Molecular Diet Analysis of Leaf-Grazing Katydids Based on DNA Barcoding

Area of Science:

• Ecology
• Genetics
• Zoology

Background:

• Insect herbivore diversity is linked to host plant diversity, making dietary profile determination crucial in insect ecology.
• DNA barcoding has significantly advanced food web research by enabling standardized taxon identification using DNA regions.

Purpose of the Study:

• To investigate the dietary profiles of 18 leaf-grazing katydid species in China using DNA barcoding.
• To identify ingested plant DNA in katydid specimens and analyze their feeding preferences.

Main Methods:

• DNA from 207 katydid specimens was analyzed using three plant barcoding loci: rbcL, matK, and trnH-psbA.
• Sequences were compared against the Barcode of Life Database (BOLD) and GenBank for identification.

Main Results:

• Katydid subfamilies showed varied dietary breadth, with Mecopodinae consuming the most plant families (18) and Phaneropterinae consuming 43.
• Poaceae, Fabaceae, Vitaceae, Juglandaceae, and Balsaminaceae were preferred plant families among different subfamilies.
• Species-level identification was achieved for only 81 out of 207 samples, highlighting limitations in current databases.

Conclusions:

• This study significantly expands dietary information for Chinese leaf-grazing katydids.
• Understanding katydid diets is vital for coevolution studies, resource management, and habitat conservation efforts.