Survival and lifespan of Diaphorina citri on non-host plants at various temperatures

Abstract

Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the insect vector of Candidatus Liberibacter asiaticus (Las), the causal bacteria of the devastating citrus disease Huanglongbing (HLB). Many citrus orchards in China have been destroyed by HLB infection.The survival time of ACPs without food was related to the temperature they experienced. The longest survival time of adult ACPs was 5.93 ± 0.12 days when the mean temperature was approximately 12 °C. The shortest lifespan of ACP adults was 2.33 ± 0.12 days when the mean temperature on the test day was approximately 26 °C. Surprisingly, ACP could feed on herbaceous plants in the absence of preferred hosts. The most suitable weed species for the ACP was Solanum nigrum, with the longest survival time of 41 days for all individuals tested. The survival time of ACPs feeding on herbaceous plants was also related to temperature. The surviving 20% and 10% of ACP adults in the Solanum nigrum treatment showed no decline but slight improvement as compared with control in the fecundity.In conclusion, some ACPs may be able to live for a month or even longer in an orchard if suitable plants and temperatures are available. The Las-infected ACPs that can survive by feeding on herbaceous plants may be sources of Las infection in replanted orchards. The suggested time to replant citrus in groves that were previously infected with Las is summer to autumn, or it is recommended to leave the land idle for more than three months.