. Contributions to the biology of the Danish Culicidae. Mosquitoes; Malaria. 106. Textfig. 14. Tceniorhynchus pupa, frontally. parts a very remarkable, highly specialised structure; in the part nearest to the cephalothorax the structure resembles that of a trachea, being striped transversely; where the tube attenuates, the transversal stripes cease and are succeeded by a more homogeneous structure with a very fine irregular rhomboidal stripening, resembling that of a common pupa tube. A little before the spot where the tube attenuates, passing into the accuminated part, there is a weak point,
. Contributions to the biology of the Danish Culicidae. Mosquitoes; Malaria. 106. Textfig. 14. Tceniorhynchus pupa, frontally. parts a very remarkable, highly specialised structure; in the part nearest to the cephalothorax the structure resembles that of a trachea, being striped transversely; where the tube attenuates, the transversal stripes cease and are succeeded by a more homogeneous structure with a very fine irregular rhomboidal stripening, resembling that of a common pupa tube. A little before the spot where the tube attenuates, passing into the accuminated part, there is a weak point, where the chitin is thin and where the apical part breaks off very easily. At the same spot a chitinous ring runs round the tube, on the inner side leaving a cleft open. Out- side this ring the tube acuminates; the inner half has almost the same structure as that on the other side of the ring, but the outer part is formed quite differently. It has a broad fringe of long hairy excrescences and the utmost part, which is commonly corkscrew-shaped, and lying in another plane, has a hyaline transversally striped membrane on each side, which has inconspicuous saw- teeth along the edges. It is this extreme part which must be used as a piercing organ. The tracheal tube, which runs from the apical opening to the above-named chiti- nous ring, has a rather narrow lumen, being only one- third broader than the tube in this part; immediately behind the ring it expands to almost the whole width of the tube, but tapers again and now runs as a narrow tube through the whole air-tube. The tubes, which in the case of all other mosquito pupae are directed outward and divergent, are convergent in the Tceniorhynchus pupae (Fig. 16); the acuminated parts are laid against each other when pierced into the stem; it looks as if the two tubes only made one single hole when piercing; perhaps it is not quite improbable that the two acuminating parts act along each other when piercing and in this way saw a ho
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectmalaria, bookyear1920
