Relative toxicity of ethylene dibromide, methyl bromide and phospine to the adults of Caloglyphus krameri (Berlese) and Tyrophagus putrescentiae (Schrank)(Acarina, Acaridae).

Tyrojhzgus putrescentiue (Schrank) and Culoglyphus krumeri (Berlese) were found to
infest packaged ‘chappaties’ (a baked wheat preparation commonly consumed in
India) during storage. These mites were also seen in the spillage collected from a
cashew processing factory. Studies in both situations showed that the two mites
work in succession to bring about the decay of the host material. ?Y putrescentiue
was observed in large numbers in the first stage of decay and this was followed by a
relative abundance of C. krumeri. The infested product is covered by mites and
their cast skins and presents an unwholesome appearance. In extreme cases of
infestation the host material is reduced to a moist sticky mass with an offensive
smell.
Ethylene dibromide (EDB) p roved to be very effective in eradicating T. putrescentiue
in the steel cupboard wherein the ‘chappaties’ had been stored. The susceptibility
of 1. putrescentiue to methyl bromide (MB) (BARKER, 1967) and the
effect of phosphine (PH,) on mites of bin-stored grain (SINHA et al., 1967) have
focussed the importance of evaluation of fumigants for the control of the storage mites.
The relative toxicities of EDB, MB and PH, to C. krumeri and Z+. putrescentiue
are reported here.