Three Years in Western China / A Narrative of Three Journeys in Ssu-ch'uan, Kuei-chow, and Yün-nan

by Sir Alexander Hosie

Although the province of Ssŭ-ch’uan has always been recognized as the chief breeding country of the white wax insect, and the great field for the production and manufacture of the white wax of commerce, the wax is found and manufactured in several other provinces, notably in Kuei-chow, Hu-nan, Fuh-kien, Chê-kiang, and An-hui, and in reality exists in small quantities from Chih-li in the north to the island of Hainan in the south of China.

INSECT WHITE WAX.

In the spring of the year 1884, I received instructions from the Foreign Office to procure for Sir Joseph Hooker dried specimens of the foliage and flowers of the trees on which the insects are propagated and excrete the wax; specimens of the twigs incrusted with the wax; samples of the cakes in the form in which the wax occurs in commerce; and Chinese candles made from the wax. I was also instructed to obtain, if possible, information on the whole subject of wax production, in addition to that furnished in Mr. Baber’s Report. My report on this interesting subject was published as an Appendix to a Parliamentary Paper in February, 1885; but at the time that that Paper was written and despatched I had not completed my investigations, and, unfortunately, some further notes which I sent to the Foreign Office were too late for publication with the Parliamentary Paper. As, therefore, the information already made public is but fragmentary, and as there are some mistakes into which, owing to my distance from scientific advice, I have fallen, I think it right that I should take the first opportunity that has offered since my arrival in England of supplying details and correcting mistakes.

If we glance at a map of China, we will find that the upper Yang-tsze, or Golden River as it is there called, is joined by a river called the Ya-lung or Ta-ch’ung, a little to the west of the one hundred and second degree of longitude, and that the united waters flow south-east below the twenty-sixth degree of latitude, and again turn north, forming, as it were, a loop towards the province of Yün-nan. Between these two rivers flows another smaller river called the An-ning, which joins the Ya-lung before the latter unites with the Golden River. The An-ning flows down a valley called the valley of Chien-ch’ang, the local name of Ning-yuan Fu, the principal town within the river loop. This valley, the northern boundary of which is lat. 29° 20′, and southern boundary, lat. 27° 11′, is the great breeding ground of the white wax insect. In the valley, which is about 5000 feet above the level of the sea, and on the hills which bound it, there is one very prominent tree, called by the Chinese of that region the Ch’ung shu, or “Insect Tree.” It is known under different names in the same province of Ssŭ-ch’uan; it is called the Tung-ching shu, or “Evergreen Tree,” and the Pao-kê-ts’ao shu, or “Crackling-flea Tree,” from the sputtering of the wood when burning. It is an ever-green with leaves springing in pairs from the branches. They are thick, dark-green, glossy, ovate, and pointed. In the end of May and beginning of June, the tree bears clusters of small white flowers, which are succeeded by fruit of a dark purple colour. From the specimens of the tree which I forwarded to Kew Gardens, the authorities there have come to the conclusion that it is Ligustrum lucidum, or large-leaved privet.

In the month of March 1883, I passed through the Chien-chang valley; but, knowing that Mr. Baber had already furnished a report on the subject of white wax, I confined myself to a mere cursory examination of the insect tree. In that month, however, I found attached to the bark of the boughs and twigs, numerous brown pea-shaped excrescences. The larger excrescences or scales were readily detachable, and, when opened, presented either a whitey-brown pulpy mass, or a crowd of minute animals like flour, whose movements were only just perceptible to the naked eye.

THE WHITE WAX INSECT.

In the months of May and June 1884, when I was called upon for more detailed information on the subject, I had the opportunity of examining these scales and their contents with some minuteness in the neighbourhood of Ch’ung-k’ing, and also within the jurisdiction of Chia-ting Fu, the chief wax producing country in the province of Ssŭ-ch’uan. Ten miles to the east of Ch’ung-k’ing, I plucked the scales from the trees—the Ligustrum lucidum—and on opening them (they are very brittle) I found a swarm of brown creatures, crawling about, each provided with six legs and a pair of antennae. Each of these moving creatures was a white wax insect—the coccus pe-la of Westwood. Many of the scales also contained either a small white bag or cocoon covering a pupa, or a perfect imago in the shape of a small black beetle. This beetle is a species of Brachytarsus. For this information I am indebted to Mr. McLachlan, to whom the insects forwarded by me to Kew were submitted for examination.

If left undisturbed in the broken scale, the beetle, which, from his ungainly appearance, is called by the Chinese the niu-êrh, or “buffalo,” will, heedless of the cocci which begin to crawl outside and inside the scale, continue to burrow in the inner lining of the scale, which is apparently his food. The Chinese declare that the beetle eats his minute companions in the scale, or at least injures them by the pressure of his comparatively heavy body; and it is true that the scales from Chien-ch’ang in which the beetles are numerous are cheaper than those in which they are absent. But, although Chinese entomology is not to be trusted, there is, after all, a grain of truth in the statement. The genus brachytarsus is parasitic on coccus, and the grub, not the imago, is the enemy of the white wax insect. The Chinese, therefore, are not far wrong when they pay a lower price for the beetle-infested scales.

When a scale is plucked from the tree, an orifice where it was attached to the bark is disclosed. By this orifice the cocci are enabled to escape from the detached scales. If the scales are not detached, but remain fixed to the bark, it may be asked, “How are the cocci to find their way out?” It has been stated by entomologists that they know not of any species of the family Coccidae that cannot find their way from underneath the mother-scale without assistance. This may also hold good in the present case; but all I contend for is, that the cocci pe-la take eager advantage of the opening pierced from inside the scale by the beetle to escape from their imprisonment. In addition to the branches with intact scales, which I carried home with me for examination, I closely observed the scales that had been left undetached on the ligustrum, and found only one orifice in each scale—a circular hole similar in every respect to the orifice pierced by the beetles in the scales which I had beside me. At Chia-ting I examined scales that had been brought from the Chien-ch’ang valley. They were suspended on the wax trees and were for the most part empty. They had only one orifice—that by which they had been attached to the bark of the ligustrum, and by which the cocci had no doubt escaped. In the very first scale I opened there, however, I found a solitary beetle.

The Chien-ch’ang valley is the great insect-producing country; but the insects may be, and are, propagated elsewhere, as in Chien-wei Hsien to the south of Chia-ting Fu, and even as far east as Ch’ung-k’ing. These insects are, however, declared by the Chinese to be inferior, and they fetch a lower price.