 Since common starlings eat insect pests such as wireworms , they are considered beneficial in northern Eurasia , and this was one of the reasons given for introducing the birds elsewhere . Around 25 million nest boxes were erected for this species in the former Soviet Union , and common starlings were found to be effective in controlling the grass grub Costelytra zelandica in New Zealand . The original Australian introduction was facilitated by the provision of nest boxes to help this mainly insectivorous bird to breed successfully , and even in the US , where this is a pest species , the Department of Agriculture acknowledges that vast numbers of insects are consumed by common starlings . 
 Since common starlings eat insect pests such as wireworms , they are considered beneficial in northern Eurasia , and this was one of the reasons given for introducing the birds elsewhere . Around 25 million nest boxes <a href='uninflect' title='1'><mark>were</mark></a> erected for this species in the former Soviet Union , and common starlings <a href='uninflect' title='2'><mark>were</mark></a> found to be effective in controlling the grass grub Costelytra zelandica in New Zealand . The original Australian introduction was facilitated by the provision of nest boxes to help this mainly insectivorous bird to breed successfully , and even in the US , where this <a href='drop_aux' title='3'><mark>is</mark></a>a pest species , the Department of Agriculture <a href='uninflect' title='4'><mark>acknowledges</mark></a> that vast numbers of insects are consumed by common starlings . 
Since common starlings eat insect pests such as wireworms , they r considered beneficial in northern Eurasia , and this was one of da reasons given for introducing the birds elsewhere . Around 25 million nest boxes was erected fa this species in the former Soviet Union , and common starlings was found to be effective in controlling the grass grub Costelytra zelandica in New Zealand . The original Australian introduction was facilitated by tdaprovision of nest boxes to help this mainly insectivorous bird to breed successfully , and even in the US , where this a pest species , the Department of Agriculture acknowledge that vast numbers of roaches are consumed by common starlings .