11

H.—26

Cateepillae. The gooseberry is also attacked by a caterpillar bearing a strong resemblance to the species which infests the currant, but further information is required before it can be identified. It may be treated in a similar manner.

HOP. Bed Spider (Tetranychus telarius). ' This minute spinning-mite is a troublesome pest not only to the hop but to the apple and other fruit-trees in many parts of the colony. I have observed it in all the districts except Taranaki, Westland, and Otago, and it would doubtless be found to occur in the first and last if searched for. Unless occurring in large numbers it may easily pass unnoticed by a casual observer. In the autumn months it forms dense reddish or brownish patches on the stem and leaves, and as winter approaches seeks the shelter of crevices, especially near the base of the plant. It increases rapidly during periods of drought, but is rarely able to cause serious injury in moist seasons. Its structure cannot be made out without the assistance of a pocket-lens, when the minute speck is found to consist of an oval body, differing from that of an insect in having four pairs of legs, two pointing forwards and two backwards ; it also has a suctorial mouth and a short pair of antenn®. Plants infested by this mite are characterized by curled, shrivelled leaves, which assume a brown or rusty hue, changing to a dull yellow before they fall. On examination the under-surface of the leaves is found to be covered with a web, which affords shelter to the mite. The eggs are thickly attached to the delicate threads of the web, and only require about eight days before hatching, so that new colonies are formed with great rapidity.

Prevention and Bemedy. Frequent syringing with cold water is sufficient to prevent this troublesome pest from becoming established. Dusting sulphur over infested trees is an effectual remedy. Mr. Goodhue's preparation of sulphur and lime, used as a thin liquid and applied with the syringe or garden-engine, is excellent and inexpensive; or the powder may be used, although it would be less easy of application, and for this purpose less effective. A thin solution of soft-soap containing sulphur might be used with advantage. Sulphur and lime might be dusted over the surface of the ground at the base of the stem. In exceptionally-bad cases it may be found advisable to wash the trunk and main branches of affected fruit-trees with a thin solution of soft-soap containing sulphur and lime. In late, dry seasons the hop suffers severely from the ravages of this pest, the crop being deteriorated in quality and diminished in quantity. The hop-aphis (Phorodon humuli) has not been observed in New Zealand.

LEMON, OEANGE, CITEON, ETC. 1. FOOT-BOT. This disease is attended with more serious results than any to which the lemon and citron are liable in this colony. The first indication is afforded by the leaves turning yellow and falling; in a short time the branches are partially denuded, and, as the luxuriant growth of young shoots is severely checked, the tree assumes a straggling habit. At the same time the affected tree usually produces flowers in profusion, and the flowers develop fruit. Although diseased, it may continue in a fruit-bearing condition for several years, and even carry heavy crops ; but with the progress of the disease the fruit becomes gradually reduced in size, and at length the power of maturation is lost. In the last stage the tree becomes almost leafless, yet still develops flowers, although the pollen is usually abortive, and the ovaries do not become fertilized. It may linger in this condition for several years. The disease commences with the decay of the minute fibrils of the root; the fibres are next affected, and the decay extends to the larger arms ; the epidermis peels off in flakes or rots away, when the decay spreads to the woody parts, and, after attacking the bark of the collar, makes its appearance above ground, ascending the stem for a foot or more, the decaying bark emitting a nauseous odour, and falling away in pieces; even before it falls, and while apparently sound, it may often be rubbed off by the fingers. The bark is sometimes attacked by fungi, but their inroads are simply due to the progress of the disease, which has prepared a suitable nidus for the parasite, and must not be mistaken for the cause.* If the decay of the bark is confined to one side of the stem the plant may continue to produce fruit for years, but if the entire circumference is affected, so that the outer layers of tissue are destroyed, death speedily ensues.

* la this stage I have seen a trunk clothed on one side with a dense growth of Hirneola polytrioha, the fungus so much in demand amongst the Chinese.