 They are also required to withhold employee's share of Social Security and Medicare taxes under FICA, and pay the employer's share for the non-exempt income.Both the tithe ("diezmo"), a levy of 10 per cent on all agricultural production, and "first fruits" ("primicias"), an additional harvest levy, were collected in Spain throughout the medieval and early modern periods for the support of local Catholic parishes.The tithe crossed the Atlantic with the Spanish Empire; however, the Indians who made up the vast majority of the population in colonial Spanish America were exempted from paying tithes on native crops such as corn and potatoes that they raised for their own subsistence.