I. ■< 



68 ENTOMOLOGY FOR MEDICAL OFFICERS 



the thoracic scales ever show any periodic or seasonal 



variation. , , , , 



Synopsis of Subgenera <y Anopheles. 



A. The covering of the scutum consists mainly either of hairs or of 



narrow scales. In any ambiguous case the palpi are slender {i.e., 

 are not shaggy with outstanding scales) = i. 



B. The covering of the scutum consists mainly of recumbent, broadish or 



spindle-shaped scales. In any ambiguous case palpi shaggy = 4. 

 '^Abdomen either without scales, or with some inconspicuous narrow 

 scales on the genital lobes and terminal segment, or with a 

 tuft of scales on the ventral surface of the penultimate seg- 

 ment = 2. 

 Abdomen with an outstanding tuft of stiff and slender scales of 

 extraordinary length on each side of every segment (Chiefly 

 hairs on the scutum) = Christya. 

 Abdomen with conspicuous scales on several segments, some of 

 them sometimes forming regular, outstanding tufts ; wing- 

 scales broad. (Chiefly hairs on the scutum) = Arribahagia. 



Wings either not spotted at all, or having a few dark spots formed 

 merely by clumps of scales, or if spotted in contrasted colours 

 then there are not more than two distinctly formed spots of 

 colour on their anterior edge. In any ambiguous case {e.g., 

 where a spot at the tip of the wing is counted as anterior) 

 then the palpi are shaggy with outstanding scales. (Chiefly 

 hairs on the scutum) = 3. 



Wings much spotted in contrasted colours, their anterior edge 

 barred or banded with numerous alternate dark and light 

 spots or streaks. In any ambiguous case the palpi are not 

 shaggy. Inconspicuous narrow scales occasionally present on 

 the terminal abdominal segment and genital lobes. (Either 

 hairs or narrow scales on scutum) = * Myzomyia. 



'No scales on the abdomen {very rarely a few scattered on the 

 genital lobes) = Anoplieles. 



Abdominal scales present, usually as a small outstanding tuft on 

 the ventral surface of the penultimate segment, rarely as a 

 uniform covering to the terminal segment and genital lobes 



= Myzorhynchus. 



(The predominant scales of the head are of the " upright forked " 

 kind = %Nyssorhynchtts. 



The predominant scales of the head are not of the "upright 

 forked "kind = Chagasta. 



* Myzomyia Series. 



a. The covering of the field of the scutum consists mainly of hairs 



,„,.,, = Myzomyia. 



b. The covermg of the scutum consists mainly of narrow scales 



= " Pyretophorus." 



