Microbracon hancocki, sp. n.

♂♀. Black; the front legs completely, the middle legs except the coxae, hind trochantines, hind femora, basal third of hind tibiae, mouth-parts largely, all ventrites, the lateral membranous margins of the 1st tergite, about each lateral quarter of the 2nd and succeeding tergites, bright red testaceous.

The variation of A. mauritianus was discussed long ago by Alcock (Jl. Lond. Sch. Trop. Med., i, pp. 89–93, 1912), who concluded that the differences observed were due to mere individual variation. In my key to African Anopheles (Bull. Ent. Res., iii, p. 250, 1912) I suggested that an East and a West African form might be distinguished by the amount of white on the hind tibia and first tarsal segment. Careful study of more extensive material has shown that this generalisation cannot be maintained, but that there are four varieties of the species which can be rather easily distinguished, and fortunately the published names can be applied to them. Diagnoses of these varieties have been given by Miss A. M. Evans in her recently published guide to the African Anophelines (Memoir No. 3, New Series, Liverpool Sch. Trop. Med., Oct. 1927), but the definitions are somewhat expanded in the notes below, and a further account of the distribution is given. The variations are certainly of more than individual significance, because they show a distinct tendency to localisation, and bred series from one place do not exhibit much variation. On the other hand, I do not consider that there is more than one species, because no differences are apparent in the male hypopygium; I have mounted specimens of each of the four varieties and find them all to agree rather closely with Christophers' description and figure. In one point, however, Christophers' account seems to be at fault: the mesosome has always two or three pairs of distinct leaflets, the longest of which are nearly one-third as long as the tube.

Microbracon kirkpatricki, sp. n.

♂♀. Pale reddish testaceous with the 1st and 2nd tergites often almost stramineous ; antennae of a darker red ; extreme apex of tarsi black ; ovipositor sheaths dark brown to black ; the male often with the 2nd–5th tergites discally brownish ; ocelli black, the ocellar area sometimes darkened ; legs, particularly the hind legs, often stramineous or nearly so ; stigma and wing veins pale reddish, except that in the forewing the 1st abscissa of the anal vein and the basal half of the 1st abscissa of the medial vein are virtually colourless, and that the costal vein is brownish, and that the stigma in the males is brownish.

♀. Integument noticeably coriaceous throughout, except the appendages. Head broadly rounded behind, 1·75 times as broad as long ; ocelli on a more or less distinct tubercle, not close together, the posterior ones only somewhat nearer to one another than to the eye ; flagellum with 25–29 joints, the majority of specimens with 27–29 joints ; apical joint of antennae wth a short apical style ; head impunctate and narrowly coriaceous. Thorax impunctate, with mesonotum, scutellum, and propodeon, more broadly coriaceous than the head ; mesopleurae more broadly coriaceous again ; the lines of the notauli only faintly indicated, but noticeable, chiefly on account of the enclosed median area which is raised somewhat and which, tapering to a point, reaches almost to the scutellar depression ; scutellar depression apparently sometimes weakly crenulate and sometimes plain ; propodeon completely plain except for a median, very weak, longitudinal excavation extending about half the length of the propodeon, when it becomes a fairly well marked longitudinal carina which extends to apex, where it joins the transverse apical ridge.

The importance of the reaction of mosquito breeding water was established by MacGregor in 1921, and since then observations have been reported from various parts of the world. In the original paper MacGregor showed that, in the laboratory, three species of English mosquitos could survive an alkalinity of pH 9·6 and died in acid water of pH 4·4, while two other species developed in pH 4·4. Later, in Mauritius, he found the local Anophelines in water ranging from pH 9·5 to pH 8·4 and rarely in places giving the reading pH 7·4 ; and maintained that the reaction of any water there was a reliable index of the presence of Anopheline larvae. Senior White, in Ceylon, found the local Anophelines in water with readings from pH 5·8 to pH 8·6 usually, and decided that on the whole the local Culicines had a more restricted range. Buxton, in Palestine, found six species of Anopheles in water varying from pH 9·2 to pH 7·4, and of these only one occurred in water less alkaline than pH 8. He notes that Nablus, where the water supply is unusually acid for Palestine (pH 7 to 7·5), is free from malaria.

From the above it will be seen that in the writers' opinion, based it must be admitted on but a single year's observations, the three species of Dysdercus (D. fasciatus, D. nigrofasciatus and D. superstitiosus) occurring in the northern rain-cotton belt of the Sudan are essentially associates of the tebeldi and are not as yet other than accidental pests of cotton. By this is meant that there is no definite migration from the tebeldi to cotton, nor are wandering adults greatly attracted by cotton. The dispersal of a proportion of the adults composing a colony on a tebeldi is the natural effort on the part of the species to establish itself on other tebeldis. Emigrants from a colony that in the course of their wanderings chance on cotton may remain to breed. It is possible that when cotton has been grown in the district on a large scale for some years, the bugs, unless they are kept in check, may develop the habit of migrating definitely from the tebeldis to the cotton and, later in the season, from the cotton back to the tebeldis.

The most promising line of attack appears to be that of destroying, so far as possible, the colonies on the tebeldis during the active breeding season.

The writers' thanks are due in particular to Mr. G. F. March, Inspector of Agriculture, who in a variety of ways has rendered them the greatest assistance in their work.

It is highly regrettable that in the past whenever Cecidomyid or midge larvae have been found in ears of wheat the presumption has been that the species concerned was the wheat midge, and it was therefore recorded as Contarinia tritici (Kirby).

In summarising, the following points are to be noted:—

1. The thermal death point of the blow-fly was definitely influenced by the factor of humidity.

2. Saturated and dry air had the effect of lowering the thermal death point.

3. Relative humidities from 60 per cent. to 80 per cent. were more favourable, while relative humidity of 70 per cent. actually was found to be an optimum point.

4. From the weighings it may be concluded that death in saturated air was due to the inability of the flies to regulate their heat by evaporation.

During November 1926, a few days were spent in making a rapid investigation of the insect pests of cotton occurring on the coast of Kenya Colony, between Mombasa and Mambrui, some eighty miles to the north.

The pink boll-worm, Platyedra gossypiella, Saund., was found to occur in every plot of cotton visited ; it was also noticed that a certain proportion of the worms were parasitised by a species of Braconid, which has been described above by Mr. D. S. Wilkinson under the name of Microbracon kirkpatricki.

A second visit was paid to the coast during the beginning of February 1927, to ascertain to what extent, if any, the pink boll-worm was controlled by this parasite, and to report on the possibilities of its introduction to other countries.

Owing to the short time available for this work, these notes are naturally very incomplete ; it is hoped however that they will be of some value should anyone be of the writer's opinion that it is well worth while attempting to introduce this parasite into other countries.

Like other species of its genus in different parts of the cotton-growing areas of the world, Dysdercus sidae is a serious pest of cotton, not as has been stated from staining the lint by its excrement or being crushed in the gins, but from being the agent by which internal boll-rot fungi enter the green cotton boll.

The Tachinidae described herewith have been forwarded for determination through Dr. Guy A. K. Marshall, Director of the Imperial Bureau of Entomology, and constitute three of five species reared by Mr. E. Ballard. The types of the new species will be found in the British Museum of Natural History.

The Mediterranean fruit-fly (Ceratitis capitata, Wied.) first reached Bermuda about 1865, and since that time has been a pest of the first importance on all kinds of thin-skinned fruits. Peaches, which formerly grew in great abundance in the island, were rendered unproductive, and loquats, sapodillas, Surinam cherries, peppers, and to a lesser extent citrus, papaws, sugar-apples and guavas, were severely infested.

During 1925–1926 a number of tulip bulbs and iris corms infested with Aphides were received from various sources, as well as Aphides from growing tulips. These species were reared and observations made on the progress of the infestation on tulips. It is evident that one species Anuraphis tulipae (B. de Fonsc.) is a serious pest of stored bulbs, especially tulips, and another species, Rhopalosiphoninus tulipaella (Theo.), may also be of importance in this respect. Since these two species are not well known, it may be desirable to give detailed drawings of the species together with some notes on the observations made. It is hoped that the complete life-cycles and alternative food-plants of these species may be traced later.

In addition to the two species mentioned above, Macrosiphum gei (Koch) and Myzus persicae (Sulz.) were also found infesting tulips.

The inclusion of species of the order Collembola among the list of injurious insects has, from time to time, given rise to considerable scepticism among those concerned with economic entomology. It is, therefore, thought desirable to place on record controlled experiments which leave no doubt as to the depredations of one species, Sminthurus viridis, Lubb., of this primitive group of insects. Further, our knowledge of the bionomics of Collembola is so scanty that data obtained with reference to the life-history and habits of this particular species may be of interest.

The two new species described below were included in collections sent to the Imperial Bureau of Entomology by Dr. P. A. Buxton, of the London School of Tropical Medicine, having been obtained in Kashmir by Major Stevenson in 1926, and again in 1927. The same collections contain examples of a third species of Simulium which appears indistinguishable from the European S. equinum (L.) Edw. Examples of this species had previously been obtained in Kashmir by Mr. F. J. Mitchell.

Many anti-malarial workers have recorded the larval habitats of Anopheline species, and while their records usually reveal a variety of types of breeding-places for the same species even in one and the same country, the characterisation of the breeding waters usually lacks precision. This is hardly surprising, since descriptions are based upon naked eye observations, and only physical aspects of the breeding-places, or in addition only the most striking characteristics of the associated forms of vegetation are recorded, more or less casual information being given concerning the depth, clear or muddy character, and stagnation or currency, of the water, together with even more incomplete statements relating to the plants growing in or near it. The statement, not unimportant in itself, is, for example, often volunteered that larvae of a particular species are found in streams or pools with grassy margins, while information is usually lacking relating to the species of even the more conspicuous plants which grow in the water itself, and which are characteristic of it or of the presence of particular Anopheline larvae. For example, it has been found that in Malaya in ricefields on the flat coastal plain, the presence of the floating plant Utricularia flexuosa is widely associated with larval associations in which Anopheles sinensis predominates over A. barbirostris, other Anophelines being generally absent (Williamson, 1925). It seldom if ever happens, however, that an aquatic plant has the same range of adaptability as the associated mosquitos. For example, in the case quoted, U. flexuosa abounds over many square miles in the Krian rice-fields, from which all Anopheline larvae are absent, despite the proximity of their breeding-grounds; and conversely, A. sinensis and A. barbirostris are very commonly found unassociated with Utricularia.

In the course of the beekeeping work of this Department we have had a number of hives weighed at regular intervals of about a week by means of a steelyard and tripod, and two permanently standing on platform weighing machine and weighed every day. The information obtained from these has been of great value in showing the seasonal variation in activity, the periods of honey flow, and the effect on the hives of the presence of enormous numbers of hornets in the late summer.

There were, however, many problems, such as the daily periods of activity and honey-collecting, the effect of high midday temperature, etc., that could only be dealt with by more frequent weighings, and it was felt that a machine to record continuously the weight of the hive by means of a rotating clock drum and pen would be a most valuable instrument of research.

The present paper contains the descriptions of two new species of mosquitos from North Queensland, Mucidus chrysogaster and Aëdes (Finlaya) mackerrasi. The former, the second Australian species of the genus, is a very interesting and most beautiful insect, of which only the female is so far known ; the latter is also of interest in that it adds yet another species to the closely interwoven group of Australian Finlaya.

My thanks are specially due to Dr. I. M. Mackerras, B.Sc., for his kind assistance in the determination of the latter species, since I was unable to do so myself, as the Institute does not possess a male specimen of Aëdes (Finlaya) occidentalis (Skuse). The comparative notes on the genitalia are from his pen.

♂. Black ; flagellum brownish red, hind legs from the femora to the claws blackish red ; scape, fore and middle legs, hind trochanters and hind trochantines, light testaceous red ; palpi almost white ; basal ventrites whitish ; stigma and wing veins brown.

♂. Head rugose throughout, except that the occiput is rugoso-reticulate and that the vertex between the ocelli and the toruli is rugoso-striate ; face with indications of a median keel ; antennae moderately thick and strong ; basal joint of flagellum a little longer than twice its breadth, about 0·24 mm. long ; clypeus apparently emarginate, just about half as long as distance between facial depressions, which latter are nearer to the eyes than to the apex of the clypeus ; posterior ocelli nearer to the eyes than to each other. Thorax : mesonotum closely and strongly punctate, anteriorly almost rugose, as are also the mesopleurae except for a posterior median smooth and shining area ; mesopleural sulcus apparently smooth ; scutellum apparently rugose ; metanotum apparently not crenulate ; propodeon with an extremely short median longitudinal carina which, bifurcating at its apex, emits two strong carinae which, on each side, run transversely across the basal half of the propodeon and join a strong carina which in conjunction with a strong lateral longitudinal carina encircles the spiracles, as in M. kuchingensis ; remainder of the propodeon apparently rugose between broad reticulations, except outside the lateral keels, where it is only rugose.

The black currant gall-Mite, Eriophyes ribis (Westw.) Nal., may reasonably be described as being one of the most important amongst the numerous pests that infest soft fruits in this country.