Figure 1.
Behavioural sequence of coccinellid larval encounters.
Grey shaded behaviour indicates end of the observation (adapted from Yasuda et al., 2001 [20]).
Table 1.
Description of larval coccinellid behaviour.
Figure 2.
Effect of species combination on time until first contact.
Survival curves of difference in time until contact between fourth-instar larvae per species combination during 1000-second observations. Censored observations are marked with ‘+’. Abbreviations: H = H. axyridis, C = C. septempunctata, and A = A. bipunctata. Time until contact significantly differs between combinations when all contacts are pooled together (Log-Rank test, pooled pairwise comparisons, P = 0.008).
Table 2.
Results of observations in leaf experiment.
Figure 3.
Effect of previous contact on time until contact.
Survival curves of differences in time until first (solid line) and second or later contact (dashed line) are shown for each species combination. Two fourth-instar larvae were observed for 1000 seconds. Censored observations are marked with ‘+’. Abbreviations: H = H. axyridis, C = C. septempunctata, and A = A. bipunctata. Difference between first and second or later contact is significant (Log-rank test, pooled pairwise comparisons, p = 0.018).
Figure 4.
Effect of temperature on time until first contact.
Survival curves of differences in time until first contact at temperatures below and above 25°C are shown for each species combination. Two fourth-instar larvae were observed for 1000 seconds. Censored observations are marked with ‘+’. Effect of temperature on time until first contact is significant (Cox’ regression model, Wald test = 13.521, df = 1, p<<0.001).
Figure 5.
Behaviours observed in leaf experiments.
Two fourth-instar larvae were observed for 1000 seconds on one leaf. A: Total number of contacts made per species combination during all observations. Total number of observations per species is given in table 2. B: Total number of non-aggressive responses after contact, when paired with conspecifics or heterospecifics (abbreviated to ‘con’ and ‘het’ respectively). C: Total number of aggressive responses after contact, when paired with conspecifics or heterospecifics (abbreviated to ‘con’ and ‘het’ respectively). Catch frequency of H. axyridis is significantly higher when paired with heterospecifics than when paired with conspecifics X21 = 6.081, Fisher’s exact test p = 0.013). Abbreviations: H = H. axyridis, C = C. septempunctata, and A = A. bipunctata.
Figure 6.
Incidents observed in tree experiment.
Total number of incidents per species combination of two fourth-instar larvae observed on a lime tree during 540 time points (all data summed over 36 time intervals of 15 3-hour observations). Incidents are: ‘on same leaf’, ‘contact’, ‘predation after 3 hours’, and ‘predation after 24 hours’. The number of observations is indicated for the three treatments where the larvae were observed on the same leaf more than once. Abbreviations: H = H. axyridis, C = C. septempunctata, and A = A. bipunctata. Predation in the combination HA and HC was always by H. axyridis.
Figure 7.
Larvae dropping from lime tree.
Total number of incidents (dropping from and returning to lime tree) by fourth-instar larvae during 540 time points (all data summed over 36 time intervals during 15 3-hour observations per species combination). Abbreviations: H = H. axyridis, C = C. septempunctata, and A = A. bipunctata. Difference in drop frequency was significant between species X22 = 89.902, Pearson p<0.001); difference in returning to tree between sunny or cloudy conditions was significant X21 = 8.400, Pearson p = 0.004).
Table 3.
Attack, catch, and predation frequencies in literature.