Progress 02/19/99 to 02/18/05
Outputs
Field and laboratory studies were conducted over a five-year period to determine the effect of vegetative canopy cover on productivity of immature stages of the horn fly in bovine manure pats in rangeland environments in central Texas. Rangeland environments were selected and/or modified, based upon their degree of vegetative canopy cover, to evaluate the degree of solar radiation received on horn fly survival in the manure pat. A statistically significant positive correlation was found to exist between the degree of vegetative canopy cover and mortality of horn fly larvae and pupae due to increased manure pat temperature profiles which, in turn, were directly related to increased levels of solar radiation. Diurnal manure pat vertical temperature profiles at different manure pat depths in habitats lacking vegetative canopy cover were found to be directly proportional to their degree of exposure to solar radiation; vertical temperature profiles were inversely related to
manure pat depth. Developing larvae dispersed to the bottom of the manure pat during periods of maximum solar radiation in an apparent attempt to escape high temperatures. Horn fly mortality frequently reached 100 percent in these habitats. Greatest horn fly survival was found to occur in those manure pats deposited in vegetative areas where canopy cover was the greatest, thereby affording provided protection from solar radiation.
Impacts
Results of these studies should provide ecological information to assist in the development of integrated range management programs designed to minimize the use of toxic chemicals for horn fly control of beef cattle.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
Yearly replicated field and laboratory studies are being conducted to determine the effects of rangeland vegetative canopy cover reduction management practices on survival and productivity of immature stages of the horn fly in isolated bovine manure droppings. A significant positive correlation appears to exist between range management techniques that significantly reduce levels of vegetative canopy cover and survival of horn fly immature stages as a result of increased manure pat temperatures and desiccation rates.
Impacts
Results of these studies should provide ecological information to assist in the development of integrated range management programs designed to minimize the use of toxic chemicals for horn fly control of beef cattle.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
Studies on central Texas rangeland continue to be replicated on a yearly basis to provide data for the statistical analysis of the effects of vegetative canopy cover reduction management strategies on survival and productivity of the horn fly in beef cattle manure pats. A statistically significant postive correlation appears to exist between rangeland canopy cover reduction and mortality of immature stages of the horn fly as a direct result of both increased manure pat desiccation and higher manure pat temperature profiles which are inversely proportional to manure pat depth.
Impacts
Results of these studies should provide ecological information to assist in the development of integrated range management practices designed to minimize the use of toxic chemicals for fly control on beef cattle.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
Field studies were continued to determine the effects of degree of rangeland vegetative canopy cover, on productivity and survival of the horn fly, Haematobia irritans (L.), in bovine manure pats in pasture and rangeland environments. Significant postive correlations exist between those rangeland management practices that decrease the degree of vegetative canopy cover and survival of horn fly larvae and pupae due to increased manure pat temperature profiles that, in turn, result from increased levels of solar radiation. Diurnal manure pat temperature profiles have been found to be inversely proportional to the depth of the manure pat, and these temperatures frequently exceed the lethal limits for developing fly larvae.
Impacts
Results of these studies should provide further ecological information on horn fly development to assist in the development of integrated control programs that will minimize the use of toxic chemicals on beef cattle for fly control.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
Field studies are being conducted to determine the effects of vegetative canopy cover, as influenced by various range management practices, on survival and productivity of immature stages of the horn fly, Haematobia irritans (L.), in bovine manure pats on pasture and range environments. A significant positive correlation is found to exist between range management regimes that significantly reduced levels of vegetative canopy and survival of horn fly immature stages as a result of increased manure pat temperature profiles due to increased levels of solar radiation. Dirual manure pat temperature profiles were inveresely proportional to pat depth, and frequently exceeded lethal limits.
Impacts
Results of these studies will aid in providing ecological information to assist integrated control programs which will minimize the use of toxic chemical on beef cattle for fly control.
Publications
- No publications reported this period
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Progress 01/01/99 to 12/31/99
Outputs
Continued long-term field studies were conducted to determine the impact of vegetative canopy cover on productivity and survival of immature stages of the horn fly, Haematobia irritans (L.), in undisturbed bovine manure pats in rangeland environments. Treatment regimes that resulted in significantly reduced levels of vegetative canopy cover also resulted in increased temperature profiles throughout the manure pat that were directly proportional to levels of solar radiation received. Dirual manure pat temperatures were inversely proportional to pat depth and were found to frequently exceed the upper limits for larval survival. Greatest horn fly productivity was found in those pats deposited in untreated vegeatative areas where canopy cover was greatest.
Impacts
Results of these studies should provide ecological information to further enhance integrated control programs which will minimize the use of toxic chemicals to beef cattle.
Publications
- No publications reported this period
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Progress 01/01/98 to 12/31/98
Outputs
Two chaining treatments, a conventional surface level chaining and chaining with the striking height elevated to 0.6 meter by a roller ball, for rangeland brush management were evaluated to determine their respective effects on populations of adult cedar flies, Tabanus abactor. Two trap types, a white bucket elevated on a T-post and a brown board on the ground, were coated with polyisobutylene to ensnare adult female flies. The mean numbers of flies captured per day were lower than the control on both trap types for both treatments; however, the only significant difference detected was on the bucket traps in the plots that had received the surface level chaining treatment. The board traps did not detect any significant differences among the treatments and controls. This may be the result of the observed tendency of the roller-ball treatments to leave more small trees intact, thereby providing enough cover in these plots that they were not as strongly avoid by the
female flies.
Impacts
(N/A)
Publications
- Holmes, S.P., Slosser, J.E., Moore, T.R., Wiedemann, H.T., and Bay, D.E. 1998. Chaining as a control method for Tabanus abactor in the Texas Rolling Plains. Southwestern Entomologist. 23:283-284.
- Boyd, L.S., 1998. Effects of vegetative canopy cover and fluctuating temperatures on horn fly, Haematobia irritans (L.), developmental rate and survival. Ph.D. Dissertation. Texas A&M University.
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Progress 01/01/97 to 12/31/97
Outputs
Developmental rates, relative fecundities, and relative biotic potential of one strain of susceptible and one strain of pyrethroid-resistant horn flies, Haematobia irritans (L.), were measured under insecticide free conditions. Resistant flies pupated significantly less successfully, and their rate of adults produced/100 eggs was significantly less than that for susceptible flies. The relative biotic potential of the resistant strain was 0.57, and it developed more slowly than the susceptible strain. Results suggest that the decrease in pyrethroid resistance that has been observed in early season field populations is a result of competitive disadvantage of the resistant flies in the absence of pyrethroids. Resurgence of resistant populations may be forestalled by treating with pyrethroids only when economic thresholds are reached, and by seasonal alteration of pyrethroids with insecticides that have different modes of action.
Impacts
(N/A)
Publications
- Julie S. Scott, Frederick W. Plapp, Jr., and Darrell E. Bay. 1997. Pyrethroid resistance associated with decreased biotic fitness in horn flies (Diptera:Muscidae). Southwestern Entomologist. 22:405-410.
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Progress 01/01/96 to 12/30/96
Outputs
A scanning electron microscopy (SEM) survey of the sensilla situated on the ovipositor of the horn fly, Haematobia irritans (L.), was conducted as part of a larger study of horn fly behavioral responses to bovine manure pats. Rings of 8-10 tactile hairs averaging 110, 120, and 90 # in length were found to encircle the distal margins of the 6th, 7th, and 8th abdominal segments, respectively. All sensilla on the 9th segment were situated on six plates: dorsal plate, paired anal leaflets, median plate, and paired ventral plates. All six plates were found to contain posteriorly directed tactile hairs of various lengths; however, such hairs were especially abundant on the median plate and the paired anal leaflets. Hairs located at the posterior tip of the median plate and anal leaflets provide guidance for the ovipositor and physcial placement of the eggs within the manure pat. Bilateral rows of tactile hairs on the ventral surface of the median plate are ideally situated
to monitor the passage of eggs from the oviduct. Two olfactory chemoreceptive sensilla, characterized by numerous irregularly spaced surface pores, occur on elevated circular bases only on the terminal end of each anal leaflet. As with the tactile hairs, these pegs are ideally situated to receive chemical information of an olfactory nature during the act of oviposition. Four to five sunken cone-shaped receptors, whose function could not be determined based upon their morphology, were found on each of the two ventral plates.
Impacts
(N/A)
Publications
- BAY, D.E., S.M. MEOLA, and S.L. WHITE. 1996. Scanning electron miscroscopy of the ovipositor of the horn fly. Southwestern Entomologist. 21: 337-339.
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Progress 01/01/95 to 12/30/95
Outputs
Long-term field studies were continued on the effects of rangeland brush management practices, such as burning as herbicide treatments, on productivity of immature stages of the horn fly, Haematobia irritans (L.), in isolated bovine manure droppings. Brush treatment regimes producing significantly reduced vegetative canopy cover resulted in increased manure pat temperature profiles directly attributable to increased levels of solar radiation. Daytime manure pat temperature profiles were found to be inversely related to manure pat depth in the brush-treated areas, and manure pat temperatures were found to frequently exceed the upper limit of survival for horn fly larvae. Most horn fly development occurred in those pats which were deposited in untreated areas. Adjunct studies indicated that the number of cattle visitations and the average length of stay of such visitations was also greatest in untreated habitats during the summer.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/94 to 12/30/94
Outputs
Field studies were continued for the third consecutive year on the effects of rangeland brush management practices on productivity of the horn fly, Haematobia irritans (L.), in isolated bovine manure droppings. Reductions in vegetative canopy cover resulted in significant increases in amounts of solar radiation received by manure pats and were directly correlated with manure pat temperature profiles. Diurnal pat temperatures, which were found to be inversely proportional to pat depth in unprotected (exposed) areas, frequently exceeded the constant 37(degree)C upper limit of horn fly survival, and temperature profiles in the upper strata frequently exceeded the 42(degree)C temperature tolerated up to four hours. The greatest productivity occurred in manure pats deposited in relatively protected (shady) area.
Impacts
(N/A)
Publications
- STAFFORD III, K.C., and D.E. BAY. 1994. Dispersion statistics and sample size estimate for house fly (Diptera:Muscidae) larvae and Macrocheles muscaedomesticae (Acari:Macrochelidae) in poultry manure. J. Med. Entomol. 31:732-737.
- TEEL, P.D., D.E. BAY, S.R. ARCHER, O.F. STREY, and M.T. LONGNECKER. 1994. Ecological basis of integrated pest management for beef cattle on rangeland, pp. 1518-1560. In J.W. Turner ed.
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Progress 01/01/93 to 12/30/93
Outputs
Field studies were continued for the second consecutive year on the effects of rangeland brush management practices on horn fly, Haematobia irritans (L.), productivity in bovine manure pats. Brush management practices which resulted in reductions of vegetative canopy cover were again found to significantly increase temperatures in exposed manure pats due to increased levels of solar radiation. Diurnal pat temperatures, which were found to be inversely proportional to pat depth, frequently exceeded the upper limits of horn fly survival; greatest productivity continued to occur in those pats which were protected from solar radiation by vegetative canopy cover. Corresponding studies indicated that the number of hourly visitations and the average length of stay by cattle was also greatest in canopied habitats during the summer.
Impacts
(N/A)
Publications
- No publications reported this period.
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Progress 01/01/92 to 12/30/92
Outputs
Rangeland studies have demonstrated an inverse relationship between the degree of vegetative canopy cover and horn fly productivity in isolated bovine manure pats. Reductions of canopy cover resulted in significant increases in the amounts of solar radiation received by the manure pats, and were directly correlated with manure pat temperature profiles. Temperatures in unprotected (exposed) pats were inversely proportional to pat depth during the diurnal period. Temperatures throughout much of the pat during this time exceeded the constant 37(degree)C upper limit for horn fly larval survival, and temperatures in the upper strata frequently exceeded the 42(degree)C temperature tolerated up to 4 hours. The greatest horn fly productivity occurred in manure pats deposited in relatively protected (shady) areas.
Impacts
(N/A)
Publications
- HUNTER III, J.S., FINCHER, G.T., BAY, D.E. and BEERWINKLE, K.R. 1991. Seasonal distribution and diel flight activity of Staphylinidae (Coleoptera) in open and wooded pasture in east-central Texas. Journal of the Kansas Entomological Soc.
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Progress 01/01/91 to 12/30/91
Outputs
Development rates, relative fecundities and relative biotic potentials of one strain of susceptible and one strain of pyrethroid-resistant horn flies, Haematobia irritans (L.) were measured under insecticide-free conditions. Resistant flies pupated significantly less successfully (P<0.0005), and their rate of adults produced/100 eggs was significantly lower than for susceptible flies (P<0.0005). The relative biotic potential of the resistant strain was 0.57, and it developed slower than the susceptible strain. Results suggest that the decrease in pyrethroid resistance that has been observed in early season field populations is a result of a competitive disadvantage of resistant flies in the absence of pyrethroids. Resurgence of resistant populations may be forestalled by treating with pyrethroids only when economic thresholds (250 flies per animal) are reached, and by seasonal alteration of pyrethroids with insecticides that have a different mode of action.
Impacts
(N/A)
Publications
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Progress 01/01/90 to 12/30/90
Outputs
Horn fly, Haematobia irritans (L.), adult emergence rhythms were evaluated by rearing immature stages in either constant light, constant dark, or a 12:12 light-dark cycle. Temperatures at these lighting regimes oscillated between 17-23C or maintained at a constant 22C. Emerging flies were segregated at hourly intervals by an emergence collector. Results indicated that female horn flies emerged approximately 24 hours before male flies. Emergence of both sexes coincided with diurnal temperature and is thus extrinsic in nature. Flies began to emerge approximately two hours after temperature began to increase and peaked during the warmest portion of the temperature cycle.
Impacts
(N/A)
Publications
- HUNTER, J.S., III, BAY, D.E. and FINCHER, G.T. 1989. Laboratory and field observations on the life history and habits of Philonthus cruentatus and Philonthus flavolimbatus. The Southwestern Entomologist. 14:41-47.
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Progress 01/01/89 to 12/30/89
Outputs
Differential screening techniques and pitfall trap collections of dung fauna were used to evaluate scarab activity and predation as mortality factors of the buffalo fly, Haematobia irritans exigua (de Meijere), at a site in central Queensland, Australia as part of a study evaluating the potential of foreign predators and parasites for control of the the horn fly, Haematobia irritans (L). Six species of introduced scarabs have been established at this location. These tests indicated that the activity of these scarabs and predation by other fauna periodically caused significant reductions in the numbers of buffalo flies emerging from cattle dung pats. Scarab activity was considered to be the most important mortality factor since it was associated with low buffalo fly emergence more frequently than was predation. The feces of four species of domestic animals alone and in combination with two vegetative materials commonly associated with animal production practices were
evaluated against a standardized rearing medium for production of the stable fly, Stomoxys calcitrans (L.). Pupal production in cattle and horse manure was not significantly different from one another nor from the control media; swine and chicken feces yielded significantly fewer pupae. Of the various animal manures evaluated, pupal weight was greatest from that of horses followed by cattle, swine and chickens, respectively.
Impacts
(N/A)
Publications
- BOIRE, S., BAY, D.E. and OLSON, J.K. 1988. An evaluation of various types of manure and vegetative material as larval breeding media for the stable fly. The Southwestern Entomologist. 13:247-249.
- ROTH, J.P., MACQUEEN, A. and BAY, D.E. 1988. Scarab activity and predation as mortality factors of the buffalo fly, Haematobia irritans exigua, in central Queensland. The Southwestern Entomologist 13:119-124.
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Progress 01/01/88 to 12/30/88
Outputs
As part of a study evaluating the potential of foreign predator and parasites for control of the horn fly, Haematobia irritans, the effectiveness of Macrocheles peregrinus, a predator of the buffalo fly, Haematobia irritans exigua, in Australia was examined. In laboratory tests, mites were confined with eggs or larvae of the buffalo fly to assess the effect of prey location and predator/prey ratio on fly survival, to determine the main life stage attacked, and to determine the prey preference of the mite in the presence of the mite in the presence of other dipterous species. In field tests, the impact of the mite on buffalo fly survival was measured in natural manure pats enclosed in screened cages. Buffalo fly mortality was highest when eggs of this species were placed on tops of dung pats rather than underneath them. The maximum mortality obtained was 83%; there was no increase in mortality at predator/prey ratios above one mite per two fly eggs. The mite caused
highest mortality when exposed to hatching eggs and young larvae of the buffalo fly, but a strong preference for eggs of other dipterous species characterized by softer egg chorions was demonstrated. Mites acting alone produced an average 33% suppression of buffalo fly breeding in field pats. Macrocheles peregrinus was considered to be a relatively ineffective predator of the buffalo fly, and judged unworthy of futher consideration for control of the horn fly in the United States.
Impacts
(N/A)
Publications
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Progress 03/01/87 to 12/30/87
Outputs
Toxicity of the juvenile hormone analogue, methoprene, to the horn fly was foundto be inversely proportional to culture density when incorporated into the larval diet in the laboratory. This relationship was more pronounced at lower concentrations of 0.0025 and 0.005 ppm than at the highest concentration tested of 0.02 ppm. Field studies have been initiated this past summer at the La Copita Research Area, near Alice, Texas, on the interrelationships of range management techniques, pasture canopy cover, and horn fly biodynamics in the manure pat. A microhabitat gradient, based on degree of canopy cover, has been established through a series of clearcut-herbicide treatments. Manure pats, to which 100 horn fly eggs have been added, are placed in each habitat. Pat temperature is monitored hourly at 5 depths and automatically recorded. Emerging flies are collected and enumerated.
Impacts
(N/A)
Publications
- BAY, D.E. and BOYD, L.S. 1987. Effect of horn fly larval density on methoprene toxicity. The Southwestern Entomologist. 12:259-261.
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