Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.

Control of tsetse flies constitutes a cornerstone of trypanosomiasis control and elimination efforts in Africa. The use of eco-friendly odor-based bait technologies has been identified as a safer method for control of tsetse flies. These technologies are significantly augmented by development of eff...

Full description

Saved in:
Bibliographic Details
Main Authors: Benson M Wachira, Richard Echodu, Johnson O Ouma, Imna I Malele, Daniel Gamba, Michael Okal, Kennedy O Ogolla, Clement Mangwiro, Robert Opiro, Deusdedit J Malulu, Bernard Ochieng, Raymond E Mdachi, Paul O Mireji
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-07-01
Series:PLoS Neglected Tropical Diseases
Online Access:https://doi.org/10.1371/journal.pntd.0013367
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850039164237512704
author Benson M Wachira
Richard Echodu
Johnson O Ouma
Imna I Malele
Daniel Gamba
Michael Okal
Kennedy O Ogolla
Clement Mangwiro
Robert Opiro
Deusdedit J Malulu
Bernard Ochieng
Raymond E Mdachi
Paul O Mireji
author_facet Benson M Wachira
Richard Echodu
Johnson O Ouma
Imna I Malele
Daniel Gamba
Michael Okal
Kennedy O Ogolla
Clement Mangwiro
Robert Opiro
Deusdedit J Malulu
Bernard Ochieng
Raymond E Mdachi
Paul O Mireji
author_sort Benson M Wachira
collection DOAJ
description Control of tsetse flies constitutes a cornerstone of trypanosomiasis control and elimination efforts in Africa. The use of eco-friendly odor-based bait technologies has been identified as a safer method for control of tsetse flies. These technologies are significantly augmented by development of effective repellents that reduce contact between trypanosome-infected tsetse flies and their vertebrate hosts. Waterbuck Repellent Compounds (WRC) and Novel Repellent Blend (NRB) are recently developed tsetse fly repellent formulations. Information on relative efficacy of these formulations against major tsetse fly vectors of trypanosomiasis in Kenya is limited. Such information can inform choices of repellent technology for optimal control of the flies. Here we assessed relative field responses of Glossina pallidipes and G. fuscipes fuscipes, representative of savannah (morsitans) and riverine (palpalis) groups of tsetse flies, respectively. We deployed NG2G traps or sticky panels and tiny targets using randomized Latin Square experimental design. We then assessed catches of G. pallidipes or G. f. fuscipes respectively on the traps/panels in the absence or presence of WRC or NRB. We additionally baited the NG2G traps with G. pallidipes-responsive 3-propylphenol, octenol, p-cresol, and acetone (POCA) attractant blend, that effectively served as proxy for the preferred vertebrate natural host. We performed the G. pallidipes and G. f. fuscipes experiments in Shimba Hills National Reserve and Ndere Island National Park respectively in Kenya and incorporated a no-odor control for each set of experiments. Mean catches of male G. pallidipes in traps without odor (control), baited with POCA, POCA with WRC or POCA with NRB were 9.86 (95% CI; 6.50- 14.74), 42.71 (95% CI; 28.11 - 64.62), 14.30 (95% CI; 8.50 - 23.60) and 3.03 (95% CI; 0.89 - 7.59) respectively, while for females, the catches were 24.43 (95% CI; 13.65 - 47.42), 70.93 (95% CI; 42.95 - 120.50), 23.85 (95% CI; 16.33 - 37.84) and 6.82 (95% CI; 3.59 -17.02) flies per trap per day respectively. Consequently, the NRB was 4.72 and 3.50-folds and significantly (P < 0.001) more repellent to male and female G. pallidipes respectively, than WRC. In contrast, catches of G. f. fuscipes on targets were similar (P > 0.05) across all the three treatments (including no-odor control). The NRB and WRC are thus efficacious against G. pallidipes but not G. f. fuscipes, with efficacy of NRB being several-folds that of WRC against G. pallidipes. Whether these profiles represent general responses of morsitans and palpalis group of tsetse flies remains to be determined. Additionally, G. f. fuscipes merits further research to formulate an effective repellent against this fly. The NRB can potentially provide better protection to vertebrate hosts, including humans and their livestock than WRC from G. pallidipes. Consequently, NRB can be integrated into routine trypanosomiasis control program to stem transmission of trypanosomes by G. pallidipes, especially in eastern and southern Africa where G. pallidipes is naturally abundant.
format Article
id doaj-art-bf609fb29cdb4e91bc1fefa91c091806
institution DOAJ
issn 1935-2727
1935-2735
language English
publishDate 2025-07-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Neglected Tropical Diseases
spelling doaj-art-bf609fb29cdb4e91bc1fefa91c0918062025-08-20T02:56:25ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352025-07-01197e001336710.1371/journal.pntd.0013367Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.Benson M WachiraRichard EchoduJohnson O OumaImna I MaleleDaniel GambaMichael OkalKennedy O OgollaClement MangwiroRobert OpiroDeusdedit J MaluluBernard OchiengRaymond E MdachiPaul O MirejiControl of tsetse flies constitutes a cornerstone of trypanosomiasis control and elimination efforts in Africa. The use of eco-friendly odor-based bait technologies has been identified as a safer method for control of tsetse flies. These technologies are significantly augmented by development of effective repellents that reduce contact between trypanosome-infected tsetse flies and their vertebrate hosts. Waterbuck Repellent Compounds (WRC) and Novel Repellent Blend (NRB) are recently developed tsetse fly repellent formulations. Information on relative efficacy of these formulations against major tsetse fly vectors of trypanosomiasis in Kenya is limited. Such information can inform choices of repellent technology for optimal control of the flies. Here we assessed relative field responses of Glossina pallidipes and G. fuscipes fuscipes, representative of savannah (morsitans) and riverine (palpalis) groups of tsetse flies, respectively. We deployed NG2G traps or sticky panels and tiny targets using randomized Latin Square experimental design. We then assessed catches of G. pallidipes or G. f. fuscipes respectively on the traps/panels in the absence or presence of WRC or NRB. We additionally baited the NG2G traps with G. pallidipes-responsive 3-propylphenol, octenol, p-cresol, and acetone (POCA) attractant blend, that effectively served as proxy for the preferred vertebrate natural host. We performed the G. pallidipes and G. f. fuscipes experiments in Shimba Hills National Reserve and Ndere Island National Park respectively in Kenya and incorporated a no-odor control for each set of experiments. Mean catches of male G. pallidipes in traps without odor (control), baited with POCA, POCA with WRC or POCA with NRB were 9.86 (95% CI; 6.50- 14.74), 42.71 (95% CI; 28.11 - 64.62), 14.30 (95% CI; 8.50 - 23.60) and 3.03 (95% CI; 0.89 - 7.59) respectively, while for females, the catches were 24.43 (95% CI; 13.65 - 47.42), 70.93 (95% CI; 42.95 - 120.50), 23.85 (95% CI; 16.33 - 37.84) and 6.82 (95% CI; 3.59 -17.02) flies per trap per day respectively. Consequently, the NRB was 4.72 and 3.50-folds and significantly (P < 0.001) more repellent to male and female G. pallidipes respectively, than WRC. In contrast, catches of G. f. fuscipes on targets were similar (P > 0.05) across all the three treatments (including no-odor control). The NRB and WRC are thus efficacious against G. pallidipes but not G. f. fuscipes, with efficacy of NRB being several-folds that of WRC against G. pallidipes. Whether these profiles represent general responses of morsitans and palpalis group of tsetse flies remains to be determined. Additionally, G. f. fuscipes merits further research to formulate an effective repellent against this fly. The NRB can potentially provide better protection to vertebrate hosts, including humans and their livestock than WRC from G. pallidipes. Consequently, NRB can be integrated into routine trypanosomiasis control program to stem transmission of trypanosomes by G. pallidipes, especially in eastern and southern Africa where G. pallidipes is naturally abundant.https://doi.org/10.1371/journal.pntd.0013367
spellingShingle Benson M Wachira
Richard Echodu
Johnson O Ouma
Imna I Malele
Daniel Gamba
Michael Okal
Kennedy O Ogolla
Clement Mangwiro
Robert Opiro
Deusdedit J Malulu
Bernard Ochieng
Raymond E Mdachi
Paul O Mireji
Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
PLoS Neglected Tropical Diseases
title Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
title_full Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
title_fullStr Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
title_full_unstemmed Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
title_short Field responses of Glossina pallidipes and Glossina fuscipes fuscipes tsetse flies to Novel Repellent Blend and Waterbuck Repellent Compounds in Kenya.
title_sort field responses of glossina pallidipes and glossina fuscipes fuscipes tsetse flies to novel repellent blend and waterbuck repellent compounds in kenya
url https://doi.org/10.1371/journal.pntd.0013367
work_keys_str_mv AT bensonmwachira fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT richardechodu fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT johnsonoouma fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT imnaimalele fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT danielgamba fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT michaelokal fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT kennedyoogolla fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT clementmangwiro fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT robertopiro fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT deusdeditjmalulu fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT bernardochieng fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT raymondemdachi fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya
AT paulomireji fieldresponsesofglossinapallidipesandglossinafuscipesfuscipestsetsefliestonovelrepellentblendandwaterbuckrepellentcompoundsinkenya