Konstantinov S A, Veselkin A G
Parazitologiia. 1989 Jan-Feb;23(1):3-10.
The effect of group was studied on cattle being attacked by horse flies of three genera. The method of simultaneous registrations of attacking horse flies in herds of 8 to 100 animals and on single cows was used. It has been shown that the effect of group reveals itself only when animals in the herd reach a certain minimum number, the effect rate depending on peculiarities of attacking of a given species of bloodsuckers, such as a part of responding individuals, distance of an attack, duration of contact with an object. These parameters tend to change with increasing number of animals in the herd. Therefore differences in the intensity of attacks on herds with different cattle stock cannot be explained proceeding only from differences in the occupied areas. The number of attacking horse flies decreases from the periphery of the herd to its centre and is not the same in different parts of the periphery. The effectiveness of attacking, ie the part of sucking individuals of a given species (genus) from the number of horse flies attacking for a definite period of time, is the highest in a large herd and increases in its ranges from the periphery to the centre. This dependence leads to a more even distribution of sucking individuals as compared to attacking ones.
研究了群体对遭受三种属厩螫蝇攻击的牛的影响。采用了在8至100头动物的牛群以及单头牛身上同时记录攻击厩螫蝇的方法。结果表明，群体效应只有在牛群中的动物达到一定最低数量时才会显现出来，效应率取决于特定种类吸血者的攻击特性，如反应个体的比例、攻击距离、与物体接触的持续时间。这些参数往往会随着牛群中动物数量的增加而变化。因此，仅从占用面积的差异来解释对不同牛群数量的牛群攻击强度的差异是无法解释的。攻击厩螫蝇的数量从牛群外围向中心减少，且在外围的不同部位也不相同。攻击的有效性，即在一定时间段内攻击的厩螫蝇数量中特定种类（属）吸食个体的比例，在大群体中最高，并从外围到中心在其范围内增加。与攻击个体相比，这种依赖性导致吸食个体的分布更加均匀。
