Chironomus strenzkei

Author: Fittkau, 1968

Diagnosis (Paratypes coll. ZSM.)
Exuviae 5.5-6.1mm long (n=4).
Colour: Exuviae golden-brown to brown. Contrast in colour between thorax and abdomen not so strongly marked: specimens dark anteriorly also have the abdomen infuscated; outer margin of the anal lobes coloured except at base.
Cephalothorax: Cephalic tubercles LxB 75x77-108x90µm (n=3). Frontal setae 40, 50µm long (n=2). Thoracic horn much branched; basal ring of horn 90x70-108x50µm; tracheal patch 65x23-85x30µm; 9-11 tracheoles across (n=4); 2µm in diameter. Tracheal patch of thoracic horn without an "eye". Thoracic granulation strong anteriorly, elsewhere reduced to reticulate markings or absent.
Abdomen: Hook row II entire, length of row 0.48x width tergite (n=1); hooks 63-66 (n=4). Armament of tergites II-VI in the form of an undivided, usually extensive patch of strong points, the points in each segment increasing in size posteriorly. The point patches increase in extent from tergite II to V, but on VI the patch is more or less reduced. Armament of tergites II-VI not strongly waisted and with the posterior transverse band not successively increasing in extent to tergite VI; usually reduced on VI. Sternites III and IV without shagreen. Parasternite II shagreened. Pleura of segment IV spinulate, spinules up to 16µm long. Comb of segment VIII with 1(2) stout tooth, set on the end of an elongate ventral cuticular mound which exceeds appreciably the apico-lateral corner of the segment. Lateral taeniae of segments V-VIII: 4,4,4,5.
Anal segment: Anal lobes strongly rounded externally. Anal lobe with 53-72 fringe taeniae (n=4).

Species keys out at Page 169: Chironomini 66 Chironomus of the Text Key.

Neotropical species: Amazon, Brazil (Fittkau, 1968a).
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
A central American species which occurs in aquatic plants sold for tropical fish tanks in Europe. It swarms close to the substratum and can thus maintain populations even in covered aquaria. On one occasion a swarm of this species developed over the knees of the author sitting in his living room in England!