Host Suitability of Phaseolus lunata for Trichoplusia ni (Lepidoptera: Noctuidae) in Controlled Carbon Dioxide Atmospheres

Abstract

Elevated atmospheric carbon dioxide (CO2) levels of 1,000 parts per million (ppm) significantly increased consumption of foliage by Trichoplusia ni (Hübner) and significantly enhanced growth of Phaseolus lunata L. when compared with ambient levels of 340 ppm. Mean pupal weight was less under treatments with elevated atmospheric CO2 under a high fertilization regime, but larval survival and percent nitrogen content of pupae were not affected by level of CO2 treatments at high, medium, or low fertilizer rates. Regardless of CO2 concentration, larval survival and pupal weight were reduced in absence of fertilizer. Nitrogen and protein consumption increased with fertilization rate. Because percent leaf area of plants consumed by T. ni larvae was not affected by CO2 concentration, this study suggests that increased plant growth resulting from elevated atmospheric CO2 may benefit the plant proportionately more than the insect.