T. Van Opijnen et Jaj. Breeuwer, High temperatures eliminate Wolbachia, a cytoplasmic incompatibility inducing endosymbiont, from the two-spotted spider mite, EXP APPL AC, 23(11), 1999, pp. 871-881
Wolbachia can induce cytoplasmic incompatibility (CI) in the arrhenotokous
two-spotted spider mite between uninfected females and infected males. Cyto
plasmic incompatibility is expressed through a male-biased sex ratio and a
low hatchability, and can be suppressed by removing Wolbachia from spider m
ites reared on a diet with antibiotics. Here we investigated whether heat-t
reatment can elimate Wolbachia from infected mites. Using a PCR assay with
a Wolbachia-specific primer pair (ftsZ), and by standard crosses, we were a
ble to show that 71 per cent of the mites had lost the Wolbachia infection
after rearing the infected population at 32 +/- 0.5 degrees C for four gene
rations. The infection could be completely removed when mites were reared a
t 32 +/- 0.5 degrees C for six generations. Curing through high temperature
s could be one of the reasons why mixed infected/uninfected populations occ
ur in the field. An additional consequence of rearing mites at 32 +/- 0.5 d
egrees C was the shortened development time. The effect of environmental te
mperature on the abundance of Wolbachia and possible behavioural consequenc
es for the spider mite are discussed.