Vasiliy D. Kravchenko

Decline Of Anopheles sergentii and Aedes caspius Populations Following Presentation Of Attractive Toxic (Spinosad) Sugar Bait Stations In An Oasis

ABSTRACT The effect of attractive sugar bait stations, including sucrose, juice of nectarine, slow-release substances, preservatives, red food-dye marker, and the oral insecticide spinosad, on Anopheles sergentii and Aedes caspius populations was studied in a small oasis in a southern desert of Israel. Feeding on similar baits without an insecticide was monitored as a control in a similar neighboring oasis. The insecticide caused a drastic decrease in the number of mosquitoes. Compared to the control site, the An. sergentii population was reduced to less than a tenth and that of Ae. caspius declined to a third. The majority of the mosquitoes, 76.0% of An. sergentii females and 74.8% of Ae. caspius females, were marked by the food dye in the control site.

INDOOR PROTECTION AGAINST MOSQUITO AND SAND FLY BITES : A COMPARISON BETWEEN CITRONELLA, LINALOOL, AND GERANIOL CANDLES

ABSTRACT The repellent effect of 3 essential-oil-based candles was evaluated in a high biting pressure environment in Israel. In human landing assays, the repellency rate of 5% citronella candles against mosquitoes was 29.0%, of 5% linalool candles was 71.1%, and of 5% geraniol candles was 85.4%. The candles with geraniol were about twice as effective as those with linalool and were about 5 times as effective as citronella candles in protecting a person from being bitten indoors by mosquitoes. The repellency rate of 5% citronella candles towards sand flies was 24.7%, of 5% linalool candles was 55.2%, and of 5% geraniol candles was 79.7%. A geraniol candle was almost 5 times as effective as a citronella candle and about twice as effective as a linalool candle in protecting a person from being bitten indoors by sand flies.

Evaluation of attractive toxic sugar bait (ATSB)—Barrier for control of vector and nuisance mosquitoes and its effect on non-target organisms in sub-tropical environments in Florida

The efficacy of attractive toxic sugar baits (ATSB) with the active ingredient eugenol, an Environmental Protection Agency exempt compound, was evaluated against vector and nuisance mosquitoes in both laboratory and field studies. In the laboratory, eugenol combined in attractive sugar bait (ASB) solution provided high levels of mortality for Aedes aegypti, Culex quinquefasciatus, and Anopheles quadrimaculatus. Field studies demonstrated significant control: >70% reduction for Aedes atlanticus, Aedes. infirmatus, and Culex nigripalpus and >50% reduction for Anopheles crucians, Uranotaenia sapphirina, Culiseta melanura, and Culex erraticus three weeks post ATSB application. Furthermore, non-target feeding of six insect orders, Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, and Orthoptera, was evaluated in the field after application of a dyed-ASB to flowering and non-flowering vegetation. ASB feeding (staining) was determined by dissecting the guts and searching for food dye with a dissecting microscope. The potential impact of ATSB on non-targets, applied on green non-flowering vegetation was low for all non-target groups (0.9%). However, application of the ASB to flowering vegetation resulted in significant staining of the non-target insect orders. This highlights the need for application guidelines to reduce non-target effects. No mortality was observed in laboratory studies with predatory non-targets, spiders, praying mantis, or ground beetles, after feeding for three days on mosquitoes engorged on ATSB. Overall, our laboratory and field studies support the use of eugenol as an active ingredient for controlling important vector and nuisance mosquitoes when used as an ATSB toxin. This is the first study demonstrating effective control of anophelines in non-arid environments which suggest that even in highly competitive sugar rich environments this method could be used for control of malaria in Latin American countries.

Evaluation of commercial products for personal protection against mosquitoes.

Human landing catch studies were conducted in a semi-field setting to determine the efficacy of seven commercial products used for personal protection against mosquitoes. Experiments were conducted in two empty, insecticide free, mesh-enclosed greenhouses, in Israel, with either 1500 Aedes albopictus or 1500 Culex pipiens released on consecutive study nights. The products tested in this study were the OFF!(®) Clip-On™ Mosquito Repellent (Metofluthrin 31.2%) and the Terminix(®) ALLCLEAR(®) Sidekick Mosquito Repeller (Cinnamon oil 10.5%; Eugenol 13%; Geranium oil 21%; Peppermint 5.3%; Lemongrass oil 2.6%), which are personal diffusers; Super Band™ Wristband (22% Citronella oil) and the PIC(®) Citronella Plus Wristband (Geraniol 15%; Lemongrass oil 5%, Citronella oil 1%); the Sonic Insect Repeller Keychain; the Mosquito Guard Patch (Oil of Lemon Eucalyptus 80mg), an adhesive-backed sticker for use on textiles; and the Mosquito Patch (vitamin B1 300mg), a transdermal patch. It was determined that the sticker, transdermal patch, wristbands and sonic device did not provide significant protection to volunteers compared with the mosquito attack rate on control volunteers who were not wearing a repellent device. The personal diffusers: - OFF!(®) Clip-On™ and Terminix(®) ALLCLEAR(®) Sidekick - provided superior protection compared with all other devices in this study. These diffusers reduced biting on the arms of volunteers by 96.28% and 95.26% respectively, for Ae. albopictus, and by 94.94% and 92.15% respectively, for Cx. pipiens. In a second trial conducted to compare these devices directly, biting was reduced by the OFF!(®) Clip-On™ and the Terminix(®) ALLCLEAR(®) by 87.55% and 92.83%, respectively, for Ae. albopictus, and by 97.22% and 94.14%, respectively, for Cx. pipiens. There was no significant difference between the performances of the two diffusers for each species.

Indoor use of attractive toxic sugar bait (ATSB) to effectively control malaria vectors in Mali, West Africa

BackgroundAttractive toxic sugar bait (ATSB) solutions containing any gut toxins can be either sprayed on plants or used in simple bait stations to attract and kill sugar-feeding female and male mosquitoes. This field study in Mali demonstrates the effect of ATSB bait stations inside houses as a vector control method that targets and kills endophilic African malaria vectors.MethodsThe studies were conducted in five villages located near the River Niger, Mali. Baseline village-wide assessments of densities for female and male Anopheles gambiae sensu lato were performed by pyrethrum spray collections (PSC) in ten houses in each of five villages. To determine the rate of mosquito feeding on bait stations, one bait station per house containing attractive sugar bait (ASB) (without toxin) plus a food dye marker, was set up in ten houses in each of the five villages. PSC collections were conducted on the following day and the percentage of female and male mosquitoes that had fed was determined by visual inspection for the dye marker. Then, a 50-day field trial was done. In an experimental village, one bait station containing ATSB (1% boric acid active ingredient) was placed per bedroom (58 bedrooms), and indoor densities of female and male An. gambiae s.l. were subsequently determined by PSC, and female mosquitoes were age graded.ResultsIn the five villages, the percentages of An. gambiae s.l. feeding inside houses on the non-toxic bait stations ranged from 28.3 to 53.1% for females and 36.9 to 78.3% for males. Following ATSB indoor bait station presentation, there was a significant reduction, 90% in female and 93% in male populations, of An. gambiae s.l. at the experimental village. A 3.8-fold decrease in the proportion of females that had undergone four or more gonotrophic cycles was recorded at the experimental village, compared to a 1.2-fold increase at the control village.ConclusionThe field trial demonstrates that An. gambiae s.l. feed readily from ATSB bait stations situated indoors, leading to a substantial reduction in the proportion of older female mosquitoes. This study demonstrates that ATSB inside houses can achieve impressive malaria vector control in Africa.

Attractive Toxic Sugar Baits: Control of Mosquitoes With the Low-Risk Active Ingredient Dinotefuran and Potential Impacts on Nontarget Organisms in Morocco

ABSTRACT We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and field with the low-risk active ingredient dinotefuran against mosquito populations. Preliminary laboratory assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus Say and Aedes aegypti Linnaeus. Field studies demonstrated >70% reduction of mosquito populations at 3 wk post-ATSB application. Nontarget feeding of seven insect orders—Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, Orthoptera, and Neuroptera—was evaluated in the field after application of attractive sugar baits (ASB) on vegetation by dissecting the guts and searching for food dye with a dissecting microscope. Nontargets were found stained with ASB 0.9% of the time when the application was applied on green nonflowering vegetation. Only two families were significantly impacted by the ASB application: Culicidae (mosquitoes) and Chironomidae (nonbiting midges) of the order Diptera. Pollinators of the other insect orders were not significantly impacted. No mortality was observed in the laboratory studies with predatory nontargets, wolf spiders or ground beetles, after feeding for 3 d on mosquitoes engorged on ATSB applied to vegetation. Overall, this novel control strategy had little impact on nontarget organisms, including pollinators and beneficial insects, and was effective at controlling mosquito populations, further supporting the development of ATSB for commercial use.

Reduction of mosquito biting-pressure: Spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel

The present study assessed the personal protection efficiency of seven commercially available mosquito control devices (MCD) under field conditions in Israel. Trials were performed in a high biting-pressure area inhabited by large populations of mosquito and biting midge species, using human volunteers as bait in landing catch experiments. Results show that under minimal air-movement, three spatial repellent based products (ThermaCELL(®) Patio Lantern, OFF!(®) PowerPad lamp, and Terminix(®) ALLCLEAR Tabletop Mosquito Repeller) significantly reduced the biting-pressure (t-test - P<0.01) when positioned at short distances from a volunteer (3, 7.5, and 10ft.), with the ThermaCELL unit being most effective (96.1, 89.9, and 76.66% reduction, respectively). No significant differences were seen between the three aforementioned devices at distances of 3 and 7.5ft., while at a distance of 10ft., only the ThermaCELL patio lantern repelled significantly more mosquitoes then the Terminix ALLCLEAR Tabletop Mosquito Repeller (t-test, P<0.05). In contrast, mosquito traps using attracting cues to bait mosquitoes (Dynatrap(®), Vortex(®) Electronic Insect Trap, Blue Rhino(®) SV3100) either significantly increased or had no effect on the biting-pressure at short distances compared with the unprotected control. Trials conducted over large areas showed that only the Blue Rhino trap was able to significantly reduce the biting-pressure (40.1% reduction), but this was only when operating four units at the corners of an intermediate sized area.

Ability of Essential Oil Candles to Repel Biting Insects in High and Low Biting Pressure Environments

ABSTRACT The first goal of this study was to compare the degree of personal protection against biting insects provided by geraniol, linalool, and citronella candle (5%) vapors outdoors, where such products are commonly used. At a distance of 1.0 m, citronella candles reduced the number of female mosquitoes caught in Centers for Disease Control and Prevention traps by 35.4% and sand flies by 15.4%, linalool candles reduced female mosquitoes by 64.9% and sand flies by 48.5%, while geraniol candles reduced female mosquitoes by 81.5% and sand flies by 69.8%. By increasing the distance to 2 m and 3 m, the repellency dropped significantly. The second goal was to compare the degree of personal protection provided by the best performing candle, geraniol, under conditions of high and low biting pressure. The introduction of geraniol candles to protect volunteers in a high biting pressure environment reduced the mosquito pressure by an average of 56% and the sand fly pressure by 62% over a distance of 1.0 m. In the low biting pressure environment, geraniol reduced the mosquito pressure by an average of 62%. No sand flies were present at this site.

Characteristics of resting and breeding habitats of adult sand flies in the Judean Desert

ABSTRACT: Recently, in several areas of the Middle East, a sharp increase of cutaneous leishmaniasis was observed in suburbs of larger towns including Jerusalem. In some of these areas, poor housing conditions and unsuitable waste management was suspected to provide ideal conditions for sand fly breeding, but hard data on diurnal resting sites and breeding habitats of most sand fly species are scant. In this study, we chose 16 sites on both slopes and the bottom of a natural valley in the Judean Desert to conduct a survey of sand fly distribution with emergence traps. Altogether, 1,261 sand flies, 52% Phlebotomus syriacus, 22% P. sergenti, 14% P. papatasi and 12% P. tobbi were caught. About two thirds of the flies caught were resting, while the other third emerged from breeding sites. All four species showed clear preferences for resting and breeding sites, but generally, most sand flies were breeding in the more humid habitats, namely the bottom of the valley, the adjacent north facing slope, terraces on the north facing slope, and caves. The vegetation cover also appeared to be important for resting habitats; on the bottom of the valley more than six times as many sand flies were collected in areas covered by dense vegetation than in areas with low vegetation cover. P. sergenti seemed also to better tolerate the drier habitats, which might explain the abundance of this species in the arid Judean Desert.

Characteristics of Resting Habitats of Adult Phlebotomus papatasi in Neot Hakikar, an Oasis South of the Dead Sea

ABSTRACT: Knowledge about diurnal resting sites of sand flies is scanty and often anecdotal. In this study, we explored a part natural - part agricultural oasis in Neot Hakikar, Israel, looking for sand fly resting sites. To achieve this, we developed a new type of emergence trap. Sixteen types of microhabitats were examined and in seven of these, we also investigated the rodent burrows. We found that Phlebotomus papatasi showed clear preferences for resting sites characterized by vegetation cover, type of vegetation, and the presence of a mulch layer. In habitats with bare soil and little shade, few or no resting sand flies were found outside rodent burrows. Apart from the trunks of date trees, most resting P. papatasi were found in disturbed habitats, especially in large piles of organic waste and in a plowed field. Though catches from rodent burrow exits were always higher than from the nearby ground, it is safe to assume that the few burrows in this vast oasis do not play an important role for breeding and resting of P. papatasi. It also appears that disturbing the natural environment further increases the already considerable sand fly population.