♂♀. Integument black, with brown scaling ; the pronotum with two indefinite paler stripes ; the elytra with vague paler markings which sometimes form a very ill-defined band across the middle, broadly interrupted at the suture.

Head with the forehead divided into four areas by three deep sulci, the straight median one slightly narrower than the others, which are shallow in front and much deeper behind, curving at first inwards and then transversely outwards, so as to separate the lateral areas from the vertex ; the frontal areas of approximately the same width anteriorly, the median pair broader in front than behind and continuous with the vertex, the outer pair dilated and obtusely elevated behind, not projecting over the eyes ; the surface, when denuded of scales, with numerous minute punctures and sparse larger ones ; the eyes strongly convex, deepest behind the middle. Rostrum transverse (3 : 2), almost parallel-sided, the transverse basal incision very broad and deep ; the dorsum with a low median carina which begins to fork at or a little beyond its middle, and which at the base is as high as the narrowly separated areas on each side of it ; adjoining the carina a more or less deep curved impression, and a shallow oblique furrow on each side in the basal half ; the posterior margin of the epistome not higher than the median carina. Antennae with joint 1 of the funicle twice as long as 2, 3–7 a little longer than broad, 3–5 of equal width, 6 and 7 each becoming wider. Prothorax transverse (8 : 5), very strongly rounded (almost obtusely subangulate) at the sides, widest well before the middle, and scarcely constricted near the apex ; the apical margin truncate or shallowly sinuate, the base truncate ; the dorsum very convex longitudinally, highest at the middle, coarsely and confluently foveate, and with an abbreviated low median carina ; the scales small, subcircular and closely placed ; the setae short, scale-like and recumbent.

During the study of the Nearctic Tachinidae it became obvious that, in order to secure an adequate idea of the relationships of the various genera, it would be advisable to study representatives of the family from all parts of the world, and requests for African material met with hearty response from several sources. The extensive collection made by the American Museum of Natural History Congo Expedition has already been dealt with, and the report will appear elsewhere. Mr. H. K. Munro, of Pretoria, South Africa, has forwarded his entire collection with the request that it be worked over, since very few of the species were determined. Dr. Guy A. K.Marshall, Director of the Imperial Bureau of Entomology, has also been kind enough to forward a large amount of material, and a great deal more has been promised from other sources. It was originally intended to prepare a synopsis of the South African Tachinidae preparatory to a more detailed study. However, the large number of species and genera represented in the thousands of specimens at hand makes such an undertaking so extensive that it is deemed advisable to report upon certain genera or larger groups in order that most of the material may be returned to the owners, retaining such specimens as may be necessary for further study.

Notwithstanding the undoubted economic importance of the Tabanidae, which is second only to that of the Culicidae among blood-sucking insects, our information concerning the habits and life-histories of Canadian species is very meagre indeed. What knowledge we possess has been chiefly derived from the studies made by entomologists of the United States, who have discussed among others some of the species that occur on both sides of the international boundary. Of the species dealt with in the present paper, Hart (1896, p. 227) observed oviposition by Chrysops moerens, Walk., in Illinois, and a description of the egg was given. This brief account was supplemented by Hine (1906, p. 36) in Ohio, who published a detailed description of the process of oviposition of the same species and was, moreover, successful in rearing Tabanus lasiophthalmus, Macq., from the egg to the adult—the first time that this had been accomplished for a Tabanid species. Jones & Bradley (1923, p. 310), working in Louisiana, discovered in the course of their investigations on the Tabanidae a single larva of T. reinwardtii, Wied., from which an adult was reared, but no description of the larva was offered. Webb & Wells (1924) published an account of the partial life-cycle of T. phaenops, O.S., including descriptions of the early stages, as well as of T. insuetus, O.S., in which all stages other than the egg were obtained and described.

Aëdes (Stegomyia) variegatus (Dol.) is a widely-spread species in the Australasian region, and under its synonym of Stegomyia pseudoscutellaris is well-known as the carrier of filaria in Fiji and Polynesia in general. Up to the present the existence of definite local variations has not been suspected, partly because the species itself has been regarded as the Australasian representative of the Oriental A. albopictus (Skuse). Recently, however, Dr. P. A. Buxton has discovered that larvae from Samoa and the New Hebrides differ in a constant manner, and at his suggestion I have scrutinised the whole series of specimens of this species in the British Museum. This examination appears to show that there are at least five distinct varieties, distinguishable by small differences of colour and also by the male hypopygium, especially in the form of the basal lobe of the side-piece. The characters are fairly well defined, but are perhaps best treated as varietal rather than specific, especially as their significance appears to be mainly geographical.

Examination of a limited number of specimens of Leptoconops occurring in America indicates that at least several undescribed species exist in North and Central America and the West Indies. Paucity of material, however, prevents any detailed study of the group for the regions mentioned. Two members of the genus have, through their biting tendencies, made themselves decidedly obnoxious in the sections where they occur.

Since the appearance of the first paper in this proposed series our attention has been called by Mr. E. E. Green to the desirability of developing a terminology for the various structures of the Diaspid scales which shall be more satisfactory than that at present in general use. We are entirely in accord with his view that many of the terms at present employed are not suitable and that they need to be replaced by others of more precise application.

We have decided, however, not to make any attempt at the development of such a terminology at the present time, the controlling reason for this decision being found in the belief that the morphology of the Diaspid scales—not to speak of the other groups—is still too insufficiently understood to permit the formulation of a terminology which shall be at all enduring. It is our belief that any system now devised is too likely to require extensive later modification. This is certainly the case with one recent attempt thus to devise such a system, an attempt that fails of its purpose because of lack of knowledge. From this point of view it seems best to leave the question of such a terminology until such time as at least a large proportion of the Diaspid types have been examined in greater detail.

For the present we shall content ourselves with the use of common and, in general, well understood terms or with simple descriptive phrases. An exception will be made in the case of certain terms which it seems well should be eliminated as soon as possible. One such term is the expression “ pygidial lobes ” for the usually paired structures of the pygidial margin. For these Mr. Green suggests that the term “ trulla,” which has already been employed by some authors, is better. Another substitution suggested by Mr. Green is that of “ perivulvar ” to designate the cluster of pores about the genital opening, and this we shall utilise.

The following description is based on material submitted for determination by the Imperial Bureau of Entomology.

The observations here recorded were made during the rearing of Alysia manducator, Panz., as a parasite for Australasian sheep-maggots by the Imperial Bureau of Entomology, and are published by permission of the Director, Dr. G. A. K. Marshall. They form merely a supplement to the accounts of this species included in two excellent papers by G. S. Graham-Smith (1916, 1919), and one equally thorough by G. M. Altson (1920).

The present studies were carried out in North Essex during August-November, 1926. I am very much indebted to Mr. B. Golding and Miss Golding, for giving me all possible facilities for working at Street Farm, Ashen ; and to my wife for keeping the time during the heart-beat observations.

Alysia manducator is a blackish, rather stoutly-built Braconid about a quarter of an inch in length. The female lays usually one egg in a Muscid maggot of considerable size. Very little further development appears to take place until the maggot pupates, when the Alysia larva rapidly consumes it and accomplishes its own metamorphosis within a silken cocoon with which it lines the puparium. The adult Braconid emerges a few weeks later at the anterior end of the puparium ; but eggs deposited in autumn do not complete their cycle until the following year, when about a third of the imagines appear in spring and two-thirds in the following autumn (Graham-Smith). No hyperparasites are known, but Graham-Smith has recorded destructive superparasitism by Melittobia acasta, Walk. (1916, pp. 533–535), and by Mormoniella (Nasonia) brevicornis, Ashm. (1919, p. 378). Altson (1920) has shown that buried puparia are normally beyond the reach of Mormoniella, which is not adapted for burrowing.

Grasshoppers of the genus Oxya, Serv., are well known to economic entomologists in India and Malaya as pests of rice and other crops cultivated under irrigation. An enormous confusion in systematics of the genus was responsible, however, for gross inaccuracies in records of these pests with regard to the actual species involved in each case. Indeed, no other species except O. velox has been ever recorded as a pest, so far as I know, simply because this was popularly supposed to be a most widely spread and common species, while the descriptions of it by different authors were sufficiently vague to enable one to apply the name to almost any species of the genus.

It is widely known that the biological method for the control of insect pests is receiving considerable attention from Economic Entomologists at the present day. One of the insects against which this method is being tried is the common earwig (Forficula auricularia), which is a very serious pest of orchards, etc., in such countries as New Zealand where it it has been accidentally introduced from Europe.

Through co-operation between the Imperial Bureau of Entomology, Rothamsted Experimental Station, and the Cawthron Institute, Nelson, attempts have been made to control the earwig in New Zealand by the introduction of two Tachinid flies that are parasitic on it, Digonochaeta setipennis, Fln., and Rhacodineura antiqua, Meig. These flies are obligatory parasites, being entirely dependent on this particular host for the completion of their life-cycle, and they are lethal in effect. The larvae having emerged from their dead or moribund host, soon pupate, and it is in the pupal stadium that these insects can most conveniently be transmitted in cold storage. Mr. A. M. Altson, of the Imperial Bureau of Entomology, was in charge of this work in England in 1924 and 1925, but, unfortunately, owing to ill-health he was obliged to give it up. In the autumn of 1926, at the request of Dr. Tillyard, it was decided to forward a further batch of parasitic puparia to New Zealand. For this purpose large quantities of earwigs had to be captured in the field, and transferred to cages in the laboratory, in order that the parasites which emerged from the earwigs could be collected.

During recent years banana plantations in some parts of tropical America have suffered somewhat severely from attacks of a Eumolpid beetle, Colaspis hyperchlora, Lefevre (1878). This species has up to now been recorded from the following countries : Colombia (type locality), British Guiana, Panama, Costa Rica, Guatemala, Nicaragua, British Honduras and Mexico.

The egg is pale lemon-yellow in colour, becoming brownish as the embryo approaches maturity, and broadly oval in shape with one end slightly more acute than the other ; length, 1·2 mm. The larva is whitish, with the head somewhat amber-coloured, the body being slender and hairy ; length, 1–1·5 mm. The pupa is dirty yellow, becoming darker as the adult becomes ready to emerge.

The eggs are deposited singly or in clusters varying in number from 5 to 45, in cavities gnawed by the female in the leaf-sheath of bananas near the crown just above the surface of the ground, on the surface roots in natural depressions or in cavities made by the female, and on the surface roots of the old “ mats.” The duration of the egg stage is from 7 to 9 days.

The larvae feed on the young roots, gnawing the soft epidermal tissues of the older roots, into which they tunnel. The duration of the larval stage is from 20 to 22 days.

Having recently studied a large collection of Myiodaria from the Fiji Islands, and having received, through the courtesy of Dr. P. A. Buxton, a number of species from Samoa and other South Pacific Islands, I am able to make a revision of the Calliphoridae now before me, and to describe some new forms. I have also taken into consideration the specimens from New Zealand and from Eastern Australia in my collection, as well as the forms recently described by Aldrich, Hardy, Malloch, Patton and Surcouf, together with the taxonomic changes proposed by Senior-White, Shannon and Townsend.

It seems that some species, probably those more closely associated with man, are widely spread through the Pacific Islands ; while several others seem to be very localised.

(1) D. albipictus, known as the winter or moose tick, is a common parasite of moose, elk and deer in the forests of northern Saskatchewan. As in the outbreak described in this paper, it may attack and cause serious losses among the cattle and horses of settlers which are permitted to graze in the haunts frequented by its native hosts. Deaths among the moose are frequently attributed to the ravages of the tick.

(2) The eggs of D. albipictus are deposited in the ground by the engorged females, which continue to drop from the hosts throughout the winter until the beginning of May. The larvae emerge from the eggs during the late summer and probably remain dormant until such time as the period of drought passes and cooler weather arrives. Attachment to the host is achieved by the larvae in the autumn, and both the larval and nymphal moults are undertaken on one and the same host. During the summer months the hosts are free from its attacks.

(3) Infestation of cattle and horses may be prevented by their maintenance in fenced, tick-free pastures or in barns from the end of September until the beginning of May. Animals that have become infested may be treated with an arsenical dip. Dipping, however, cannot be safely accomplished after September in northern Saskatchewan because of the risk of severe chills that may be contracted by treated animals consequent on the low prevailing temperatures of the autumn months.

Tick-infested fields may be cleaned by being ploughed in the spring after all the ticks have dropped. The engorged females are buried, and even though the eggs may hatch, the larvae will find difficulty in reaching the surface in the autumn to attach themselves to a host.

The question to which we have tried to find an answer is why malaria is almost absent in the southern region (II) within our field of observation, whereas it is endemic in the northern (I). We found Anopheles slightly less frequent in the former, but the difference is irrelevant, and the density of the Anopheline population in Region II is considerable, compared with almost all the European malarious countries we visited and where A. maculipennis is the local vector.

If this difference in the incidence of malaria is at all caused by a difference of the Anopheline faunas of the two regions (which need not be the case), then the biological distinctions are the only important ones. Morphological differences cannot interest us unless they are correlated with the former. Still we began by studying the latter, because they are easier to observe and to measure.

To lure tourists to the West Indies, the makers of travel literature are most apt to use for illustrations more or less accurate drawings of the coconut palm, as being the most easily recognisable and distinctive tree of these islands. Not so well-known, but quite as characteristic of their sandy beaches, and probably even more abundant, is the sea-grape with its stiff, erect shoots, its large, stiff, rounded leaves, and the gnarled and wind-distorted trunks of the older trees.

There appear to be two main causes of “ blight,” namely, the attacks of the froghoppers (Tomaspis saccharina) and the attacks of root fungi (Marasmius and Odontia).

The susceptibility of the cane to the attacks of these root fungi has been shown to be largely due to unsatisfactory conditions as regards the health of the plant and particularly to conditions of drought—physiological or actual. Moreover, this root disease tends to intensify the effect of the water-shortage. It is suggested that a careful analysis of the evidence might also show that the susceptibility to froghopper attack is due to causes which disturb the water balance of the cane, a disturbance which would be even more marked where root disease was present.

The balance in the water content is dependent upon the simultaneous working of the absorption that takes place through the roots and the transpiration that takes place through the leaves ; if transpiration is excessive the plant makes too great a demand upon the supply of available water in the soil. The humid climate of Trinidad is, therefore, particularly favourable to the growth of the sugar-cane. A favourable climate can, however, be offset by unfavourable soil conditions. The distribution of the rainfall, the conditions of the soil, the degree of atmospheric humidity, the effect of the disturbance of the water-balance upon the nature of the cell-sap, etc., all need to be taken into account. As regards rainfall and blight, it would appear that : (1) Prolonged periods of drought, or of excessive rainfall ; and (2) periods of drought following on spells of excessive wet weather, are both particularly harmful.

In view of the part played by root absorption in the maintenance of the water-balance, a detailed consideration of the root system of the sugar-cane in connection with blight might possibly throw fresh light upon the subject.

A disturbance of the water-balance may also affect the cane's susceptibility to the attacks of insects through its effect upon the physiology of the cane. Is it possible that drought (physiological or actual) or other unfavourable climatic and soil conditions may affect the concentration or constitution of the sugars in the sap in such a way as to render them more attractive to sap-feeding insects ?

The problem is extremely complex. We have seen that root disease is dependant upon the weakness and debility of the cane, resulting from unfavourable environmental conditions and from shortage of water ; that the root disease thus caused intensifies the effect of this water-shortage by lowering the plant's capacity for root absorption ; that the plant, susceptible in any case to attacks of froghoppers as the result of any disturbance in the water-balance, is rendered even more susceptible as a result of root disease. On the other hand, root disease is said to be due to a lack of vitality in the plant ; a plant attacked by froghopper is greatly reduced in vitality, and thus the tendency to root disease is increased.

We have considered the interrelation between the absorption of water by the roots and the transpiration of water through the leaves, and the effect of the water content on the physiology of the plant. We must also consider the interrelation between the attacking froghopper and root fungus, and the cane which is attacked.

Can we decrease the number of attacking organisms, or is it more feasible to increase the cane's resistance to their attack ? In the past the economic entomologist has directed his attention almost entirely to answering the first question ; it is now realised that an answer to the second question is quite as, perhaps even more, urgently demanded. Unhealthy canes are undoubtedly more susceptible to attack than healthy canes, that is, if we use the term “ health ” in its rightful sense as denoting vigour and the capacity to resist adverse environmental conditions, and not merely luxuriant growth.

The larvae of certain flies belonging to the family Syrphidae have long been recognised as plant pests. Merodon equestris, Fab., was recorded in Great Britain as far back as 1869, having probably been imported in narcissus bulbs from Holland (Verrall). This fly is now universally known as the “ Large Narcissus Fly,” the larvae causing serious losses in nearly every locality where the narcissus is grown commercially. More recently flies of the genus Eumerus have been associated with a type of injury very similar to that caused by the larger fly, and the larvae have been recorded on a variety of host-plants in Europe and America. Chief among these hosts may be included narcissus, onion, hyacinth, parsnip, iris, and potato. The flies are commonly referred to as “ Lesser Bulb Flies ” or alternatively in some parts of North America, where they were first recorded as European introductions in 1904, as “ Lunate Onion Flies.”

So far as I know the larva of Aëdes pulchritarsis has not yet been described. Meanwhile, some of the peculiarities of its external anatomy and biology are worth recording.

The adults that I have bred from these larvae have been kindly determined by Mr. A. A. Stackelberg and described in his “ Revision of the Mosquitos of U.R.S.S.” With his kind permission I take the liberty of citing the description of this new variety from his manuscript.

The cultivation of the fig tree in Palestine has not yet attained any great or highly valuable proportions, though there are many thousands of these trees scattered over the cultivatable portions of the country, all of which yield a certain amount of annual profit. In some parts a few, small, regularly-planted collections of trees exist which can, with dignity, be termed plantations.

The fig tree in this country is of hardy growth and seldom receives much attention beyond a yearly ploughing of its surrounding soil and the removal of the crop. It is, perhaps, because of its resistance to the rigours of heat, cold and dryness which are experienced in the gamut of the country's climates, and its ability to flourish and bear a crop of profitable fruit with a minimum of expenditure on upkeep, that it is so popular with the agricultural inhabitants of Palestine.

The fruit of this tree is either sold fresh or else marketed locally after a process of sun-drying, which forms a profitable industry in the hill districts and is quite capable of considerable expansion. Some eleven species of figs are grown in Palestine, four of which are excellent for drying.

The pests of this tree are not numerous and include the fig wax scale (Ceroplastes rusci, L.), the Mediterranean fruit-fly (Ceratitis capitata, Wied.), and a recently discovered Psyllid, which is confined to a comparatively small area. Of these the fig wax scale is by far the most important.

Two of the weevils referred to by Mr. Wolcott in the foregoing paper as feeding on Coccoloba uvifera are new to science, and descriptions of them are therefore appended.