Contrasting Starvation Strategies in Congeneric Pentatomids: A Predator ( Arma chinensis ) Versus a Pest ( Halyomorpha halys )

Closely related insect species with different feeding habits may exhibit divergent physiological responses to starvation. Here, we compared the predatory Arma chinensis and the phytophagous pest Halyomorpha halys under identical starvation conditions. A. chinensis survived significantly longer than H. halys (females: 39 vs. 9 days; males: 29 vs. 7 days), with slower body weight decline. Starvation severely suppressed reproduction in both species, associated with arrested ovarian development and downregulation of vitellogenin (Vg) genes. In carbohydrate, lipid, and amino acid metabolism, A. chinensis showed relatively stable expression of key metabolic genes, while H. halys exhibited transient upregulation followed by rapid attenuation. These results suggest that feeding habits may drive divergence in physiological and molecular responses to starvation. The strong starvation tolerance of A. chinensis may have implications for its use in biological control, while the vulnerability of H. halys to food deprivation could be relevant for pest management strategies.