Objective To compare the similarities and differences between the morphology and biology of two insects of the Ceracris, Ceracris kiangsu Tsai and Ceracris nigricornis Walker.

Method The adults of two kinds of Ceracris collected from the same geographical area were reared in a greenhouse, and their morphological characteristics: body length, antennae, hind femur, head width, external genitalia, etc., and living habits: activity rules, mating habits. The feeding habits of host plants were observed, recorded and statistically analyzed.

Result The results showed that the body length of the female adult C. kiangsu was 36.55 ± 1.42 mm, the antennae was 23.46 ± 1.29 mm, the hind femur was 21.68 ± 0.28 mm, and the head width was 5.33 ± 0.2 mm; the body length of the male adults was 31.35 ± 0.75 mm, the antennae was 23.22 ± 0.9 mm, the hind femur was 17.86 ± 0.23 mm,and the head width was 4.08 ± 0.19 mm. The body length of the female adult of C. nigricornis was34.63 ± 0.44 mm, the antennae was 18.34 ± 0.56 mm, the hind femur was 18.67 ± 1.62 mm, and the head width was 4.61 ± 0.18 mm; the body length of the male adult was 26.82 ± 2.77 mm, the antennae was 17.75 ± 1.58 mm, the hind femur was 16.09 ± 0.47 mm, the head width was 3.5 ± 0.29 mm. There were significant differences in body length between male and female adults of the same species of Ceracris insects. There were significant differences in body length, antennae, hind femur, and head width between the two types of Ceracris insects. The peak mating period of the C. kiangsu was 14-17 o'clock, and the peak mating period of the C. nigricornis was 9-12 o'clock. Two kinds of Ceracris adults showed the same feeding preference when faced with three different host plants, and they all preferred to eat bamboo (Phyllostachys edulis), followed by plantain (Musa basjoo), and finally brome (Bromus inermis), but the C. nigricornis consumed more food than the C. kiangsu.

Conclusion The similarity and difference in morphology and biological learning of the two kinds of Ceracris insects are the basis for the sympatric occurrence of the two kinds of Ceracris insects, which provides some basic information support for the monitoring and control of the two kinds of Ceracris insects.