Clostera anachoreta is one of the important Lepidoptera insect pests in forestry, especially in poplars woods in China, Europe, Japan, and India, and so forth, and also the target insect of Cry1Ac toxin and Bt plants. Six genes, HSC70, GNB2L/RACK1, PNLIP, BI1‐like, arylphorin type 2, and PKM were found in this study, and they might be associated with the response to the Cry1Ac toxin, found by analyzing the transcriptome data. And the PI3K‐Akt pathway was highly enriched in differentially expressed unigenes and linked to several crucial pathways, including the B‐cell receptor signaling pathway, toll‐like receptor pathway, and mitogen‐activated protein kinase signaling pathway. They might be involved in the recovery stage of the damaged midgut during the response to sublethal doses of Cry1Ac toxin. This is the first study conducted to specifically investigate C. anachoreta response to Cry toxin stress using large‐scale sequencing technologies, and the results highlighted some important genes and pathways that could be involved in Btcry1Ac resistance development or could serve as targets for biologically based control mechanisms of this insect pest.

This experiment was conducted to define changes in metabolic pathways in response to mandibulate insect feeding and to provide a reference for further investigation of the molecular mechanisms underlying the development of conifer resistance. Chinese pine (Pinus tabuliformis Carr.) in good growth status in natural condition was chosen for stimulation by 10 pine caterpillars (Dendrolimus tabulaefomis Tsai et Liu) as feeding stimulation (FS), leaf clipping control (LCC) as mechanical damage, and CK group (with no treatment) (recorded as 0 h). The metabolome and total flavonoid content were measured in the needles at 0, 2, and 8 h after treatment. Plant hormones were measured with needles at 0, 0.5, 1, 1.5, 2, 4, 6, and 8 h after different treatments. The results show that a total of 30.8% flavonoids are identified by metabolomics analysis. Compared with leaf clipping control, feeding stimulation of Chinese pine caterpillars significantly induced the upregulation of metabolites in the flavonoid pathway in Chinese pine, and the plant hormones JA and IAA showed expression trends consistent with those of the metabolome. According to the biological processes of the four plant hormones involved, JA and SA are mostly involved in resistance formation, and in this study, both of them also have fluctuating expressions influenced by feeding stimulation, while the expressions of the growth-related hormones IAA and ABA have no significant changes at other time points except for 1 h after treatment. Thus, the flavonoid pathway is one of the main pathways involved in resistance formation in conifers, and JA and IAA are involved in the formation of resistance.

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To define changes in metabolic pathways in response to mandibulate insect feeding and to provide a reference for further investigation of the molecular mechanisms underlying the development of conifer resistance, Chinese pine ( Pinus tabuliformis Carr.) in good growth status in Huangtuliangzi Forest Farm Pingquan city, Chengde city, Hebei Province, was stimulated by 10 pine caterpillars ( Dendrolimus tabulaefomis Tsai et Liu) as feeding stimulation (FS) and leaf clipping control (LCC) as mechanical damage. The metabolome and total flavonoid content were measured in the needles at 0 (with no treatment, CK), 2, and 8 h after treatment. Plant hormones were measured with needles at 0, 0.5, 1, 1.5, 2, 4, 6, and 8 h after different treatments. The plant hormones jasmonic acid (JA) and auxin (IAA) were upregulated within a short time (2 h) after treatment, showing an expression trend consistent with the corresponding substances in the metabolome. A total of 30.8% of flavonoids were identified by metabolomics analysis. Analysis of KEGG metabolic pathways for the different accumulated metabolites (DAMs) showed that the top pathway annotated and enriched for DAMs in comparison to 2 h after FS (marked as 2 h) and 2 h after LCC (marked as LCC 2 h) was flavonoid biosynthesis; the top pathway mainly annotated and enriched for DAMs in comparison to 8 h and LCC 8 h was the same. Thus, the flavonoid pathway is one of the main pathways involved in resistance formation in conifers, and JA and IAA are involved in the development of resistance and growth during biotic stress.