Apple orchards are host to many species of both pest and beneficial invertebrates. Many of the pest species can cause severe economic damage if populations are left unchecked. Within Northern Irish Bramley apple orchards only four species are deemed to be of economic importance; Panonychus ulmi
, Aculus schlechtendali
, Rhopalosiphum insertum
and Archips podana
. Little information exists on the current population status and economic damage potential of these four pests. The population levels of these species and their potential to cause economic damage on the Bramley fruit is therefore discussed in regard to current economic spray thresholds.