Cold tolerance strategies of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)

Abstract

The fall armyworm (FAW), Spodoptera frugiperda, is native to the tropical and subtropical areas of the American continent and is one of the world's most destructive insect pests and invaded Africa and spread to most of Asia in two years. Glycerol is generally used as a cryoprotectant for overwintering insects in cold areas. In many studies, the increase in glycerol as a main rapid cold hardening (RCH) factor and enhancing the supercooling point was revealed at low temperatures. There are two genes, including glycerol-3-phosphate dehydrogenase (GPDH) and glycerol kinase (GK), that were identified as being associated with the glycerol synthesis pathway. In this study, one GPDH and two GK sequences (GK1 and GK2) were extracted from FAW transcriptome analysis. RNA interference (RNAi) specific to GPDH or GK1 and GK2 exhibited a significant down-regulation at the mRNA level as well as a reduction in survival rate when the RNAi-treated of FAW larvae post a RCH treatment. Following a cold period, an increase in glycerol accumulation was detected utilizing high-pressure liquid chromatography and colorimetric analysis of glycerol quantity in RCH treated hemolymph of FAW larvae. This research suggests that GPDH and GK isozymes are linked to the production of a high quantity of glycerol as an RCH factor, and glycerol as main cryoprotectant plays an important role in survival throughout the cold period in this quarantine pest studied.

Fitness and cold tolerance of Spodoptera frugiperda fed on corn and two winter crops

“…For example, abscisic acid, a component of nectar, pollen and honey, increased the tolerance of honeybees ( Apis mellifera ) to low temperatures (Ramirez et al., 2017), and D. melanogaster flies developed on feeds with rich carbohydrates recovered from chill coma faster than reared on feeds with rich proteins (Andersen et al., 2010). On the other hand, stress tolerance of FAW could be improved by several strategies, such as life‐history change, transcriptional regulation of heat shock proteins and accumulation of small molecular protectants (Samanta et al., 2021; Vatanparast & Park, 2022; Wu et al., 2022). However, it needs further research to expose the mechanism that cold tolerance of FAW larvae was improved by feeding on cabbage.…”

“…For example, abscisic acid, a component of nectar, pollen and honey, increased the tolerance of honeybees (Apis mellifera) to low temperatures (Ramirez et al, 2017), and D. melanogaster flies developed on feeds with rich carbohydrates recovered from chill coma faster than reared on feeds with rich proteins (Andersen et al, 2010) heat shock proteins and accumulation of small molecular protectants (Samanta et al, 2021;Vatanparast & Park, 2022;Wu et al, 2022).…”

Different development and fecundity between Spodoptera frugiperda USA and China populations, influenced by ecdysone‐related genes

“…OR743236 and OR743237, respectively. Insect rearing and determination of larval instar were conducted according to Vatanparast and Park (2022). In brief, larvae were raised until pupation under laboratory‐controlled conditions (26 ± 1°C, 70 ± 5% RH, and a photoperiod of 14 h:10 h [L:D]) with an artificial diet according to the manufacturer's instructions, and adults were fed 10% sucrose solution.…”

Predicting the Global Potential Suitable Distribution of Fall Armyworm and Its Host Plants Based on Machine Learning Models

“…The results (Figure S1) indicate that temperature indicators have the greatest impact on the global suitable areas for the FAW, with an average relative importance of 0.19, and the minimum temperature of the coldest month having the most significant impact, with a relative importance of 0.21. This may be due to the lack of diapause in the FAW, making it difficult for them to overwinter in cold regions [66]. Low winter temperatures limit their distribution in high-latitude areas.…”