•
Methods
Searching behaviors
No Response
Response
Make choice
Only Searching
Choice A
Choice B
Y-tube
Host finding behavior of corn leaf aphids
aCO
2
eCO
2
Chambers
Barley rearing in
ambient CO
2
condition
( aCO
2
)
Barley rearing in
elevated CO
2
condition
( eCO
2
)
Nymphs
Wingless
adults
Winged
adults
Prefer
？
•
Results
Clean air vs. aCO
2
barley seedlings
(* P ≤ 0.05 ; **P ≤ 0.01 ; ***P ≤ 0.001) 25 0 50 75 100 25 50 75 100 No responses Responses
Only searching Make choice
Clean air eCO2
nymph wingless winged Tested No. 180 180 180 nymph wingless winged 147 151 76 nymph wingless winged 59 132 65 (%) P *** *** *** *** * * n.s n.s * 18.3 16.1 52.2 81.7 83.9 47.8 59.9 12.6 14.5 45.8 40.9 33.8 40.1 87.4 85.5 54.2 59.1 66.2
Figure 5 Choice (%) of corn leaf aphids toward clean air vs. eCO2 barley seedling.
25 0 50 75 100 25 50 75 100 No responses Responses
Only searching Make choice
aCO2 nymph wingless winged Tested No. 180 180 180 nymph wingless winged 152 158 98 nymph wingless winged 86 144 90 (%) P *** *** *** *** * * n.s n.s 15.6 12.2 45.6 n.s 43.4 8.9 8.2 53.5 37.5 34.4 84.4 87.8 54.4 56.6 91.1 91.8 46.5 62.5 65.6 eCO2
Figure 6 Choice (%) of corn leaf aphids toward eCO2 vs. aCO2 barley seedling.
Nymphs, wingless and
winged adults preferred the
odors of aCO
2
barley
seedlings to clean air.
Clean air vs. eCO
2
barley seedlings
Wingless and winged
adults like choosing the
odors of eCO
2
barley
seedlings when tested
against clean air.
eCO
2
vs. aCO
2
barley seedlings
Wingless and winged
adults were more attracted
by odors from aCO
2
barley seedlings than eCO
2
barley seedlings.
Figure 1 Three different morphs of corn aphids and barley seedlings reared in
ambient and elevated CO
2conditions
Figure 2 Experiment equipment
Figure 3 Experimental technology roadmap
• Conclusion and Discussion
Yu Chen
1,2
, François Verheggen
2
, Junior Corneille Fingu Mabola
2
, KangLai He
1
*
, Frederic Francis
2
*
1
State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection,
Chinese Academy of Agricultural Science, Beijing, China
Effects of elevated CO
2
concentrations on host finding
behavior of corn leaf aphids Rhopalosiphum maidis
25 0 50 75 100 25 50 75 100 No responses Responses
Only searching Make choice
Clean air aCO2
22.8 8.9 42.8 49.6 5.5 13.6 37.1 26.5 32.6 77.2 91.1 57.2 50.4 94.5 86.4 62.9 73.5 67.4 nymph wingless winged Tested No. 180 180 180 nymph wingless winged 139 164 103 nymph wingless winged 70 155 89 (%) *** *** *** *** *** * * n.s n.s
Figure 4 Choice (%) of corn leaf aphids toward clean air vs. aCO2 barley seedling
P
