Parisitology

Honey bees are important pollinators of agricultural crops and the dramatic losses of honey bee colonies have risen to a level of international concern. Potential contributors to such losses include pesticide exposure, lack of floral resources and parasites and pathogens. The damaging effects of all of these may be exacerbated by apicultural practices. To meet the pollination demand of US crops, bees are transported to areas of high pollination demand throughout the year. Compared to stationary colonies, risk of parasitism and infectious disease may be greater for migratory bees than those that remain in a single location, although this has not been experimentally established. Here, we conducted a manipulative experiment to test whether viral pathogen and parasite loads increase as a result of colonies being transported for pollination of a major US crop, California almonds. We also tested if they subsequently transmit those diseases to stationary colonies upon return to their home apiaries. Colonies started with equivalent numbers of bees, however migratory colonies returned with fewer bees compared to stationary colonies and this difference remained one month later. Migratory colonies returned with higher black queen cell virus loads than stationary colonies, but loads were similar between groups one month later. Colonies exposed to migratory bees experienced a greater increase of deformed wing virus prevalence and load compared to the isolated group. The three groups had similar infestations of Varroa mites upon return of the migratory colonies. However, one month later, mite loads in migratory colonies were significantly lower compared to the other groups, possibly because of lower number of host bees. Our study demonstrates that migratory pollination practices has varying health effects for honey bee colonies. Further research is necessary to clarify how migratory pollination practices influence the disease dynamics of honey bee diseases we describe here. How to cite this article Alger et al. (2018), Home sick: impacts of migratory beekeeping on honey bee (Apis mellifera) pests, pathogens, and colony size. PeerJ 6:e5812; DOI 10.7717/peerj.5812

A study of the Helminth parasites of fish of River Swat was conducted from September, 2012 to August, 2013. A total of 250 fish belonging to five genera and six species were examined. The parasites collected were Diplozoon khyberensis, Bathybothrium rectangulum, Bothriocephalus, Nippotaenia, Cucullanidae, Proteocephalus, Rhabdochona charsaddiensis, Rhabdochona schizothoracis and Neoechynorhynchus devdevi. They were identified by morphological characteristics through microscopic technique. Overall prevalence of the fish parasites was 58% (145/250), among these Schizothorax plageostomus fish 93.04% (107/115), Schizothorax labiatus 61.11 % (33/54), Salmo trutta fario 17.85% (05/28), Gara gotyla 0% (0/09), Rita rita 0% (0/25) and Oncorhynchus mykiss were 0 % (0/19). The intensity of the parasite varied from 1 % to 9.2 %. Among them high intensity was noted in Rhabdochona schizothoracis (9.2%) and Schizothorax labiatus.