17 November, 2009

Chemical scorpion control in Brazil

Scorpions constitutes a public health problem in many parts of Brazil. This is specially a problem in many urban areas where the effects of human activity and expansion into the scorpions natural habitats have increased the number of human-scorpion contacts. Some species has also adapted well to urban environments.

Chemical control of scorpions by the use of insecticides is common in Brazil, in addition to community involvement and education. The effects of insecticides against scorpions are controversial and not documented properly. Some insecticides actually may have an irritant effect on scorpions by increasing their activity and aggression, and thereby causing an increased risk of sting incidents.

Cleide Maria Ribeiro de Albuquerque and co-workers have now published a very interesting study on the effects of chemical control on the medical important species Tityus stigimurus (Buthidae) and the importance of community knowledge of scorpionism.

In this study, the events following application of the insecticide Demand 2.5 concentrated solution (CS) in the field, to control Tityus stigmurus, were investigated. Data on attitudes and practices relating to scorpionism were collected using a questionnaire. During the months of May to July 2005, 69 premises were monitored on different days following insecticide treatment, focusing on scorpion frequency and mortality. According to the results, 42% of the premises showed scorpion incidence, with an average of three specimens per house. The highest incidence was recorded during the first week following the treatment. Only 7% of the specimens were found dead. Most (72%) of the population showed knowledge about prevention and control measures. Despite this, 100% of the premises presented breeding sites, mainly in debris (79.7%). These results indicate that the scorpion control method used by health agents during this investigation was not efficient, and the results suggest that the method may have had a dispersive effect on these animals.

De Albuquerque CMR, Barbosa MO, Iannuzzi L. Tityus stigmurus (Thorell, 1876) (Scorpiones; Buthidae): Response to chemical control and understanding of scorpionism among the population. Rev Soc Bras Med Trop. 2009;42(3):255-9. [Free fultext]

Family Buthidae

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