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Seed predation due to the yucca moth symbiosis

January 1, 1984

All species of Yucca (Agavaceae) require the pollinator services of a species of moth in the genus Tegeticula (Lepidoptera: Incurvariidae). These moths oviposit in the ovary of the plants and the larvae are entirely dependent upon Yucca seeds for food. The extent and distribution of larval seed predation was examined in nine Yucca species in the southwestern United States. The proportion of seeds destroyed by the yucca moth ranged from 3 % in Y. schidigera from coastal southern California to 45 % in one population of Y. angustissima from southern Utah. This sampling was done in 1979 at which time the Y. schidigera population averaged 0.6 larvae per fruit and the population of Y. angustissima averaged 9.3 larvae per fruit. A second sampling of these populations in 1982 averaged 0.5 for Y. schidigera and 5.6 for Y. angustissima. Several species showed significant differences between populations in the number of larvae per fruit. Contrary to expectation, based on the dogma that fruit production is dependent upon Tegeticula pollination (which is always followed by oviposition), a large number of fruits were found without larvae. The proportion varied greatly between populations but was as high as two thirds of all fruits in some populations. Observations suggested that these flowers had been pollinated by Tegeticula and the moths had oviposited in them but that the eggs failed to hatch.

Publication Year 1984
Title Seed predation due to the yucca moth symbiosis
DOI 10.2307/2425472
Authors Jon E. Keeley, Sterling C. Keeley, C. C. Swift, J. Lee
Publication Type Article
Publication Subtype Journal Article
Series Title American Midland Naturalist
Index ID 1007755
Record Source USGS Publications Warehouse
USGS Organization Western Ecological Research Center