Comparison of the Olfactory Preferences of Four of Filth Fly Pupal Parasitoid Species (Hymenoptera: Pteromalidae) for Hosts in Equine and Bovine Manure.

The research examines the olfactory preferences of four filth fly pupal parasitoid species, relating to hosts in equine and bovine manure. The objective is to understand the behaviors of these species within agricultural environments, which might help in managing pest control.

Study Context

• The study revolves around House flies and stable flies, common irritants in equine and cattle facilities. Pupal parasitoids, specifically from the genera Spalangia and Muscidifurax can be utilized for biological control of these flies.
• However, not much data exists regarding the habits and preferences of these parasitoids when seeking hosts. This gap is what the current study aims to fill.

Methodology

• To decide the preferences, a Y-tube olfactometer was used in the laboratory. This equipment allows the study of response to odors.
• The odor stimuli investigated were from manure (without flies), manure with third-instar house flies, and manure with fly host puparia.
• Two species each from the Spalangia and Muscidifurax genus were studied for their olfactory preferences.

Findings

• It was observed that S. cameroni and S. endius showed a strong attraction to the odor associated with equine manure.
• S. cameroni also showed attraction to bovine manure-containing treatments, while S. endius was attracted only to bovine manure with third-instar flies.
• Contrarily, neither of the Muscidifurax species showed an attraction towards equine manure. They only preferred bovine manure with puparia over clean air.

Implications of the Study

• The study suggests that different host-seeking behaviors might promote coexistence between the competing Pteromalid parasitoid species.
• The particular preferences of these species suggest their suitability for deployment in specific livestock and equine facilities to control pest populations.