Host and environmental factors influencing 'Candidatus Liberibacter asiaticus' acquisition in Diaphorina citri

Pest Manag Sci. 2018 Dec;74(12):2738-2746. doi: 10.1002/ps.5060. Epub 2018 Jul 7.

Abstract

Background: Diaphorina citri is a vector of 'Candidatus Liberibacter asiaticus' (CLas) associated with citrus Huanglongbing. In this study, the infection and titers of CLas in the psyllid, were monitored for life cycle stage, sex, host-plant CLas titer, host-plant genotype, and ambient temperature.

Results: Acquisition efficiency of CLas by D. citri was highest in nymphs reared at 25 °C on a host plant with high CLas titers but was independent of the host genotypes assessed and of vector sex. We further observed that D. citri nymphs acquired CLas more rapidly than adults based on acquisition access periods (AAPs). CLas did not multiply in the alimentary canal, hemolymph, and salivary glands of adults for 18 days after a 3-day AAP as adult. However, CLas multiplication was detected in hemolymph and salivary gland of adults after the bacterium was acquired by nymphs. Eighty percent of salivary glands of adults contained CLas 18 days after a 3-day AAP as nymph compared to 10% 18 days after a 3-day AAP as adults.

Conclusion: Different factors tested herein influenced CLas acquisition efficiency of D. citri, CLas multiplication and spread inside the psyllid. These observations serve to better understand mechanisms of CLas infection in D. citri. © 2018 Society of Chemical Industry.

Keywords: Asian citrus psyllid; CLas infection proportion; life stage; relative titers; spread of CLas infection.

MeSH terms

  • Animals
  • Environment*
  • Hemiptera / microbiology*
  • Host-Pathogen Interactions*
  • Insect Vectors / microbiology
  • Nymph / microbiology
  • Rhizobiaceae / physiology*