Communication Between Coccinella Septempunctata And Myzus Persicae And Its Role In Functional Response

the author studied the visual and olfactory communicationbetween Coccinella septempunctata and Myzus persicae, and the effect of thesecues on the functional response. The main conclusions were summarized asfollows:(1) the ladybird forages the aphids main depending on the volatilesderived from their prey, and the background colour was also involved in thisprocess;(2) the reponse threshod of the ladybird to EβF was4.0μg, larger dosesexhibited attraction; and the reponse threshold to (-)-β-caryophyllene was20μg,also exhibited attraction. When the dose of EβF was fixed at20μg, the additionof (-)-β-caryophyllene with more than5μg showed significant attraction; andwhen the dose of(-)-β-caryophyllene was fixed at20μg, attraction was alsofound when large doses of EβF was added. However, none of the treatmentsindicated that (-)-β-caryophyllene could inhibit the attraction of EβF;(3) the reponse threshold of the aphid to EβF was0.4μg showingextremely significant repellence; However, larger doses showed extremelysignificant attraction. These results are not inaccordance with previous reports inthe reponse threshod. The cause may be different bioassays used. For example,in the Y-typed olfactometer, dropping behaviour can not be tested, and thealarmed aphids ordinarily exhibit feigning death, and recovered after somewhatperiod, and the recovered individuals would search their host plants after along-term wabble. We found that (-)-β-caryophyllene could not inhibit the alarmresponse of the aphids, the previous findings may be the prolonging of feigningdeath when the two compounds were tested in combination.(4) Different sensory impairments of the ladybirds extremely affected theprey consumption. Compound eye blacken did not affect the foraging process,even exhibited weak feeding promotion. While the removal of the antenna(e)significantly reduced the searching efficiency of the ladybirds, altered the functional response pattern from HollingⅡ to HollingⅠ type, and increased theinstantaneous attack rate. The prey consumption of the ladybirds under thepresence of refuge was far lower than that of without refuge, and this effect wasincreased along with the prey density. This indicates that space heterogeneityand the distribution pattern of the prey patches should be considered for theapplication of Holling’s theory into practice.