WAYS OF THE WILD.

Auckland Star, Volume LXII, Issue 2, 3 January 1931, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK

THE BRONZE BEETLE.

(By A. T. PYCROFT.)

Mrs. J. B. Mcintosh, of Corunna Avenue, Parnell, lias sent me several beetles for identification. Mr. E. F. Gourlay, of the Cawtliron Institute, informs me the specimens are New Zealand bronze beetles, Eucolaspis Brunnea. Mrs. Mcintosh's roses have suffered severely by the ravages of this pest, both the foliage and blooms being attacked. My friend wishes to knowhow these pests can be eradicated. 7 have before me a bulletin on the bronzf beetle, recently issued by the Depart ment of Scientific and Industrial Re search. This bulletin is the result oi two years' research work by Miss Averii M. Lysaglit, M.Sc., Cawtliron Institute Miss Lysaght states that this pest is widely distributed throughout the Dominion and is much more abundant id some localities than in others. It is to be found from sea level to an altitude of 2000 to 3000 feet. It is not known how far the beetles are able to fly. Probably the prevailing westerly winds have been a factor of considerable importance in their establishment in the important orchard areas of the East Coast. They certainly appear to migrato down the prevailing winds from a care-lessly-kept orchard to clean areas. The following fruits are attacked: —Apples, cherries, raspberries, blackberries, gooseberries. The foliage of seven native plants are also attacked. The beetle appears, however, to he practically omnivorous, and occurs in far greater numbers on introduced than upon native plants. The following introduced plants have been attacked: —Peach, acacia, eucalyptus, hollyhock, plum,, blackberry, black currant, gooseberry, apple, hawthorn, laurel, cherry, clover, mallow, elm, violet, geranium and rose. Damage Done. The worst damage done is that to the fruit of apples. The apples are attacked at a very early stage, the beetles nibble them and large scabs form, which result in abnormal growth, rendering the fruit unfit for export., Short-stemmed varioties, providing Shelter for the beetles, are the most readily attacked, thus Cos's Orange Pippin are an especial favourite, while the long-stemmed Delicious apples are scarcely damaged. Small fruits are damaged in different ways. The stems of the clusters 'of currants are so much eaten that the halfripe fruit withers and falls. Gooseberries are eaten through to the pulp. The leaves and fruit of cherries are attacked. With raspberries the halfformed fruit is eaten, but the most serious damage is that of defoliation, which may completely ruin the late crops. With regard to foliage, the beetle first attacks the soft tissues of young leaves on their lower surface, gradually eating through to the upper side, riddling the leaf with small holes. Considerable damage is done to the trees in this way, and plum trees may be completely defoliated. Rosebuds are eaten through in the same manner, the bloom being either disfigured by these perforations or completely consumed. The larvae live on grass roots, but they dp not appear to do any appreciable damage. The first of these beetles were collected by Sir Joseph Banks, who accompanied Cook to New Zealand in 1769. In 1868 there appears in volume one of the Transactions of the New Zealand Institute, a paper describing the damage then done by this beetle to young apples. The writer states that he first saw this beetle about 1863 and in 1868 its numbers had increased enormously, and in his orchard that season the dropping of the insects sounded like a shower of rain on the leaves. In general outline the adult beetle is a brown oval insect, barely a quarter of an inch in length, and is generally found on the under surface of leaves, and ip the early part of the morning and in the late afternoon are to be seen pairing and feeding/ In the middle of the day they are not to be observed in any number. This may be the time when they fly to different localities. When the tree or branch is jarred ever so slightly the beetles drop to the ground. They are able also to jump a considerable distance, owing to the enlarged hind legs, hence the name flea beetle is sometimes applied. Control. It has been estimated that a serious infestation results in the destruction of 40 per cent of the annual apple crop. The loss to the country is accordingly heavy, though it is impossible to assess the actual decrease in the value of apples exported. , As far as is known, biological control is limited to that effected by some predaceous larvae. Probably birds;do a certain amount of good when the soil is under cultivation. Serious infestations can be limited by careful and constant cultivation in the orchards, especially when the beetles are on the wing during November, December and January. For some years a Greytown orchardist has harrowed his orchard once a week through the summer. He states that the infestations are much less serious than they were, but he still loses a large percentage of his crop, especially with regard to the small fruits where such treatment is impossible. Clean farming in areas adjoining the orchards is important in limiting the habitat of the larvae, while removal of scrub and rubbish, which attract the adults, should be carried out with just as much caro. As regards chemical control, lead arsenate has been found to be of very little value. Calcium cyanide was effective in one ease, but the method of application is too costly. Mr. Gourlay states that no successful method of extermination has so far been found, and in the meantime, apart from clean farming, he is unable to recommend any control measures. Arsenical sprays, as far as we can see, are quite palatable to them, and except for the use of a substance which would destroy the plant, there does not at present appear to be any vulnerable point from which they can be successfully attacked. Cuckoo Notes. Mr. Ralph H. Ward, of Taupo, writes aa follows: — "After reading your account of a shining cuckoo seen with a chaffinch's egg in its bill, I am reminded of the following note in my diary: 'When we were at Waimarino last January, I was informed by Mr. Harry Wilcox that he had seen a shining cuckoo fly out of a pine tree hedge with an egg in its beak. The bird was only a few feet from him and the egg was plainly visible. Mr. Wilcox followed the bird for about a hundred yards, then lost it in the manuka.'" " Mr. Ward states that the bird had either robbed a nest or that it was on its way to deposit its own egg in another bird's nest. In any case, the observation is interesting, as another instance of this bird's ability to carr£ an egg in jtj bilL -i