Synergism between ammonia and phenols for Hybomitra tabanids in northern and temperate Canada

Abstract

Baits for tabanids (Diptera: Tabanidae) were tested in the Northwest Territories (60 °N) and Ontario (45 °N) using Nzi traps. Tests targeted ammonia, phenols/cow urine and octenol. About 200 000 tabanids were captured in 15 experiments with a maximum capture of 4182 in one trap in 1 day. In the Northwest Territories, phenols, urine and octenol were effective single baits for only some species. At both locations, adding ammonia to an unbaited or an octenol-baited trap had no effect on catches. By contrast, catches were increased for several species when ammonia was combined with phenols or urine. In Ontario, including ammonia in various baits increased catches by 1.5- to 3.4-fold relative to octenol alone for three Hybomitra and one Tabanus species. Synergism between ammonia and phenols was clearly demonstrated for the dominant Hybomitra species in Ontario (Hybomitra lasiophthalma), but not for the dominant species in the Northwest Territories (Hybomitra epistates). In five other northern Hybomitra species, baits of ammonia and/or octenol in combination with phenols resulted in a 1.7- to 4.1-fold increase in catch relative to an unbaited trap. Further tests of ammonia as a synergist for biting flies may prove useful in, for example, tsetse, which respond strongly to phenols.

Olfactory and behavioural responses of tabanid horseflies to octenol, phenols and aged horse urine

“…(Hribar et al ., ; Leprince et al ., ), and, in Canada, catches of Hybomitra spp. were not increased in traps using ammonia alone relative to unbaited Nzi traps (Mihok & Lange, ). Ammonia has also been tested in combination with octenol in Denmark using canopy traps (Kristensen & Sommer, ) and in Canada using Nzi traps (Mihok & Lange, ), but both studies found that adding ammonia to an octenol‐baited trap had no significant effect.…”

“…Mean release rates for ammonia and urine were calculated by assessing the volume of liquid that evaporated in the field at, respectively, 7.9 mL/day and 6.8 mL/day. In the cow urine tested by Mihok and Lange (), ammonia content dropped from 6140 mg/L to 1480 mg/L with exposure to air for 19 days. Thus, we expected to find similar relative evaporation rates of ammonia for the 5% ammonia solution and for aged horse urine.…”

“…The synergism between ammonia and phenols demonstrated for Hybomitra spp. may explain the attractiveness of aged urine (Mihok & Lange, ).…”

Behavioural and electrophysiological responses of females of two species of tabanid to volatiles in urine of different mammals

“…Results have shown that aged cow urine, octenol (1-octen-3-ol) and phenols (3-and 4-methylphenol)-but not ketones (including acetone)-are effective attractants for species of Tabanidae, although there are differences in efficacy among groups and species (Gibson & Torr, 1999;Mihok et al, 2007;Mihok & Mulye, 2010). Synergism between ammonia and phenols, a combination that frequently occurs in aged urine, has also been demonstrated for Hybomitra species (Diptera: Tabanidae) in Ontario (Mihok & Lange, 2011).…”

Capturing tabanids by traps: Development history, visual and olfactory attractants and future of tabanid trap

“…Swynnerton, 1933;Lloyd, 1935Hassanali et al, 1986Bursell et al, 1988;Madubunyi et al, 1996 Canopy trap Krčmar et al, 2006 Canopy trap 6.4 Krčmar and Lajoš, 2011Baldacchino et al 2012Reeves, 1951 e.g. Fallis and Smith, 1964;Nelson, 1965;Knox andHays, 1972 Wilson et al, 1966;DeFoliart and Morris, 1967;Everett and Lancaster Jr., 1968 Hribar et al, 1992;Kristensen and Sommer, 2000;Mihok and Lange, 2012 1-octen-3-ol Vale and Hall, 1985;French and Kline, 1989;Downer and Stoffolano Jr., 2006;Cilek and Olson, 2008 Cilek…”