10 Annals Entomological Society of America [Vol. VI, 



water and algae. This prevents frequent disturbance of the 

 water, and allows the frightened mosquitos to regain their 

 equilibrium. When dishing-up the water, a shadow should not 

 pass over the surface of the pond, as this causes the larvae to 

 wriggle away. The alg£e in the bucket should be removed after 

 the larvae clinging to them have been dislodged. The contents 

 of the bucket may then be strained through a clean piece of 

 surgical gauze. In this manner the larvae and pupae are not 

 lost, while the very young larv^, small debris, etc., are allowed 

 to wash into the pond or stream. The gauze should be inverted 

 over a wide-mouthed jar, and water applied very carefully 

 with a pipette to the larvse. These are thereby released from 

 the gauze and placed in the jars. Small pails are as servicable 

 as jars. 



The receptacles containing the larvae and pupae must be 

 kept in a cool, shaded spot, otherwise the water will quickly 

 foul. Not more than one and a half inches of water should be 

 allowed in these jars. The larvae should not be left in these 

 containers for more than one half a day. Overcrowding must 

 be avoided and at least once each half day the water should be 

 aerated. A Paquelin Cautery bulb, with a capillary tube 

 attached, serves well this object, and one or two bulbfuls will 

 be found ample. 



B. Transportation: The larvae in these wide-mouthed jars 

 should be taken each half day to the field laboratory, and here 

 emptied into plates or larger receptacles. Prior to transporta- 

 tion, the jars should be placed into a basket and separated from 

 each other with excelsior or cotton wadding, and while carried, 

 shaking must be reduced to a minimum. Constant shaking 

 prevents the larvae from reaching the surface of the water to 

 breathe and hence repeated unsuccessful attempts to reach the 

 surface bring fatigue and a large percent if not all of the larvae 

 succumb as a result. Protection from heat and direct light 

 must be considered. The jars themselves must be covered 

 with a close-mesh gauze to prevent the escape of adults emerged 

 en route. If larvae or pupae are transported in trains or vehicles, 

 extra precaution should be taken regarding shaking, and 

 additional precaution to prevent inquisitive people from hand- 

 ling these jars and shaking them "to see the wrigglers wriggle," 



