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Bumblbebees (Bombidae) along pollution gradient - heavy metal accumulation, species diversity, and Nosema bombi infection level

Szentgyorgyi H., Blinov A., Eremeeva N., Luzyanin S., Grześ I., Woyciechowski M.

Polish Journal of Ecology

2011

Vol. 59, nr 3

599-610

Pollinator crisis (Kearns et al. 1998) and its possible causes has become a worldwide issue during the last two decades. Although pollution is among the possible causes of the widely observed pollinator loss, it is still poorly investigated and no studies are known, so far to test the effects of heavy metal contamination in bumblebees (Bombidae) - the second most important group of managed pollinators after honey bees (Apis mellifera Linneaus). We have tested heavy metal (Pb, Cd, and Zn) accumulation, species diversity and parasite load (focusing on the common Nosema bombi Fantham and Porter, Microsporidia: Nosematidae) in bumblebees. For this purpose, we have chosen three heavy metal gradients (Guryevsk, Belovo and Olkusz) and two additional control sites (Kouznetskiy Alatau and Gornaya Shoria). All gradients were approximately 20 km long, starting in close proximity (1.3 km or less) of an active zinc or metal smelter, and each consisting of 5 sites located on semi-natural or drgraded meadows in various distance from the smelter. On each site min. 50 bumblebees were caught by sweep nets, each individual identified to species level and next, its abdomen homogenized and used for assessment of N. bombi infestation. Heavy metal levels in soil of the tested gradients varied between (Pb: 13.6-814.2 mg kg[^-1], Cd: 0.14-20.3 mg kg[^-1], Zn: 67.0-889.3 mg kg[^-1]) Bumblebees accumulated Pb and Cd (Pb: 0.21-3.3 mg kg[^-1], Cd: 0.002-0.069 mg kg[^-1]) in their bodies. The content of these metals in bumblebee bodies correlated with their content in soil (Pb: P <0.01, Cd: P = 0.002). However, no correlation was found between the Zn contents in bumblebees (Zn: 74.7-81.9 mg kg[^-1]) and the soil. We have also found that the metal contents in soil or in the bodies of bumblebees caused no changes in species diversity or dominance on polluted sites, irrespective of type and the level of contamination. The variation of Shannon diversity (H.), as well as Simpson.s diversity (D) were similar in all studied sites and ranged from 0.543 to 0.81 and from 0.152 to 0.484 respectively. The proportion of infected individuals was generally not higher than 0.29 and did not differ significantly among the studied sites. Incidentally, based on variation in the small subunit ribosomal RNA (SSU-rRNA) gene, we have found a new strain of Nosema bombi in the Kouznetskiy Alatau and Gornaya Shoria (West Siberia, Kemerovo Region) samples. The new small subunit RNA sequence in the new strain of N. bombi was named N. bombi WS2 (West Siberia) SSU rRNA. Based on the obtained results we conclude, that bumblebees can withstand or even successfully deal with heavy metal contamination at certain levels.

Oviposition patterns in the myrmecophilous butterfly Maculinea alcon denis & schiffermüller (Lepidoptera: Lycaenidae) in relation to characteristics of foodplants and presence of ant hosts

Nowicki P., Witek M., Skórka P., Woyciechowski M.

Polish Journal of Ecology

2005

Vol. 53, nr 3

409-417

To test the hypothesis of random oviposition by Maculinea butterflies we investigated the oviposition patterns of M. alcon Denis & Schiffermüller in wet meadows in the Vistula valley, southern Poland, in relation to the stem length and flower number of Gentiana pneumonanthe Linnaeus foodplants as well as to their spatial distribution, the height of the surrounding vegetation and the presence of potential ant hosts. Analysis conducted for 403 gentians recorded within the 0.96 ha study plot indicated that plants with M. alcon eggs present were significantly higher and had more flowers. On the other hand, neither the local density of gentians nor the presence of ant hosts had any apparent effect on oviposition preferences of M. alcon. Our conclusion is that females of the butterfly select visually conspicuous plants as the oviposition sites regardless of their clumping or ant presence. As a consequence, the two factors do not need to be included in computer models developed to study the population dynamics of the species and its trophic interactions with foodplants and ant hosts.