Development of an improved and accessible diet for western corn rootworm larvae using response surface modeling

Area of Science:

• Entomology
• Pest Management
• Insect Nutrition

Background:

• The western corn rootworm (WCR), *Diabrotica virgifera virgifera*, is a significant pest impacting maize (*Zea mays*) cultivation.
• Existing WCR diets rely on corn root powder, a component unavailable for commercial purchase, hindering practical application.
• The lack of accessible WCR diet formulations limits research and effective pest management strategies.

Purpose of the Study:

• To formulate a practical and effective WCR diet utilizing readily available ingredients, excluding corn root powder.
• To optimize WCR larval performance using a mixture design approach and response surface modeling.
• To develop a WCR diet that matches or exceeds the performance of current public and proprietary formulations.

Main Methods:

• Employed response surface modeling and mixture designs to systematically explore eight protein sources (animal, plant, yeast).
• Evaluated larval performance based on weight gain, molting success, and survival rates.
• Compared the novel WCRMO-2 diet against established public and proprietary WCR diets.

Main Results:

• The new WCRMO-2 diet, free of corn root powder, achieved approximately 97% larval survival and successful molting.
• Larval weight gain on WCRMO-2 was fourfold greater than on the best previously published WCR diet after 10 days.
• WCRMO-2 demonstrated comparable larval performance to the best proprietary WCR diet and a commercial version performed similarly.

Conclusions:

• A novel WCR diet (WCRMO-2) has been successfully formulated using available ingredients, overcoming limitations of previous formulations.
• WCRMO-2 supports WCR larval development, survival, and growth at levels equal to or exceeding existing diets.
• This accessible formulation provides a valuable tool for WCR research and the development of sustainable pest management strategies.