Are the provisions for wall studs and plates in the International Residential Code (IRC), Section R602 limited to the four major lumber species groups (i.e., Douglas fir-Larch, Hem-fir, Southern Pine and Spruce-pine-fir)?

No. In the southeastern U.S. where the ultimate design wind speeds are 130 mph or less (and in other areas where the ultimate design wind speeds are less than 140 mph), framing provisions for wall studs and plates and fastening schedules in IRC Section R602 are independent of the lumber species and assigned specific gravity; therefore, these wall framing provisions are not limited to the four species groups tabulated in the IRC for headers, joists, and rafters. In areas where the ultimate design wind speeds are greater than these thresholds, the wind provisions in the IRC do not apply, and the user is directed to design the structure in accordance with one or more of the following methods:

ICC’s International Building Code (IBC).
ASCE’s Minimum Design Loads for Buildings and Other Structures (ASCE 7), which for wood construction would be used with AWC’s National Design Specification (NDS) for Wood Construction and AWC’s Special Design Provisions for Wind and Seismic.
AWC’s Wood-Frame Construction Manual for One- and Two-Family Dwellings (WFCM).
ICC’s Standard for Residential Construction in High-Wind Regions (ICC 600).