180 MOSQUITOES OF NORTH AMERICA 



taper to a small rounded point; integument smooth. The eggs hatched by a sUt 

 on one side, nearly half the length of the egg, no lid being detached. 



The larvae live in water rich in decomposing organic matter or the remains 

 of insects, such as collect in dead plant-tissues or occasionally at bases of living 

 leaves or in artificial receptacles. They develop fairly rapidly under suitable 

 conditions of temperature and food, but may live a long time when the food- 

 supply is insufficient. The water in old cocoanuts and cacao-husks becomes often 

 as thick as syrup from the decomposing pulp of the fruit, and so black as to-be 

 opaque. In these conditions the Joblotia larvae flourish, to the exclusion of 

 other mosquito larvae. Dead insects which have fallen into the water furnish 

 additional food. We quote the following from Mr. Knab's notes : 



" The larvae are opaque, cream-white ; head ferruginous yellow ; tube and anal 

 plate brown; tracheae narrow, but slightly dilated, gray; stomach caecae small; 

 digestive tract brown; anal segment greatly dilated towards the orifice, with 

 four large, rather long tracheal gills which are almost continually vibrated. 

 When at the surface the larvae hang perpendicularly. They feed upon dead in- 

 sects that have fallen into the water ; the bodies of some dead larvae were eaten 

 into by them. The water contained dead ants, staphyUnids, flies, etc. The pupa 

 is pitchy brown, the segmental incisures dirty white; pale brownish beneath. 

 Air-tubes dull orange, rather short, very broad at tip. Abdomen long and 

 pendant when the pupa is at the surface. Paddles very short, dull yellow; last 

 two segments with lateral ample fan-tufts of hairs. The pupa can remain at the 

 bottom for some time without moving and without any hold, even in a smooth 

 bottle." 



At Sonsonate, Salvador, Mr. Knab found the larvae in eocoanut-husks, asso- 

 ciated with lAmatus cacophrades, Mmmagogus albomaculatus, Wyeomyia aporo- 

 noma, Wyeomyia hemisagnosta, and Megarhinus moctezuma. 



Mr. Busck says : 



" The fat short-tubed larvae were to be found in any bamboo-joint which con- 

 tained the thick, saturated, often ill-smelling fermenting fluid, to which they 

 seem partial. They were bred in Trinidad from cacao-husks, in which the 

 fluid was as thick as gruel. 



" Transferred to water, which is less rich in food, these larvae remain alive 

 unchanged for long periods. Some of my Trinidad larvae lived for four months 

 after reaching Washington, and some of the Panama material did nearly as well. 

 The normal development, under natural conditions, with abundant food, takes 

 about two weeks." 



Dr. Goeldi says : 



" It is a forest mosquito. The images bred by us in captivity never would 

 accept blood. Fed with honey and water, they lived, in four cases of which I 

 took notes, from five to nine days. Neither of the females captured at large 

 would lay eggs in captivity, nor would the females reared from larvse." 



Forested regions of tropical America, southern Mexico to Brazil. 



Santa Lucrecia, State of Vera Cruz, Mexico, adult captured, June 21, 1905 

 (F. Knab) ; Sonsonate, Salvador, larvs in eocoanut-husks and cacao-shells, 

 August 19 to 30, 1905 (F. Knab) ; Izalco, Salvador, larvae in eocoanut-husks, 

 August 21 to 31, 1905 (F. Knab) ; Port Limon, Costa Rica, larvae in an old 

 kerosene-tin, half filled with dirt and rubbish, and in a cocoanut-husk, with 

 thick, slimy water, September 30, 1905 (F. Knab) ; Tabernilla. Canal Zone, 

 Panama, larvae in bamboo, May 21, June 15, July 18, 1907 (A. Busck) ; Gatun, 

 Canal Zone, Panama (A. H. Jennings) ; Montserrat, Trinidad, British West 

 Indies, larvae in old half cacao-shells in cacao woods, very dirty black water, 

 June 20, 1905 (A. Busck) ; Upper Pequini River, Panama, March 30, 1909^ 



