Krüppel-homologue 1 regulates the development of Tuta absoluta and its cascade regulation pattern in the juvenile hormone signalling pathway.

Tomato leaf miner, (Meyrick), is one of the most destructive quarantine pests globally. It has been confirmed that () plays a key role in the regulation of juvenile hormone (JH). However, it is unclear how regulates the synthesis of JH and its cascade regulation pattern in tomato leaf miner. Here, we obtained the six JH signalling genes (, , , , and ), and applied RNA interference to explore the role of and the seven genes (plus ) regulation relationship in . Bioinformatics analysis revealed the structural characteristics of kr-h1 protein and JH receptor Met, which contained eight C2H2 zinc finger structures and three typical domains of the bHLH-PAS family, respectively. The expression levels of and were upregulated after RNAi of gene, while the gene levels of and were downregulated. Furthermore, topical application of JH analogue to second instar larvae could induce the expression of and inhibit the expression of . Our study reveals the mechanism by which regulates JH pathway genes, which could be applied to control the growth of tomato leaf miners.