Pintomyia evansi (Diptera: Psychodidae) larvae susceptibility to hydrated lime under laboratory conditions

Acta Trop. 2022 Aug:232:106505. doi: 10.1016/j.actatropica.2022.106505. Epub 2022 May 11.

Abstract

This study evaluated the effect of Calcium hydroxide (Ca(OH)2 Mg(OH)2) on third stages Pi. evansi larvae mortality under experimental laboratory conditions. Three treatments containing a mixture of phlebotomine natural breeding soil (substrate) and Calcium hydroxide at different concentrations were used: Treatment 1 (T1), 1 kg of substrate mixed with 56.2 g of lime; Treatment 2 (T2), 1 kg of substrate mixed with 62.5 g of lime; and Treatment 3 (T3), 1 kg of substrate mixed with 70 g of lime. in addition, a sample of substrate without lime was used as a control for each treatment. The mortality in T1 was 1% at 24 h and 12% at 48 h, reaching a maximum of 56% at 72 h of exposure. For T2, mortality was progressive, starting with 12% at 12 h, 36% at 24 h, 52% at 48 h, and 100% at 72 h; while T3 showed mortality percentages of 94% and 100% between 12 and 24 h of exposure. Therefore, T3 was the most effective to according to the Kaplan-Meier survival analysis. This study showed that treatments over 62 g of Calcium hydroxide per 1 kg of substrate offer a starting point for immature stage control under laboratory conditions. With these results, we propose to evaluate the cost-effectiveness and feasibility of the application, of the latter concentration, under field conditions in urban environments for its application in vector control programs.

Keywords: Control; Hydrated lime; Immature stages; Leishmaniasis; Pintomyia evansi.

MeSH terms

  • Animals
  • Calcium Compounds / pharmacology
  • Calcium Hydroxide
  • Larva
  • Oxides
  • Psychodidae*

Substances

  • Calcium Compounds
  • Oxides
  • lime
  • Calcium Hydroxide