Lawrence Area School's William Haywood, Maniototo Area School's Doug Smith and Ethan Kitto and Brayden Whyte, both of Roxburgh Area School, have made the 22-man team.
First five-eighth Smith also got the nod as vice-captain.
The team was selected following the recent New Zealand Area Schools Sports Tournament held in Rotorua last month.
Convener of selectors Mike Smith noted it was the first time four from the region had made the cut.
"In the past we have only had one or two from the Southern zone, and sometimes none," he said.
Smith said the four players had all shown positional strength over the duration of the tournament.
The quartet represented the South of the South zonal team in round robin matches against Northland, Central and Top of the South teams.
"Basically the players come from the remote areas of New Zealand from schools who are too small to field a first XV," Smith said.
"Many have to travel long distances to play for a nearby high school, play for their senior club team or do not play regular rugby at all."
Smith said the development squad catered for pupils in remote areas where advancing a playing career could be hard.
"Generally these boys do not have a pathway through to the top level because of geographic location or need to attend a boarding school at great expense."
Next month, the squad will travel to Palmerston North for a four-day camp at the Massey University Sport and Rugby Institute.