Host identity and quality drive parasitoid fitness and have implications for biocontrol

Augmentative biocontrol depends on mass-rearing high-quality parasitoids.
Host size and quality directly affect parasitoid fitness and
effectiveness, making the identification of suitable hosts essential for
successful pest control. This study assessed the influence of two pyralid
hosts on the fitness of Venturia canescens (Gravenhorst) (Hymenoptera:
Ichneumonidae), an endoparasitoid of the carob moth Ectomyelois ceratoniae
Zeller (Lepidoptera: Pyralidae) utilizing the natural host, E. ceratoniae,
and an alternative host, the Mediterranean flour moth Ephestia kuehniella
Zeller (Lepidoptera: Pyralidae). A type II functional response was
observed on larval stages of both hosts, indicating similar behavioral
responses of emergent parasitoids to host density. No significant
differences were found for attack rates, handling times, or life history
and morphological traits between hosts.  However, host stage
significantly affected these parameters, with the L5 stage producing
parasitoids with maximal life history and morphological traits. Results
indicate that E. kuehniella is a viable alternative host for the
mass-rearing of V. canescens, supporting its use in biocontrol programs.