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Keywords:

  • Sand flies;
  • sugar feeding;
  • flowering plants;
  • attraction;
  • trapping

ABSTRACT:

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

Sugar is the main source of energy for the daily activities of sand flies. Considering its importance, there is surprisingly little information on sugar meal specific sources and sand fly attraction to plants, particularly in the field. In this study, we first needed to develop an effective sand fly trap that would be suitable for mass screening of potentially attractive flowering plants. Next, we used this trap to screen a total of 56 different flowering plant species and five plant species soiled with different types of honeydew. The plant baited traps together caught 21,978 P. papatasi. Out of the 56 types of flowering plants which were tested, 13 were shown to bait significantly more female sand flies, and 11 baited more male sand flies than the control. Based on an attraction index, the top three attractive plants in this study were the flowering plants Ochradenus baccatus, Prosopis farcta, and Tamirix nilotica. We believe that plants and phyto-chemicals have untapped potentials to attract sand flies. These could be used for control and, in combination with simple glue traps, as an alternative for existing monitoring systems.


INTRODUCTION

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

Sand flies are known for their blood-feeding behavior which makes them vectors of pathogens like Leishmania, Bartonella and arboviruses. In some areas, the troublesome bites of the females are also a serious nuisance factor (Ashford and Bettini 1987, Hogsette et al. 2008). Female sand flies need blood for egg production, but sugar is their main source of energy and the only food taken by males (Killick-Kendrick 1999). The sugar feeding behavior of sand flies, therefore, influences longevity and fecundity, dispersal, host seeking behavior and ultimately blood feeding and disease transmission (Dye 1987, Gibb et al. 1988, Yuval et al. 1988, Müller and Schlein 2004).

According to the literature, sand flies obtain sugar meals mainly from honeydew excreted by aphids and coccids (Moore et al. 1987, Mac Vicker et al. 1990, Wallbanks et al. 1991) and by feeding directly on tissues of plants in the field (Schlein and Jacobson 1994, Schlein and Müller 1995). To the best of our knowledge, there are no records on fruit and extra-floral nectar feeding of sand flies, unlike for mosquitoes and other blood feeding flies. Surprisingly, there are also only a few records of sand flies feeding on flowers, the main sugar source of mosquitoes (Petts et al. 1997, Muller and Schlein 2004). At least in arid areas, there is evidence that availability of suitable sugar sources is a limiting factor for sand fly fitness and survival (Schlein and Jacobson 2002). Considering the importance of sugar to sand flies, it is surprising that there is little information on its specific sources and little is known about sand fly preferences and their attraction to plants, particularly in the field.

There is evidence however, that mosquitoes are selective when a variety of sugar sources are available (Foster 1995), and in a previous study we showed that flowering Tamarix nilotica is a highly attractive sugar source for sand flies (Müller and Schlein 2004). As a continuation of this research, we demonstrate here that if sand flies are given the choice in the field there are clear preferences for different types of flowers.

MATERIALS AND METHODS

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

Study site

The study took place in May 2008 in Neot Hakikar, southern Israel, in the largest natural oasis along the western shore of the Dead Sea, where the average altitude is 390 m below sea level. The region belongs to the Sahara-Arabian phyto-geographical zone (Zohary and Orshansky 1949). The area is an extreme desert with occasional natural oases consisting of marshland and artificial agricultural oases created by irrigation; the conditions in these sites are tropical (Danin 1988). The climate here is arid with an average humidity of 57% and an annual winter rainfall average of 50–100 mm. The average temperature ranges from 20° C at the end of September to early April, to 30° C from May to August (Beaumont et al. 1976, Ashbel 1951). The eastern part of the study oasis is used mainly for agriculture. In the western part, there is a large, non-irrigated, organic date plantation. This plantation covers an area of approximately 10 hectares and is surrounded mainly by reed thickets, Chenopodiaceae shrubs and Tamarix bushes. The vegetation between the date trees is regularly cleared. The eastern part of the oasis is a known focus of zoonotic L. major and P. papatasi is practically the only Phlebotomus species found in this habitat (Müller and Schlein 2004).

Setup of the experiments

Two experiments were conducted in May 2008 at the date plantation, the first in early May and the second in late May. In the first experiment, different types of traps and designs were evaluated in combination with flower baits for sand fly capture. In a second experiment, the best performing and easiest to handle trap model was chosen to screen local flowering plants for their attractiveness to sand flies. In each experiment, traps were placed 10 m apart along both sides of an unpaved road crossing the site. The traps were operated simultaneously on consecutive nights and were rotated daily to eliminate positional bias. Sand flies were recovered daily in the early morning from 0700–0800. In both experiments, P. papatasi recovered from glue traps were identified and sexed “on the spot” with the help of a 10× Zeiss pocket magnifying glass and the data were transferred to spreadsheets. From the suction traps used in the first experiment only, the catch was recovered, stored in Petri dishes and sorted in the lab. Traps in the first experiment were baited with 2 kg of 80 cm long flowering T. nilotica branches (which proved to be highly attractive for sand flies in a previous project (Müller & Schlein, 2004). Traps in the second experiment were baited with 2 kg of branches of the species being evaluated (see list below). During the experiments, there were no potential attractive sugar sources in the vicinity for at least 100 m.

Experiment 1: Trap evaluation

Glue-net-traps were constructed by rolling 100 × 100 cm long nets into cylinders that were secured with plastic tie wraps (Figure 1). The top of the cylinders were closed with circular pieces of the same material. The following nettings were used: dark green colored, rigid plastic with 0.1 cm wide netting separated by 0.3 cm square holes; 0.2 cm wide netting separated by 0.8 cm square holes; and 0.2 cm wide netting separated by 2.0 cm square holes. Light metal chicken wire with 0.03 cm wide netting separated by hexagonal openings 2.6 cm across was also used to construct a glue-net cylinder trap. The traps were set the following way: 1.5 liter plastic bottles were cut to form 20 cm long beakers and were buried in the ground so the rims of the beakers were slightly higher than the soil surface. Soil around the beakers was moistened with water and packed down to stabilize the beakers. Later, single 2 kg bundles of plants were placed in the cut bottles; the mesh-cylinders were placed on top and were fixed to the ground with 20 cm long wooden stakes. The four trap designs were painted with a glue (tangle foot, Rimi, Petah Tiqua, Israel) to capture insects that were attracted to the baits. Additionally, another set of mesh-cylinders from green colored netting (0.8 cm square holes) as described above was painted with castor oil. Mesh cylinders were repainted with adhesive every day to neutralize dirt and non-target insects.

image

Figure 1. Cylindrical glue-net-trap developed for this study (see Materials and Methods).

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The different types of glue traps were compared to two types of suction traps, namely unlighted CDC traps (model 512, John W. Hock, Gainesville, FL, USA) and un-baited BG Sentinel traps (monitoring model, BG Regensburg, Germany). The CDC traps were operated upright, with their lid on top of the body (4 cm gap between rim and lid). Traps were mounted in the center of four plant bundles on tripods with the upper rim of the trap body (suction entrance) 60 cm above ground. Each trap was baited with four plant bundles (0.5 kg each). For this, the same types of beakers were buried at fixed positions (at the four corners of a 60 cm rectangular) in the ground. BG Sentinel traps were baited with a single plant bundle (2 kg) through a hole in the bottom of the trap and placed on top of a single buried beaker. The cut opening was secured with a sleeve to keep caught sand flies inside the trap. To anesthetize the insects the nets of the CDC traps and the whole BG traps with flowers were introduced for 2 min. into a plastic bag that had a piece of cotton wool soaked with 2 ml ethyl acetate inside. For all traps plants and water were exchanged on a daily basis in the late afternoon.

Experiment 2: Screening flowering and honeydew soiled plants for attractiveness

The plastic net cylinders with 0.8 cm square holes were used to test flowers for their relative attraction to sand flies because it was one of the best performing traps from experiment 1 (see results) and because the size of the mesh made this trap easier to handle in the field. A total of 63 traps was used and simultaneously operated for this experiment. In total, 56 different flowering plant species of 27 families and 5 plant species soiled with different types of honeydew were used as baits. Sponges soaked either with one liter of water or one liter freshly prepared 10% sucrose solution were used to control for moisture and sugar content. There were eight replicates per bait. Mesh cylinders were repainted with glue following every collection to neutralize dirt and non-target insects.

A total of 55 flowering plant species, belonging to 27 families, as well as five non- flowering plants soiled with honeydew, were used as baits in the screening experiment (Tables 1 and 2).

Table 1.  List of plants tested for attractiveness in this study.
Family NameSpecies NameAuthority
AizoaceaeMesembryanthemum nodiflorumL.
AsclepiadaceaePergularia tomentosaL.
BoraginaceaeHeliotropium bacciferumForssk.
CapparaceaeCapparis aegyptiaLam.
CaryophyllaceaeGypsophila capillaries(Forssk) C. Chr
ChenopodiaceaeSuaeda fruticosa(Forssk) ex. J.F Gmel
 Suaeda monoica(Forssk) ex J.F. Gmel
 Suaeda vermiculataL.
 Salsola tetrandraForssk.
 Salsola vermiculataL.
 Halogeton alopecuroides(Delile) Fenzl
 Arthrocnemum macrostachyum(Moric.) K. Koch
 Atriplex halimusL.
 Atriplex leucocladaBoiss
CompositaeSenecio glaucus coronopifolius(Maire) C. Alexander
 Reichardia tingitana(L.) Roth
 Launaea nudicaulis(L.) Hook.
 Pulicaria incise(Lam.) DC.
 Pulicaria undulate(Forssk.) C.A.Mey
CruciferaeReboudia microcarpaBoiss.
 Zilla spinosa(L.) Prantl.
CucurbitaceaeCitrullus colocynthis(L.) Schrad
EphedraceaeEphedra aphyllaForssk.
EuphorbiaceaeRicinus communisL.
LabiataeMentha longifoliaL.
MalvaceaeMalva nicaeensisAll.
MimosaceaeAcacia raddianaSavi
 Acacia tortilis(Forssk.) Hayne
 Prosopis farcta(Banks & Sol.) J.F.Macbr
NyctaginaceaeCommicarpus plumbagineus(Cav.) Standl
 Bougainvillea glabraChoisy
PapilionaceaeAlhagi maurorumBoiss.
 Astragulus spinosus(Forssk.) Muschl.
PlumbaginaceaeLimonium pruinosum(L.) Chaz.
PolygonaceaePolygonum palaestinumZohary
ResedaceaeReseda muricataC. Presl
 Caylusea hexagyna(Forssk.) M. L. Green
 Ochradenus baccatusDelile
RhamnaceaeZiziphus spina-christi(L.) Desf
SalicaceaePopulus euphraticaOliv.
SalvadoraceaeSalvadora persicaL.
ScrophulariaceaeScrophularia desertiDelile
 Kickxia floribunda(Boiss.) Taeckh. & Boulos.
 Verbascum fruticulosumPost
SolanaceaeLycium shawiRoem. & Schult.
 Nicotiana glaucaGraham
 Solanum villosum(L.) Mill
TamaricaceaeReaumuria hirtellaJaub. & Spach
 Tamarix nilotica(Ehrenb.) Bunge
 Tamarix palaestinaBertol
UmbelliferaePituranthos tortuosus(Desf.) DC
ZygophyllaceaePeganum harmalaL.
 Nitraria retusa(Forssk.) Asch.
 Zygophyllum simplexL.
 Balanites aegyptiaca(L.) Delile
 Fagonia mollisDelile
Table 2.  List of non-flowering plants soiled with honeydew. Family names, species names and authority names are given for the infesting insect.
PlantsInsects
      Species NameFamily Name: Species NameAuthority
Tamarix niloticaMembracidae:Oxyrrhachis versicolorDistant
Ziziphus spina-christiAleurodideae:Aleotracheolus citriPriesner & Et. Hosny
Phragmites euphraticaAphidoidea:Chaitophorus leucomelasKoch
Phragmites australis altissimusAphididae:Hyalopterus prunii(Cav.) Trin. ex. Steud.
Bougainvillia glabraAphididae:Myzus persicaeSulzer

Statistical analysis

Statistical analysis was carried out using the GraphPad Prism 5.03 statistical package (GraphPad Software Inc., La Jolla CA). In the first experiment, Two-Way Analysis of Variance (ANOVA) was performed to check for statistical differences among the overall efficiencies and sex ratios of the traps. Differences between trap groups were determined using Bonferroni's post hoc test. Significance was taken at P < 0.05.

Student's T-tests were used to compare the number of sand flies caught by each plant species compared to the water control (there was no significant difference between the water and sugar control – see results). Significance was taken at P < 0.05. Plants were ranked by being assigned an attraction index which was calculated by taking the average catch with the plant bait (AP) divided by the average catch with the water soaked sponge control (AC); AP/AC = Attraction Index (Table 1).

RESULTS

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

Experiment 1: Trap evaluation

Altogether, 3,831 female and 3,063 male P. papatasi were collected (7 traps × 8 trapping nights). Though generally it appears that all traps caught more females than males, the mean differences (Figure 2) between male and female catches among the lowest performing traps and among the highest performing traps, were not significant. There was no significant difference between the mean catches of the CDC trap, the Sentinel trap, and the metal glue cylinder trap with 2.6 cm holes (t = 1.680; t = 1.744; t = 1.236 respectively; P > 0.05).

image

Figure 2. Mean catches of male and female sand flies by 7 trap types (± S.E.).

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The plastic glue cylinder with 2.0 cm holes caught significantly more sand flies than previous three traps (t = 3.582; P < 0.01) but significantly less than other plastic traps (t = 2.355; P < 0.01). The plastic glue cylinder traps with 0.3 and 0.8 cm holes and the plastic castor oil trap with 0.8 cm holes did not differ significantly in their mean number of caught sand flies (t = 6.499; t = 5.357; t = 4.248 respectively; P < 0.001).

Experiment 2: Screening flowering and honeydew soiled plants for attractiveness

Altogether, 21,978 P. papatasi (11,755 females and 10,223 males) were caught by 56 flowers, five honeydew soiled plants and two types of control traps (63 traps × 8 trapping nights). There was no significant difference between average catches from water baited controls (13.88 females and 12.75 males/trap) and sugar water baited controls (12.75 females and 10.38 males/trap). Out of the 56 types of flowering plants which were tested, 13 (Table 1) were shown to bait significantly more female sand flies and 11 baited more male sand flies then the water soaked sponge control trap (t-test, P < 0.05).

DISCUSSION

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

Currently, sand flies are monitored with different types of sticky papers and CDC traps in combination with light sources, CO2, chemical lures or even volatiles from oviposition sites (Bernier, et al. 2008, Faiman et al. 2009, Sahin and Nurdan 2007, Schlein et al. 1989). CDC traps, motorcycle batteries, CO2 tanks and propane tanks for combustion traps are expensive, need regular maintenance, are heavy and can stay in the field for only a limited amount of time. In remote areas, logistics can be a serious problem. Simple un-baited or light baited sticky traps, on the other hand, often yield only small catches. Phytochemicals have untapped potentials not only for mosquitoes, but also for sand flies and could be in combination with simple glue traps an alternative for existing monitoring systems (Foster 2008). Such traps would be extremely cheap, easy to maintain and they could stay for long periods in the field.

In this study, out of necessity, we developed a trap that is better for mass screening studies compared to the CDC trap because in previous studies the handling of CDC traps was always a limiting factor in screening large amounts of plants (Schlein and Yuval 1987, Müller and Schlein 2006, Schlein and Müller 2008). This trap could also serve as an alternative to mass screening compounds with olfactometers in laboratories. We therefore decided to use the plastic net cylinder with the 0.8 cm openings for our mass screening of flowers experiment because it caught significantly more sand flies than most of the other traps (Figure 2) while still being easy to use in the field.

In total, 56 different flowering plant species from 27 families and 49 genera were used to bait the new type of glue cylinder traps. The only ornamental plant in this study was the phanerophyte shrub Bougainvillea. All others were collected within the oasis or in the nearby surrounding desert. From the remaining 56 plants, nine were trees, 23 Chamaephytes, ten Phanerophyte shrubs, seven Hemicryptophytes and seven annuals. The chorotype of the bulk of the studied flowering plants (n = 24) is of a Saharo-Arabian distribution pattern followed by 14 species with an Irano-Turanian and 12 with a Sudanian distribution. Only a few tested plant species were poly-regional; three subtropical, three Euro-Siberian – Mediterranean – Irano-Turanian, and one Boreal-Tropical. It is worthwhile mentioning that from all plant varieties, most of the tested trees (7/9) were attractive while only a relatively small proportion of the Chamaephytes (3/23), Phanerophyte shrubs (2/10), Hemicryptophytes (1/7) and annuals (1/7) were attractive for sand flies. Furthermore, most of the attractive plants (8/14) are of a Sudanian or Saharo-Arabian (5/14) distribution patterns. There is only one, the second most attractive plant, which is centered in the Irano-Turanian region (Zohary 1966, 1972).

Though honeydew is regarded as one of the main sugar sources of sand flies (Killick-Kendrick 1999, MacVicker et al. 1990), it appeared that the five tested types of honeydew in this study were not attractive. It is not clear if other types of honeydew are attractive or if contamination with bacteria or fermentation processes influence attractiveness of otherwise unattractive excretions. Also, optical cues might play a role in honeydew detection. It is a well known fact that sand flies aggregate near honeydew soiled plants (Cameron et al. 1995a, 1995b, Müller and Schlein 2004) but the higher catches in these sites could be also due to a long arresting time of the feeding flies which found this sugar source at random. In further studies, the attractiveness of honeydew and how it is found by sand flies in the field deserves special attention.

From the wild flowering plants, one quarter (14/55) was significantly attractive for sand flies. Experiments were conducted during spring (in May), but from the 16 examined winter / spring flowering plants, only one N. retusa was significantly attractive. The remaining 13 attractive plants all flower for long periods, from late spring to at least late autumn. Eight of them even flower for 10 to 12 months, and the reminder for at least six months (Zohary 1966, 1972). Like for P. papatasi, trees and shrubs flowering in oasis/desert habitats during the hot and dry summer months are generally very attractive for all kinds of sugar searching insects, especially night active ones (unpublished data of the authors, oral communication with V.D. Kravchenko, Tel Aviv University). The question arises if the local P. papatasi population is adapted to plants supplying reliable nectar in the dry season, or if the attractive plants are generally attractive to all or at least some groups of sand flies. We assume that the second hypothesis is the case, bearing in mind that mosquitoes of the genera Aedes, Culex, Anopheles and many other night active dipterans were also attracted to all these flowers in significant amounts (unpublished data of the authors). If this is the case, then these and other plants could prove to be of a general interest for sand fly research and control.

In a hyper-arid habitat, Schlein and Yuval (1987) exposed sugar questing sand flies, in the midst of a fallow, field to CDC traps baited with non-flowering plants and humidity as a control. P. papatasi was significantly attracted to two thirds of the plants (8/12) as well as to the control. None of these plants were flowering, and some of the attractive plants were not fed upon in the laboratory. It was speculated that humidity or the search for shelter and breeding sites might have played a role. In our experimental site, in the midst of an oasis, humidity and shelter are not limiting factors (Muller and Schlein 2004) and we assume that the sand flies were attracted by the scent emitted by the flowers. Optical cues were partially covered by the glue-net-traps, and in this experiment, played probably no important role.

In a recent study, the ornamental plant Bougainvillea significantly attracted and killed sand flies in the field (Schlein et al. 2001). In the present study, the most attractive plant, flowering O. baccatus, attracted about 14 times as many sand flies as Bougainvillea. Unlike Bougainvillea, the 14 attractive plants identified in the current study are not toxic to sand flies and leishmania parasites in the gut if fed upon (Schlein and Müller 1995, Schlein and Yuval 1987). Nevertheless, these plants could be sprayed in both natural and peri-urban habitats, with a toxic sugar solution which would kill feeding sand flies once attracted to them. This principle was shown to work in numerous cases with different mosquito species and in different types of habitats (Schlein and Müller 2008, Müller and Schlein 2006, Müller et al. 2010).

Further studies with emphasis on ornamental plants are needed and if found to be highly attractive, they could at least be removed from problematic areas if spraying them with toxic sugar is not an option. In preliminary experiments, we showed that low risk toxins, harmless for vertebrates, like boric acid (used as an eye wash) and spinosad (used for grain storage for human consumption) in sugar baits reliably kill sand flies in the field (Schlein and Müller 2010).

Acknowledgments

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED

This work was a direct extension of studies supported by the Bill and Melinda Gates Foundation Grant # 0304721.

LITERATURE CITED

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgments
  8. LITERATURE CITED
  • Ashbel, D. 1951. Bio-Climatic Atlas of Israel. Meteorology Dept. of the Hebrew University. Jerusalem . 151 pp. (Hebrew and English).
  • Ashford, R.W. and S. Bettini. 1987. Ecology and epidemiology: Old World. In: W.Peters and R.Killick-Kendrick (eds.) The Leishmaniases in Biology and Medicine. Vol.1. London : Academic Press, 365424.
  • Beaumont, P., G.H. Blake, and J.M. Wagstaff. 1976. The Middle East, a Geographical Study. John Wiley & Sons, London , 572 pp.
  • Cameron, M.M., P.J.M. Milligan, A. Llanos-Cuentas, and C.R. Davis. 1995a. An association between phlebotomine sandflies and aphids in the Peruvian Andes. Med. Vet. Entomol. 9: 127132.
  • Cameron, M.M., A.W. Pessoa, A.W. Vasconcelos, and R.D. Ward. 1995b. Sugar meal sources for the phlebotomine sandfly Lutzomyia longipalpis in Ceara State, Brazil. Med. Vet Entomol. 9: 263272.
  • Danin, A. 1988. Flora and vegetation of Israel and adjacent areas. In: Yom-Tov & Tchernov (eds.) The Zoogeography of Israel. Junk Publishers, Dordrecht , Netherlands . pp. 251276.
  • Dye, C.M., W. Guy, D.B. Elkins, T.J. Wilkes, and R. Killick-Kendrick. 1987. The life expectancy of phlebotomine sand flies: first field estimates from southern France. Med. Vet. Entomol. 1: 417425.
  • Faiman, R., R. Cuno, and A. Warburg. 2009. Comparative efficacy of three suction traps for collecting phlebotomine sand flies (Diptera: Psychodidae) in open habitats. J. Vector Ecol. 34: 114118.
  • Foster, W.A. 1995. Mosquito sugar feeding and reproductive energetics. Annu. Rev. Entomol. 40: 443474.
  • Foster, W.A. 2008. Phytochemicals as population sampling lures. J. Am. Mosq. Contr. Assoc. 24: 138146.
  • Gibb, P.A., J.C. Anderson, and C. Dye. 1988. Are nulliparous flies light shy? Trans. R. Soc. Trop. Med. Hyg. 82: 342343.
  • Hogsette, J.A., H.A. Hanafi, U.R. Bernier, D.L. Kline, E.F. Fawaz, B.F. Furman, and D.F. Hoel. 2008. Discovery of diurnal resting sites of phlebotomine sand flies in a village in southern Egypt. J. Am. Mosq. Contr. Assoc. 24: 601603.
  • Killick-Kendrick, R. 1999. The biology and control of phlebotomine sand flies. Clin. Dermatol. 17: 279289.
  • MacVicker, J.A.K., J.S. Moore, D.H. Molyneux, and M. Maroli, 1990. Honeydew sugars in wild caught Italian phlebotomine sandflies (Diptera: Psychodidae) as detected by high performance liquid chromatography. Bull. Entomol. Res. 80: 339344.
  • Müller, G.C. and Y. Schlein. 2004. Nectar and honeydew feeding of Phlebotomus papatasi in a focus of Leishmania major in Neot Hakikar oasis. J. Vector Ecol. 29: 154158.
  • Müller, G.C. and Y. Schlein. 2006. Sugar questing mosquitoes in arid areas gather on scarce blossoms that can be used for control. Intl. J. Parasitol. 36: 10771080.
  • Müller, G.C., A. Junnila, and Y. Schlein. 2010. Effective control of adult Culex pipiens by spraying an attractive toxic sugar bait solution in the vegetation near larval developmental sites. J. Med. Entomol. 47: 6366.
  • Petts, S.L., Y. Tang, and R.D. Ward. 1997. Nectar from the wax plant Hoya sp., as a carbohydrate source for Lutzomyia longipalpis (Diptera: Psychodidae). Ann. Trop. Med. Parasitol. 91: 443446.
  • Sahin, T. and O. Nurdan. 2007. Distribution of sand fly (Diptera: Psychodidae) species and efficiency of capturing methods in Sanhurfa Province, Turkey. J. Med. Entomol. 44: 2328.
  • Schlein, Y. and B. Yuval. 1987. Leishmaniasis in the Jordan Valley IV. Attraction of Phlebotomus papatasi (Diptera: Psychodidae) to plants in the field. J. Med. Entomol. 24: 8790.
  • Schlein, Y. and G.C. Müller. 1995. Assessment of plant tissue feeding by sand flies (Diptera: Psychodidae) and mosquitoes (Diptera: Culicidae). J. Med. Entomol. 32: 88288.
  • Schlein Y., R.L. Jacobson, and G.C. Müller. 2001. Sand fly feeding on plants: a potential method for the control of leishmaniasis. Am. J. Trop. Med. Hyg. 65: 300303.
  • Schlein, Y. and R.L. Jacobson. 2002. Linkage between susceptibility of Phlebotomus papatasi to Leishmania major and hunger tolerance. Parasitology 125: 343348.
  • Schlein, Y. and G.C. Müller. 2008. An approach to mosquito control: Using the dominant attraction of flowering Tamarix jordanis trees against Culex pipiens. J. Med. Entomol. 45: 384390.
  • Schlein, Y and G.C. Müller. 2010. Experimental control of Phlebotomus papatasi by spraying attractive toxic sugar bait (ATSB) on vegetation. Trans. Trop. Med. Hyg. 104: 766771.
  • Wallbanks, K.R., J.S. Moore, L.R. Bennet, R. Soren, D.H. Molyneux, J.M. Carlin, and J.E. Perez. 1991. Aphid derived sugars in the neotropical sandfly Lutzomyia peruensis. Trop. Med. Parasitol. 42: 6062.
  • Yuval, B., A. Warburg, and Y. Schlein. 1988. Leishmaniasis in the Jordan Valley. V. Dispersal characteristics of the sandfly Phlebotomus papatasi. Med. Vet. Entomol. 2: 391395.
  • Zohary, M. 1966. Flora Palaestina Part I. The Israel Academy of Sciences and Humanities. Jerusalem . 364 pp.
  • Zohary, M. 1972. Flora Palaestina Part II. The Israel Academy of Sciences and Humanities. Jerusalem . 489 pp.
  • Zohary, M. and G. Orshansky. 1949. Structure and ecology of the vegetation in the Dead Sea region of Palestine. Palest. J. Bot. 4: 177206.