Postdoctoral Associates

Postdoctoral Associates


Dr. Mark Hoffman

Entomology and Nematology

Phone : 863.956.8667

Email :

Ongoing projects 

1) Diversity of Wolbachia in Diaphorina citri (Kuwayama)

The genus Wolbachia is one of the most common bacterial endosymbionts in arthropods. It is able to cause a wide range of effects on physiology, reproduction and life span of its host, ranging from essential effects on host reproduction to life shortening. In pest management, particular Wolbachia strains could be introduced into insects to reduce their vector competence, especially in dengue fever control. The Asian Citrus Psyllid (ACP, Diaphorina citri) is also host organism for Wolbachia. To investigate as to how (native and artificial) Wolbachia strains can be utilized as a potential tool to control citrus greening (huanglongbing, HLB), a basic knowledge about "what is there?" is essential. Currently I am investigating these questions by assessing the diversity of Wolbachia in Florida ACP populations. 

2) Impact of Candidatus Liberibacter asiaticus on the behavior of Diaphorina citri (Kuwayama)

The Asian Citrus Psyllid (ACP, Diaphorina citri) is vector of Candidatus Liberibacter asiaticus (Las), the causal agent of citrus greening (huanglongbin, HLB). Currently HLB control is highly depending on monitoring and controlling the ACP by the application of insecticides. Knowledge about as to whether and how Las influencing the ACP behavior could be critical in terms of insecticide application plans and monitoring strategies. At the Citrus Research and Education Center, I am investigating the impact of Las on the behavior of the ACP, particularly on its ability to spread HLB. View more ...


Dr. Calum Russell


Phone: 863.956.8667


I obtained my PhD from the Departement of Entomology at Cornell University in June 2013. My thesis work dealt with determining howBuchnera aphidicola, the intracellular endosymbiosic bacteria within aphids, produced essential amino acids when several key genes coding for enzymes were missing from its genome. Our work showed that aphid enzymes were mediating these missing reactions, and that both the host and the bacteria were required to make certain essential amino acids. I am currently a postdoctoral researcher in Dr. Kirsten Pelz-Stelinski's lab working on the Asian citrus psyllid, their endosymbionts, and the pathogene Liberibacter asiaticus. My research interests range from determining the contribution of the resident endosymbionts to psyllid physiology, to the interactions between the endosymbionts and the Liberibacter pathogen, and to the nutritional physiology of the psyllids.