Oviposition in flight: the Sabethes albiprivus incredible egg-throwing behavior

ABSTRACTMosquitoes display highly variable oviposition strategies and behavior. By using a high-speed camera, we detailly documented for the first time the egg-throwing strategy of the sylvatic yellow fever vector Sabethes albiprivus Theobald in laboratory. An oviposition trap made with sapucaia nut for field collection of tree-hole mosquitoes and obtaining Sa. albiprivus eggs either in the field or in the laboratory colony is described.

Oviposition Deterrent Activity and Ovicidal Effect of Pometia pinnata Leaves Extract against Dengue Vector, Aedes aegypti (Diftera: Culicidae)

Aedes aegypti is the main vector of dengue fever that most commonly occurred in Indonesia. The application of botanical insecticides is being developed as an alternative vector control. Botanical components have been reported as the potential alternative to inhibit the process of oviposition and fecundity suppression. This study aims to determine the oviposition deterrent activity and ovicidal effects of ethanol extract of Pometia pinnata leaves against Aedes aegypti. Oviposition deterrent assay was conducted on twenty bloodfed females in a cage (40 cm x 40 cm x 40 cm). One treated oviposition trap and one control oviposition trap were placed in the opposite corner of the cage. Four replicates were performed for each concentration. The eggs were counted and analyzed after 72 hours of trial. Ethanol extract of Pometia pinnata leaves have antioviposition effect on female mosquitoes Aedes aegypti at 400 ppm (effective repellency / ER = 56.38%; oviposition active index/OAI = -0.39) and 500 ppm (ER = 66.4%; OAI = -0.49). In the ovicidal assay, twentyfive eggs are used for determination ovicidal effect and five replicates were performed for each concentration. The hatched larvae were collected and counted daily. The ethanolic extract of Pometia pinnata leaves at 0.05%, 0,1%, 0.15%, 0.2%, and 0.25% concentration have ovicidal activity of 11%, 28%, 87%, 94%, and 98% against Aedes aegypti eggs, respectively. This study revealed that the ethanol extract of Pometia pinnata leaves could be a potential alternative in controlling the dengue vector.

Comparison Between Larval Survey Index and Positive Ovitrap Index in the Evaluation of Populations of Aedes (Stegomyia) aegypti (Linnaeus, 1762) North of Paraná, Brazil

Aedes ( Stegomyia) aegypti (Linnaeus, 1762) is one of the world’s most widely distributed mosquitoes and is the vector of the dengue virus, one of the most important reemerging diseases. Besides dengue, A. aegypti can also transmit urban yellow fever, chikungunya, and Zika virus, making it of great medical importance. Thus, it is of extreme importance to find reliable methods to evaluate the presence of A. aegypti in urban areas. In Brazil, rapid index surveys of Aedes aegypti by means of larval survey (LIRAa) is the official method to estimate the Breteau (BI) and property infestation (PII) indexes, which indicates how many infested containers with larvae of A. aegypti were found by the total number of properties surveyed and the proportion of houses infested, respectively. As the LIRAa requires access to private residences and trained personal to find breeding sites and do not reveal the mosquito’s presence when in low density, it has not demonstrated efficacy in determining the presence of A. aegypti. To evaluate an alternative method, the LIRAa method was compared with an oviposition trap, made with hay infusion and a hardboard pallet, to evaluate the BI and the PII. The 2 methods were carried out simultaneously through 4 surveys, sampling 60 homes per survey. To evaluate the best configuration of ovitraps for surveillance of A. aegypti, the ovitraps were installed in intradomicile and peridomicile areas, with 1 to 5 traps per residence and with 1 to 3 pallets per trap, and these different configurations were compared using the positive ovitrap index (POI) and egg density index (EDI). The ovitraps showed greater sensitivity for detecting the presence of A. aegypti, with a BI of 72.5% and PII of 54.2%, whereas the LIRAa revealed only 2.1% for the BI and 1.3% for the PII. Therefore, the use of sentinel traps can provide information in a more rapid and precise manner. As there were no differences in the ovitraps distributions patterns, the ovitraps can be installed in the peridomicile area, with 2 traps per surveillance point and 1 pallet per trap, making their installation easier and more cost-efficient, facilitating the work of health agents in future surveillances complementing LIRAa’s actions for efficient monitoring.

Field Evaluation of a Redesigned Oviposition Trap to Monitor Gravid Invasive Aedes Mosquitoes in a Suburban Environment

ABSTRACT Oviposition cup traps (OCT) are commonly used to detect gravid invasive Aedes mosquitoes. Employing OCT during hot summer months or over broad geographic areas is labor intensive because the water in these small-volume traps must be frequently replenished to maintain their attractiveness to mosquitoes. We developed low-cost and simple-to-build oviposition bucket traps (OBT) that attract mosquitoes for more than 1 wk. Comparison of adjacently placed OCT and OBT in the city of Madera, CA, showed OBT captured significantly more Ae. aegypti eggs per trap-night relative to the OCT (8.8 ± 2.6 and 4.1 ± 1.1, respectively; paired t-test, P = 0.0076), and a significantly greater proportion of OBT contained Ae. aegypti eggs relative to OCT (83% of OBT and 65% of OCT; Fisher's exact test, P = 0.0214). The results suggest that OBT can collect larger quantities of Ae. aegypti eggs relative to OCT while potentially offering greater flexibility in scheduling trap inspections.

PERBEDAAN EFEKTIFITAS PENGGUNAAN ATRAKTAN LARUTAN FERMENTASI GULA-RAGI DAN AIR RENDAMAN CABAI MERAH (Capsicum Annum) TERHADAP JUMLAH TELUR Aedes Sp. YANG TERPERANGKAP

Oviposition trap (Ovitrap) is one of the Aedes sp mosquito controlling method without insectide. The purpose of this study was to determine the effectiveness of the use of attractant solution of yeast- sugar and water soaking red chilii to the number of trapped eggs of Aedes sp. Type of this research was experimental study. The subject of this research were all the eggs were trapped on ovitrap, while the research unit was a group of houses, building / construction in the research area which consisted of 15 houses. The study was conducted in kelurahan Mersi,Mersi District of Purwokerto. This research applies 3 treatment, so that the object consists of 15 houses with the total number of installed ovitrap 45 indoors and 45 outdoors. Total number of eggs of Aedes sp which trapped in ovitrap were 1021 grain. Number of trapped eggs in control (water wells), water of soaking red chili attractant and solution of yeast-sugart attractant were 929 grains (91%), 60 grains (5,9%) and 32 grains (3.1%) respectively. Number of eggs which trappped in ovitrap outdoor were 639 grains (62.6%) while in ovitrap indoor wwere 382 grains (37.4%). There was significant difference in the number of eggs that trapped in each type of attractant, however there was no significant difference in the number of eggs that are trapped on the basis of location.