131 



C. nigritulus Theobald non Zett. 

 PI. XXI. 



Extremely small mosquitoes only 3 — 3.5 mm. in length, dark with greyish- 

 brown thorax, without any reddish tint. Abdomen dark, dusky brown with rather 

 distinct pale basal hands, widest in the middle. Venter dusky, not yellow. Legs 

 brown, rather dark. Claw formula of female 0.0 — 0.0 — 0.0; of male 1.1 — 1.1 — 0.0; 

 those of fore and mid legs unequal. - First submarginal cell longer and narrower 

 than second posterior cell, hut only about one-fourth longer; knees faintly yellow 

 not bright white. 



Theobald (1901 p. 140) has referred some extremely small gnats found in 

 England to Zetterstedfs C. nigritulus. He says that it looks very distinct from C. 

 pipiens, ,,but when one comes to examine them, however, the structural differences 

 seem very slight". Edwards (1912 p. 263) maintains that these small gnats are cer- 

 tainly not C. nigritulus Zett., which he regards as a synonym of Aedes cinereus Mg. 

 I suppose that Edwards is quite right in this last supposition. As Edwards how- 

 ever further says "At first sight this variety appears to be totally distinct from C. 

 pipiens, as it is much smaller and darker, the thorax being without any reddish 

 tint. No external structural differences are however observable, and after carefully 

 comparing the larva? of this and typical C. pipiens I could find no differences what- 

 ever" I do not agree with Mr. Edwards. 



Having found the larvae in great numbers in August in a little pond in Arne- 

 have near Tjustrup I have hatched many of these delicate creatures. The pond was 

 very shallow, covered with vegetation; the larvae were always to be found in the 

 waterrim; they were extremely small, and the pupa; much smaller than any mos- 

 quito pupa; I have seen. Unfortunately a large Crabro had one morning eaten all 

 my needled specimens, put them in her nest holes and used them as food for her 

 young ones. No more specimens were hatched and in the two following years the 

 pond contained no water, and I have never seen the species again. The above given 

 description is only based upon my provisional notes. 



As will be seen by the description of the larva? these differ very much from 

 the true C. pipiens larva?, but undoubtedly belong to the pipiens group. Owing to 

 the fact that these small mosquitoes never enter houses (already stated by Theo- 

 bald 1901 p. 141), and to the very conspicuous differences in the larva, I do not 

 refer them to C. pipiens and suppose it is best to refer my specimens to C. nigri- 

 tulus Theob. 



Larva: Head very large, subquadratic, almost rectangular broader than long; 

 a notch at insertion of antenna;; front margin slightly arcuate. Antennae very long, 

 highly arcuate, basal two thirds thickened, spinose; apical third very slender, a very 

 large tuft, much nearer to the apex than to the base; two long setae before tip; 

 a long terminal seta, a short one and a small digit on a pedestal. Anteantennal 

 tufts and lower and upper frontal tufts almost at line. Anteantennal tuft always, lower 



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