Behavioral studies of A. pisum aphid subclones. (A) Ninety-nine adult wingless aphids (33 white, 33 green, and 33 pink) were placed in an arena and exposed to saturating odors generated by Vicia faba plant extracts as described in Supplemental material. When animals were immobilized, the arena was opened and the time course of the percentage of insects that remained immobile was calculated. Experiments were repeated eight times and the bars indicate the SD. *P < 0.001. (B) The same experiment was performed as described in A except that the three phenotypes analyzed (pink, green, and white) are winged. (C) Aphid survival under conditions of starvation at room temperature. The adult green aphid (induced and propagated at 10°C), the adult pink aphid (propagated at 20°C), and the white aphid (propagated on declining plants at 20°C) were placed at room temperature without a host plant. The mortality rates were then measured every 24 h. This experiment was carried out with 60 aphids and repeated 10 times. The results are presented as a percentage of surviving animals. SD, standard deviation. **P < 0.001. (D) Aphid survival in starving and cold conditions. Adult aphids (pink, green, and white) were placed in an incubator at 5°C in the dark without a host plant and mortality was again measured every 24 h. This experiment was carried out using a group of 60 aphids and repeated 10 times. The results are presented as the percentage of surviving animals. SD, standard deviation. *P < 0.01; **P < 0.001. (E) Photograph of the apparatus and system used for behavioral studies (pusher, syringe, and arena).
