Genera of the bee tribe Reedapini (Hymenoptera: Colletidae)

Those bees classified in the genera Reedapis Michener and Cephalocolletes Michener are discussed and organized into a new tribe, Reedapini Engel. In addition, three species formerly classified in Cephalocolletes are removed to two new genera: Lonchopriscus Engel, new genus, with the species Lonchopriscus crassipunctatus (Urban), new combination, and Cactocolletes Engel, new genus, for Cactocolletes isabelae (Urban), new combination, and C. rugatus (Urban), new combination. The tribe and its constituent genera are diagnosed, and a key is provided for the identification of the latter along with their included species

A new species of Mermiglossa from Kenya, with comments on the arrangement of Old World Panurginae (Hymenoptera: Andrenidae)

A new species of the panurgine bee genus Mermiglossa Friese (Panurginae) is described and figured from females captured near Voi in the southern part of the former Coast Province, Kenya, a historical type locality for several bee species.  Mermiglossa voicola Ascher & Engel, new species, is distinguished from the only other species of the genus, M. rufa Friese from central Namibia.  The new species is readily identified due to its black rather than red metasoma and compound eyes slightly convergent above rather than parallel-sided.  The new species raises the total number of described bee species for Kenya to 343, extends the known distribution of its genus and subtribe from the Namib Desert of southwestern Africa to the western edge of the Nviri Desert of East Africa, and provides further evidence of extensive biogeographic connections between these disjunct xeric areas.  Recent changes in the family-group classification of Old World Panurginae are discussed in relation to recognition of Mermiglossina as a valid subtribe within an expanded tribe Panurgini also including the New World perditines

A new species of Ptiloglossa from Mexico, with new records of Ptiloglossa cyaniventris from Panama and Costa Rica (Hymenoptera: Colletidae)

A new bee species of the genus Ptiloglossa Smith (Colletidae: Diphaglossinae: Caupolicanini) is described and figured from Jalisco, Mexico, while new records are provided for Ptiloglossa cyaniventris Friese from Panama and a single locality in Costa Rica.  Ptiloglossa chamelensis Ayala & Engel, new species, is endemic to Mexico and is close to P. rugata Moure, both sharing a similar shape in the fused metatibial spur, but in the new species the metatibia is widest at the level of the spur, and the female has black integument with dense yellow pubescence on metasomal terga I–IV.  Ptiloglossa cyaniventris is newly recorded from males collected in Panama and Costa Rica and is characteristic for its dark integument, with intense metallic blue highlights on the metasomal terga, the narrow and long metatibia, and elongate metabasitarsus with an anterior, longitudinal ridge and slightly depressed outer surface

The Distribution of Exchange Rates in the EMS

Exchange rates of currencies in the Exchange Rate Mechanism of the EMS are characterized by long periods of stability interrupted by periods of extreme volatility. The periods of volatility appear at times of realignments of the central parities and at times when the exchange rate is within the ERM bands. We begin by considering a procedure for finding outliers based on measuring distance as a quadratic form. The evidence suggests that the exchange rates of the EMS can be described by a mixture of two distributions. We therefore model the exchange rate as switching between two distributions--one that holds in stable times and the other that holds in volatile times. In particular, we use Hamilton's Markov-switching model. In addition, we extend Hamilton's model by allowing the probability of switching from one state to another to depend on the position of the exchange rate within its EMS band. This model has the interesting implication that near the edge of the band, large movements--either realignments or large jumps to the center of the band--are more likely if the move to the edge of the band has been precipitous.