Below is an unformatted, plain-text file of the article starting on page 476 of the December 2000 issue of Florida Entomologist (vol. 83, no. 4). It is put on WWW only to facilitate automated indexing and retrieval. Tables are scrambled and illustrations are omitted.
View, read, or make a reprint of this item in its original format, including tables and illustrations.
Go to homepage of Florida Entomologist on WWW for more information about this service.
Evaluation of "TRED-NOT™ DEERFLY PATCHES" against host-seeking deer flies (Diptera:Tabanidae) in north Florida
James E. Cilek
John A. Mulrennan, Sr. Public Health Entomology Research & Education Center, Florida A & M University, 4000 Frankford Avenue, Panama City, FL 32405
Abstract
"TRED-NOT™ DEERFLY PATCHES" (6.4 × 14.2 cm adhesive strips) affixed to the back and front of nylon mesh solid black and solid white "baseball" caps were evaluated for their ability to trap host-seeking Chrysops celatus Pechuman, C. vittatus Weidemann, and Diachlorus ferrugatus (F.). Trials were conducted in a commercial pine bottomland forest habitat in northwestern Florida during peak seasonal abundance of these species. No D. ferrugatus were captured on patches but approximately 26% of host seeking Chrysops (regardless of patch location, cap color or fly species) were captured compared with a standard aerial sweep net method. Significantly more deer flies were captured on patches affixed to the back of the cap compared with patches placed on the front. No statistical difference (>0.05) existed in number of flies trapped on patches when cap colors (white versus black) were compared.
Key Words: Chrysops celatus, Chrysops vittatus, Diachlorus ferrugatus, personal protection
Resumen
Parches marca "TRED-NOTMR" para la captura de moscas Chrysops celatus Pechuman (tiras adhesivas de 6,4 × 14,2 cm) pegadas al frente y al dorso de mallas de nylon en gorras de "béisbol" de colores s-lidos blanco y negro fueron estudiadas para determinar su habilidad de atrapar a los busca-hospedantes Chrysops celatus Pechuman, C. Vittatus Weidemann, y Diachlorus ferrugatus (F.). Se realizaron pruebas en un hábitat de bosque de pino comercial al noroeste de Florida durante un periodo estacional de alta abundancia para estas especies. No fueron capturados D. ferrugatus en parches pero aproximadamente 26% de Chrysops busca-hospedantes (sin importar lugar, color de la gorra o especie de mosca) fueron capturados en comparaci-n a un método estándar de rastrear con red aérea. Mas moscas significativamente fueron capturadas en parches pegados al dorso de la gorra comparado con parches colocados al frente. No existi- diferencia estadística (>0,05) en el numero de moscas capturadas en parches cuando se compararon los colores de las gorras (blanco versus negro).
Host-seeking deer flies can often become a serious nuisance and large pestiferous populations can certainly discourage enjoyment of outdoor activities. Repellents applied to exposed skin have not been very effective against these pests especially for extended periods of time (Anderson 1985). Insecticides applied to, or impregnated in, clothing have been reported to provide some repellency in field situations (Schreck et al. 1978 and Carlson 1996). Recently, adhesive patches (affixed to headwear) have been advertised in various retail/outdoor recreational supply catalogs as an effective way to "stop biting deer flies". This author is unaware of any published studies, conducted under Florida conditions, where such products have been evaluated. As a result, a field study to evaluate a commercially available adhesive patch against three species of host-seeking deer flies was conducted late spring, 1998. Materials and Methods This study was conducted from May 27 through June 8, 1998 in Walton and Bay Counties, Florida, at a time when Chrysops vittatus Weidemann, C. celatus Pechuman and Diachlorus ferrugatus (F.) were at seasonal peak abundance as documented by Jones & Anthony (1968), Cilek and Schreiber (1996, 1999) and Cilek et al. (1994), respectively. "TRED-NOT™ DEERFLY PATCHES" (6.4 × 14.2 cm double-sided adhesive-coated fabric patches Detex, Leroy, Michigan) were used in all evaluations. Although package directions indicated that one strip be affixed to the back of a hat, or cap, comparisons were made with a strip placed in front and back to determine if location affected patch trapping effectiveness. Patches were affixed to "baseball" caps made of nylon mesh with solid foam fronts (Cobra Caps, Bangladesh). Solid-colored white and black hats were compared to determine if color influenced fly collections. Controls consisted of similar mesh caps with patches affixed in same locations as treatments but covered with a non-adhesive backing strip (used by the manufacturer to prevent adhesive strips from adhering to the packaging material). Adhesive patches were used once per test. Evaluations were conducted in three geographically separate but similar habitats (at least 50 km apart) where only one fly species occurred. Each habitat consisted of abandoned commercial pine bottomland forests that contained a mixture of slash pine (Pinus elliotii Ex. Chapm.) magnolia (Magnolia grandiflora L.), and live oak (Quercus virginiana Mill.). Two non-continuous linear transects, each 30-m, were staked out in each location. One person walked the length of each transect back and forth (i.e. 60 m) and total number of deer flies attached to adhesive strip(s) recorded at the end of that transect. After this, aerial net (32 cm diam) samples were then conducted by the same person in the same area. Sampling consisted of continually swinging the net in figure "8" sweeps that started at ankles and ended above the head while walking each transect (Cilek and Schreiber 1996). This method (herein referred to as a standard) was used as a "best estimate" to quantitatively compare abundance of host-seeking flies in the immediate vicinity of the sampler (i.e. control) with those captured on patches (i.e., treatment). Net collected flies were counted at the end of each transect and released. Treatments and standards were replicated twice per habitat per species on ten different dates. Statistical Analysis Data were transformed using Ö×+1 prior to analysis and subjected to ANOVA (PROC GLM, SAS Institute 1990). A Student-Newman-Keuls test was used to determine differences (<0.05) in overall mean fly abundance relative to patch (treatment) vs standard (control) collections, patch location (front vs back), hat color (white vs black), and Chrysops species (Sokal and Rohlf 1981). These data sets did not include D. ferrugatus as none were captured on adhesive patches. All mean data in tables are untransformed means. Results Overall, significantly fewer host-seeking Chrysops (F = 343.07, df 1, 159; P < 0.0001) were collected from adhesive patches compared with the standard (Table 1). Adhesive patches captured approximately 26% of the fly population netted by the standard. Moreover, about 21% (17 out of 80) of the patches captured no flies at all. Patches affixed to the back of caps captured significantly more flies than those affixed to the front (F = 193.03 df 1, 159; P < 0.0001) (Table 1). No significant difference was observed in number of deer flies caught on white hats versus black hats (F = 0.81; df 1, 159; P = 0.37). Overall, significantly more C. vittatus (9.9 ± 0.9) were collected from the standard and patches compared with similar collections for C. celatus (5.4 ± 0.5) (F = 6 8.98, df 1, 159; P < 0.0001). This difference was probably related to location/habitat, and/or relative population size, rather than species preference. As stated earlier, no D. ferrugatus were trapped on adhesive patches regardless of cap color or patch location although they were collected in the aerial net sampling standard (mean 11.4 ± 0.5). Discussion The effectiveness of TRED-NOT™ DEERFLY PATCHES to trap deer flies was influenced by a fly's host-seeking behavior. Chrysops preferred the upper regions, especially the head, and were readily trapped on the patches. D. ferrugatus was not captured because this species primarily visited the lower extremities when trying to obtain a blood-meal (Fairchild and Weems 1973, McKeever and French 1997). Adhesive patches did capture both Chrysops species. Collection differences relative to patch location (i.e. front vs back) were interesting. Attraction of host-seeking deer flies to a person walking is well known (Bram 1978) but the orientation to the back of a human's head may result from a "downwind" plume of expired carbon dioxide. Carbon dioxide has long been recognized as a strong attractant for host-seeking Tabanidae (Bram 1978). Table 1. Mean (±SE) comparison of host-seeking Chrysops celatus and C. vittatum (pooled data) trapped by TRED-NOT DEERFLY PATCHESä, Florida 1998. Treatment n Mean flies ±SE I. Overall abundance adhesive patch 80 3.2 ± 0.4a standard 80 12.1 ± 0.7b II. Patch location front 80 3.0 ± 0.4b back 80 0.3 ± 0.1a III. Cap color white 80 1.5 ± 0.3a black 80 1.8 ± 0.3a Paired means within rows (I, II, and III) followed by different letters are significantly different (P < 0.05; SNK) after Ö×+1 transformation of means), untransformed means are shown in table. There appeared to be no cap color preference relative to number of Chrysops trapped on patches, although, it has been well documented that tabanids are generally attracted to dark objects (Bram 1978). Because the study area bordered well-known tabanid developmental habitats (i.e. bottomland swamps/marshes), color preference may have not been an important factor for short-range host seeking, when expired carbon dioxide (signalling a potential blood host) was present. In conclusion, TRED-NOTä DEERFLY PATCHES captured some of the Chrysops attracted to a person's head but did not completely trap all these pests visiting this body region. However, the amount of personal annoyance perceived from host-seeking deerflies is often relative. Therefore any device or method, including the one evaluated here, that removed or reduced host-seeking Chrysops (either percieved or actual) may be of general benefit to those seeking relief from such outdoor pests. References Cited Anderson, J. F. 1985. The control of horse flies and deer flies (Diptera: Tabanidae). Myia 3: 547-598. Bram, R. A. (ed.) 1978. Surveillance and collection of arthropods of veterinary importance. USDA. Animal Plant Health Insp. Serv. Agric. Handbook 518. Carlson, D. A. 1996. Insect repellents. Pp. 283-297. In: Pest management in the subtropics. Integrated pest management-a Florida perspective. Intercept Ltd., UK. Cilek, J. E., and E. T. Schreiber. 1996. Diel host-seeking activity of Chrysops celatus (Diptera: Tabanidae) in northwestern Florida. Florida Entomol. 79: 520-525. Cilek, J. E., and E. T. Schreiber. 1999. Diel host-seeking activity of adult Diachlorus ferrugatus (F.) (Diptera: Tabanidae) in northwestern Florida. J. Entomol. Sci. 34: 462- 466. Cilek, J. E., W. Ansell, and G. Medrano. 1994. Seasonal abundance of Diachlorus ferrugatus (Diptera: Tabanidae) in north Florida. J. Florida Mosq. Control Assoc. 65: 45- 48. Fairchild, G. B., and H. V. Weems. 1973. Diachlorus ferrugatus (Fabricius), a fierce biting fly (Diptera: Tabanidae). Florida Dept. Agric. Consum. Serv., Div. Plant Industry, Entomol. Circ. 139. Jones, C. M., and D. W. Anthony. 1964. The Tabanidae (Diptera) of Florida. USDA, Agric. Res. Serv. Tech. Bull. 1295. McKeever, S., and F. E. French. 1997. Fascinating beautiful blood feeders. Amer. Entomol. 43: 217-226. SAS Institute. 1990. SAS user's guide: statistics, version 6 ed. SAS Institute, Cary, NC. Schreck, C. E., K. Posey, and D. Smith. 1978. Durability of permethrin as a potential clothing treatment to protect against blood-feeding arthropods. J. Econ. Entomol. 71: 397-400. Sokal, R. R., and F. J. Rohfl. 1981. Biometry (2 ed.), W. H. Freeman and Co., San Francisco.