. Blood-sucking mosquitoes of the subtribe Culisetina (Diptera, Culicidae) in world fauna. Mosquitoes. 29 The radial vein R2 is well developed. Beginning at the basal portion, it runs through the whole surface of the wing parallel to the costal vein and ends at the wing apex forming the boundary between the anterior and outer margins of the wing (the ptermen). There is significant variability in the sector radii (Rs) and their branches. In most members of Culisetina, the sector radius branches out smoothly from R (Fig. 20a, 1). In other cases, Rs begins independ- ently and is joined to the rad
. Blood-sucking mosquitoes of the subtribe Culisetina (Diptera, Culicidae) in world fauna. Mosquitoes. 29 The radial vein R2 is well developed. Beginning at the basal portion, it runs through the whole surface of the wing parallel to the costal vein and ends at the wing apex forming the boundary between the anterior and outer margins of the wing (the ptermen). There is significant variability in the sector radii (Rs) and their branches. In most members of Culisetina, the sector radius branches out smoothly from R (Fig. 20a, 1). In other cases, Rs begins independ- ently and is joined to the radial vein with a distinct crossvein which could be called the proximal radial crossvein, Pr (Fig. 20a, 2, 3). The base of the sector radii is sometimes shifted some distance from this crossvein (Fig. 20a, 2); sometimes the displacement is toward the base (Fig. 20a, 3). An examination of these structures leads one to agree with Zalesskii (1943) that Rs is far from invariably an actual branch of the radial vein, but is an independent structural element of the wing. He named it "antemedian". However, all branches of the sector radii in mosquitoes (R2, R3, and R4+5) represent veins of the same sign as the radial vein itself, that is, upper veins (Rodendorf, 1946) and this supports the stated view and the corresponding terminology. The last radial vein R4+5 in some cases branches smoothly from the Rs (Fig. 20b, 1) and in others is connected to the Rs with a 29 distinct crossvein called the distal-radial crossvein Dr (Fig. 20b, 2,3). Sometimes this vein and the radio-medial vein serve as a continua- tion of each other (Fig. 20b, 2); however, sometimes it is shifted distally (Fig. 20b, 3) or proximally from R-M. These variations of the proximal and distal-radial crossveins are not detected to the same extent in various species and groups of 3 ^*<?*??*. wm-cT2E«m1+2 28 Fig. 20. Variation of some wing veins. a, b and c—wing sections (in the horizontal plane); 1, 2 a
Size: 1986px × 1259px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversi, booksubjectmosquitoes
