Location: Mosquito and Fly Research Unit
Title: Spatial distribution, seasonality and trap preference of stable fly, Stomoxys calcitrans L. (Diptera: Muscidae), adults on a 12-hectare zoological park Authors
|Ose, Gregory -|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 26, 2013
Publication Date: N/A
Technical Abstract: Stomoxys calcitrans (L.) is a biting fly of extreme economic importance and can cause adverse economic effects on host animals. Within zoological parks, hosts may include practically any accessible animal (e.g., sheep, goats, cows, camels, equines, primates, canids, and felids). In many animals, e.g. cheetahs and wolves, stable fly feeding creates open lesions on the ear tips, typical of the damage seen with dogs. Although stable flies are known to be a problem in zoological parks, we are only familiar with the study by Rugg (1982) in Australia. If the seasonality and distribution of stable flies in zoological parks were known, this could facilitate control efforts. The primary objective of this study was to evaluate the efficacy of blue-black cloth targets modified into sticky traps (BCTs) to capture S. calcitrans. BCTs were compared with Alsynite fly traps (AFTs) at 10 selected sites for 15 weeks at a 12-ha zoological park in Reston, VA, near Washington, DC. Results elucidate relative trap efficacy, and stable fly distribution at the zoo and seasonality in northern Virginia. A total of 12,557 adult stable flies were captured during the 15-wk study. AFTs captured approximately 4 times more stable flies than BCTs except at site 5, which was inside of the poney barn. Significantly more stable flies were captured at sites 9 and 10 (goats) than at the other sites during the study and sites 9 and 10 were ranked either first or second (out of 10 sites) in numbers of flies captured for 12 and 10 weeks, respectively. Sites most attractive to stable flies after sites 9 and 10 were site 5 (the pony barn), sites 1 and 2 (east end of the paddock), and sites 7 and 6 (the dumpsters). Significantly fewer flies were captured at sites 4 and 3 (south side of paddock) and site 8 (porcupine) than elsewhere on the zoo property. If trap type and site are overlooked, significantly more stable flies in 3 significance groupings were captured during weeks 1-7 than during the remainder of the study. Stable fly populations increased during the first 2 weeks of the study, peaked during the third week (13 Jun), began to decrease gradually through week 7, then dropped into single digits after week 9. In summary, the BCTs did not catch enough stable flies to be useful in a trapping program. The attractive qualities of the cloth targets are essentially eliminated by wrapping them in sticky sleeves. The sites at the zoo where the most stable flies were consistently captured were at the goat exhibit. This was either because of the attractive nature of the exhibit or because flies tended to aggregate at this exhibit before moving farther into the zoo. During the study, stable flies peaked in June and then began to decrease in numbers. This indicates that fly interventions should be in place in early May as adults begin to appear. This study demonstrates how urban zoos can be aggregation sites for adults of S. calcitrans. Although the Reston zoo has few true exotic animals, it has a collection of animals that are attractive to stable flies, similar to the herds of cattle and horses seen in more rural areas. Management systems for zoos must be developed so the animals and visitors can be protected from the painful bite of the stable fly.