), St. Lucia (68), St. Vincent (93), and Grenada (88). Undoubtedly, the real number of species on Martinique is much higher than now reported and may actually be around 1600 or more species