Transmission potential of the entomopathogenic fungi Isaria fumosorosea and Beauveria bassiana from sporulated cadavers of Diaphorina citri and Toxoptera citricida to uninfected D. citri adults

Abstract

Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the vector of the causal agent of Huanglongbing disease, and Toxoptera citricida Kirkaldy (Hemiptera: Aphididae) is the vector of the citrus tristeza virus. D. citri and T. citricida share the same habitat and both are susceptible to Beauveria bassiana and Isaria fumosorosea. Therefore, the aim of this study was to evaluate the horizontal transmission of B. bassiana ESALQ-PL63 and I. fumosorosea ESALQ-1296 between D. citri cadavers and uninfected D. citri adults, as well as between T. citricida cadavers and uninfected D. citri adults under laboratory and semifield conditions. In the laboratory, the presence of one to ten D. citri cadavers infected with B. bassiana and I. fumosorosea in citrus plants resulted in mortality rates of D. citri adults ranging from 51.2 to 81.9 % and 36.2 to 68 %, respectively. When T. citricida cadavers were used, the mortality rates of uninfected D. citri adults ranged from 35.4 to 87.7 % with B. bassiana and from 41.7 to 80.4 % with I. fumosorosea. The horizontal transmission was also confirmed under semi-field conditions. The results indicate that the control of D. citri using I. fumosorosea and B. bassiana can be promoted through conidial cycling in T. citricida, by generating new infection cycles, which may contribute to the overall performance of microbial control in citrus. Keywords Biological control Á Citrus pests Á Entomopathogen Á Horizontal transmission Á Diaphorina citri Á Toxoptera citricida

Understanding psyllid transmission of Candidatus Liberibacter as a basis for managing huanglongbing

“…Current research is focusing on the development of biorational methods for D. citri control involving natural enemies, such as entomopathogens (Conceschi et al 2016;Dorta et al 2020), parasitoids, and predators (Parra et al 2016). Some of these natural enemies, e.g., the parasitic wasp Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) (Chien et al 1991;Qureshi et al 2009;Hoddle 2012;Parra et al 2016), predatory mites (Fang et al 2013), and the entomopathogenic fungus Isaria fumosorosea, have proved to be efficient against D. citri under field conditions (Stauderman et al 2012;Lezama-Gutiérrez et al 2012;Ullah et al 2018).…”

Transmission of Metarhizium anisopliae and Beauveria bassiana to adults of Kuschelorhynchus macadamiae (Coleoptera: Curculionidae) from infected adults and conidiated cadavers

“…High inoculum levels and strong persistence suggest that conidia present on cadavers have the potential to suppress pest populations in the field, however, only a few studies have explored the potential for conidia transmission via physical contact with conidiated cadavers (e.g. diamondback moth, Plutella xylostella L. 25 , the Asian citrus psyllid, Diaphorina citri Kuwayama 26 , sweetpotato weevil, Cylas formicarius F. 17 and the Colorado potato beetle, Leptinotarsa decemlineata Say 27 , 28 ).…”

Virulence Screen of Beauveria Bassiana Isolates for Australian Carpophilus (Coleoptera: Nitidulidae) Beetle Biocontrol

“…Earlier instar larvae are generally more susceptible to EPF than later instars [34,35]. Transfer of the pathogen between inoculated adults and larvae can occur through direct contact between the insects and through contamination of niches and residual nut habitats through sporulation on mycotic cadavers [33,36]. The high rates of mycosis observed with isolate B54 support the use of an autoinoculation strategy as it presents a greater opportunity for the pathogen to spread among pest groups.…”