Distribution and abundance of insects colonizing cattle dung in South West England

The succession of insects colonizing cow dung in south west England was examined over 2 years, using arrays of standardized 1.5 kg artificially constructed cow-dung pats in cattle pasture. The seasonal pattern of colonization was examined using batches of 10 pats each week for 24 weeks in 2001. Pats were left exposed in the field for 7 days, to allow colonization, and were then brought back to the laboratory to await insect emergence and identification. Overall seasonal changes in community structure were relatively gradual and subtle; Coleoptera were generally more abundant earlier and Diptera later in the season, and the number and order of species arrival broadly matched previous studies in similar habitats. The temporal pattern of colonization of individual pats was examined in six batches of 30 pats constructed in May, June, and August/September in 2002. Groups of five pats were recovered and brought back to the laboratory 1, 2, 4, 7, 14, or 21 days after construction. Overall, three broad, but statistically distinct, successional groups were identified, with the maximum number of colonizers present in pats that were 4–7 days old. The data contribute valuable information on the temporal distribution and abundance of dung-colonizing taxa in South West England, a clear local understanding of which is essential to allow the effects of agricultural practices which may damage dung invertebrate communities, such as livestock anthelmintic treatment, to be assessed.