<*9 



Addition of a Liquid Insect Growth Regulator ( 1 G R ) to Larva] Media of 

 Flies 



In order to simulate conditions in the field, larval diets were 

 moistened with water containing various levels of a liquid 1GR. 

 Control diets were prepared using plain water. 



Diets were placed in 360-ml cups and first-instar house fly larvae 

 were added instead of eggs. Cups were covered with screen and put in 

 the growth chamber until pupae eclosed and adults died. 

 Laboratory Tests with Granular Baits 



Knockdown tests. Test baits were sprinkled in brown paper bags, 

 21 by 13 by 6 cm, which had been stapled side by side to a piece of 

 wood ca. 61 cm in length. This arrangement of baits was stored outside, 

 under the eaves of the laboratory, to simulate actual weathering 

 cond i t ions . 



On the morning that baits were placed in the bags, the knockdown 

 test was conducted. Three- to five-day-old female colony house flies 

 were transferred by means of a vacuum system to cylindrical window 

 screen cages, 12 cm high by 7 cm in diameter. Cages were inverted over 

 the baits with 10 flies per cage and four cages per bait. The cages 

 had no bottom surface and allowed flies to come in direct contact with 

 the baits. Mortality was noted at 10-min intervals throughout the day 

 until all flies had died. Criterion for death was total lack of move- 

 ment. After the test, baits 'were stored as described above. 



Residual tests. At some time interval after the knockdown test 

 and at selected intervals thereafter, the residual activity of the same 

 bait samples used above was tested until daily fly mortality was less 

 than 50%. Flies were exposed to the baits as described above and 

 mortality was recorded after a 6-hr exposure period. 



