Development of an artificial diet with a mass-rearing and low-cost approach for Spodoptera frugiperda reproduction

The fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a pest that causes up to 70% of economic losses in low-input (e.g., non-transgenic) maize in Mexico, but also reproduces for commercial purposes in artificial or natural diets that require either abundant capital or intensive labor, respectively. The objective of this work was to develop an artificial diet with a mass-rearing approach and low-cost to reproduce S. frugiperda, which once achieved will allow us to reproduce under this same rearing concept the parasitoid Telenomus remus Nixon (Hymenoptera: Scelionidae), a beneficial insect reported to parasitize up to 91% of the egg masses of lepidopteran pests. After the execution of three sequential experimental phases, a diet was developed that produced adults 27.02% biologically inferior to those reproduced on corn foliage (control colony). This diet featured a low cost innovative approach for mass-rearing S. frugiperda: it consisted of inexpensive ingredients (considering only the ingredients, producing one full-grown larvae costs 0.032 USD), it did not require agar, its preservatives are commonly used in the bakery industry, and both household equipment as well as simple facilities were used; therefore, although it was inferior to corn foliage, it is considered a viable option. We hope that the simplicity of this diet in terms of facilities, procedures, and ingredients will open the possibility for rural farmers to produce T. remus under a mass-rearing and low-cost approach; thus, it can become a viable option for lepidopteran pest control in maize, especially within low-input systems worldwide.