The Scottish Conservative leader on Friday criticised Ms Harper’s claims that a border with England would “create jobs”.
She had said: “If a border will work, we can show that a border will work. There are issues that have been brought to my attention that show that jobs can be created if a border is created.
"And again, we want the softest of borders.”
Responding this afternoon, Mr Ross claimed Ms Harper’s comments only reflected a wider view within the SNP.
He said: “I think people in Dumfries and Galloway will view her comments very poorly, they know they’ve got an outstanding local champion in Finlay Carson.
“The comments from Emma Harper shed a light on the thinking within the SNP.
“It’s always about independence, separating from the rest of the United Kingdom.
“To somehow claim that there are benefits of a border in between Scotland and the rest of the UK are completely false and fanciful.
“For Nicola Sturgeon to say she hadn’t seen the clip, she must be the only person in Scottish politics who hadn’t seen that clip.
“It shows when it comes to more challenging questions Nicola Sturgeon tries to duck away from them.”
Speaking to Radio Clyde, Ms Sturgeon had earlier claimed not to have heard the comments and insisted it was the Conservatives who were focused on borders.
She said: “I’ve not seen Emma’s comments directly, but nobody in the SNP wants to see a border between Scotland and England.
“This is only being talked about because the UK Government has decided to leave the EU and rip Scotland out of the EU.
“I want Scotland to trade freely across the UK and to trade freely within the world’s biggest single market, which is the European single market.
“It is the Tories that are about borders. It’s the SNP [that] are about Scotland being an independent country, but then operating economically and socially on the basis of equality.”
Scottish Liberal Democrat campaign chairman Alistair Carmichael also ridiculed Ms Harper’s comments.
He said: “Wanting a border between Scotland and England is literally the foundational policy of the SNP.
“Nicola Sturgeon must think the Scottish public are complete mugs, especially just one day after one of her MSPs was talking up the prospect of a hard border.
“No amount of tall tales from the First Minister will change the reality that independence would throw up a hard border, dividing families and decimating trade with our partners to the south.
“Boris Johnson promised there would be no new barriers in Northern Ireland, only to renege on what he had pledged further down the line.
“It’s disappointing to see Nicola Sturgeon taking a leaf out of the Tory Brexiteer playbook.”
Labour shadow Scottish secretary Ian Murray added: “The phrase fantasy economics fails to cover this bizarre admission.
“Every credible economist since Adam Smith would warn that erecting a border between two parts of that one market would be a disaster for jobs.
"The SNP simply have no answers to the big questions.
“But the SNP have shown in this campaign that they are unwilling to look past their constitutional blind spot and will put jobs and livelihoods at risk."