Effect of temperature on predation by Harmonia axyridis (Pall.) (Coleoptera: Coccinellidae) on the walnut aphids Chromaphis juglandicola Kalt. and Panaphis juglandis (Goeze)

Egyptian Journal of Biological Pest Control

Table 1 Functional response of H. axyridis on C. juglandicola and P. juglandis under four different temperature regimes

Aphids	Temp. (°C)	Attacking efficiency (a)	Handling time T_h (d)	Predation capacity a/T_h	Maximum predation number 1/T_h	Holling’s type II equation	R²
C. juglandicola	15	0.7944	0.0031	256.2604	322.5806	Na = 0.7944N/(1 + 0.0025N)	0.8756
	20	0.9169	0.0021	434.5543	473.9336	Na = 0.9169N/(1 + 0.0019N)	0.9821
	25	1.0158	0.0020	495.5050	487.8049	Na = 1.0158N/(1 + 0.0021N)	0.9964
	30	1.0862	0.0019	565.7481	520.8333	Na = 1.0862N/(1 + 0.0021N)	0.9923
P. juglandis	15	0.5798	0.0075	77.2065	133.1558	Na = 0.5798N/(1 + 0.0044N)	0.9641
	20	0.8034	0.0042	189.4811	235.8491	Na = 0.8034N/(1 + 0.0034N)	0.9969
	25	0.8386	0.0035	236.8973	282.4859	Na = 0.8386N/(1 + 0.0030N)	0.9978
	30	0.8468	0.0029	293.0194	346.0208	Na = 0.8468N/(1 + 0.0024N)	0.9923