Effects of caffeine and used coffee grounds on biological features of Aedes aegypti (Diptera, Culicidae) and their possible use in alternative control

Abstract

Caffeine and used coffee grounds completely blocked the development of Aedes aegypti in the early stages, in treatments with the concentrations 1.0 mg/mL and 50 mg/mL, respectively. More advanced stages and even adults were obtained in lower concentrations of both substances, enabling observations to be made of mortality rate, longevity and esterase patterns. The experiments involved treatments using either eggs or 3 rd instar larvae (L3), with or without the addition of fish food. Mortality rates prior to the adult stage and adult longevity were significantly different in the comparisons among treatments, in every kind of experiment, but in those using L3 larvae, their percentages were smaller. Observations of the time of larva and adult onset suggested that developmental time was also delayed in treatments with both substances. The addition of fish food increased significantly the number of adults produced in caffeine 0.2 and in the control, but in used coffee grounds, the opposite effect occurred. Longevity was apparently not affected by the addition of food, except again in coffee grounds, in which it decreased. In an attempt to detect a mechanism involved in the action of caffeine and coffee grounds, esterases (enzymes involved in the detoxification of xenobiotics) were analyzed in polyacrylamide gels of treated 4 th instar larvae (L4). In treatments with both substances, the expression of some carboxylesterases was affected, suggesting that they may be involved in the observed impairment.

Effect of Used Coffee Grounds on Larval Mortality of Aedes aegypti L. (Diptera: Culicidae): Suspension Concentration and Age versus Efficacy

“…The present results reinforce those obtained by Laranja et al (2003) showing that UCG causes larval mortality in A. aegypti and then may be considered a potential agent for alternative control, when used in the appropriate concentration and with the addition of new UCG suspension at appropriate intervals. The present study shows that 300 mg/ml is a secure concentration.…”

“…Even when larvae do not die in three or four days, the development is arrested in this stage (Laranja et al 2003). In the same study UCG also affected developmental time increasing it.…”

“…UCG includes, in addition to caffeine, anti-physiological components such as tannins, chlorogenic acid, caffeic acid and potassium in excess (Brenes 1979). Laranja et al (2003) considered that some of these components of UCG, in addition to caffeine, might be involved in the detrimental effects on A. aegypti because the effects of UCG on the esterase pattern differed from those of caffeine when used isolated. In fact, data in literature shows that tannins have larvicidal activity (Silva et al 2004).…”

“…Used coffee grounds (UCG), the powder that is left after coffee has been filtered out to drink was used in tests for mortality of A. aegypti (Laranja et al 2003). UCG suspensions in appropriate concentrations blocked the development of the mosquito before reaching the adult phase, in which the virus transmission occurs through the bites of the female.…”

Variabilidade Genética em Populações de Aedes aegypti (L.) (Diptera: Culicidae) Utilizando Marcadores de RAPD

“…O estudo da estrutura genética da população é essencial para o entendimento da dinâmica das populações do A. aegypti e para a análise de fatores responsáveis pela resistência e adaptação ecológica. Vários estudos têm investigado a variabilidade genética de populações de culicídeos, utilizando marcadores moleculares tais como isoenzimas (Laranja et al 2003, Souza-Polezzi & Bicudo 2004, DNA mitocondrial (Bosio et al 2005), RAPD (Polimorfismo de DNA Amplificado ao Acaso) (Paduan et al 2006) e microssatélites (Chambers et al 2007).…”