A severe outbreak of the Spruce Sawfly (Diprion polytomum, Htg.) in Eastern Canada led to a request to Farnham House Laboratory to investigate, and if possible collect and export, the parasites of this insect in its native home in Europe.

Work started in 1932 and it was found that D. polytomum was a comparatively rare insect in Europe, though widely distributed. It is heavily parasitized, 31 species of Hymenopterous and Dipterous parasites having been found up to the present. Nearly twenty-eight million parasitized cocoons and eggs of this and other species of Diprion have been collected and despatched from Europe, and work is still continuing.

Previous to the present work only 13 species of parasites, a list of which is given, were recorded from this host.

Of the 31 species now known, 15 are primary, 5 can be primary or secondary, and 9 secondary only; in 2 cases the status is not known.

Descriptions of all the species are given and in the case of the obligatory and facultative primaries, the biology and immature stages are also described and notes added on their suitability for introduction into Canada. A key to the adult parasites is given, and a key to the larval stages of the primary and facultative primary parasites. Some practical notes are also given, including methods of accelerating the emergence of parasites in winter and methods of preparing parasite larvae for examination and identification.

An investigation of the “ fly-belts ” in the Ol Orokuti area of the Masai Reserve was carried out early in April 1934, in response to a request from the European farmers of the Sotik district.

Phyllocoptes lycopersici, Massee, sp. n.

Tryon, Rept. Queensland Agric. Dept. 1916–17, pp. 49–63. (No description.)

Body spindle-shaped, stout, tapering sharply towards anal end. Thoracic shield triangular, sides sinuate, apex produced and rounded, not completely covering rostrum. Centre of shield smooth, sides ornamented with two longitudinal furrows at end near lateral margins. Shield 44 μ long.

1. Anopheles maculipennis, Meigen.

The larvae are found in the low-lying districts of the Island in shallow pools and irrigation ditches containing a medium amount of aquatic vegetation yet well exposed to sunlight. They are sometimes present along the edges and in the back-waters of drainage canals with an appreciable current, and frequently in slightly brackish(up to 10 per cent. salinity) waters by the sea-shore. They are most plentiful in Lake Antiniotissa among the floating masses of Monostroma (? bullosum, Roth-Wittr.) at the mouths of several fresh-water springs which flow into that shallow and slightly brackish mere from the south.

The adult bites most frequently after sunset and is the principal transmitter of the malarial parasite in the Island.

1. Reference is made to the proven capacity of aphides of the genus Capitophorus to transmit virus disease among strawberries, and attention is drawn to the confusion existing as to the actual synonymy of the insect principally concerned.

2. For the first time sexual and asexual forms of the species commonly present in England have been observed together. Evidence is considered which suggests that the aphis is Capitophorus fragariae, Theo., and that American forms are in reality other, but closely related, species.

3. The incidence of the aphis in the field is considered, and the biology as observed in field and laboratory is discussed.

4. The economic significance of the aphis is referred to, and attention is drawn to the practical difficulties attending efforts to keep it in control, particularly in commercial strawberry-growing areas.

A pronounced variation in the time taken by hopper bands of Nomadacris septemfasciata, Serv., to become adult swarms in different localities in the Nyasaland Protectorate during the four breeding seasons from 1932 to 1936, led to an investigation and comparison of certain climatic factors occurring during the critical months of hopper development at a number of stations where such variation had been particularly noticeable.

It was found that temperature and percentage relative humidity appeared to have considerable influence on the rate of development of the hopper bands, and that the quiescent nature of the bands in certain areas in some years, together with the unexpectedly small adult swarms that matured from these bands, seemed to be correlated with these same factors. It was noticeable that conditions during the first season, when development was generally normal, were somewhat hotter and drier throughout the country than in the later years and that, in most places, a marked increase in humidity usually accompanied by a decline in temperature was recorded each year up to 1936. In certain areas where hopper development occurred each year without much variation in length of time or intensity, such as the lower Shire River Valley, temperatures and humidity were found to have fluctuated only slightly from year to year.

1. The male of Pseudococcus is co-equal in importance with the female for the propagation of the species. Virgin females of P. citri, Risso (both aerial and root forms), P. maritimus, Ehr., P. gahani, Green, P. longispinus, Targ., and T. peregrinus, Green, are incapable of producing offspring. No form of parthenogenesis occurs in these five species. Only fertilised eggs develop.

2. The relative abundance of the male sex varies greatly from species to species. The specific sex ratio of citri is 101·62± 1·54 ♂♂ per 100 ♀♀, estimated from 11,413 progeny from 47 females; that of maritimus is 59·65± 9·39 ♂♂ per 100 ♀♀, estimated from 4,630 progeny from 42 females; that of gahani is 43·025± 2·28 ♂♂ per 100 ♀♀ estimated from 12,092 progeny from 61 females; that of longispinus (for bisexual families only) is 19·28± 2·27 ♂♂ per 100 ♀♀, estimated from 4,084 progeny from 19 females; and that of peregrinus 37·01± 7·906 ♂♂ per 100 ♀♀, estimated from 3,946 progeny from 24 females.

Apanteles myeloenta, sp. n.

♀. Black; the front femora in the apical half or third, the front tibiae and tarsi (save for the black feet), middle femora in about the apical fifth or sixth, middle tibiae (save commonly for some darkening in the apical two-thirds above), middle tarsi (save for the feet and last joint, which are black), and the hind tibiae in about the apical fifth or sixth, red testaceous; tegulae testaceous; palpi pale; tibial spurs white; wings hyaline, the setae apparently coloured; trie costal veins in the basal half more or less colourless, as are all the wing-veins; costal veins apically, and the borders of the stigma, light brown or brown, the metacarp brown or dark brown; stigma otherwise hyaline.

Blosyrus ipomoeae, sp. n. (Plate XII, fig. 1).

♂. Derm black, with dense brown scaling; prothorax with an indefinite paler patch in a line with interval 3 of the elytra and extending from the base to the middle; elytra with variable black patches on intervals 3 and 5 and the usual ill-defined oblique paler band from the middle of interval 3 to the shoulder.

In the course of entomological investigations of the rubber-producing plants, Scorzonera tau-saghyz, Lipsch. & Bossé, Taraxacum kok-saghyz, Rodin, and Taraxacum megalorhizon, Hand.-Maz., at the Ukrainian Rubber-Plants Experimental Station (near Kremenchug), it was discovered that the destruction of these plants can be caused by root Aphids and the ants associated with them.

These crops are all either indigenous or of early introduction, except in the case of special varieties and they have achieved within the limits of their present distribution an equilibrium with their insect pests. Where there is no reasonable chance of a return for his labours, the native has ceased to grow a particular crop. This equilibrium is unstable, since pests increase in numbers at intervals owing to a variety of causes. For example, the introduction of cassava into new areas to prevent famine during the locust invasions brought to light the stem-borer moth, Opogona chlorophanes Meyr. In some cases cassava could not be grown and sweet potato had to be substituted. Acridids such as Eupropacris uniformis suddenly appear in great numbers at long intervals and do. considerable damage, then disappear just as suddenly. Similarly the adverse effect of climate on the crop will render it susceptible to particular pests, especially Aphids, during periods of drought. Agricultural practice is also concerned in this equilibrium, as for example where the time of planting legumes is governed by the attacks of various Galerucid beetles, particularly Ootheca bennigseni, Wse., which are most active during the early rains.

In summing up the results of our study of the local varieties of maculipennis in a region of Macedonia, we have tried to deal with the region as a thing by itself, without allowing ourselves to be influenced by what we might know regarding the varieties of maculipennis found elsewhere.

We found a maculipennis nearly uniform throughout the whole region as regards habits and morphology, and not varying greatly except with respect to one character, the sculpturing of the eggs. On the basis of this character, we may make two groups, provisionally called typicus and messeae, but we must use statistical methods to establish these two groups, for we find much variability in them. The amount of variability is not uniform over the whole region; in some localities the egg-type is nearly all typicus, in others messeae greatly predominates. Our problem has been to test the validity of this characteristic, especially with regard to its persistence from parent to offspring and its constancy in varying environments.

In the course of studies of the behaviour of the tsetse-fly, Glossina morsitans, certain facts of considerable interest concerning its phototropic reactions have been established.

It is considered desirable to place on record some data relating to insects attacking economic plants in Sierra Leone; little information has hitherto been available, and it is hoped that this list will prove of interest and use to other workers. Families, genera and species are arranged alphabetically.