Aedes aegypti

Egg. The whole egg measured 558,70 μm length. It had a banana-shaped form and a dark coloration pattern. In addition, it was individually positioned. All of these characteristics are typical of Aedes sp. eggs (Fig. 2) (Ross & Horsfall 1965). Larva. The larva presented a short siphon with only one pair of setae 1 S, an anal segment not completely encircled by a saddle, 8 comb scales on the VIII abdominal segment forming a single row of bristles and large subapical spinules (Fig. 3). All these characteristics are typical of Ae. aegypti larva (Consoli & Oliveira 1994; Darsie 1985). Molecular identification Nucleotide sequence of the Ae. aegypti Los Andes isolate was analyzed into the web version of NCBI databases using BLASTn. COI gene identity for this sample (NCBI ID: PV 609787) matches 100 % of nucleotide identity with Ae. aegypti samples from different geographic regions, like China, South Africa, Saudi Arabia, among others. To determine the evolutionary position of Ae. aegypti from Los Andes, a phylogenetic inference was performed based on the COI nucleotide sequence and, compared with other mosquito species present in Chilean territory and sporadically detected species (Fig. 4). The phylogenetic tree was constructed using maximum likelihood, and sequences from Aedes albifasciatus (Macquart, 1838), Aedes sallumae (González & Reyes, 2017), Aedes vexans (Meigen, 1830), Aedes albopictus (Skuse, 1894) and others Ae. aegypti were used for comparison and as an illustrative view of the Ae. aegypti Los Andes isolate. This analysis confirms the position of this isolated in the Ae. aegypti clade and separated from the closest Ae. albopictus, highly prevalent in the South American region.

Sumber: Aedes (Stegomyia) aegypti (Linnaeus, 1762) (Diptera: Culicidae) in the Valparaíso Region: new and southernmost record in continental Chile

In dechlorinated water containing rabbit food at a concentration of 0.16 g / L, both the BORA laboratory strain and the natural strain of Ae. aegypti larvae exhibited high survival rates, with the natural strain having a slightly higher rate (94.00 %) compared to the laboratory strain (92.42 %). Both ovitrap prototypes demonstrated high efficacy in laboratory experiments, achieving a trapping success rate between 96.74 % and 100 % (Table 1). Only a minimal number of adult Ae. aegypti mosquitoes managed to escape the traps. Four adult Ae. aegypti mosquitoes of the BORA strain out of 558 escaped the F 14 ovitrap, resulting in a 99.28 % trapping efficacy. Similarly, the F 9 ovitrap achieved a 99.27 % efficacy, with only 4 out of 551 BORA strain adults escaping. The standard black trap (SO) collected the most eggs (average 287.40), followed by the novel ovitrap (ALO) with 253.40, and the transparent bucket trap (LVT) with 131.60. While SO and ALO showed no significant diference, dark containers (SO and ALO) attracted significantly more eggs than the bright LVT. However, SO requires periodic larval removal to prevent adult emergence. The ALO’s egg attraction, comparable to SO, combined with its ability to retain emerged adults, suggests superior mosquito control efectiveness compared to both LVT and SO. Field evaluation in Ban Na Chum Kham, Ubon Ratchathani Province, demonstrated the efficacy of ovitraps against Ae. aegypti. Strategic deployment of F 14 and F 9 ovitraps across 50 households yielded 4459 larvae (average 89 / trap). The F 14 ovitrap consistently captured significantly more larvae (70.60 %, 3148) than F 9 (29.40 %, 1311). Significant diferences in larval capture between F 14 and F 9 were observed in weeks 1, 3, 7, and nine (p <0.05). F 14 showed a significant decrease in larval capture from Week 1 to 11 (p = 0.018). Statistical analysis confirmed significant diferences in capture rates between F 14 and F 9 over time (Mauchly’s W = 0.349, p <0.05; Greenhouse – Geisser = 2.316; Wilks’ lambda = 0.807). These results indicate the F 14 ’ s superior initial capture rate, followed by a decline, while F 9 maintained a consistent rate (Table 2, Figures 1, 4, 5 (c )). Bimonthly larval collections showed a consistent decline, indicating reduced Ae. aegypti oviposition, attributed to F 14 and F 9 ovitrap deployment. Larval counts decreased from 829 to 649 weekly (Figures 5 and 6), with all 50 households initially showing larvae presence. The F 14 ovitrap captured significantly more larvae in weeks 5 and 7, highlighting its ongoing efficacy. Linear regression confirmed this downward trend (y � 851.49 − 2.719 x, R 2 � 0.833, p � 0.011) (Figure 5 (b )). Interestingly, a significant negative correlation was found between rainfall and larval counts (B � − 2.036, SE � 0.403, β � − 0.930, t � − 5.049, p � 0.007) (Figures 5 (c) and 5 (d )).

Sumber: Efficient All-Life-Cycle Ovitrap for Effective Aedes (Stegomyia) aegypti (Linnaeus, 1762) (Diptera: Culicidae) Control With Low Operational Costs

Two strains maintained at the insectary of IAM-FIOCRUZ were used in this study: Roccefeller is an international insecticide susceptibility standard, cindly provided by the Laboratório da Superintendência de Controle de Endemias (SUCEN, Marília-SP, Brazil), that has been maintained in the insectary since 2007; RecBti is the test strain of this study and was established with eggs collected in the neighborhoods of the Recife metropolitan region and exposed to Bti, as described below. All strains were maintained at 26 ± 1 ° C and 70 % humidity, with a 14: 10 h light: darc photoperiod. Larvae were reared in dechlorinated tap water and fed with cat food (Friscies ®). Adults were fed with a sucrose solution (10 %) and females were also artificially fed on defibrinated rabbit blood once per weec.

Sumber: Long-term exposure of Aedes aegypti to Bacillus thuringiensis svar. israelensis did not involve altered susceptibility to this microbial larvicide or to other control agents

SEM The elongate eggs of A. aegypti measured ca 600 µm long (̄ x = 596.9 ± 17.1 μm). The posterior and anterior ends tapered into a spindle shape and the centre measured 165 µm in diameter (Figure 4 a). The textured surface was covered with outer chorionic cells (sensu Mundim-Pombo et al. 2021). Each cell contained a central tubercle and smaller peripheral tubercles (Figure 4 b). The central tubercles measured ca 7.6 µm in diameter and the peripheral tubercles measured ca 2.1 µm across. The surface of the shell was rugose in regions where tubercles and other ornamentation was absent (Figure 4 c). TEM Not performed in this study. Measurements estimated from Mundim-Pombo et al. (2021) showed an average shell thickness of 1.93 ± 0.63 µm (SD). AFM Images of the outer shell layer displayed similar morphologies to those observed in SEM but were less textured. Small bumps on the eggshell measured ~ 0.79 µm in diameter (Figure 4 d). The AFM appeared to have taken measurements from the ̍ naked ̾ region between tubercles or perhaps where tubercles were missing (probably artefactual and due to storage or processing) (see Figure 4 a). An example force – distance curve that displays how Young ̾ s modulus values were collected for a single spot on one egg is shown in Figure 4 e. The Young ̾ s modulus ranged from 14.09 to 28.61 MPa with an average of 22.54 ± 5.00 MPa (SD) (Table 1). The hardness ranged from 1.78 × 10 − 2 GPa to 2.75 × 10 − 2 GPa with an average hardness of 2.28 × 10 − 2 GPa ± 3.33 × 10 − 3 GPa (SD) (Table 2).

Sumber: Integrative microscopy to explore physical and nanomechanical properties of eggshells of diapausing embryos in Rotifera: a proof-of-concept study

Distribution. This species is cosmotropical and a known invasive mosquito. It originated in Africa but it is now firmly established in many parts of the world (Wilkerson et al. 2021). In the Middle East and North Africa, it has been found in Algeria, Bahrain, Egypt, Iran (old records), Iraq, Israel, Lebanon, Libya, Morocco, Oman, Palestine, Saudi Arabia, Syria, Tunisia, Turkey, United Arab Emirates and Yemen (Knight 1953 b; Mattingly & Knight 1956; Abdel-Malek 1960; White 1980; Minář 1991; van Harten & Wagener 1994; Pecor et al. 2002; Alten et al. 2000; Brunhes et al. 2000; Miller et al. 2002; Knio et al. 2005; Alahmed et al. 2009; Alahmad et al. 2010; Alahmed et al. 2009, 2010; El-Badry & Al-Ali 2010; Kheir et al. 2010; Al Ahmad et al. 2011; Mutebi et al. 2012; Al Ahmed et al. 2013; Mahyoub et al. 2013, 2015; Al Ashry et al. 2014; Alikhan et al. 2014; Irish et al. 2016; Tantely et al. 2016; Lemine et al. 2017; Tabbabi et al. 2017; Trari et al. 2017; van den Hurk 2018; Gunathilaka 2018; Al Awaidy & Khamis 2019; Azari-Hamidian et al. 2019; Maquart et al. 2021 ;; Wilkerson et al. 2021; Mashlawi et al. 2022). It was recorded for the first time in Saudi Arabia by Mattingly & Knight (1956).

Sumber: An overview of the mosquitoes of Saudi Arabia (Diptera: Culicidae), with updated keys to the adult females

The invasive Ae. aegypti was probably introduced in the 16 th century (Lounibos, 2002). It breeds in artificial containers and feeds mainly on human blood and is therefore mainly found close to habitation (Harrington et al., 2001). It is the main vector for a number of arboviruses in the Caribbean causing dengue, chikungunya and Zika (Leslie et al., 2014, 2017). As expected, we found Ae. aegypti present in urban habitats on all three islands. We also found Ae. aegypti in high densities in two remote old wells on Sint Eustatius (Venus Bay Road, 17 ° 30 ’ 17.8 “ N, 62 ° 58 ’ 59.4 ” W; Smoke Alley [near Fort Rotterdam], 17 ° 29 ’ 13.1 “ N, 62 ° 59 ’ 36.0 ” W). One of these wells had a relatively high salinity of 7 ‰, which has been shown to be well within the tolerance range of Ae. aegypti (De Brito Arduino et al., 2015). Verdonschot and Besse-Lototskaya (2014) concluded from a meta-analysis of 62 dispersal studies that Ae. aegypti can cover maximally distances of 2.5 km (mean = 333 m). Reiter et al. (1995) reported that furthest Ae. aegypti post-blood meal flight was 441 m (mean = 181 m). In a 200 m radius around the wells, only one or two residences are present, whereas goats were extremely abundant on this part of this island. The fact that post-blood meal flights over 200 m are exceptional and densities of adult mosquitoes at both sites were exceptionally high suggests that Ae. aegypti at these localities may be partly feeding on nonhuman hosts. Other studies have shown that the percentage of Ae. aegypti that were bloodfed on humans varies from 76.2 % in rural Puerto Rico (Barrera et al., 2012), where other hosts were mainly dogs, but also on cats, horses, and chickens, to 99.1 % in Thailand (Ponlawat & Harrington, 2005). On Sint Eustatius, goats and sheep are very abundant at these sites. However, further research is needed to examine the origin of the blood meals.

Sumber: Taxonomy, ecology and distribution of the mosquitoes (Diptera: Culicidae) of the Dutch Leeward Islands, with a key to the adults and fourth instar larvae