ABSTRACT
The aim of this study was to evaluate the effect of the latex from Euphorbia splendens var. hislopii (N.E. Br.) Ursch & Leandri, Euphorbiaceae, on the eggs and engorged larvae of Rhipicephalus (B.) sanguineus (Latreille, 1806) (Acari: Ixodidae). Six aqueous concentrations: 25, 50, 100, 125, 250 and 500 μL/L of the latex of this plant were tested. The control group was tested only with distilled water. The latex of E. splendens var. hislopii presented an LD50 of 18.031 μL/L and LD90 of 84.610 μL/L against the eggs of R. (B.) sanguineus. The larvae of all the groups treated with the latex presented a low survival rate of 0 percent at 25 μL/L, 1 percent at 50 μL/L, 2 percent at 100 μL/L, 3 percent at 125 μL/L, 9 percent at 250 μL/L, 5 percent at 500 μL/L when compared with the control group (91 percent). On day 7 and 14 after the application the latex killed more efficiently the treated groups (25, 50, 100, 125, 250 and 500 μL/L). As from day 21 the latex became less effective for all treatments. Our results clearly show that the aqueous concentration of the latex have a strong effect on tick eggs and larvae suggesting that it could become an important acaricide.
ABSTRACT
This paper evaluates the alterations in the glycogen content of tissues (digestive gland and cephalopedal mass) and glucose in the haemolymph of Biomphalaria glabrata BH strain infected with Schistosoma mansoni BH strain and exposed to the latex of Euphorbia splendens var. hislopii. A reduction in the glycogen deposits was observed in infected snails exposed and not exposed to latex. However, the exposure to latex caused a greater depletion of the glycogen levels in both sites analysed, especially from the third week onward. The utilisation of latex as a molluscicide to control the population of infected B. glabrata selectively is proposed.
Subject(s)
Animals , Biomphalaria , Carbohydrate Metabolism , Euphorbia , Glucose , Hemolymph , Latex , Biomphalaria , Schistosomiasis mansoni , Schistosomiasis mansoni/transmissionABSTRACT
Aqueous solutions of the molluscicidal latex of Euphorbia splendens are irritant to the rabbit eye in concentrations higher than 0.35% and to the rabbit skin in concentrations higher than 0.5%. Although this irritant potential does not proclude its use as a molluscicide, special precautions are recommended for hanbdling and application of the product and the hazard of skin tumor-promoting potencial should be carefully investigated before its use for schistosomiasis vector control.
