▁leaf ▁surface . ▁The ▁mines ▁are ▁solit ary ▁and ▁normally ▁with ▁two ▁fol ds , ▁but ▁rarely ▁one . ▁These ▁fol ds ▁are ▁not ▁necessarily ▁parallel ▁to ▁each ▁other . ▁The ▁leaf ▁is ▁bow ed ▁up ▁with ▁a ▁sun ken ▁area ▁at ▁the ▁middle ▁of ▁leaf . ▁ ▁Et ym ology ▁The ▁specific ▁name ▁is ▁derived ▁from ▁the ▁type ▁of ▁soil ▁( i . e ., ▁ser pent ine ) ▁on ▁which ▁one ▁of ▁its ▁host ▁occurs . ▁ ▁References ▁ ▁Category : C amer aria <0x0A> </s> ▁R ao iella ▁is ▁a ▁genus ▁of ▁m ite ▁belonging ▁to ▁the ▁family ▁T enu ip al p idae . ▁ ▁Species ▁ ▁R ao iella ▁ind ica ▁H irst , ▁ 1 9 2 4 , ▁the ▁red ▁pal m ▁m ite ▁ ▁R ao iella ▁austral ica ▁W om ers ley , ▁ 1 9 4 0 ▁ ▁R ao iella ▁mac far lane i ▁P rit ch ard ▁& ▁Baker , ▁ 1 9 5 8 ▁ ▁R ao iella ▁p and ana e ▁Moh anas und aram , ▁ 1 9 8 9 ▁( T amil - N adu ) ▁ ▁R ao iella ▁p ho en ica ▁Smith - M ey er , ▁ 1 9 7 9 ▁( S ud an ) ▁ ▁R ao iella ▁sh im ap ana ▁Smith - M ey er , ▁ 1 9 7 9 ▁( Trans va al ) ▁ ▁References ▁ ▁Jo el ▁Hall an ' s ▁Bi ology ▁Catalog :