The following account is from Sarnat et al. (2015) and figure numbers refer to that publication.
Pheidole parva is a very small and inconspicuous species that is thus far reported only from Asia, a few localities in Arabia, and the islands of the Indian Ocean and the Pacific Ocean. It belongs to an Old World clade scattered across Indomalaya and into Oceania, and was treated as part of the P. rinae complex by Eguchi et al. (2007). The minor workers are completely covered in punctate sculpture and are difficult to differentiate from those of the Neotropical P. flavens complex. The similarity is so close that an introduced population of P. parva from the Seychelles was described by Forel, on the basis of the minor worker, as Pheidole flavens var. farquharensis.The similarity is entirely convergent, as these lineages are distantly related. Pheidole parva minors can be separated from those of the P. flavens complex most reliably by the interrupted striae that are interlaced among the punctate ground sculpture of the posterior head (Fig. 59vs. Fig. 60). This character can also be viewed in the dorsal view. Pheidole parva minors can be separated from those of the P. punctatissima clade treated here by the glossy gaster (Fig. 32vs. Fig. 33) and finer mesosomal hairs of unequal length (Fig. 54vs. Fig. 53). The major workers are characterized by a defined and moderately depressed antennal scrobe and a thick network of reticulated rugulae on the posterior lobes. This pattern is most similar to that of the broadly sympatric P. fervens and P. indica, but P. parva is much smaller than those species (HW < 0.95 mm vs HW > 1.10 mm) and lacks the distinct prominence on the posterior slope of the promesonotal dorsum (Fig. 4vs. Fig. 5). The majors of P. parva can be separated from those of the P. flavens and P. punctatissima group species treated here by the much stronger and more reticulated carinae which reach the posterior margin (Fig. 26vs. Fig. 25and Fig. 27) in addition to other characters given in the key. Readers are referred to Eguchi (2008; 2007)for characters separating P. parva from its Asian congeners.