The Pamphlet Collection of Sir Robert Stout: Volume 14
In old hop plantations it is somewhat difficult to prevent the attacks of the click beetle, especially in small fields and those surrounded with woods and hedgerows. Where hop plantations are in masses the injury from this source is usually comparatively inconsiderable. It is most desirable to keep the land clear from weeds upon which the insect might deposit eggs; also the out-sides well cleaned and closely brushed and free from grass and nettles. This weed is, it should be stated, very attractive to many insects hurtful to hop plants, and should therefore be studiously eliminated from their neighbourhood.
Caustic substances dug in round the plant-centres will prevent, or, at all events, retard an attack from outside or below, but will not prevent the action of wireworms generated close to and upon the plant-centres. Opening a trench in the autumn, after the poles are down, and forming a ring close round the plant-centres, and putting in earth, ashes, or sawdust saturated with paraffin oil is an excellent plan in the case of plantations that are badly infected. Hard frosts do not affect wireworms since they go down into the earth to a depth of nearly 15 inches.
Before planting pasture land or meadow land with hop plants it is most necessary that it should be kept well fed down by sheep up to the time of ploughing in the autumn. With regard to arable land taken for hop plantation, this should be freed from weeds during the summer. A crop of white mustard might be taken with much advantage before planting, as the wireworms cannot live in this, and would be starved out.
Planters who suspect the presence of wireworms very frequently set a row of potatoes between the rows of hop plants in order to draw the wireworms from the young hop plants.
Birds should be encouraged in infested fields. Rooks devour quantities of these insects. Pheasants, partridges, and many small birds also greedily eat them. Moles are especially devoted to them. Instead of every farming man's and every farming boy's hand being set against moles, instigated thereto by a page 17 reward of 2d. per tail, farmers, and hop planters in particular, should rather encourage their increase. In the United States the State entomologists recommend the protection of the disagreeable skunk on account of the service it renders the hop planter by discovering and destroying the grub of the otter moth, which attacks the roots of the hop plants, and many other insects upon which it feeds. The barbarous traps for killing moles should be prohibited, and when it might be necessary to banish moles, in gardens and where small and delicate plants are cultivated, traps might be made for catching them alive and transporting them to insect affected spots.*
In a young hop plantation this year potatoes were set between the rows of plants. Upon hoeing the potatoes it was found that moles had made a subterranean gallery up almost every row of potatoes in search of their favourite food.
* Miss Ormerod states that special traps. "mole pots," are made in Gloucestershire for catching moles alive. These are earthen jars, which are let into the ground, level with the runs of the moles. They fall into these and cannot get out, and may be taken out alive.