INTRODUCTION White grubs are the pest of national importance in India (Mehta et al., 2010). They belong to the two subfamilies viz., Melolonthinae and Rutelinae of the family Scarabaeidae under the order Coleoptera. In India, occurrence of more than 1700 species of white grubs have been reported (Ali, 2001). Due to the subterranean nature, white grubs cause remarkable damage to the roots of several agricultural and horticultural crops. The damage and can be visualized by drying, wilting and withering of plants in patches (Rai et al., 1969). Many times, the infestation is misunderstood with physiological wilting and detected only after complete destruction of crops. The grubs are “C” shaped, fleshy with three pairs of thoracic legs (Sreedevi et al., 2014). The first instar grub feeds on soil debris rich in organic matter whereas later instars are phytophagous and feed voraciously on roots. Grubs exploits the roots of sugarcane, groundnut, potato, maize, pearl millet, wheat, sorghum and barley; whereas adults feed on leaves of bhendi, neem, acacia, grapes etc., (Fujiie et al., 1996; Ranga Rao et al., 2006). Active adult emergence of most species coincides with monsoon showers (Yadava and Sharma 1995). The impact of soil properties on the abundance of white grub population is lacking in Tamil Nadu, so a study on the effect of physicochemical properties on distribution and abundance was undertaken in the districts of Erode and Thoothukudi in Tamil Nadu. MATERIALS AND METHODS Study site. An exploratory survey was conducted from December 2021 to April 2022 in two districts of Tamil Nadu to collect white grub adults associated with garden land crops. The details of the sampling area are given in Table 1. Adult sampling. Each location sampled once in a square meter area delineated in five places on a one-acre crop area. Adult white grubs were collected by excavation of soil (50 - 60 cm deep) in the crop ecosystem and also from the emergence sites. In Kayathar block, adult collections were made from the bhendi, maize, sorghum and black gram fields and in Sathyamangalam block, adults were collected from sugarcane, jasmine and tuberose fields. Identification of adults. Adult white grub identification was done by following keys of Arrow (1917) and Dadmal (2013) Soil physico-chemical analysis. In both locations, soil samples were collected by following the methodology of Cherry and Allsopp (1991). Samples collected from 50 × 50 cm area up to a depth of 40 cm. A representative sample of 500g soil was collected from each sampling site. Soil physical parameters such as texture, bulk density, particle density, porosity and chemical properties such as pH, electrical conductivity and soil organic carbon, surface soil organic matter and sub surface soil organic matter were analyzed at Soil Science Laboratory, Department of Remote sensing and GIS, TNAU, Coimbatore. The details of the methods used for analysis are presented in Table 2. Statistical analysis. Mean adult population transformed by square root transformation (√(2&X+0.5)) (Gomez and Gomez, 1984). To understand the influence of soil physico-chemical parameters on adult white grub abundance, correlation and regression studies were performed. RESULTS AND DISCUSSION Morphological characterization of white grub adults, collected in the study, revealed the occurrence of Holotrichia serrata (Fabricius) (Melolonthinae; Scarabaeidae; Coleoptera) and Adoretus sp (Rutelinae; Scarabaeidae; Coleoptera) in Erode and Thoothukudi districts, respectively. Abundance of white grub species and physico-chemical properties of soil collected from Erode and Thoothukudi districts are presented in Table 3 and 5, respectively. Results of correlation performed between adult white grub population and soil physico-chemical properties are given in Table 4 and 6, respectively. Figures 1–12 depict a regression study between the mean adult population of Holotrichia serrata and Adoretus sp with each physicochemical parameter. Bulk density of soil exhibited positive and negative relation with H. serrata (r = -0.268) and Adoretus sp (r = 0.368) abundance, respectively. The results are in accordance with the findings of Pujari et al. (2018) and Pal (1997). Pujari (2018) concluded that bulk density had a negative (significant) relationship with the average population of Lepidiota mansueta Burmeister larvae, whereas clay and silt content had a positive (non-significant) relationship with larval population as well as the report validating the textural preferences of Holotrichia serrata. Pal (1997) documented that population of white grubs influenced by coarse texture and low precipitation of rainfall, and the study corroborating those textural preferences of adults of Adoretus sp. Particle density of soil non significantly affecting the both the population but, positive relationship with Adoretus sp (Table 6) and negative relationship with Holotrichia serrata (Table 4). Soil porosity had a significant negative correlation (r = - 0.995) with abundance of Adoretus sp and non-significant negative correlation (r = -0.643) with H. serrata abundance. Both species preferred loam, sandy loam and silt loam soils. Earlier findings indicated that white grubs’ oviposition (Potter, 1983; Allsopp, 1992) and migration of larvae depend on the proportion of soil particles (Gustin and Schumacher, 1989). Chemical parameters such as pH and Electrical Conductivity (EC) had negative and positive correlation (non-significant) with H. serrata abundance whereas vice-versa was observed for Adoretus sp. Soil organic content was found to be positively linked with the abundance of both species of white grubs, acting as a facilitating factor. Present findings are analogous with Cherry and Coale (1994), they reported that Tomarus subtropicus Blatchley positively correlated with organic matter of the soil. Afore mentioned parameter also determines the feeding nature of Dasylepida ishigakiensis (Niijima and Kinoshita) (Oyafuso et al., 2002) and tunneling depth of Phyllophaga ephilida Say (Diagne 2004).