Cephaline gregarines of the earwig,Forficula auricularia,in England

From morphological data and polypeptide patterns two species of eugregarine were distinguished in the intestine of the earwig, Forficula auricularia L., in England. One was Gregarina ovata Dufour, 1828 and the other G. forficulae Lipa, 1967 previously reported from Poland.     

European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), at the Hanford Reach National Monument, Washington State

The European earwig, Forficula auricularia L., was surveyed using pitfall traps at 3 sites at the Hanford Reach National Monument in south central Washington State. Pitfall traps were collected weekly from April 2002 through April 2003. The earwig was consistently taken during all months of the year at a disturbed, weedy site along the Columbia River (White Bluffs Ferry site) but was rare or not collected in 2 less-disturbed shrubsteppe habitats. Highest numbers occurred during April–May, when immatures accounted for the majority of the catch; immatures reached the adult stage during mid-July, and the species is univoltine at the site. Possible reasons why earwigs have not colonized the monument’s shrubsteppe habitat include the arid climate with lack of available moisture, especially for breeding purposes, and a lack of burrow sites. La tijereta Europea, Forficula auricularia L., fue estudiada usando trampas de caída en tres sitios del Hanford Reach National Monument en el sur del estado de Washington. Se colectaron los contenidos de las trampas de caída semanalmente desde abril de 2002 hasta abril de 2003. La tijereta apareció constantemente durante todos los meses del año en un sitio perturbado de vegetación herbácea en la orilla del Río Columbia (el lugar del antiguo transbordador White Bluffs) pero su colecta fue escasa o nula en dos hábitats de estepa arbustiva menos perturbados. Los mayores números ocurrieron durante abril y mayo cuando los organismos inmaduros representaron la mayoría de los especímenes capturados; éstos alcanzaron la etapa adulta a mediados de julio y la especie es univoltina en este sitio. Posibles causas de que las tijeretas no hayan colonizado el hábitat de estepa arbustiva del Monumento podrían incluir su clima árido carente de agua disponible, especialmente para la reproducción, y una falta de sitios para madrigueras.     

Oostegite development during the sexual maturation of females of Tmetonyx similis (G. O. Sars, 1891) (Amphipoda,Lysianassidae)

The development of the oostegites was studied in the females of Tmetonyx similis (Crustacea, Amphipoda) during the period of sexual maturation. The process is complex and involves a series of variably long sequences. These sequences may constitute a means of adjusting the animals' sexual maturation to environmental conditions in order to increase their reproductive efficiency. The age and lifespan given by most authors working on amphipod species have probably been underestimated and should be regarded as minimum data. The physiological significance of the development of the oostegites is probably more complex than has generally been thought to be the case up to now.     

Lepeophtheirus pectoralis (O. F. Müller, 1776); a description,a review and some comparisons with the genus Caligus Müller, 1785

Summary

The parasitic copepod Lepeophtheirus pectoralis (Müller, 1776) is described. A review of the hosts indicates that this species is primarily a parasite of members of the family Pleuronectidae although it has been recorded from representatives of ten other families of fishes. The geographical range of L. pectoralis includes the North Eastern Atlantic Ocean, the western part of the Baltic Sea and the White Sea. The similarities between Lepeophtheirus Nordmann, 1832 and Caligus Müller, 1785 are discussed and it is concluded that the only constant morphological discriminant between these two genera is the presence or absence of lunules.