Ecophysiological responses of individually and group reared Cydalima perspectalis (Lepidoptera: Crambidae) to alkaloid-containing host plants

Abstract

The box tree moth, Cydalima perspectalis (Walker), is an invasive pest of Hyrcanian forests in Iran. In the current study, the effects of two boxwood species, Buxus hyrcana Pojark and B. microphylla Sieb. and Zucc. (Buxales: Buxaceae), were examined on ecophysiology of the pest. The demographic parameters were evaluated based on the age-stage, two-sex life table theory. The physiological characteristics of C. perspectalis were considered through fresh/dry weights and individually/group rearing methods. The results showed that C. perspectalis larvae were able to develop, survive and reproduce on both boxwood species. The developmental times were 41.62 and 41.46 days on B. hyrcana and B. microphylla, respectively. The total lifespan did not differ on boxwood species. However, the difference of fecundity on B. hyrcana (412.82 eggs/female) and B. microphylla (286.06 eggs/female) was significant. The intrinsic rate of increase (r) and finite rate of increase (λ) were significantly higher on B. hyrcana than B. microphylla. The nutritional indices showed that the consumption index (CI) on B. hyrcana were significantly lower than on B. microphylla based on fresh/dry weights in both rearing methods. Conversely, the efficiency of conversion of digested food (ECD) and the efficiency of conversion of ingested food (ECI) on B. hyrcana were significantly higher than on B. microphylla. Despite nonsignificant differences in leaf nutrient contents (except calcium), total protein, triglyceride, and alkaline phosphatase activity were inversely different in larvae compared to adult stage on boxwood species. These findings could help to comprehensively understand the performance of the pest on boxwood species.

Defense Responses of Different Rice Varieties Affect Growth Performance and Food Utilization of Cnaphalocrocis medinalis Larvae

“…Insects exhibit physiological and behavioral adaptations in response to plant defense compounds, resulting in alterations such as modifying the food consumption rate or enhancing their digestive efficiency. These adaptations ultimately lead to increased energy allocation from food intake to body mass (Kholghahmadi et al 2023;Rayapuram and Baldwin 2006). After infestation by C. medinalis, YY1540 may produce defense substances such as protease inhibitors that inhibit larval feeding and decrease the digestibility of leaf proteins (Cheah et al 2020;Bolter and Jongsma 1997), resulting in lower protein accumulation.…”