scholarly journals Activity of Some Plant and Fungal Metabolites Towards Aedes Albopictus (Diptera, Culicidae)

2020 ◽  
Author(s):  
Sonia Ganassi ◽  
Marco Masi ◽  
Pasqualina Grazioso ◽  
Antonio Evidente ◽  
Antonio De Cristofaro
Keyword(s):  
Aedes Albopictus ◽  
Mosquito Control ◽  
Adult Emergence ◽  
Post Treatment ◽  
Fungal Metabolites ◽  
Plant Metabolites ◽  
Control Programs ◽  
First Instar ◽  
The Mean ◽  
Third Instar Larvae

Abstract Background: Aedes albopictus (Skuse), a globally spread species, vector of important human arboviruses, and of Zika virus, is extremely difficult to control even for the onset of resistances to chemicals insecticides. Ecofriendly biopesticides for vector control are urgently needed. In this study, the activity of some plant metabolites as Amaryllidaceae alkaloids and some their semisynthetic derivatives and 2-methoxy-1,4-naphthoquinones, and two analogues, and of the fungal metabolites cyclopaldic acid and epi-epoformin on the development and survival of Ae. albopictus larvae was evaluated. Methods: A preliminary screening, on first-instar larvae, with lycorine semisynthetic derivatives and cyclopaldic acid at 100 ppm was conducted. The living larvae were recorded 24 and 48 h post treatment. Based on the results, first-instar larvae were exposed to increasing doses of the compounds tested until adult emergence. The mean larval and pupal duration was calculated. Third instar larvae were exposed to increasing doses of naphthoquinones for 72 h. The mortality rates were recorded every 24. The larvicide Device® SC-15 was used as control.Results: First instar larval exposure to cyclopaldic acid at 50 and 100 ppm for 48 h, resulted in mortality mean percentage of 82.444 and 96.889% respectively; LC50 and LC90 were 40.119 and 105.092 ppm. 1,2-O,O-diacetyllycorine at 50 ppm, 48h post-treatment caused 84.667% mean percentage mortality with LC50 27.769 and LC90 88.316 ppm. Significant differences in the larval and pupal duration were proved when larvae were exposed to cyclopaldic acid (H=16.386; df 4; P=0.003; H=31.835; df 4; P=0.000), 1,2-O,O-diacetyllycorine (H=9.044; df 3; P=0.029; H=18.115; df 3; P=0.000) and N-methyllycorine iodide (H=19.457; df 4; P=0.001; H=15.400; df 4; P=0.004).Statistical analyses revealed that the number of third-instar larvae surviving to naphthoquinones significantly decreases over the time when exposed to 2-methyl-1,4-naphthoquinone 12.5, 25, 50 ppm; 2-hydroxy-1,4-naphthoquinone 12.5, 25 ppm, 2-metoxy-1,4-naphthoquinone 50 ppm. The mean number of surviving larvae exposed to: 2-methyl-1,4-naphthoquinone 12.5, 25, 50, 100 ppm, 2-hydroxy-1,4-naphthoquinone 25, 50, 100 ppm, 2-metoxy-1,4-naphthoquinone 50, 100 ppm was significantly lower than the number of correspondent control larvae, respectively.Conclusions: This study indicated that 1,2-O,O’-diacetyllycorine, N-methyllycorine iodide, cyclopaldic acid and 1,4-naphtoquinone structural derivatives have good potential to develop bioinsecticides for mosquito control programs.

scholarly journals Activity of Some Plant and Fungal Metabolites towards Aedes albopictus (Diptera, Culicidae)

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 285
Author(s):  
Sonia Ganassi ◽  
Marco Masi ◽  
Pasqualina Grazioso ◽  
Antonio Evidente ◽  
Antonio De Cristofaro
Keyword(s):  
Aedes Albopictus ◽  
Mosquito Control ◽  
General Interest ◽  
Fungal Metabolites ◽  
Control Programs ◽  
First Instar ◽  
Survival And Development ◽  
Good Potential ◽  
The Mean ◽  
Derivatives Of

Aedes albopictus (Skuse) is a widespread mosquito, a vector of important human arboviruses, including Chikungunya, Dengue and Zika. It is an extremely difficult species to control even for the onset of resistances to chemicals insecticides, therefore ecofriendly products are urgently needed. In this study, the activity of Amaryllidaceae alkaloids and some of their semisynthetic derivatives, of 2-methoxy-1,4-naphthoquinone and two analogues, of cyclopaldic acid and epi-epoformin on the survival and development of Ae. albopictus larvae was evaluated. First-instar larval exposure for 24 and 48 h to cyclopaldic acid, resulted in mortality mean per-centage of 82.4 and 96.9 respectively; 1,2-O,O-diacetyllycorine 48h post-treatment caused 84.7% mortality. Larval and pupal duration were proved to decrease significantly when larvae were exposed to cyclopaldic acid, 1,2-O,O-diacetyllycorine and N-methyllycorine iodide. The mean number of third-instar larvae surviving to 2-methyl-1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone and 2-methoxy-1,4-naphthoquinone was significantly lower than the number of correspondent control larvae over the time. This study indicated that 1,2-O,O’-diacetyllycorine, N-methyllycorine iodide, cyclopaldic acid and 1,4-naphthoquinone structural derivatives have good potential for developing bioinsecticides for mosquito control programs. The obtained results are of general interest due to the global importance of the seri-ous human diseases such a vector is able to spread.

scholarly journals FIELD COMPARISON OF AUTOCIDAL GRAVID OVITRAPS AND IN2CARE TRAPS AGAINST AEDES AEGYPTI IN DOWNTOWN SAINT AUGUSTINE, NORTHEASTERN FLORIDA

2021 ◽  
Vol 68 (1) ◽  
pp. 92-96
Author(s):  
Dena Autry
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Cost Effective ◽  
Post Treatment ◽  
Adult Mosquito ◽  
Treated Area ◽  
Mosquito Trap ◽  
Significant Difference ◽  
The Mean ◽  
Pre Treatment

Mosquito Control programs are utilizing cost-effective long term autocidal gravid traps because they minimize labor needs while targeting the gravid population of container-breeding mosquitoes. This field study compared the efficacy of the In2Care Mosquito Trap and the Centers for Disease Control and Prevention autocidal gravid ovitrap (CDC-AGO). The study consisted of two control and two treatment sites, and each treatment site had either 100 In2Care Mosquito Traps or 100 CDC-AGOs. Aedes aegypti populations in each site were monitored using Biogent (BG) Sentinel 2 mosquito traps and ovitraps. Analysis of pre- and post-treatment data indicated no significant difference in adult mosquito populations detected by BG traps from either the In2Care or CDC-AGO sites. However, the mean number of eggs collected by ovitraps showed significant reduction in both trap type treated areas posttreatment, compared to pre-treatment. Furthermore, the mean number of egg collections from the In2Care mosquito trap treated area was much less than the collection from the CDC-AGO trap treated area post-treatment.

EFFECTS OF DIFLUBENZURON ON LARVAL DEVELOPMENT OF ZAPRINONUS PARAVITTIGER (GODBLE AND VAIDYA) (DIPTERA: DROSOPHILIDAE)

1985 ◽  
Vol 20 (1) ◽  
pp. 109-114
Author(s):  
Parvesh K. Chopra ◽  
Pushpinder J. Rup
Keyword(s):  
Larval Development ◽  
Differential Susceptibility ◽  
Adult Emergence ◽  
Morphological Abnormalities ◽  
First Instar ◽  
Zaprionus Paravittiger ◽  
Total Body ◽  
Third Instar Larvae

Feeding of diflubenzuron to different-aged larvae of banana fruitfly, Zaprionus paravittiger (Godble and Vaidya), produced a differential susceptibility. The first-instar larvae were significantly more susceptible than the second- and third-instar larvae. The ID 50 (50% inhibitory dose) values for adult emergence were 0.16, 0.32 and 0.95 ppm for first-, second-, and third-instar larvae, respectively. The frequency of morphological abnormalities increased and F1 adults failed to reproduce. Furthermore, the total body glycogen increased and total body proteins decreased after feeding diflubenzuron to second-instar larvae for 24 h.

scholarly journals Aedes albopictus bionomics in Procida Island, a promising Mediterranean site for the assessment of innovative and community-based integrated pest management methods

2021 ◽  
Author(s):  
B. Caputo ◽  
G. Langella ◽  
V. Petrella ◽  
C. Virgillito ◽  
M. Manica ◽  
...  
Keyword(s):  
Aedes Albopictus ◽  
Temporal Dynamics ◽  
Mosquito Control ◽  
Effective Control ◽  
Control Programs ◽  
Gulf Of Naples ◽  
New Public Health ◽  
Incompatible Insect Technique ◽  
New Public ◽  
Study Sites

AbstractThe colonization of Mediterranean Europe and of other temperate regions by Aedes albopictus created in the last decades an unprecedented nuisance problem in highly infested areas, as well as a new public health threat due to the species competence to transmit exotic arboviruses, such as dengue, chikungunya and zika. The Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) are insecticide-free mosquito-control methods relying on mass release of irradiated/manipulated males which are believed to have a potential in complementing existing and only partially effective control tools. Testing and implementing these approaches are challenging and selection of study sites is an instrumental and crucial step. We carried out a 4-year study in Procida Island (Gulf of Naples, Italy) in strict collaboration with local administrators and citizens to estimate: i) the temporal dynamics, spatial distribution, and population size of Ae. albopictus; and ii) the dispersal and survival of irradiated males. Overall, results provide insights on the bionomics of the mosquito in Southern Europe and draw attention to Procida Island as an ideal site to test innovative control programs against Ae. albopictus which may be used in other Mediterranean and temperate areas.”

scholarly journals Aedes albopictus life table: environment, food, and age dependence survivorship and reproduction in a tropical area

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guzhen Cui ◽  
Saifeng Zhong ◽  
Tuquan Zheng ◽  
Zhangrui Li ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Life Table ◽  
Aedes Albopictus ◽  
Environmental Conditions ◽  
Tap Water ◽  
Adult Emergence ◽  
Egg Mass ◽  
Larval Rearing ◽  
Pupation Rate ◽  
Age Dependent ◽  
The Mean

Abstract Background Environmental conditions affect the biology of mosquito vectors. Aedes albopictus is a major vector of many important diseases including dengue, Zika, and chikungunya in China. Understanding the development, fecundity, and survivorship of Ae. albopictus mosquitoes in different environmental conditions is beneficial for the implementation of effective vector control measures. Methods Aedes albopictus larval and adult life-table experiments were conducted under natural conditions in indoor, half-shaded, and fully shaded settings, simulating the three major habitat types in Hainan Province, a tropical island in the South China Sea. Temperature, humidity, and light intensity were recorded daily. Larval rearing used habitat water and tap water, with and without additional artificial food. Development time, survivorship, pupation rate, and adult emergence rates were monitored. Adult mosquito survivorship and fecundity were monitored daily and reproductive rates were determined, and age-dependent survivorship and reproduction were analyzed. Results The pupation time and male and female emergence times were significantly shorter in indoor conditions than in shaded and half-shaded conditions for both tap water with added food and habitat water with added food groups. For habitat water with added food, the shaded environment had the lowest pupation rate among the settings. For tap water with added food group, the shaded environment had the lowest pupation rate. The mean survival time of females was 27.3 ± 0.8 days in the indoor condition, which was significantly longer than that in the half-shaded (18.4 ± 0.6 days) and shaded (13.8 ± 1.2 days) conditions. Adult mortality was age-dependent, and the rate of change in mortality with age was not significantly different among different environmental conditions. The mean net replacement rate (R0) of female mosquitoes showed no significant difference among the three conditions, whereas the per capita intrinsic growth rate (r) in the shaded condition was 42.0% and 20.4% higher than that in the indoor and half-shaded conditions, respectively. Female daily egg mass was also age-dependent in all the settings, decaying exponentially with age. Conclusions Our results imply that half-shaded conditions are likely the best natural condition for adult emergence and female reproduction, and food supply is crucial for larval development and pupation. The results provide new avenues for integrated mosquito management in indoor and outdoor areas, especially in half-shaded areas. Graphical Abstract

scholarly journals Toxicity of Terahertz-Based Functional Mineral Water (Plant-Derived) to Immature Stages of Mosquito Vectors

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 211
Author(s):  
Tai-Chih Kuo ◽  
Chien-Chung Lin ◽  
Ching-Chu Tsai ◽  
Shiang-Jiuun Chen ◽  
Tso-Min Hung ◽  
...  
Keyword(s):  
Crop Production ◽  
Mineral Water ◽  
Mosquito Control ◽  
Mosquito Species ◽  
Adult Emergence ◽  
Agricultural Crop ◽  
Mosquito Vectors ◽  
Control Programs ◽  
Low Concentrations ◽  
Water Plant

Functional mineral water and related products are popular in some Asian countries as health drinks and, recently, have been employed in agricultural crop production as well as pest control. This study aimed to investigate the survival of mosquito vectors exposed to plant-derived functional mineral water produced by terahertz technology. The terahertz-based functional mineral water used in the current study not only decreased the hatching of Culex quinquefasciatus (Say) larvae but also showed concentration-dependent toxicity to the 3rd instar larvae and pupae of the three mosquito species tested. Aedes albopictus (Skuse) and Cx. quinquefasciatus pupae were more susceptible to terahertz-based functional mineral water than the larval stage, as indicated by their lower LC50. Lower concentrations (<100 ppm) of terahertz-based functional mineral water were not lethal to the pupae; however, these low concentrations still resulted in a reduced adult emergence. Although terahertz-based functional mineral water did not significantly affect Aedes aegypti (Linnaeus) hatching, it could potentially be used for vector control at the larvae and pupae stages. The larvicidal and pupicidal activity of diluted terahertz-based functional mineral water gradually diminished after 24 h, indicating that it is a biodegradable and eco-friendly bioinsecticide. However, as the terahertz-based functional mineral water is also toxic to larvivorous predatory-copepods, it should not be utilized in aquatic environments where predatory-based mosquito control programs are employed.

scholarly journals Visual outcome of endogenous endophthalmitis in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Preeyachan Lourthai ◽  
Pitipol Choopong ◽  
Dhanach Dhirachaikulpanich ◽  
Kunravitch Soraprajum ◽  
Warinyupa Pinitpuwadol ◽  
...  
Keyword(s):  
Retrospective Chart Review ◽  
Visual Outcome ◽  
Post Treatment ◽  
Endogenous Endophthalmitis ◽  
Infectious Episode ◽  
Hand Motion ◽  
Phthisis Bulbi ◽  
Causative Agents ◽  
Corneal Decompensation ◽  
The Mean

AbstractTo evaluate a 10-year visual outcome of endogenous endophthalmitis (EE) patients. A 10-year retrospective chart review of EE patients. Thirty-eight patients (40 eyes) were diagnosed with EE at the mean age of 42. Among the identifiable pathogens (71.1% culture positive), the causative agents were predominantly gram-negative bacteria (48.1%). The most common specie was Klebsiella pneumoniae (25.9%). About a quarter of the patients required surgical eye removal, and the remaining 45.7% had visual acuity (VA) worse than hand motion at one month after the infectious episode. The most common complication was ocular hypertension (52.5%). Poor initial VA was significantly associated with a worse visual outcome in the early post-treatment period (p 0.12, adjusted OR 10.20, 95% CI 1.65–62.96). Five patients continued to visit the clinic for at least ten years. One patient had gained his vision from hand motion to 6/7.5. Two patients had visual deterioration, one from corneal decompensation, and the other from chronic retinal re-detachment. Two patients developed phthisis bulbi, with either some VA perception of light or no light perception. Poor initial VA is the only prognostic factor of a poor early post-treatment visual outcome of EE.

scholarly journals Is High Whitefly Abundance on Cassava in Sub-Saharan Africa Driven by Biological Traits of a Specific, Cryptic Bemisia tabaci Species?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal
Keyword(s):  
Food Security ◽  
Bemisia Tabaci ◽  
Development Time ◽  
Adult Emergence ◽  
Sub Saharan Africa ◽  
Biological Traits ◽  
Population Development ◽  
Species Classification ◽  
First Instar ◽  
Sub Saharan

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.

scholarly journals Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 947
Author(s):  
Rishi Kondapaneni ◽  
Ashley N. Malcolm ◽  
Brian M. Vazquez ◽  
Eric Zeng ◽  
Tse-Yu Chen ◽  
...  
Keyword(s):  
State Government ◽  
Mosquito Control ◽  
Control Strategies ◽  
Mosquito Species ◽  
Research Priorities ◽  
Current Control ◽  
Control Programs ◽  
Common Control ◽  
Surveillance Programs ◽  
Research Questions

Florida lies within a subtropical region where the climate allows diverse mosquito species including invasive species to thrive year-round. As of 2021, there are currently 66 state-approved Florida Mosquito Control Districts, which are major stakeholders for Florida public universities engaged in mosquito research. Florida is one of the few states with extensive organized mosquito control programs. The Florida State Government and Florida Mosquito Control Districts have long histories of collaboration with research institutions. During fall 2020, we carried out a survey to collect baseline data on the current control priorities from Florida Mosquito Control Districts relating to (1) priority control species, (2) common adult and larval control methods, and (3) major research questions to address that will improve their control and surveillance programs. The survey data showed that a total of 17 distinct mosquito species were considered to be priority control targets, with many of these species being understudied. The most common control approaches included truck-mounted ultra-low-volume adulticiding and biopesticide-based larviciding. The districts held interest in diverse research questions, with many prioritizing studies on basic science questions to help develop evidence-based control strategies. Our data highlight the fact that mosquito control approaches and priorities differ greatly between districts and provide an important point of comparison for other regions investing in mosquito control, particularly those with similar ecological settings, and great diversity of potential mosquito vectors, such as in Florida. Our findings highlight a need for greater alignment of research priorities between mosquito control and mosquito research. In particular, we note a need to prioritize filling knowledge gaps relating to understudied mosquito species that have been implicated in arbovirus transmission.

scholarly journals Permethrin Resistance in Aedes aegypti Affects Aspects of Vectorial Capacity

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Tse-Yu Chen ◽  
Chelsea T. Smartt ◽  
Dongyoung Shin
Keyword(s):  
Aedes Aegypti ◽  
Sodium Channel ◽  
Mosquito Control ◽  
Vector Competence ◽  
Vectorial Capacity ◽  
Parental Population ◽  
Control Programs ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Specific Pcr

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.

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