You should provide more information such as the method used for DNA extraction, DNA concentration and quality, the primers and PCR conditions etc. . Did you run the extracted DNa on a gel?

Agree. And what kind of eriophyid? Is a bud, gall or rust mite? Check Klimov, Craemer and Chetverikov et al. articles.

A new species, new records, and DNA barcodes of eriophyine mites (Eriophyidae, Eriophyinae) from southeast Crimea and remarks on ability to form galls in …

PE Chetverikov, AG Desnitskiy, VY Letukhova… - Systematic and Applied …, 2021

Description of Cecidophyes fibigiae n. sp., new combinations, records, and DNA barcodes of eriophyid mites (Eriophyoidea, Eriophyidae) from Karadag Nature …

PE Chetverikov, DS Fedorov, VY Letukhova… - Systematic and Applied …, 2021

Supplementary descriptions and DNA barcodes of two rarely encountered Trisetacus species (Eriophyoidea, Phytoptidae) associated with Tertiary relict conifers from …

…, C Craemer, PG Efimov, P Klimov… - Systematic and Applied …, 2019

Thank you @ Eid Muhammad Khan for your reply I will go through these paper of Dr. Cheyverikov

Hello Sreedhar Reddy, what gene region are you trying to amplify, and what primers are you using to do it?

Hi Ronald Ochoa :) I’m curious, are you suggesting different methods based on habit/symptoms, “bud, gall or rust”?

Hi Sreedhar,

I have used the protocol detailed in the link below for barcoding eriophyid and flat mites (Eriophyidae and Tenuipalpidae)

Article A new, sensitive and efficient method for taxonomic placemen...

I believe if you just use a conventional PCR with a final volume of 25 uL and crush the mite in the liquid (as described in the link above), the PCR reaction may still give some amplicon for appropriate barcoding primers.