107 



Resu 1 ts. The results of the predation study are shown in Table 1**. 

 The mortality rate of 0. aenesoens larvae was reduced significantly in 

 all cases by the daily addition of house fly larvae. Control mortalities 

 were 100% in all cases, indicating that neither fly species is canni- 

 balistic and that in order to survive, larvae of 0. aenesoens were 

 preying upon larvae of M. domestica. This was, in fact, the case and 

 it was observed on numerous occasions. 



Ophyra larvae never fed for extended periods on a single house fly 

 larva. After killing and feeding briefly on one, they moved on in search 

 of another. When a house fly larva was killed by Ophyra, other house fly- 

 larvae were attracted to the site and began feeding on the dead larva. 

 The clustering of house fly larvae aided Ophyra larvae in their search 

 for prey. This hypothesis was corroborated by fitting the data in 

 Table 14 to a binomial regression model and plotting the graph in Figure 

 20. The goodness of fit was highly significant (p < 0.0001). Larvae of 

 0. aenesoens can destroy more than 20 first- instar house fly larvae per 

 day during the larval developmental period, but further testing is 

 necessary to arrive at a more accurate number. On at least one occasion, 

 a third- instar larva of 0. aenesoens was seen feeding on a pupa of M. 

 domestioa that had not completed the tanning process. 



Since Ophyra adults were allowed to emerge prior to processing, no 

 pupal weights were available to check for differences in the sizes of 

 the adults. An attempt was made to find a correlation between eclosed 

 pupal weight and adult weight, but results were negative. Adults 

 raised in vermiculite did not appear to be smaller than adults from 

 larvae raised in the usual manner. 



