5 research outputs found
Courtship activity, copulation & insemination success in a mosquito vector fed a herbal aphrodisiac: Implications for sterile insect technology
Background & objectives: In sterile insect technology (SIT), mating competitiveness is a pre-condition for the reduction of target pest populations and a crucial parameter for judging efficacy. Still, current SIT trials are being hindered by decreased effectiveness due to reduced sexual performance of released males. Here, we explored the possible role of a herbal aphrodisiac in boosting the mating activity of Aedes aegypti.
Methods: Males were fed one of two diets in this study: experimental extract of Eurycoma longifolia (MSAs) and sugar only (MSOs). Differences in life span, courtship latency, copulation activity and mating success were examined between the two groups.
Results: No deaths occurred among MSA and MSO males. Life span of MSOs was similar to that of MSAs. The courtship latency of MSAs was shorter than that of MSOs (P<0.01). MSAs had greater copulation success than MSOs (P<0.001). In all female treatments, MSAs mated more than MSOs, but the differences in rate were significant only in the highest female density (P<0.05). In MSAs, mating success varied significantly with female density (P<0.01), with the 20-female group (P<0.01) having the lowest rate. Single MSA had better mating success at the two lowest female densities. In MSOs, there were no significant differences in mating success rate between the different female densities.
Interpretation & conclusions: Our results suggested that the herbal aphrodisiac, E. longifolia, stimulated the sexual activity of Ae. aegypti and may be useful for improving the mating competitiveness of sterile males, thus improving SIT programmes
Exposure of a Dengue Vector to Tea and Its Waste: Survival, Developmental Consequences, and Significance for Pest Management
Dengue
mosquitoes are evolving into a broader global public health
menace, with relentless outbreaks and the rise in number of Zika virus
disease cases as reminders of the continued hazard associated with <i>Aedes</i> vectors. The use of chemical insecticidesî—¸the
principal strategy against mosquito vectorsî—¸has been greatly
impeded due to the development of insecticide resistance and the shrinking
spectrum of effective agents. Therefore, there is a pressing need
for new chemistries for vector control. Tea contains hundreds of chemicals,
and its waste, which has become a growing global environmental problem,
is almost as rich in toxicants as green leaves. This paper presents
the toxic and sublethal effects of different crude extracts of tea
on Aedes albopictus. The survival rates
of larvae exposed to tea extracts, especially fresh tea extract (FTE),
were markedly lower than those in the control treatment group. In
addition to this immediate toxicity against different developmental
stages, the extracts tested caused a broad range of sublethal effects.
The developmental time was clearly longer in containers with tea,
especially in those with young larvae (YL) and FTE. Among the survivors,
pupation success was reduced in containers with tea, which also produced
low adult emergence rates with increasing tea concentration. The production
of eggs tended to be reduced in females derived from the tea treatment
groups. These indirect effects of tea extracts on <i>Ae. albopictus</i> exhibited different patterns according to the exposed larval stage.
Taken together, these findings indicate that tea and its waste affect
most key components of <i>Ae. albopictus</i> vectorial
capacity and may be useful for dengue control. Reusing tea waste in
vector control could also be a practical solution to the problems
associated with its pollution