Table 2.

Comparative efficacy of different optical devices for red palm weevil infestation detection at different heights of date palm trunk above ground level at Riyadh, Saudi Arabia.

Devices	Red palm weevil infestation detection accuracy assessment at different heights of date palm trunk
	n	20 cm	n	100 cm	n	150 cm
Actual	31	100 ± 0.0a	31	100 ± 0.0a	31	100 ± 0.0a
Radar 2000	41	73 ± 7b	33	72 ± 8a	23	91 ± 6ab
Radar 900	9	78 ± 15ab	3	67 ± 33a	3	67 ± 33b
Resistograph	25	76 ± 9ab	21	62 ± 11a	13	85 ± 10ab

Means followed by the same letter in same column were not significantly different at α: 0.05. n = number of date palm trees observed.