Do cytotypes of black flies of the Simulium arcticum complex (Diptera: Simuliidae) arise from sibling species?

To better understand the evolutionary radiation of the Simulium arcticum complex of black flies (Diptera: Simuliidae), we compared the geographic distributions of present-day larvae to their sex-chromosome diversity. We used the 5 known data sets including collections and sex-chromosome analysis from 307 geographic locations of 31 taxa of approximately 20,000 larvae from throughout the geographic range of distribution of the complex, from Alaska, western Canada, and the western United States to southern California, Arizona, and New Mexico. Siblings (reproductively isolated in sympatry) have considerably larger geographic distributions than do cytotypes (not reproductively isolated in sympatry), suggesting that the former may have been in existence longer than the latter. Simulium negativum (the oldest member of the complex), S. brevicercum (standard noninverted sex chromosomes), S. saxosum (sex determination on the X chromosome), and S. arcticum s. s. (IIL-3) share geographic distributions with all other siblings. Notably, 21 of 22 cytotypes share geographic distributions within those of siblings. Cytotypes are almost always discovered within the geographic distributions of siblings, suggesting that the former might be arising sympatrically.

Para comprender mejor la radiación evolutiva del complejo Simulium arcticum de moscas negras (Díptera: Simuliidae), comparamos las distribuciones geográficas de las larvas actuales con la diversidad de sus cromosomas sexuales. Utilizamos cinco bases de datos conocidas, incluyendo colecciones y análisis de cromosomas sexuales de 307 zonas geográficas de 31 taxones, de aproximadamente 20,000 larvas a través del rango geográfico de distribución del complejo. Desde Alaska, el oeste de Canadá y el oeste de los Estados Unidos hasta el sur de California, Arizona y Nuevo México. Las especies hermanas (reproductivamente aisladas en simpatría) poseen distribuciones geográficas considerablemente más grandes que los citotipos (no reproductivamente aislados en simpatría), sugiriendo que los primeros pueden haber precedido a estos últimos. Simulium negativum, el miembro más antiguo del complejo, S. brevicercum (cromosomas sexuales estándares no invertidos), S. saxosum (determinación sexual en el cromosoma X) y S. arcticum s. s. (IIL-3) comparten sus distribuciones geográficas con todas las demás especies hermanas. Cabe destacar que 21 de los 22 citotipos comparten distribuciones geográficas con las de las especies hermanas. Los citotipos casi siempre se descubren dentro de las distribuciones geográficas de especies hermanas, indicando que los primeros podrían surgir en simpatría.

A Taxonomic Checklist of the Mosquitoes of Montana With Notes On New Geographic Distributions.

An updated checklist of 50 species of mosquitoes found in Montana is presented and includes 2 new records (Aedes niphadopsis and Anopheles walkeri) that can be added to the 2005 state list by Darsie and Ward. The results of a statewide mosquito surveillance program, conducted annually from 2004 to 2015, facilitated the establishment of an abundance rating of the species in the state and expanded the known geographic range for Coquillettidia perturbans, Ae. nigromaculis, and Culiseta minnesotae.

Monitoring sheep and Culicoides midges in Montana for evidence of Bunyamwera serogroup virus infection.

INTRODUCTION: A serological and entomological investigation was performed to monitor for potential Bunyamwera (BUN) serogroup virus activity in Montana. RESULTS: To facilitate the serological investigation, sera were collected from 104 sheep in 2013 and 2014 and assayed by plaque reduction neutralization test using all six BUN serogroup viruses known to occur in the United States: Cache Valley virus (CVV), Lokern virus (LOKV), Main Drain virus (MDV), Northway virus, Potosi virus and Tensaw virus. BUN serogroup virus-specific antibodies were detected in 41 (39%) sheep. Of these, three were seropositive for MDV, one was seropositive for CVV, one was seropositive for LOKV and 36 had antibodies to an undetermined BUN serogroup virus. Additionally, 30,606 Culicoides sonorensis were collected in 2013 using Centers for Disease Control and Prevention (CDC) light traps and assayed for cytopathic virus by virus isolation in African Green Monkey kidney (Vero) cells. All midges were negative. Almost one-third of the midges were further tested by reverse transcription-polymerase chain reaction using BUN serogroup virus-reactive primers and all were negative. CONCLUSIONS: We provide evidence of BUN serogroup virus infection in sheep but not C. sonorensis in Montana in 2013-2014. This study also provides the first evidence of CVV, MDV and LOKV activity in Montana.