- Open Access
Attraction of the sand fly Nyssomyia neivai (Diptera: Psychodidae) to chemical compounds in a wind tunnel
© Machado et al.; licensee BioMed Central. 2015
- Received: 8 November 2014
- Accepted: 17 February 2015
- Published: 7 March 2015
Similar to other hematophagous insects, male and female sand flies must feed on plants to obtain sugar and, subsequently, energy to complete their life cycles. A large number of compounds emitted by plants may act as volatile signals to these insects. Primary alcohols have been detected in some plants, but in small amounts. In a previous report, the attractiveness of saturated primary alcohols with 7 to 9 carbons was evaluated for Lutzomyia longipalpis, the vector of American visceral leishmaniasis, with positive results.
In the present study, a wide range of primary alcohols, 3 to 10 carbons, were tested to investigate their attractiveness to another sand fly species, Nyssomyia neivai, a putative vector of American cutaneous leishmaniasis. The mixture of compounds that induced the best sand fly response was also evaluated.
Of the eight compounds evaluated, hexanol and octanol elicited the best attractive responses for sand fly females.
Phytochemicals may be an interesting source of search for new sand fly attractants.
- Sand flies
- Wind tunnel
- Plant volatiles
- Nyssomyia neivai
Generally, the concept of kairomones for hematophagous insects is related to host volatiles, and the development of new lures is focused on those compounds. However, considering that hematophagous insects also feed on plant tissues, phytochemical attractants are very interesting targets, but less studied compared with kairomones from vertebrate animals .
There have been behavioural reports on the attractiveness of floral odours or single floral compounds to mosquitoes [2-4]. For sand flies, studies with plants [5-7] fruits  and honey  have shown their effective roles as attractants, but there has been no isolation of compounds from these different sources.
In a previous study conducted in a wind tunnel, the attractiveness of the host kairomone 1-octen-3-ol was compared with three saturated primary alcohols (1-heptanol, 1-octanol and 1-nonanol) for the sand fly Lutzomyia longipalpis . Those saturated primary alcohols are present in small quantities in some plant volatiles. The results demonstrated a relative attractive response of female L. longipalpis to 1-heptanol and 1-nonanol. Such results indicate that other saturated primary alcohols may also be attractive to sand fly species. The present study investigated the attractiveness of a broad range of saturated primary alcohols (3 to 10 carbons) for Nyssomyia neivai, a putative vector of cutaneous leishmaniasis in South America . The compounds that evoked the best responses were combined and evaluated for their attractiveness.
Sand flies and laboratory maintenance
Insects were collected, using manual aspiration on the wall of one house located at the edge of the Mogi-Guaçu River, northeast center of São Paulo State, Brazil (21 ° 35′13’S 48 ° 04′15’W). In the laboratory, the insects were maintained in netting cages with a 30% solution of sucrose fed ad libitum under controlled conditions (26 ± 1°C, 80–90%, 12:12 (L:D) photoperiod).
Experiments in the wind tunnel
The experiments were performed in a wind tunnel (previously described)  within three to four days after the field collection of insects. Tests were performed from 9:00 to 19:00 and, at the end of the assay, the insects were identified according to the classification proposed by Galati .
Groups of three females were placed in a releasing chamber, for a total of 30 different insects for each concentration of the evaluated compounds. The releasing chambers were placed in the wind tunnel 50 cm from the stimulus. Tests lasted for 2 min, and two behaviours were evaluated: activation and attraction. Activation was defined as the number of sand flies that left the releasing chamber, and attraction was defined as the number of sand flies that reached the stimulus.
The compounds evaluated were: 1-propanol (99.5%), 1-butanol (99.4%), 1-pentanol (>99.5%), 1-hexanol (98%), 1-heptanol (98%), 1-octanol (>99%), 1- nonanol (98%) and 1-decanol (>99%) (hereafter propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and decanol) (Sigma-Aldrich). The compound 1-octen3-ol (hereafter octenol) has been already shown to be attractive to N. neivai , so it was used as a positive control. All compounds were diluted in hexane and tested at concentrations of 10%, 50% and 100% (neat). When necessary, a lower concentration (5%) was also used. Each compound was delivered (200 μL) on a filter paper (4 × 4 cm) in the entrance of the tunnel. The control was hexane presented the same way prior to testing the other compounds.
After these tests, the three compounds with the best responses (heptanol, octanol, and nonanol) were combined (1:1:1) and subsequently evaluated in the wind tunnel.
The interval between a compound and another was at least two hours, when the tunnel was cleaned with hexane and allowed to dry.
Chi square tests were used to evaluate the different proportions of sand fly females activated and attracted by each compound. Initially, the tests were conducted for all concentrations simultaneously. If a significant difference was verified, each of the two groups was compared separately. The statistical analyses were performed using BioEstat(available in http://www.mamiraua.org.br/pt-br/downloads/programas/bioestat-versao-53/).
Percentages of activated and attracted N. neivai females to individual alcohols and mixture of three alcohols (n = 30 for each compound)
With octenol as a positive control and 70% used as a cut off for responses, pentanol, hexanol, heptanol, octanol, nonanol and, to a lesser extent, decanol, elicited activation behaviours. However, according to the same criteria, hexanol and octanol were the best attractants for sand fly females. Octanol was even better than octenol at lower concentrations (50% and 10%).
The concentration of 5% was added to trials with heptanol, octanol and nonanol because they elicited high responses of activation at 10%. Those compounds were mixed (1:1:1) and tested again. The results showed that 93% of females were activated and 63% were attracted by the mixture. There was an improvement in activation that was not reflected for attraction.
Our study compared the attractiveness of saturated primary alcohols to sand flies with 1-octen-3-ol, an unsaturated secondary alcohol, used as lure for hematophagous insects. The results emphasised that, similar to a previous study with the sand fly species L. longipalpis , such compounds also act as activators and/or attractants for N. neivai. The results are also in agreement with our prior survey  and showed that flies taken directly from the field can be used in laboratory olfactometer experiments, in spite of different physiological conditions, because they showed consistently higher activation and attraction responses to the evaluated compounds than to air control.
Octenol is a known host kairomone found in cattle , human breath  and human skin emanation . For sand flies, octenol has been shown to elicit a response in L. longipalpis in electrophysiological recordings  and attractive behaviours in a wind tunnel . For Nyssomyia intermedia and N. neivai, octenol also elicited attractive responses in field studies [18,19]. In addition to its occurrence in mammals, octenol is also identified in many studies with volatile organic compounds (VOC) in different species of plants such as watermelon , flowers of lucerne  and mango .
The alcohols used in the present study are not host kairomones, but they are present in plant volatiles. For example, octanol and hexanol are present in watermelon  and strawberry ; and butanol, pentanol, hexanol, and octanol are present in guava . Considering that sand flies require sugar meals from plants to survive, those compounds could be considered to be phytochemical attractants.
Previous reports have demonstrated the attractiveness of plants to sand flies [7,8,25]. A laboratory study in a wind tunnel evaluated unifloral honey odours as attractants for different populations of three sand flies species, and the responses were species and population specific .
Despite the evidence of plant attractiveness to sand flies, there is a gap in the identification of phytochemical attractants isolated from the plants. The main advantage of phytochemical attractants for hematophagous insects is that they lure males and females of all ages and females in all gonotrophic states . Our results show that, in addition to host kairomones, other compounds, such as phytochemical, should also be investigated as attractants for sand flies.
The compounds hexanol and octanol elicited the best attractive responses for N. neivai females in bioassays. The next step is to evaluate if those compounds will be attractive for other sand fly species in field.
MP received a grant (F-4587-1) from the International Foundation for Science (IFS) to build the wind tunnel and financial support for publication from Programa de Apoio ao Desenvolvimento Científico da Faculdade de Ciências Farmacêuticas at UNESP (PADC/FCFAr).
- Foster WA. Phytochemicals as population sampling lures. J Am Mosq Control Assoc. 2008;24(1):138–46.View ArticlePubMedGoogle Scholar
- Healy TP, Jepson PC. The location of floral nectar sources by mosquitoes: the long-range responses of Anopheles arabiensis Patton (Diptera: Culicidae) to Achillea millefolium flowers and isolated floral odour. Bull Entomol Res. 1988;78(04):651–7.View ArticleGoogle Scholar
- Jhumur US, Dotterl S, Jurgens A. Floral odors of Silene otites: their variability and attractiveness to mosquitoes. J Chem Ecol. 2008;34(1):14–25.View ArticlePubMedGoogle Scholar
- Otienoburu PE, Ebrahimi B, Phelan PL, Foster WA. Analysis and optimization of a synthetic milkweed floral attractant for mosquitoes. J Chem Ecol. 2012;38(7):873–81.View ArticlePubMed CentralPubMedGoogle Scholar
- Schlein Y, Muller G. Assessment of plant tissue feeding by sand flies (Diptera: Psychodidae) and mosquitoes (Diptera: Culicidae). J Med Entomol. 1995;32(6):882–7.View ArticlePubMedGoogle Scholar
- Schlein Y, Jacobson RL, Muller GC. Sand fly feeding on noxious plants: a potential method for the control of leishmaniasis. Am J Trop Med Hyg. 2001;65(4):300–3.PubMedGoogle Scholar
- Muller GC, Revay EE, Schlein Y. Relative attraction of the sand fly Phlebotomus papatasi to local flowering plants in the Dead Sea region. J Vector Ecol. 2011;36 Suppl 1:S187–94.View ArticlePubMedGoogle Scholar
- Junnila A, Muller GC, Schlein Y. Attraction of Phlebotomus papatasi to common fruit in the field. J Vector Ecol. 2011;36 Suppl 1:S206–11.View ArticlePubMedGoogle Scholar
- Wasserberg G, Kirsch P, Rowton ED. Orientation of colonized sand flies Phlebotomus papatasi, P. duboscqi, and Lutzomyia longipalpis (Diptera: Psychodidae) to diverse honeys using a 3-chamber in-line olfactometer. J Vector Ecol. 2014;39(1):94–102.View ArticlePubMedGoogle Scholar
- Magalhaes-Junior J, Barrouin-Melo S, Correa A, da Rocha Silva F, Machado V, Govone J, et al. A laboratory evaluation of alcohols as attractants for the sandfly Lutzomyia longipalpis (Diptera:Psychodidae). Parasit Vectors. 2014;7(1):60.View ArticlePubMed CentralPubMedGoogle Scholar
- Cordoba-Lanus E, De Grosso ML, Pinero JE, Valladares B, Salomon OD. Natural infection of Lutzomyia neivai with Leishmania spp. in northwestern Argentina. Acta Trop. 2006;98(1):1–5.View ArticlePubMedGoogle Scholar
- Pinto MC, Bray DP, Eiras AE, Carvalheira HP, Puertas CP. Attraction of the cutaneous leishmaniasis vector Nyssomyia neivai (Diptera: Psychodidae) to host odour components in a wind tunnel. Parasit Vectors. 2012;5:210.View ArticlePubMed CentralPubMedGoogle Scholar
- Galati EAB. Classificaçâo de Phlebotominae. In: Rangel EF, Lainson R, editors. Flebotomíneos do Brasil. Rio de Janeiro, Brazil: Fiocruz; 2003.Google Scholar
- Hall DR, Beevor PS, Cork A, Nesbitt BF, Vale GA. 1-Octen-3-ol. A potent olfactory stimulant and attractant for tsetse isolated from cattle odours. Int J Trop Insect Sci. 1984;5(Special Issue 05):335–9.View ArticleGoogle Scholar
- Xue R, Dong L, Zhang S, Deng C, Liu T, Wang J, et al. Investigation of volatile biomarkers in liver cancer blood using solid-phase microextraction and gas chromatography/mass spectrometry. Rapid Commun Mass Spectrom. 2008;22(8):1181–6.View ArticlePubMedGoogle Scholar
- Bernier UR, Kline DL, Barnard DR, Schreck CE, Yost RA. Analysis of human skin emanations by gas chromatography/mass spectrometry. 2. Identification of volatile compounds that are candidate attractants for the yellow fever mosquito (Aedes aegypti). Anal Chem. 2000;72(4):747–56.View ArticlePubMedGoogle Scholar
- Sant’ana AL, Eiras AE, Cavalcante RR. Electroantennographic responses of the Lutzomyia (Lutzomyia) longipalpis (Lutz & Neiva) (Diptera: Psychodidae) to 1-octen-3-ol. Neotrop Entomol. 2002;31:13–7.View ArticleGoogle Scholar
- Andrade AJ, Andrade MR, Dias ES, Pinto MC, Eiras AE. Are light traps baited with kairomones effective in the capture of Lutzomyia longipalpis and Lutzomyia intermedia? An evaluation of synthetic human odor as an attractant for phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae). Mem Inst Oswaldo Cruz. 2008;103(4):337–43.View ArticlePubMedGoogle Scholar
- Pinto MC, Barbieri K, Silva MC, Graminha MA, Casanova C, Andrade AJ, et al. Octenol as attractant to Nyssomyia neivai (Diptera:Psychodidae:Phlebotominae) in the field. J Med Entomol. 2011;48(1):39–44.View ArticlePubMedGoogle Scholar
- Yajima I, Sakakibara H, Ide J, Yanai T, Kazuo H. Volatile flavor components of watermelon (Citrullus vulgaris). Agric Biol Chem. 1985;49(11):3145–50.View ArticleGoogle Scholar
- Tava A, Pecetti L. Volatiles from Medicago sativa complex flowers. Phytochemistry. 1997;45(6):1145–8.View ArticleGoogle Scholar
- Kamala Jayanthi PD, Kempraj V, Aurade RM, Venkataramanappa RK, Nandagopal B, Verghese A, et al. Specific volatile compounds from mango elicit oviposition in gravid Bactrocera dorsalis females. J Chem Ecol. 2014;40(3):259–66.View ArticlePubMedGoogle Scholar
- Hamilton-Kemp TR, Loughrin JH, Andersen RA. Identification of some volatile compounds from strawberry flowers. Phytochemistry. 1990;29(9):2847–8.View ArticleGoogle Scholar
- Pino JA, Bent L. Odour-active compounds in guava (Psidium guajava L. cv. Red Suprema). J Sci Food Agric. 2013;93(12):3114–20.View ArticlePubMedGoogle Scholar
- Schlein Y, Yuval B. Leishmaniasis in the Jordan Valley. IV. Attraction of Phlebotomus papatasi (Diptera: Psychodidae) to plants in the field. J Med Entomol. 1987;24(1):87–90.View ArticlePubMedGoogle Scholar
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.