Order of inoculation affects the success of co-invading entomopathogenic fungi

Area of Science:

• Entomology
• Plant Pathology
• Biological Control

Background:

• The diamondback moth (Plutella xylostella) is a significant agricultural pest.
• Pandora blunckii and Zoophthora radicans are entomopathogenic fungi with potential for pest control.
• Understanding interactions between co-infecting pathogens is crucial for developing effective biological control strategies.

Purpose of the Study:

• To investigate the impact of inoculation order of Pandora blunckii and Zoophthora radicans on Plutella xylostella.
• To determine how co-infection affects larval mortality and pathogen dominance.

Main Methods:

• Larvae of Plutella xylostella were inoculated with either Pandora blunckii or Zoophthora radicans singly.
• Larvae were also co-inoculated with both fungi, with varying orders of application.
• Larval mortality and the proportion of larvae infected by each fungal species were assessed.

Main Results:

• Co-inoculation significantly reduced the proportion of larvae infected by either fungal species compared to single inoculations.
• The order of inoculation critically influenced the outcome of the co-infection.
• The fungal isolate inoculated last consistently resulted in higher larval mortality than the isolate inoculated first.

Conclusions:

• Co-infection dynamics between Pandora blunckii and Zoophthora radicans can lead to reduced infection prevalence in Plutella xylostella.
• The sequence of pathogen application is a key factor determining the efficacy of fungal biocontrol agents.
• Strategic sequencing of fungal inoculations may enhance pest control outcomes against Plutella xylostella.