Methodology for rearing, development, and reproduction of Iridopsis panopla Prout (Lepidoptera: Geometridae) on different diets

Abstract

Abstract Damage caused by insect pests, such as Iridopsis panopla Prout, 1932 (Lepidoptera: Geometridae), has been frequent and can reduce the volume of timber produced in eucalyptus plantations by up to 40%. This study aimed to establish a laboratory rearing methodology and evaluate the development and reproduction of Iridopsis panopla on different diets. The experiments were conducted at the Insect Biotechnology Laboratory (BIOINSECTH) of the Universidade Federal da Grande Dourados, Mato Grosso do Sul, under controlled conditions (25 ± 2 °C, 70 ± 10% RH, and a 14-hour photoperiod). We evaluated larval duration and viability, pre-pupa period and viability, morphological characteristics of caterpillars, pupae, and eggs, sexual dimorphism, as well as pre-oviposition, oviposition, and post-oviposition periods. The width of the cephalic capsule and larval length were measured daily from hatching to the prepupa stage. Five treatments were tested: a diet of Chrysodeixis includens combined with leaves from clone I144 (Eucalyptus urophylla × E. grandis) (D1); a diet of C. includens (D2); a diet of Spodoptera frugiperda combined with leaves from clone I144 (D3); a diet of S. frugiperda (D4); and isolated leaves of clone I144 (D5). The diet significantly influenced the biological performance of the species. The combination of leaves from clone I144 (Eucalyptus urophylla × E. grandis) with a C. includens diet (D1) resulted in the best development and reproduction. Diet D4 proved unviable, and the exclusive provision of leaves from clone I14. Iridopsis panopla completed five larval instars on viable diets, with variation in the interval between molts depending on the treatment. Iridopsis panopla can be successfully reared in the laboratory, showing better performance when fed with leaves from clone I144 combined with the artificial diet of Chrysodeixis includens.