High rates of parasitism in laboratory-reared bumblebee colonies introduced to farmland in the UK

  • Published source details Carvell C., Rothery P., Pywell R.F. & Heard M.S. (2008) Effects of resource availability and social parasite invasion on field colonies of Bombus terrestris. Ecological Entomology, 33, 321-327


This study is summarised as evidence for the following.

Action Category

Reintroduce laboratory-reared bumblebee colonies to the wild

Action Link
Bee Conservation
  1. Reintroduce laboratory-reared bumblebee colonies to the wild

    A replicated trial using 48 commercially-reared colonies of B. t. terrestris in the UK shows that rates of parasitism by cuckoo bees Bombus [Psithyrus]spp. can be high on colonies in nest boxes (38 colonies, 79% parasitized; Carvell et al. 2008). Parasitism is more intense when colonies are sited in areas of high resource availability (92% of colonies parasitized by three cuckoo bees on average among oilseed rape Brassica napus fields, compared to 67% parasitized by one cuckoo bee on average among wheat fields). Parasitism is also more intense if colonies are placed early in the season (early May). This suggests that if captive-reared colonies of native bumblebees are to be reintroduced, they should be placed out later in the season (early June), amongst a heterogenous landscape with intermediate levels of resource.

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