Journal: Nature Communications

Article Title: Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

doi: 10.1038/s41467-020-19715-8

Figure Lengend Snippet: Asterisks denote significantly different mean values (one asterisk: P < 0.05; three asterisks: P < 0.001). a DWV infection level in honey bees eclosed from larvae reared in vitro on a diet with or without Clothianidin (the experiment was run in triplicate, for a total of 28 and 27 individuals for Clothianidin treated and untreated controls, respectively; the horizontal bars represent the sample average; Mann–Whitney U test: n 1 = 28, n 2 = 27, U = 140, one tailed P < 0.001). b Fertility of Varroa mites on honey bee larvae treated with Clothianidin or on untreated controls (the experiment was run in triplicate, for a total of 111 and 120 individuals for Clothianidin treated and untreated controls, respectively; the proportion of reproducing mites in each replicate along with the average fertility and relative standard deviation are reported; Mantel–Haenszel test: df = 2, M–H Chi-2 = 3.970, P = 0.046).

Article Snippet: Mite fertility (i.e., proportion of reproducing females out of total female mites used in the experiment ) on bee pupae treated with 0.01 ppm of Clothianidin at the larval stage was significantly higher than on control bees (Mantel–Haenszel test: df = 2, M–H Chi-2 = 3.970, P = 0.046; Fig. ) by 23%, on average; on the contrary, fecundity (i.e., number of offspring per reproducing female) seemed not to be affected (Mann–Whitney U test: n 1 = 78, n = 68, U = 2487, n.s.

Techniques: Infection, In Vitro, MANN-WHITNEY, One-tailed Test, Standard Deviation

Journal: Nature Communications

Article Title: Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

doi: 10.1038/s41467-020-19715-8

Figure Lengend Snippet: a Mite infestation as predicted using the discrete time model we developed and the reproduction data of Varroa mites as affected by Clothianidin exposure. b Mite infestation observed in hives close to fields treated with neonicotinoids .

Article Snippet: Mite fertility (i.e., proportion of reproducing females out of total female mites used in the experiment ) on bee pupae treated with 0.01 ppm of Clothianidin at the larval stage was significantly higher than on control bees (Mantel–Haenszel test: df = 2, M–H Chi-2 = 3.970, P = 0.046; Fig. ) by 23%, on average; on the contrary, fecundity (i.e., number of offspring per reproducing female) seemed not to be affected (Mann–Whitney U test: n 1 = 78, n = 68, U = 2487, n.s.

Techniques:

Journal: Nature Communications

Article Title: Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

doi: 10.1038/s41467-020-19715-8

Figure Lengend Snippet: Clothianidin (CLT) contamination decreases NF-κB activation, impairing the immune response and enhancing mite’s fitness, as a possible consequence of a higher feeding efficiency. The decrease in NF-κB activation relaxes immune control on DWV, which, above a certain threshold, impacts NF-κB, reinforcing the negative effect on immune response. Arrows indicate positive (i.e., stimulation or upregulation) interactions; bar-headed lines mark negative interactions (i.e., inhibition or downregulation); dashed lines indicate that the effect can be impaired by Clothianidin treatment.

Article Snippet: Mite fertility (i.e., proportion of reproducing females out of total female mites used in the experiment ) on bee pupae treated with 0.01 ppm of Clothianidin at the larval stage was significantly higher than on control bees (Mantel–Haenszel test: df = 2, M–H Chi-2 = 3.970, P = 0.046; Fig. ) by 23%, on average; on the contrary, fecundity (i.e., number of offspring per reproducing female) seemed not to be affected (Mann–Whitney U test: n 1 = 78, n = 68, U = 2487, n.s.

Techniques: Activation Assay, Control, Inhibition