Objective To study phototaxis of Cryptolestes ferrugineus adults, the female adults of Cryptolestes turcicus and Cryptolestes pusillus to lights with different wavelengths.

Method A light behavior reaction device was used to test the phototactic ratios of 1-day-old, 11-day-old, 21-day-old and 31-day-old (female) adults of three species of Cryptolestes to lights with wavelengths of 303, 320, 330, 340, 351, 368, 400, 445, 460, 480, 520, 525, 545, 560, 575 and 580 nm.

Result The wavelengths of simulating lights resulting in the highest phototactic ratios of the 1-, 11-, 21-, and 31-day-old adults of C. ferrugineus were 351, 351, 400, and 480 nm respectively. The wavelengths with relatively better trapping effects for C. ferrugineus adults were 351, 400 and 445 nm. With the increase of age, the number of wavelengths that led to over 20% phototactic ratio of C. ferrugineus increased. The phototactic ratios of 1-, 11-, 21-, and 31-day-old female adults of C. turcicus ranged from 16% to 51%, 11% to 46%, 7% to 37%, and 4% to 28% respectively, and the light wavelengths resulting in the highest phototactic ratios were 351(368), 368, 330, and 351 nm respectively. The wavelengths with relatively better trapping effects for female adults of C. turcicus were 368, 351 and 303 nm. The phototactic ratios of 1-, 11-, 21-, and 31-day-old female adults of C. pusillus ranged from 51.11% to 75.56%, 18.89% to 70.00%, 33.33% to 62.22%, and 22.22% to 71.11% respectively, and the light wavelengths resulting in the highest phototactic ratios at these four ages were 575, 320, 400(445), and 320(560) nm respecticely. The wavelengths with relatively better trapping effects for female adults of C. pusillus were 320, 575 and 330 nm.

Conclusion The phototactic ratios of C. ferrugineus adults increase with age, the phototactic ratios of the female adults of C. turcicus decrease with age, and the phototactic ratios of the female adults of C. pusillus decreases slightly with age.