ABSTRACT
Although mosquitoes are well-known vectors of human and animal diseases, pathogens are only minor components of their total endogenous microbial communities. The midguts of many insects, including mosquitoes, contain diverse microbial communities. In this study, we used denaturing gradient gel electrophoresis to identify the diversity of bacteria in field-collected adult female Culiseta melanura (Diptera: Culicidae) (Coquillett) and Coquillettidia perturbans (Diptera: Culicidae) (Walker). Few significant differences in bacterial fauna between the two mosquito species were found, but the results suggest that host life history may be a determinant of the endogenous bacterial communities in mosquitoes. In the present study, the dominant bacteria are frequently identified as major components of other mosquito species' microbial flora, suggesting the establishment of a stable association between the mosquitoes and the microbes after initial acquisition from the environment.
Subject(s)
Bacteria/isolation & purification , Culicidae/microbiology , Insect Vectors/microbiology , Animals , Bacteria/genetics , DNA, Bacterial/genetics , Denaturing Gradient Gel Electrophoresis , Female , Microbiota , Molecular Sequence Data , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Rhode Island , Seasons , Sequence Analysis, DNA , Species SpecificityABSTRACT
Three studies investigating the relationship between components of evaluation anxiety and typing performance are reported. Subjects represented business college students enrolled in typing (N=49) and English (N = 39) classes, applicants for clerical positions (N=50), and college students (N=11). State-trait anxiety inventory A-trait scores (Study I only) and scores on a 10-item questionnaire designed to assess both the cognitive (worry) and emotional components of state anxiety were correlated with performance measures reflecting both typing speed and accuracy. Contrary to expectations, self-reported physiological and affective arousal (emotionality) was consistently shown to have little debilitative effect on performance. This finding was consistent across groups differing in degree of typing skill and across situations differing in amount of anxiety induced. Rather, worry scores were correlated negatively with performance as in studies of other types of academic performance.
