Annals of Applied Biology (2014) 165, 137-146

A.S. Corrêa, H.V.V. Tomé, L.S. Braga, G.F. Martins, L.O. de Oliveira and R.N.C. Guedes (2014)
Are mitochondrial lineages, mitochondrial lysis and respiration rate associated with phosphine susceptibility in the maize weevil Sitophilus zeamais?
Annals of Applied Biology 165 (1), 137-146
Abstract: Phosphine is the most widely used fumigant with ever-growing problems of phosphine resistance among insect pests of stored products. One such insect is the maize weevil Sitophilus zeamais, a key pest of stored cereals. Despite its importance as a fumigant, the mechanisms of phosphine toxicity and resistance remain unclear, although the mitochondrion is broadly recognised as its site of action. Here we explored the phosphine susceptibility of maize weevil populations and its association with insect respiration rate, and we tested the association of phosphine susceptibility with the mitochondrial lineages from the field populations studied. We also assessed the action of phosphine in the degradation of mitochondria from muscle cells. Survival under phosphine treatment varied among weevil populations and was negatively correlated with the respiration rate and body mass of the insect. Phosphine produced little lysis of mitochondria and the more phosphine-resistant population exhibited a slightly higher mitochondria fluorescence intensity under confocal imaging. Therefore, reduced respiration rate is correlated with reduced phosphine activity, but its association with high mitochondria fluorescence intensity in muscle cells seems marginal. There was no association between mitochondrial lineages and phosphine susceptibility, which evolved independently, and the mitochondrial gene fragments of cytochrome oxidase I and II were not useful molecular markers of phosphine susceptibility.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Raul Narciso C. Guedes

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sitophilus zeamais