Since the beginning, mosquito-borne diseases like dengue fever, encephalitis, yellow fever, malaria, and filariasis have been caused by numerous medically significant pathogens and parasites, including viruses, bacteria, and protozoans. This indicates the necessity for the ongoing creation of new and effective mosquito-borne disease control strategies in Saudi Arabia and internationally. This investigation has tried to assess the potential larvicidal capacity of local bacteria isolated from the soil of the Rahat region of Makkah, Saudi Arabia for the bio-control of Aedes aegypti larvae, a main cause of dengue. The bacteria were identified using morphological and molecular characteristics. Bioassays were used to determine the pathogenicity of various strains against A. aegypti larvae. A total of 66 different bacteria were isolated. Overall, four (6.06%) of the 66 bacteria caused mortality in the A. aegypti larvae, and only two (Brevibacillus centrosporus, and Cytobacillus firmus) caused 100% mortality in 24 h. After 48 h, two isolates (Escherichia fergusonii1 and E. fergusonii 2) caused mortality of over 70%. The outcomes of this investigation exhibited that local isolates of bacteria in the soils of the Rahat region of Makkah, Saudi Arabia, have larvicidal ability. These bacteria have shown larvicidal effects on the larvae of A. aegypti. In conclusion, further studies are required to evaluate other mechanisms that contribute to the production of larvicidal toxins in these bacteria.

Dengue Hemorrhagic Fever (DHF) depends on controlling Aedes aegyptimosquitoes and larvae. Currently, larvicide control still uses temefos larvicide, though several studies have reported resistance. Insecticides from plants can be used as an alternative. One of the plants reported to have larvicide potency was Melaleuca leucadendraleaves. This study aimed to look at ethanol extract of M. leucadendra leaves activity in killing Aedes aegyptilarvae and LC50 values after a 24-hour examination. This type of research was Experimental Design with Post-test Only Control Group Design. M. Leucadendra leaves was extracted through maceration process using ethanol 96%. The treatments consisted of 8 concentrations of 400mg/L (0. 04%),1000mg/L (0. 1% ),1600mg/L (0. 16%),2000mg/L (0. 2%),10, 000mg/L (1%),20, 000mg/L (2%),30, 000mg/L (3%),40, 000mg/L (4%) and the control group (0%). Each concentration was replicated four times and used twentyof the third larvae A. aegypti. The results showed that M. leucadendra has a lethal ability against A. aegypti. There was a correlation between the extract concentration and the larva mortality (p=0. 000,95%). Extract concentration 0. 04-0. 2% of the extract caused mortality less than 3%, and the highest mortality (47. 5%) reached by concentration 4%. The LOGIT test showed that the number of LC50 was 3. 7% (37, 600mg/L) with 95% significance. A high concentration (>1%) of extract M. leucadendra caused turbid, greenish-gray color, and unpleasant smell on the water. Regarding the WHO bioassay guideline, etahnol extract of M. leucadendra leaves was less effective in killing Aedes aegypti larvae, though it causes lethal effect A. aegypti.

ABSTRACT: Dengue Hemorrhagic Fever (DHF) depends on controlling Aedes aegyptimosquitoes and larvae. Currently, larvicide control still uses temefos larvicide, though several studies have reported resistance. Insecticides from plants can be used as an alternative. One of the plants reported to have larvicide potency was Melaleuca leucadendraleaves. This study aimed to look at ethanol extract of M. leucadendra leaves activity in killing Aedes aegyptilarvae and LC50 values after a 24-hour examination. This type of research was Experimental Design with Post-test Only Control Group Design. M. Leucadendra leaves was extracted through maceration process using ethanol 96%. The treatments consisted of 8 concentrations of 400mg/L (0. 04%),1000mg/L (0. 1% ),1600mg/L (0. 16%),2000mg/L (0. 2%),10, 000mg/L (1%),20, 000mg/L (2%),30, 000mg/L (3%),40, 000mg/L (4%) and the control group (0%). Each concentration was replicated four times and used twentyof the third larvae A. aegypti. The results showed that M. leucadendra has a lethal ability against A. aegypti. There was a correlation between the extract concentration and the larva mortality (p=0. 000,95%). Extract concentration 0. 04-0. 2% of the extract caused mortality less than 3%, and the highest mortality (47. 5%) reached by concentration 4%. The LOGIT test showed that the number of LC50 was 3. 7% (37, 600mg/L) with 95% significance. A high concentration (>1%) of extract M. leucadendra caused turbid, greenish-gray color, and unpleasant smell on the water. Regarding the WHO bioassay guideline, etahnol extract of M. leucadendra leaves was less effective in killing Aedes aegypti larvae, though it causes lethal effect A. aegypti.

Background: Bifenthrin and Acorus calamus Linn extract were evaluated against dengue vectors in the laboratory. Methods: Both Bifenthrin and Acorus calamus Linn crude hexane extract were bioassayed against the adults and larval stages of dengue vectors Aedes aegypti L. and Aedes albopictus(Skuse) in the laboratory. Results: The A. calamus crude hexane extract exhibited a larvicidal activity against 4th-instar Ae. aegypti larvae with LC50 and LC90 values of 0.4418 and 11.3935 ppm respectively. The plant crude extract exhibited against Ae. albopictus larvae with a higher LC50 and LC90 values of 21.2555 ppm and 36.1061 ppm, respectively. There was a significant difference on the effect of A. calamus extract on both Aedes spp. Larvae (P< 0.05). However, bifenthrin showed a significant difference on larvicidal effect to that of A. calamus hexane extract on both Aedes spp (P< 0.05). In testing the adulticidal activity, this plant extract exhibited the LC50 and LC90 values of 17.4075 and 252.9458 ppm against Ae .aegypti and a higher LC50 and LC90 values of 43.9952 and 446.1365 ppm respectively on Ae. albopictus. There was no significant difference on the effect of A. calamus extract on both Aedes spp adults (P> 0.05). Conclusion: Bifenthrin however showed a significant difference on both Aedes spp adults (P< 0.05). With the wide availability of A. calamus in Malaysia, it could be utilized for controlling dengue vectors.