Host Use and Resource Sharing by Fruit/Seed-Infesting Insects onSchoepfia schreberi(Olacaceae)

Abstract

The interactions between the fruit fly Anastrepha spatulata Stone (Diptera: Tephritidae) and two species of moths, the gelechiid Coleotechnites sp. and an unidentified tortricid species, were examined on their effects on seed production in terms of their exploitation within fruits of Schoepfia schreberi J.F. Gmel (Santalales: Olacaceae). The study was carried out in three experimental sites during 3 yr. Under conditions of abundant fruit, A. spatulata was the dominant exploiter at the population level, as shown by its ability to infest the largest number of fruits of the three herbivores and substantially displace its moth competitors. In a separate experiment, when resource-partitioning species were excluded, A. spatulata infested twice as many fruits as the two moth species (44.3%). Field observations examined the ability of A. spatulata to locate suitable fruits. We found that, the variation in fruit characters influenced fruit suitability in relation to its size (4.1261 ± 0.0272 mm [mean ± SE]) and weight (0.0618 ± 0.0005 mg [mean ± SE]). Uninfested fruits produce viable seed but the interaction of all species (exploiting for the fruits) led to limited seed formation.

Natural enemy defense, provisioning and oviposition site selection as maternal strategies to enhance offspring survival in a sub-social bug

“…In Mexico, eggs are laid in single masses on the underside of S . schreberi leaves or on the non-host vegetation that surrounds host trees in the period September-October, near the end of the rainy season [ 24 , 25 ]. We have named this first batch of eggs "core brood".…”

“…Feeding and juvenile development continues until the adult stage is reached in March-April which is the end of the dry season. Adult bugs enter an inactive phase until late in the rainy season when copulation takes place and oviposition activity begins once more [ 24 , 25 ].…”