Premium
Phylloplane bacteria increase the negative impact of food limitation on insect fitness
Author(s) -
OLSON GRANT L.,
MYERS JUDITH H.,
HEMERIK LIA,
CORY JENNY S.
Publication year - 2017
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/een.12399
Subject(s) - biology , fecundity , phyllosphere , bacteria , larva , insect , pupa , ingestion , toxicology , zoology , food quality , botany , ecology , food science , population , demography , sociology , genetics , biochemistry
1. When populations of herbivorous insects increase in density, they can alter the quantity or quality of their food. The impacts of diet‐related stressors on insect fitness have been investigated singly, but not simultaneously. 2. Foliage quantity and quality of red alder, A lnus rubra, were manipulated together with the presence of non‐entomopathogenic phylloplane bacteria to investigate their impacts, singly and in combination, on survival, pupal mass, growth rate, fecundity and egg quality of a cyclic forest insect, the western tent caterpillar, M alacosoma californicum pluviale . 3. Food limitation (half food) had strong negative impacts on all life‐history traits. When the larvae were fed continuously, however, neither ingesting phylloplane bacteria nor eating leaves from damaged branches (induced foliage) affected survival. In the half‐food treatment, ingesting bacteria further increased mortality, while feeding on induced foliage improved survival. 4. Growth rate and pupal mass of both sexes were reduced for larvae with food limitation compared with continuously fed insects and this was exacerbated when the larvae also ate bacteria‐treated leaves. A combination of bacteria and induced foliage also reduced larval growth rate by 5% in the full‐food treatment. 5. Fecundity (eggs per egg mass) was 2.7 times greater in full‐food than in food‐limited treatments but neither phylloplane bacteria nor plant induction had an effect. Insects fed induced foliage produced smaller eggs. Overall, there was no evidence of a three‐way interaction between the three stressors, although there were negative synergistic effects, primarily between food limitation and the ingestion of phylloplane bacteria.