The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions

Abstract

The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these endophytes for the biological control of aphids and other herbivores under greenhouse and field conditions.

Genetic characterization, pathogenicity and benomyl susceptibility of Lecanicillium fungal isolates from Argentina

“…However, strain CEP 108, originally isolated from M. persicae and assigned to L. lecanii sensu lato, displayed the highest MST (9.1 days) of all strains tested. In agreement with results of our study, Castillo Lopez, Zhu‐Salzman, Ek‐Ramos, and Sword () found an effect highly significant of Purpureocillium lilacinum and B. bassiana in decreased survival of A. gossypii Glover.…”

Fungi reduce preference and performance of insect herbivores on challenged plants

“…, Akello and Sikora , Castillo Lopez et al. , Lopez and Sword ). Endophytes are a very diverse group (Rodriguez et al.…”

DNA metabarcoding unveils multiscale trophic variation in a widespread coastal opportunist

“…P. lilacinum is a well-studied fungus, being abundant in terrestrial soils (Cham Thi Mai, Nhi Thi Thuy, Duong Thi Thuy, Hoang Nguyen Duc, & Xo Hoa, 2016) and detected in the marine environment (Redou, Navarri, Meslet-Cladiere, Barbier, & Burgaud, 2015;Yue et al, 2015). It is a known pathogen of nematodes and therefore of commercial importance as a biological control agent to manage pests of several crops (Castillo Lopez, Zhu-Salzman, Ek- , & Sword, 2014;Singh, Pandey, & Goswami, 2013). This fungus is even considered to be of medical importance since it can infect humans and other vertebrates with compromised immune systems (Luangsa-Ard et al, 2011).…”