25 research outputs found
Occurrence of Different Gynandromorphs and Ergatandromorphs in Laboratory Colonies of the Urban Ant, Monomorium floricola
Colonies of Monomorium floricola (Jerdon) in laboratory conditions showed gynandromorphic and ergatandromorphic specimens, the former with nine different combinations of male and female tissues and the latter with 6 different combinations. Their development from egg to adult was around 74.6 days for gynandromorphs, and 87.5 days for ergantandromorphs
Karyotype, Sex Determination, and Meiotic Chromosome Behavior in Two Pholcid (Araneomorphae, Pholcidae) Spiders: Implications for Karyotype Evolution
There are 1,111 species of pholcid spiders, of which less than 2% have published karyotypes. Our aim in this study was to determine the karyotypes and sex determination mechanisms of two species of pholcids: Physocyclus mexicanus (Banks, 1898) and Holocnemus pluchei (Scopoli, 1763), and to observe sex chromosome behavior during meiosis. We constructed karyotypes for P. mexicanus and H. pluchei using information from both living and fixed cells. We found that P. mexicanus has a chromosome number of 2nâ=â15 in males and 2nâ=â16 in females with X0-XX sex determination, like other members of the genus Physocyclus. H. pluchei has a chromosome number of 2nâ=â28 in males and 2nâ=â28 in females with XY-XX sex determination, which is substantially different from its closest relatives. These data contribute to our knowledge of the evolution of this large and geographically ubiquitous family, and are the first evidence of XY-XX sex determination in pholcids
Guerrobunus vallensis, a new species of harvestman (Opiliones : Phalangodidae), from a cave in Valle de Bravo, State of Mexico, Mexico
Caecoa Silhavy 1973 is synonymized under Guerrobunus Goodnight & Goodnight 1945. The third species of Guerrobunus is named. A taxonomic key to the species of Guerrobunus is provided. Two males and one female of the new species Guerrobunus vallensis are illustrated and described from a cave in Valle de Brave, State of Mexico, Mexico
Comparative study of the morphology of the gland opening area among Grassatores harvestmen (Arachnida, Opiliones, Laniatores)
Two New Cave-Dwelling Species of the Short-Tailed Whipscorpion Genus Rowlandius (Arachnida: Schizomida: Hubbardiidae) from Northeastern Brazil, with Comments on Male Dimorphism
Unnoticed in the tropics: phylogenomic resolution of the poorly known arachnid order Ricinulei (Arachnida)
New Proposal of Setal Homology in Schizomida and Revision of Surazomus (Hubbardiidae) from Ecuador
New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in fragments of the Atlantic Forest, Brazil
New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in Brazil. Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). Studies describing insects as potential hosts have received little attention. Specimens of an undescribed species of the genus Leptus were collected in association with predatory and phytophagous Heteroptera bugs in a secondary forest in Viçosa, Minas Gerais state, Brazil. New mite-host records and information on seasonality of this mite are presented