Changes in the biting activity of a dengue vector relative to larval and adult nutritional histories: Implications for preventive measures

Hamady Dieng,Ooi Seow Hui,Ahmad Abu Hassan,Fatimah Abang,Idris Abd Ghani,Tomomitsu Satho,Fumio Miake,Hamdan Ahmad,Yuki Fukumitsu,Wan Fatma Zuharah,Abdul Hafiz Ab Majid,Nur Faeza Abu Kassim,Nur Aida Ha 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

Themagnitude of dengue transmission depends largely on the level of human–vector contact. Therefore, knowledge regarding the biting periodicity ofmosquitoes is crucial to determine transmission periods' risk, and in planning personal protection measures. Dengue vectors are day-active and endure transitory periods of starvation overnight. However, it is unclear howtheir blood feeding activity pattern is related to body sizewhen temporarily deprived of their main source of energy — sugar. We examined the changes in Aedes albopictus diurnal biting activity, taking into account larval nutritional history and adult starvation. Overall, large body size and nonstarvation conditions were associated with better blood feeding success, but these parameters did not significantly modify the timing of first blood feeding attempt. Females of both sizes showed significant temporal variations in their blood feeding activities. Under conditions of starvation, blood meal uptake was much greater in large females from morning to evening. Similar variations of feeding activity were observed in small females, except in the morning. Under non-starvation conditions, the blood feeding activity of small mosquitoes tended to decrease over time, whereas blood meal uptake activity was high and remained almost constant from morning to evening for larger mosquitoes. Thiswork emphasizes the importance of body size and hunger on the dynamics of vector–host interaction and has important implications for the development of novel strategies for the prevention of disease transmission. Knowingwhen dengue vectors actively bite during the day can help in timing effective personal protective measures.

Sex before or after blood feeding: Mating activities of Aedes aegypti males under conditions of different densities and female blood feeding opportunities

Hamady Dieng,Tomomitsu Satho,Fatimah Abang,Erida Wydiamala,Nur Faeza Abu Kassim,Nur Aida Hashim,Wan Fatma Zuharah,Gabriel Tonga Noweg 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Blood feeding and mating are critical behaviors that regulate both mosquito population maintenance and disease transmission. However, our understanding of mosquito mating systems remains incomplete. One of the most critical issues is a lack of understanding regarding how and where males and females encounter one another. This study was performed to investigate changes in key mating behaviors of Ae. aegypti relative to female blood feeding opportunities, taking into account male density. We compared courtship latency and copulation activity between single and pooled males in a range of assays performed in the presence or absence of a blood source and after blood feeding. The time taken by grouped males to initiate courtship in the presence of a host was much shorter than that in single males. There was no significant difference in courtship latency between pooled and single males in the absence of a blood source or after blood feeding. At low male density, the presence of the host and blood meal ingestion provided better conditions for copulation. At high male density, however, copulation activity was decreased after blood feeding, but remained high regardless of the presence or absence of the host. In addition to providing insight into the mating ecology of Aedes aegypti, this study indicated that the presence of a blood source influences how males encounter and copulate with females. The observation that copulation activity decreases after blood feeding when males are numerous provides new avenues for improving mass release programs of sterile mosquitoes.

Olfactory behavior and response of household ants (Hymenoptera) to different types of coffee odor: A coffee-based bait development prospect

Abdul Hafiz Ab Majid,Hamady Dieng,Siti Salbiah Ellias,Siti Salbiah Ellias,Abd Hafis Abd Rahim,Tomomitsu Satho 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

Odor sensation is a sensory modality of considerable significance in the foraging behavior and interactionalorganization of ants. In the food bait technology, smell is the basis of attraction, which, in turn, is the line of baituse and a key parameter for judging efficacy. Yet, the currently available baits possess low attractiveness tomany ant pests. Hence, strategies to produce ant bait with increased attractiveness are needed. Despite evidencethat coffee has a diverse aroma complex that affects the behavior of honey bees and ants, its attraction to houseinvadingants has yet to be investigated. In a series of Y-tube olfactometer bioassays, we examined the behavioralresponses of Tapinoma indicum (TI), Monomorium pharaonis (MP) and Solenopsis geminata (SG) to various coffeeinducedodor stimuli, comprised of extracts from Arabica, Robusta and Liberica. All coffee extracts showed aninfluence on the behavior of TI, MP and SG workers, with Arabica showed the most significant influence to thetested ants. The workers of TI, MP and SG were more attracted to the odor of 0.01% Arabica extract (ONE), incomparison with 0.05% Arabica extract (TWO) or 0.10% Arabica extract (THREE). Arabica extract mixed withsugar (S) elicited a significant attraction from workers of all three species in a balanced competition with eitherunsweetened Arabica extract or water. These results indicated that coffee, particularly Arabica, was attractive tothe foragers of TI, MP and SG, thus, the use of coffee as a novel stimulus agent seems plausible in ant baitdevelopment.

Susceptibility and fitness cost of Aedes albopictus on their survivability after the exposure to the insecticide

Wan Fatma Zuharah,Aminoddin Sumayyah,Hamady Dieng 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

The present study was undertaken to investigate the lethal and sub-lethal effects of insecticides on the life history of Aedes albopictus mosquitoes from urban and sub-urban areas in Penang, Malaysia. The female mosquitoes aged two to five days old were exposed to; (1) diagnostic dose (lethal dose) at 5% malathion and 0.75% permethrin; and (2) sub-lethal concentration of 1.5% malathion, and 0.2% permethrin, respectively and adult female survivors from sub-lethal concentrations were evaluated for fitness parameters. Fecundity, fertility, adult longevity, development time and survival of mosquitoes were the crucial point in their life history had studied. Aedes albopictus species from urban Sg. Dua strain has developed high resistance towards 0.75% permethrin and was confirmed on resistance after 24 h of reading. While sub-urban Batu Maung strain is still susceptible to both 5% malathion and 0.75% permethrin. At the sub-lethal dose, we discovered 0.2% permethrin insecticide have significantly more effects on the fitness cost of Ae. albopictus as compared to 1.5% malathion; with decreasing on fecundity, lesser time was needed to reach each development stages, and more male adult was emerged compared to female mosquitoes for both urban and sub-urban strains. Whereas, malathion insecticide only affected the number of eggs laid by the parent mosquitoes and the development time to reach adult stages. Even though, Ae. albopictus mosquitoes had developed resistance towards permethrin resulted in decreasing mortality, but subsequent effects on their fitness cost still continued on the first generation. Thus, it will benefit in reducing the transmission of mosquito-borne diseases.

Effects of Extracts and Fractions of Gynura procumbens on Rat Atrial Contraction

Omar Saad Saleh Abrika,Mun Fei Yam,Mohd. Zaini Asmawi,Amirin Sadikun,Hamady Dieng,Elssanousi Ali Hussain 사단법인약침학회 2013 Journal of Acupuncture & Meridian Studies Vol.6 No.4

There is currently a great deal of research interest in utilizing plant compounds against humandiseases, including hypertension. The present study investigated the effects of differentextracts and fractions from leaves of Gynura procumbens Merr. on rat atrial contractionin vitro. Isolated left and right atria, mounted in a 20-ml organ bath, were allowed to equilibratefor 15 min before the application of the extracts or fractions. The extracts (petroleum-ether extract (PE) and methanol extract (ME)) and the fractions (chloroform fraction(CHL), ethyl-acetate fraction (EA), n-butanol fraction (NB) and water fraction (WA) ofthe methanol extract) were tested at three concentrations (0.25, 0.5 and 1.0 mg/ml), witha b-adrenergic agonist (isoprenaline) as a control. All data on contraction responses werelog-transformed and analyzed. When exposed to the different extracts, both atria tendedto exhibit greater contractive responses with the NB whereas cardiac contractions hada tendency to be reduced with most other extracts. For a given extract, the contraction responseswere particularly greater at 0.5 mg/ml for the right atrium and at 1 mg/ml for theleft atrium. Further analysis focusing on the NB fraction revealed that positive inotropismwas greater in left atria exposed to highly-concentrated F2 and F3 sub-fractions. Taken together,our results suggest that NB extracts and fractions from the G. procumbens-leafmethanol extract have positive inotropic activities and, hence, can be considered as an alternative/traditional medicine against increased blood pressure in humans or can be usedin strategies aimed at finding antihypertensive biomolecules from an accessible source.

Biochemical screening of Lactobacilli in midgut of wild Aedes aegypti mosquitoes. A step toward paratransgenesis candidate

Alhaji Hamisu Maimusa,Abu Hassan AHMAD,Nur Faeza Abu Kassim,Hamdan Ahmad,Hamady Dieng,Junaid RAHIM,Muhammad Ahmad DAHIRU 한국곤충학회 2019 Entomological Research Vol.49 No.2

This study was conducted to isolate and identify lactobacilli from larval and adult midgut of wild Aedes aegypti (Ae. aegypti) to find candidate bacteria for paratransgenic control. Characterization of the bacterial symbionts was done using Gram staining, motility test, catalase test, and biochemical tests, among others, and the morphological features were confirmed using a standard scheme that simplifies the identification of lactic acid bacteria. A total of 174 strains were isolated and identified, 135 strains from larval midgut and 39 strains from adult midgut (mean ± SE, 4.00 ± 0.72; P = 0.00). The isolated species were confirmed to be Lactobacillus fermentum, L. casei, L. acidophilus, L. viridescens, L. brevis and L. gasseri. It can be concluded that Ae. aegypti has the potential of harboring the cultivable bacterial symbionts. In conclusion, the isolated species were nominated for paratransgenic control, particularly L. fermentum, being found in large numbers from both larval and adulxt midgut.