Wheat-Bran-Based Artificial Diet for Mass Culturing of the Fall Armyworm, ISpodoptera frugiperda/I Smith

• Published in: Insects (Basel, Switzerland) Switzerland), 2022-12, Vol.13 (12)
• Main Authors: Ge, Shishuai, Chu, Bo, He, Wei, Jiang, Shan, Lv, Chunyang, Gao, Lingyun, Sun, Xiaoting, Yang, Xianming, Wu, Kongming
• Format: Article
• Language: English
• Subjects: Army-worms; Bran; Control; Food and nutrition; Identification and classification; Physiological aspects; Wheat
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects13121177

The fall armyworm (FAW), Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), has become a global agricultural pest. Reducing the rearing cost of FAWs will be helpful for developing new environmentally friendly management strategies for this pest. As such, we researched an artificial wheat-bran-based diet for FAWs. The biological indicators (developmental duration, pupal weight, reproductive parameters, and flight ability) of the FAWs fed this diet were consistent with those of FAWs fed a traditional artificial diet in a laboratory setting. The rearing cost of using this new diet was lower by nearly 24%. These findings indicate that this artificial diet, based on wheat bran, is suitable for rearing FAW larvae, which will effectively reduce the rearing cost of FAWs. Spodoptera frugiperda Smith (fall armyworm (FAW)) has invaded many countries in Africa and Asia in recent years, considerably restricting global agricultural production. In this study, we assessed the rearing performance of four artificial diets (D[sub.1] : an artificial FAW diet based on wheat bran and soybean, maize, and yeast powders; D[sub.2] : an artificial diet developed for Helicoverpa armigera (Hübner), based on wheat bran and soybean and yeast powders; D[sub.3] : an artificial diet based on soybean powder; D[sub.4] : an artificial diet based on wheat bran) for FAWs. We designed D[sub.4] based on a traditional diet (D[sub.2] ) but substituted the wheat bran for soybean and yeast powders. At 25 ± 1 °C, 75% ± 5% RH, and a 16:8 h L:D photoperiod, the larval stage of FAWs fed on D[sub.4] lasted 15.88 d, the pupal stage lasted 9.48 d, the pupal mass was 270.45 mg, the number of eggs deposited was 1364.78, and the mating rate was 89.53%. Most biological indicators of the larvae that were fed D[sub.4] were basically consistent with those of the larvae fed on the traditional diet (D[sub.2] ), but the intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R[sub.0] ) of the D[sub.4] FAWs were lower than those of the D[sub.2] FAWs. The flight capacity (flight distance, duration, and velocity were 19.73 km, 6.91 h, and 2.90 km/h, respectively) of the D[sub.4] FAWs was comparable to that of the FAWs fed a traditional diet and maize leaves. Compared with the three other formulas, the cost of using D[sub.4] was lower by 26.42% on average. These results show that using cheap wheat bran instead of soybean flour and yeast powder as the basic material for an artificial die