Los Angeles radio ratings for May released on Wednesday showed a drop for two Valley Spanish-language stations caught in a controversy over ratings manipulation, according to media reports. Both KSCA-FM (101.9) in Glendale and KXOS-FM (93.9) in Burbank had lower Nielsen ratings in May for its morning drive time shows when compared to the April numbers. KSCA, owned by Univision Radio, a division of Univision Communications Inc., in New York, had the No. 1 rated morning show in April but landed in a tie for fourth place in May, the Times said, based on data from Nielsen. KXOS, operated by Grupo Radio Centro, in Mexico City, had been No.4 in April with its morning show, hosted by Ricardo “El Mandril” Sanchez. The show dropped to No. 14 in May, the Times reported, Radio station executives have been questioning April’s ratings for some anomalies, including KSCA, which plays regional Mexican music, jumping past four stations to win the important morning drive-time slot. Nielsen delayed the release of the May numbers after investigating problems with two households that were part of the sample to determine station ratings. The company is expected to release revised April numbers later this week. In one instance, the family was related to an Univision Radio programming executive who was later fired from the company. The situation prompted Univision President Jose Valle to issue a statement that such conduct “seriously undermines the industry and is unacceptable.” The other family had no affiliation with a media company but was taken out of the sample for not following Nielsen’s rules for the participants, the Times reported. KXOS and Grupo Radio Centro have not commented on the matter.