No abstract

The Erythrina gall wasp Quadrastichus erythrinae Kim (Hymenoptera: Eulophidae) is an invasive insect that induces galls on coral trees (species of Erythrina, Fabaceae) in urban and suburban landscapes. Weakening and death of the tree were both observed after the infestation by this insect, wherein feeding and consequent draining of nutrients by a large population of Q. erythrinae could be playing a key role. In this article, we consolidate and summarize the information on the distribution, invasion route, ecology, infestation level, and management of Q. erythrinae populations in the last two decades and analyze the challenges in their management.

Zanthoxylum ailanthoides is a traditional spice crop in Taiwan with unique smells and tastes that differ between prickly (young) and nonprickly (mature) leaves. Different volatile terpenes between prickly young and nonprickly mature leaves were identified and considered to be one of the sources of their aromas. A transcriptome database was established to explore the biosynthesis of these compounds, and candidate terpene synthase genes were identified. The functions of these synthases were investigated using recombinant protein reactions in both purification and coexpression assays. ZaTPS1, ZaTPS2, and ZaTPS3 are germacrene D synthases, with different amino acid sequences. The main products of ZaTPS4 are trans-α-bergamotene and (E)-β-farnesene, whereas ZaTPS5 forms multiple products, and ZaTPS6 produces β-caryophyllene. ZaTPS7 forms monoterpene (E)-β-ocimene and sesquiterpene (E,E)-α-farnesene. Reverse transcription PCR of ZaTPS gene expression in young and mature leaves revealed that ZaTPS1 was responsible for the mellow aroma in mature leaves. The expression of ZaTPS6 suggested that it plays a role in the background aromas of both types of leaves. Our findings deepened the understanding of the volatile compounds of Z. ailanthoides and revealed the source of its unique aromas by clarifying the biosynthesis of these compounds.