“Bottom-up” factors strongly influenced the spatial and temporal pattern of survival of Asphondylia atriplicis Townsend (Diptera: Cecidomyiidae) on Atriplex canescens (Pursh) Nutall (Chenopodiaceae) at three locations in Phoenix, AZ. In contrast, “top-down” effects of natural enemies did not influence the pattern of A. atriplicis mortality. A. atriplicis induces a fleshy, multilocular, rounded stem-gall near the apical meristems of A. canescens. A. atriplicis survival increased as gall size increased, and as the depth of larva in the gall increased. Larval mortality from unknown factors on A. atriplicis decreased with gall size, but the overall interval parasitism rate did not change significantly with gall size. The interval parasitism rate for the eurytomid parasitoid group with the shortest ovipositor was negatively correlated with gall size, but interval parasitism by all other parasitoids was not influenced by gall size. Gall size was strongly influenced by the bottom-up forces of environmental and plant heterogeneity. Gall size varied among seasons, sites, and plants. Larval survival and gall-size covaried in each season and site and among plants.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.