DNA/DNA hybridization and sequencing of rDNA (partial 18S rDNA and ITS1) were used to investigate phylogenetic relationships among seven host-specific Bothriocephalus parasites (Cestoda, Pseudophyllidae). The small nucleotide divergence between six of the seven bothriocephalids suggests that isolation and differentiation of Bothriocephalus lineages in the different host species probably occurre...

Crossbreeding and chromosomal evidence are presented for the existence of a fifth sibling species within the taxon of Anopheles dirus in Thailand. The new species is morphologically identifiable as Anopheles balabacensis "Fraser's Hill form." Structural differences in mitotic chromosomes and extensive asynapsis in hybrid polytene chromosomes indicate that significant genetic divergence exists b...

The current investigation examined the long-term prediction of sibling jealousy assessed in a laboratory-based paradigm on sibling relationship quality 2 1/2 years later. This multi-method longitudinal study included mothers, fathers, and two children from 35 families. Younger siblings were 16 months and older siblings were, on average, 4 years at Time 1. Positive longitudinal associations were...

The host feeding specificity of Anopheles fluviatilis sibling species S, T, and U was determined by analyzing blood meal source using countercurrent immunoelectrophoresis. A distinct difference in the feeding patterns was observed among these species. Species S was found to be predominantly anthropophagic with 91% of the population having fed on human blood. In contrast, species T and U were ei...

During the past 7 years, 24 species of Nearctic mosquitoes have had extensions to their known distribution in the form of 32 new state and province records in the United States and Canada. They are included in this report along with relevant references. Additionally, 3 new United States country records have been established, 3 species have had name changes, a new species of Anopheles and siblin...

Courting males of Drosophila persimilis produce a pulsed "vibration sound," with frequency of oscillation and pulse repetition rate markedly different from that of D. pseudoobscura. These differences probably contribute to reproductive isolation. Flight frequency is the same in both species. Brief "preliminary sounds" are common and the same in both species. Males with large parts of both wings...

Maladaptive hybridization, as determined by the pattern and intensity of selection against hybrid individuals, is an important factor contributing to the evolution of prezygotic reproductive isolation. To identify the consequences of hybridization between Drosophila pseudoobscura and D. persimilis, we estimated multiple fitness components for F1 hybrids and backcross progeny and used these to c...

In the study of chironomids in Armenia several species of Orthocladiinae subfamily of Cricotopus genus, Diamesinae subfamily of Diamesa genus, and Chironominae subfamily of Chironomus genus, have been identified. In the Cricotopus genus two sibling species were found, not distinguishable by larval morphological features, but clearly distinct cytogenetically. Keywords—Armenia, Chironomidae, kary...