Defoliation of mango trees by the mango shoot caterpillar (Lepidoptera: Noctuidae) and its effect on foliage regrowth and flowering.
Schreiner I. H., Nafus D. M.
Author Affiliation: Agricultural Experiment Station, College of Agriculture and Life Sciences, University of Guam, 96923 Mangilao, Guam.
Environmental Entomology 20 : 1556-1561
Abstract : On Guam, mango trees are damaged by the noctuid Penicillaria jocosatrix. Growth variables were measured on trees defoliated by larvae, and on trees that were protected by application of carbaryl. Larvae removed 54% of the foliage of untreated trees compared with 10% in treated trees. Treated trees produced new foliage about twice during the year, whereas damaged trees flushed 4 times. Shoots on damaged trees were shorter and initiated fewer leaves, but the size of the leaves was not affected. There was a significant negative association between severity of damage to a shoot and interval until new shoot initiation. Shoots that flushed out of synchrony with the majority suffered heavier larval damage. Untreated trees compensated for damage by producing additional flushes, but at the end of one year they still had one-third less foliage than treated trees. At the end of one year, trees that had a leaf area 4-5 mē per 25 shoots did not flower in response to an inducer.