Ceratopogonidae 391 



Family ceratopogonidae 



METHODS OF COLLECTING AND REARING 

 CERATOPOGONIDAE 



Lillian Thomsex, Bethany College, Lindsborg, Kansas 



1ARVAE were collected from various localities and from such materials 

 ^ as blanket algae in ponds; algae in springs, streams, ponds, and 

 lakes; mud taken from the shores of springs, ponds, and lakes; water 

 in tree-holes; and the ooze of ulcers on maple and elm trees. 



The material was examined in different ways after being brought in. 

 The larvae in algae could be removed by placing the algae on a screen 

 over a silk bolting cloth bag and playing a strong stream of water on 

 them. This method removed about 75% of the larvae of the swimming 

 type, but such larvae as the Atrichopogon, Stilobezzia, and Dasyhelea 

 had to be removed singly from the algae, the material being examined 

 filament by filament under the binocular microscope. The larvae found 

 in mud were obtained in like manner by sifting the mud. The pebbles 

 were retained by the screen while the mud was washed into a shallow 

 enameled pan and the larvae were then readily seen swimming at the 

 edge or over the bottom of the pan. The larvae living under the bark 

 of trees had to be picked off singly with a needle under a microscope. 

 After thus collecting and sorting out the various species, each was 

 placed in a separate Syracuse watch glass containing water and material 

 from the natural environment of the larvae. The watch glasses were 

 stacked to prevent evaporation. The herbivorous larvae did not require 

 more food than the algae or bark first supplied them, but the carnivorous 

 larvae required frequent feeding. 



The food of the carnivorous forms consisted of newly hatched chiro- 

 nomids, and mosquito and trichopterous larvae. Some of the Bezzia and 

 Probezzia larvae would also attack chironomid larvae two or three 

 times their own diameter. Often a number would help to devour one 

 larva. If no food was available they would become cannibalistic, the 

 victim often being one of their own number in the prepupal stage. The 

 larger larvae such as those of the genera Bezzia and Probezzia would also 

 eat larvae of the smaller Culicoides and Alluaudomyia. 



The larvae had to be placed in individual watch glasses, where pupa- 

 tion occurred. The pupae, after remaining in the algae for one or two 

 days, worked their way to the edge of the watch glass by awkward 

 movements of the caudal end of the body. From here they were trans- 

 ferred to cotton-stoppered vials lined with wet blotting paper, where 

 with a wiggling movement they would work their way up the sides. 

 After emergence the flies were transferred to dry vials. Attempts 



