Abstract
There are gaps in our understanding of plant responses under different insect phytophagy modes and their subsequent effects on the insect herbivores’ performance at late season. Here we compared different types of insect feeding by an aphid, Lipaphis erysimi, and a lepidopteran, Plutella xylostella, and how this affected defensive metabolites in leaves of 2 Brassica species when plants gain maturity. Thiocyanate concentrations after P. xylostella and L. erysimi feeding activities were the same. Total phenolics was higher after the phloem feeder feeding than the folivore activity. The plants compensatory responses (i.e., tolerance) to L. erysimi feeding was significantly higher than the responses to P. xylostella. This study showed that L. erysimi had higher carbon than P. xylostella whereas nitrogen in P. xylostella was 1.42 times that in L. erysimi. Population size of the phloem feeder was not affected by plant species or insect coexistence. However, there was no correlation between plant defensive metabolites and both insects’ population size and biomass. This suggests that plant root biomass and tolerance index after different insect herbivory modes are not necessarily unidirectional. Importantly, the interaction between the folivore and the phloem feeder insects is asymmetric and the phloem feeder might be a trickier problem for plants than the folivore. Moreover, as both plants’ common and special defenses decreased under interspecific interference, we suggest that specialist insect herbivores can be more challenged in ecosystems in which plants are not involved in interspecific interference.
Original language | English |
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Pages (from-to) | 690-702 |
Number of pages | 13 |
Journal | Insect Science |
Volume | 25 |
Issue number | 4 |
Early online date | 16 Jan 2017 |
DOIs | |
Publication status | Published - Aug 2018 |
Funding
This study was funded by Tarbiat Modares University and Iran National Science Foundation (INSF) (grant number 91058913). CH is supported by the National Research Foundation of South Africa (grant nos. 81825 and 76912). We thank B. Salehi for her technical help in insect and plant sampling in the experiments. The authors declare that they have no conflict of interest. There are no disputes over the ownership of the data presented in the paper and all contributions have been attributed via coauthorship and acknowledgement.
Funders | Funder number |
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National Kidney Foundation of South Africa | 76912, 81825 |
Iran National Science Foundation | 91058913 |
Tarbiat Modares University |
Keywords
- glucosinolates
- herbivory mode
- plant resistance
- stoichiometric analysis
- tolerance