(1) A complete review of the classification and status of the Siricid wood-wasps occurring in Britain is given in this paper.

(2) The biology of S. cyaneus, F., which has been studied at Tubney Wood, Oxford, during the past two years, is described, together with supplementary notes on S. gigas, L.

(3) A study of the forest relations of S. cyaneus at Tubney has shown that this species cannot be considered a primary enemy of healthy green trees. Trees which are favoured by Sirex are usually markedly unhealthy from one cause or another. At Tubney unsuitable soil conditions were the principal factors.

(4) Sirex and Tetropium gabrieli, Weise, the larch longicorn beetle, may occur almost simultaneously as indicators of pathological conditions in larch woods.

(5) In North Devon Fomes annosus, a root fungus, was the predisposing factor in the case of silver fir attacked by Sirex.

(6) Both S. cyaneus and S. gigas may occur in the same tree. This was found to be the case at South Molton, North Devon, in silver fir. S. gigas appears to prefer larger trees, and it is not present in the larch at Tubney Wood, which is in the pole stage.

(7) The primary object of the work was to acquire a knowledge of the parasites of Sirex, Rhyssa persuasoria, L., and Ibalia leucospoides, Hochenw. Both parasites were studied at Tubney, and have already been dealt with (Bull. Ent. Res. xix p. 67, 1928).

(8) It is considered probable that the results obtained in the above study will throw some light on the Sirex problem in New Zealand. Emphasis is therefore laid upon the importance of studying the silvicultural conditions in relation to Sirex attack.

Head antero-posteriorly short; occipital edge sharp; from in front broader than long; eyes moderate, bare; inner orbits a little convergent ventrally; genal space long; face wide; toruli high up, distinctly above the base line of eyes and only slightly below the mid point between the anterior ocellus and mouth-edge. Labrum conspicuous, simple, transverse; mandibles similar, pear-shaped, produced apically into a fine short incurved spine-like tooth. Maxillary palpi three-jointed; labial palpi two-jointed. Inner aspect of galea and opposed side of ligula densely and finely pilose (N.B.—The first maxillary joint has an extremely narrow ill-defined annular base which may represent an obsolete joint). Antennae ten-jointed; scape, pedicel, ring joint, 6 in funicle, and solid club. Scape simple, cylindrical, reaching to about level of anterior ocellus; pedicel short; 1st funicular longer than either the 2nd or the pedicel; funicle (distally) and club somewhat flatly expanded; sensoria numerous, very narrow, short and low, not produced distally. Thorax: mesoscutum separated from scutellum by the broadly meeting axillae, distinctly shorter (measured from its posterior edge to that of pronotum) than scutellum; the latter ending over the metanotum in a short truncate plate; mesopleura posteriorly truncate. Propodeon, smooth between the spiracles; on the middle third are three linear longitudinal thickenings of the integument, the latter pair lying in shallow furrows. Round the spiracles and on the pleura the surface is densely covered with short bristles. Wings: forewings with apical fringe and completely pilose, except on the linea calva. Neuration to about one half. Radius emitted before the costa, long, gently curving towards and subequal to the postmarginal; two bands-one across radius, the other apical. Legs: mid and hind legs elongate, subequal and half longer than fore legs. Hind tibiae widened, with two unequal spurs. Tarsal ungues of all legs markedly unequal, the posterior shorter and more abruptly curved apically than the anterior. Abdomen broad; 1st visible tergite (iii) about half longer than 2nd (iv), 3rd–7th gradually decreasing in length. The last three sternites densely set with short bristles. Ovipositor weakly chitinised.

Colour.—Head irregularly punctate above, yellowish green, the tylus apically and the disc of vertex tinged with brownish yellow; eyes dark grey, ocelli each surrounded on inner side with narrow red rim; head below and rostrum yellow, rostral commissure and apex brownish black. Antennae dark brown, the first segment pale below, shading to black towards the apex of each segment; extreme base of second and third segments and a broad sub-basal annulation on the fourth segment, pale yellow; apex of fourth segment brown. Pronotum dull yellowish green, becoming deeper posteriorly, regularly covered (except for the calli) with small but deep fuscous punctures, which are more dense along the inside of the reflexed lateral margins; extreme humeral angles brown. Propleura yellowish green, punctate, only the outer punctures fuscous. Scutellum dull yellowish green, deeper towards apex, regularly covered with feebly infuscate deep punctures; extreme apex yellow, impunctate. Meso- and meta-pleura yellow, tinged with green towards the basal lateral angles of the pleura, which are rugosely punctate; sterna impunctate, sparsely covered with short erect pale hairs. Hemielytra more or less regularly punctate in series between the veins, dark brown shading to dull blood-red towards apex of corium; veins (including costal and apical margins of corium) yellow, more or less suffused on the disc of elytra with olive-brown; membrane black, the veins olivebrown. Legs yellow, apices of tarsi and claws brown. Abdomen yellow, sparsely covered with short pale obscure hairs.

The following descriptions and notes are based upon material received from H. Bennett Johnston, Assistant Government Entomologist, Wad Medani, Sudan, Africa.

During 1926 and subsequently in September 1927, two species of gall-mites were found on lilac, shoots of which were obtained from private gardens at East Mailing and Sevenoaks, Kent.

♂♀. Red; thorax dark red; orbits, vertex, ocellar tubercle, almost white; wing veins very dark; costal veins and stigma yellowish red, as are often the tibiae and tarsi; abdomen somewhat darker towards apex.

1. Insect pests of the blackberry (Rubus fruticosus, L.) are being studied with a view to discovering insects likely to assist in the biological control of this noxious plant in New Zealand. Habrosyne derasa, L., was the first species brought under observation.

2. Investigations revealed an apparently unique method of oviposition, the eggs of H. derasa being deposited on the points of the serrated leaf-edges of the blackberry.

3. Newly hatched larvae of this moth have been simultaneously tested as to their ability to feed and thrive on the following plants:—Blackberry (normal host), loganberry, raspberry, rose, apple, cherry, plum, pear, and currant. They thrived equally well on the first three plants. Ten-day-old, blackberry-fed larvae, when transferred to rose and apple, fed and some ultimately pupated. Similar larvae transferred to cherry, plum and pear fed sparingly but did not succeed in pupating.

4. When a choice of food-plants was given, feeding was concentrated on blackberry, loganberry and raspberry.

With the exception of a few isolated records nothing is known of the Coccidae of Southern Rhodesia. Dr. Brain has made a study of the family in the Union of South Africa, the results of which are to be found in his excellent Monograph,* and Prof. Newstead has described many interesting and hitherto unknown forms from Central Africa in the earlier volumes of this Bulletin.

In the grounds of the Medical Research Institute at Yaba, near Lagos, some 200 yards north-east of the laboratories there is a swamp, roughly circular, its diameter being about 20 yards. Until the present year, since first coming under observation in 1908, it has been definitely a pond, formerly used for watering cattle; small in the dry season, it sometimes assumed the dimensions of a lake in the rainy season. While it was a pond it harboured at least three different kinds of fish, and except for a few Anopheline larvae on rare occasions it was not a suitable breeding-place for mosquitos owing to the activities of the fish.

In the banana-producing area of north-eastern Colombia and in certain parts of Central America, the skins of the banana fruits are sometimes attacked by insects, which gnaw the epidermal tissues and cause unsightly, blackened scars. In some districts so much fruit is thus affected that the matter has become of considerable economic importance; measures intended to reduce the injury have been initiated and studies of the causal organisms commenced.

The paper is an accouunt of a year's work on the bionomics of Glossina morsitans in the Koalib Hills, Nuba Mountains Province, Sudan, a small area which lies 200 to 300 miles north of any other locality where G. morsitans occurs.

The fly is restricted at all times of the year to the hills, where it was found to breed in rock-shade, and is always closely associated with the Nuba inhabitants and their animals, even frequenting villages and their environs. The cattle, goats and sheep are resistant to trypanosomiasis, but all have been proved to be carriers of the disease.

Wild fauna is scarce in and near the area, and the fly is probably entirely dependent for food on the Nubas and their animals.

An experiment in direct control in a small group of hills is described. It was found impossible to reduce the fly beyond a very low minimum, but the method would be of use as a routine control in small hills.

Experiment with fly lime indicated that the shiny appearance of the lime deterred the majority of flies from alighting upon it.

Marked flies remained in the bush for ten to fifteen days during the rains, but eventually returned to the hills. Given a constant food supply there seems no reason why many parts of the bush, otherwise suitable, should not harbour fly during the rains and early dry season.

The author is indebted to Major R. G. Archibald, C.M.G., D.S.O., M.D., Director of Wellcome Tropical Research Laboratories, and to Mr. H. H. King, Government Entomologist, for much assistance and advice, also to the Provincial and District Officials for help in many ways.

The biology of Rhyssa persuasoria, L., and of Ibalia leucospoides, Hochenw., has already been sketched in a preliminary paper published in this Bulletin (xix, pp. 67–77, pl. iii, 1928) in collaboration with Mr. R. N. Chrystal, of the Imperial Forestry Institute. The following observations were made by the writer chiefly at the Farnham House Laboratory, during the spring and summer of 1928, and are gathered together in view of his departure from England. The work of collecting and rearing supplies of Rhyssa and Ibalia for shipment to New Zealand, for the biological control of Sirex nodilio (juvencus), has been continued on a larger scale. The present notes were made incidentally during this work and are arranged under nearly the same headings as in the previous paper, to which they are supplementary. One error needs correcting. It was stated (on p. 75) that the larch (Larix europaea, D.C.) is indigenous, though actually planted in the Oxford locality mentioned. As a matter of fact, of course, larch, though Palaearctic, is not indigenous to Britain.