Onthophagus taurus
To avoid possible contamination from their food, we collected samples as follows.  We dissected head and three thoracic segments from our larval samples.  Instead of dissecting head and thoracic segments from pupae, we used the whole body.  Late pupae were transferred to clean, humid chamber to let the adults emerge and not to let them consume any cow dung. To enrich the pool of expressed genes with various classes of transcripts, we included the major stages of beetle late development: mid 3rd (last) inster larva, late 3rd instar larva, prepupa within 24hrs and prepupa between 36 and 48hrs, pupa within 24hrs after pupation, between 36 and 48hrs after pupation, mid pupa (7 and 9 days after pupation), and late pupa (12 days after pupation), adults 4 days after molt.  Each stage includes two males and two females except for pupa day7 (one female) and day 9 (one male).  In total, we used 32 animals to extract total RNA. To enrich the pool of expressed genes with rare transcripts, we normalized the cDNA library.