2015•Unpublished venueRequires access
Supercooling points and freezing points of Diaphorina citri Kuwayama and Cacopsylla citrisuga Yang&Li
Huang Zhi
Open publisher page 1 citations
Abstract
Diaphorina citri Kuwayama and Cacopsylla citrisuga Yang Li are important psyllid pests of citrus. D. citri is a primary vector of citrus huanglongbing. C. citrisuga is also proved to be a carrier of the bacterium which causes huanglongbing. Supercooling point( SP) and freezing point( FP) of each instar nymph and adult of the two psyllid species were investigated in this study. The results showed that the averages of SP and FP of 1stinstar nymphs of D. citri were- 26. 32℃ and- 26. 22℃ respectively,the lowest among all tested stages of the species. The averages of SP and FP of adult were- 19. 60℃ and- 18. 71℃ respectively,the highest among all tested stages of the species. The rest order of SP and FPof the other instar nymph ranked from low to high was 2nd,4th,5th,3rdinstar nymphs. SP and FP of the1 stinstar nymph of C. citrisuga were also the lowest among all tested stages of the species,with average value of- 25. 30℃ and- 25. 08℃,respectively. SP and FP of the 5thinstar nymphs of C. citrisuga were- 19. 50℃ and- 17. 69℃ respectively,the highest among all stages. The numbers were statistically significant difference from those of other stages. The order of SP and FP of other instars from low to high was 2nd,3rd,4thnymphs,and adult. When comparing SP and FP of the two psyllid species,different stage showed different result. SP of the 3rdinstar nymph and adult of C. citrisuga were significantly lower than that of D. citri,while SP of 4thand 5thinstar of C. citrisuga were significantly higher than that of D.citri. FP of 3rdinstar of C. citrisuga was also significantly lower than that of D. citri,but FP of 1stand 4th instar nymphs of the species were significantly higher than that of D. citri. The female and male of D.citri were also compared. There was no significant difference between the 2 genders. The results indicate that SP and FP of these 2 psyllid species are both very low,which demonstrate that they might have strong cold tolerance.