We. Ralley et al., INDIVIDUAL AND GROUP-BEHAVIOR OF PASTURED CATTLE IN RESPONSE TO ATTACK BY BITING FLIES, Canadian journal of zoology, 71(4), 1993, pp. 725-734
In 1983 and 1984 the impact of biting flies on the behaviour of pastur
ed heifers was determined for two herds of cattle in eastern Manitoba.
One herd received a whole-body spray of cypermethrin (0.1% active ing
redient) per animal every 14 days and the other was an untreated contr
ol herd. Horse flies (predominantly Hybomitra spp.) were the most both
ersome to the heifers, with peak numbers of flies mostly occurring bet
ween 11:00 and 15:00. Horse flies and mosquitoes (Aedes spp.) caused a
n increase in individual avoidance responses of the animals, including
head tosses, foot stomps, ear flicks, and tail switches. In 1983, the
numbers of tail switches and foot stomps were significantly higher in
the control herd, and in 1984, the numbers of head tosses were signif
icantly higher in the treated herd. The formation of grazing lines and
bunching were the most prevalent herd responses to biting fly attack.
Stampeding was observed only under the most extreme mosquito pressure
. Using canonical discriminant analysis on behaviour data, significant
differences were identified in behaviour before and after July 10, 19
84. Similarly, animals treated with cypermethrin displayed significant
ly fewer behavioural responses to biting fly attack than nontreated an
imals.