Sex-Specific physiological strategies of Dalbulus maidis (Hemiptera: Cicadellidae) for surviving overwintering stress

Dalbulus maidis (Hemiptera: Cicadellidae), the principal vector of maize stunting pathogens in the Americas, poses a major threat to maize (Zea mays L.) productivity, especially in Argentina. Adult corn leafhoppers are known to exhibit morpho‑physiological traits, such as polyphenism and reproductive dormancy, to withstand unfavorable conditions. However, other physiological responses to seasonal stress remain poorly understood. In this study, we investigated sex‑specific metabolic and immunological adjustments that support survival under variable environmental conditions. Results showed that proteins, lipids, soluble carbohydrates, glycogen, fatty acid composition, and phenoloxidase (PO) activity significantly changed across summer, autumn, and winter. Seasonal increases in protein and lipid content were evident, with males exhibiting higher protein levels and females accumulating more lipids during autumn. Glycogen reserves varied by sex, with females storing more glycogen than males, particularly in summer and winter. PO activity showed pronounced sex‑ and season‑dependent variation: females invested in immune activation during colder months, whereas males maintained consistently low enzymatic activity. Seasonal shifts in mono‑ and polyunsaturated fatty acids were detected, although the saturated/unsaturated ratio remained stable. These findings show that D. maidis employs distinct physiological strategies—immune activation, energy storage, and lipid metabolism—that differ between sexes and across seasons. By revealing these mechanisms, our study provides novel insights into insect physiological plasticity and highlights how environmental stress shapes metabolic and immunological regulation in a major agricultural pest.