-10- 



TABLE 2. FREQUENCY AND LENGTH OF VISITS BY A^ fallacis FEMALES TO 

 FILTER PAPER DISCS HAVING TWO-SPOTTED MITE SILK. (20 

 replicates) 



Condition 

 of disc 



Avg. no. A^ fallacis 

 visits per disc 



Avg. time (seconds) 

 per visit on disc 



With silk 

 Without silk 



3.5 

 6.1 



142 

 13 



In our final experiment reported here, we ex 

 influence of solely chemical substance (s) deposit 

 mites on the host searching behavior of /u_ fallac 

 spotted mites on 1/2 inch diameter filter paper d 

 after which all mites and eggs were removed. We 

 discs in one or another of four different types o 

 water, methanol, chloroform, and hexane. The was 

 were then centrifuged at high speed to remove any 

 such as silk, that might influence /u_ fa.llacis ho 

 We reapplied each extract to a series of fresh fi 

 each of which was dried and placed in the observa 

 single starved Aj_ fallacis female. The searching 

 females was then recorded over a ten-minute perio 



amined the possible 

 ed by two-spotted 

 is . We placed two- 

 iscs for two days, 

 then washed ten such 

 f chemical solvents: 

 hings (= extracts) 



physical substance 

 St searching behavior. 

 Iter paper discs, 

 tion chamber with a 



behavior of the 

 d. 



The results (Table 3) show that host-searching A^ fallacis females'' 

 visited discs treated with the methanol extract an average of 8.2 

 times, nearly three times more frequently than they visited control 

 discs treated with solvent alone (= 3.3 visits). Although the average 

 length of each visit was approximately equal on each disc type, the 

 length of time between visits to discs treated with the methanol 

 extract was only 34 seconds, less than 1/3 the time between visits to 

 check discs (= 112 seconds) . These data, coupled with our observations 

 suggests that host-searching A^ fallacis females were stimulated to 

 repeatedly return to discs treated with methanol-extracted chemical 

 substances deposited by two-spotted mite prey. 



TABLE 3. FREQUENCY AND LENGTH OF VISITS AND RETURNS BY A. fallacis 



FEMALES TO FILTER PAPER DISCS TREATED WITH CHEMTCAL EXTRACTS 

 OF SURFACES PREVIOUSLY VISITED BY TWO-SPOTTED MITE PREY. 

 (20 replicates) 



Avg . No . A_^ fallacis 

 Solvent visits per disc 



Average time (seconds) 

 per visit on disc between visits 



