The present enumeration of the TABANIDAE known to occur in Trinidad is based almost entirely on specimens seen by myself, although I have included the very few published records apparently based on reliable identifications. None of the material was collected by me; but I am indebted for it to various museums and private collectors: Dr. J. G. Myers, Mr. D. Vesey-FitzGerald, Dr. Neal Weber, Mr. John Smart and Mr. H. Oldroyd (British Museum), Mr. L. L. Pechuman (Cornell University), and Dr. Alan Stone (U.S. Bureau of Entomology and Plant Quarantine).

1. In Canada, European holly (Ilex aquifolium) can only be grown successfully in the mild, humid climate of western British Columbia. The sales of cut holly for decorative purposes amount to several hundred thousand dollars annually, and the tree is also in good demand for ornamental planting in public parks and private estates.

2. The most serious pest of holly in this part of the world is the Agromyzid fly, Phytomyza ilicis, or the Holly Leaf-miner, which was accidentally introduced from Europe without its attendant natural enemies. The larvae of this insect produce large unsightly blotches on the leaves which greatly lower the value of the cut foliage. As a rule 75 to 80 per cent. of the leaves are attacked in this manner.

3. Since chemical forms of restraint offered little hope of success, it was decided that the biological method of control should be given a trial. Accordingly, the writer undertook a general survey of the fly and its parasites in England, the results of which are described in the preceding pages. An account of the biological control of P. ilicis will be published in a separate paper at a later date.

4. A general account of the systematics, synonymy, distribution, host relationship, and biology of the holly fly itself precedes the parasite section.

The holotypes and allotypes of all species described as new in this paper are to be deposited in the British Museum and paratypes in the United States National Museum. All the species described in this paper are parasitic in scale-insects or mealybugs.

Some of the classifications presented in these papers on African Encyrtidae are tentative only, for in the case of closely related variable species it is impossible to make final identifications on the basis of a few museum samples. The exact degrees of relationship can be expressed only when the insects are known intimately throughout their entire range and a knowledge of the limits and degrees of variation obtained. Even with this knowledge it is not always possible to make final determinations with assurance.

The following observations on cotton stainers were made in the Eastern Group of the West Indies, or Lesser Antilles, which extend from Trinidad to the Virgin Islands. Some idea of their size and geographical relationships will be obtained from fig. 1.

1. The ecological study of Sirex and its parasites was begun in 1927 and continued while making large-scale collections of the parasites for shipment to New Zealand with the ultimate object of the control of Sirex noctilio, a species of woodwasp which has been established in the Dominion for many years.

2. A brief outline of the life-cycle of Sirex and the parasites is given. The difference in the method of attack by the parasites on the host is described, and some points of interest in connection with insect behaviour are discussed.

3. The methods of collection are described and particulars given about the number of parasites collected.

4. The inter-relationship of the host and parasites is discussed. It is shown that a single generation of Sirex can support three generations of Rhyssa and one generation of Ibalia, and that the effects of parasitism by Rhyssa are cumulative. The percentage of parasitism by Rhyssa cannot, therefore, be calculated on the results of any one year. Rhyssa is intrinsically superior to Ibalia and super-parasitism of Ibalia by Rhyssa is of very frequent occurrence. It is shown that the figures for parasitism by Ibalia obtained by the dissection of Sirex larvae collected from a number of logs, over a period including summer months, are liable to be very misleading.

♂. Expanse 8–9 (Fw. 4·5)mm. Head rather small, rounded, rather rough-scaled; whitish, irrorated with large blackish scales: viewed frontally, rather broad, eyes small but projecting slightly, space between eyes rather more than twice diameter of one eye as seen from this aspect: mouth-parts aborted, represented only by a small projecting tuft of hairs edged beneath with whitish. Antenna under half: scape short, stout, beneath with pecten of short stout bristly hairs: shaft bifid at apex, bipectinate, with 13 pairs of very long, finely-ciliated branches, each of even breadth but very slightly incrassate and spatulate at its tip; shaft white-scaled, spotted with black above point of emission of each branch; branches white, spotted with blackish and pale brown, black-brown at tips. Thorax blackish with long hair-scales. Abdomen short, not reaching tornus of hindwing, blackish, posterior margins of segments narrowly white; anal tuft small, white. Legs fuscous, tarsi lined white: foreleg without epiphysis: tibiae without spurs but with slight apical spines.

At the request of Dr. W. R. Thompson, Superintendent, Farnham House Laboratory, The Imperial Institute of Entomology, England, arrangements were made in 1936 to collect and furnish to him larvae of the predacious Elaterid Pyrophorus luminosus, Illiger, indigenous to Puerto Rico. These beetles were for liberation in Mauritius to aid in the control of the white grub, Phytalus smithi, Arrow. Shipments were sent by steamer from Puerto Rico to New York and then to England for repacking and shipment to Mauritius. The Mauritius government appropriated the sum of 85 pounds sterling to defray the expense of collection, packing and shipment.

1. An examination has been made of all specimens labelled Leucoptera daricella (Meyr.), standing in the collections of the British Museum and of the late E. Meyrick.

2. Crobylophora staterias, Meyr., and Crobylophora onychotis, Meyr., two species previously regarded as synonymous with Leucoptera daricella, are thought to be good species. The specimens of the former, which were bred from Plumbago, have been received from India and Ceylon ; the latter is an Indian species.

3. A new African species, Leucoptera caffeina, Washbn., is described, which causes damage to coffee trees.

4. Records of Leucoptera daricella have been investigated, and, as a result, the writer is of the opinion that this species has not yet been recorded outside Australia, and that records from Africa, India and Burma, prove unsubstantiated.

5. Lectotypes are cited of the species Leucoptera daricella (Meyr.), Crobylophora staterias, Meyr., Crobylophora onychotis, Meyr., and these are in the British Museum (Natural History), London.

From January to July 1938, experiments with Anopheles maculipennis race atroparvus, Van Thiel, were undertaken to discover whether humidity and the age at which the females fed influenced their longevity. It was found that they lived longer at higher than at lower humidities; that most of the females which fed did so in the first three days; that those which fed on the second day after emergence lived longer than those which fed at other ages; and that the feeding period was slightly extended in the later experiments, though only a small proportion lived long enough to take their first blood meals on the fourth and fifth days.

Rather more than 50 per cent. of each batch of newly emerged adults were females.

A large proportion of the deaths of unfed males and females occurred during the first three days, most of them on the second day; this mortality decreased in successive experiments.

Culex fatigans, Wied., behaved similarly.

Representatives of three species of sawfiies attacking guava (Psidium guajava, L.)in Brazil, were recently sent for determination by Dr. Louis Pyenson, formerly head of the Entomology Section of the Instituta de Pesquisas Agronomicas, Pernambuco, Brazil.

In this paper I am redescribing and giving some interesting, new, biological information with regard to two species of Apanteles, of which one, A. compressiventris, has not previously been recorded in the Old World, and the other, A. plutellae, not previously recorded from the Western Palaearctic Region; and I believe that it is better to communicate this information at this time rather than to wait until the completion of the monograph upon which it is known that I am engaged, a matter yet of some years.

1. A method is described of using the Adam-Langmuir surface pressure trough for the direct measurement of the spreading power of oils against surface contamination.

2. Pure higher paraffins are non-spreading and pure aromatics have only a small spreading pressure. Commercial grades of oils owe what spreading pressure they have to impurities which are only present in small quantities and can be removed.

3. The spreading power of oil is greatly increased by irradiation of very thin layers of the oil. Even so, only a small fraction undergoes chemical change, the great bulk being recoverable with its original properties.

During a search over Europe for species of the genus Diprion an infestation of Diprion similis was located in Poland at Orle, near Wlosclavek. The infestation was remarkable in that the prepupae which had spun up in the autumn of 1935 did not proceed with normal development in the following year, but remained in a prolonged dispause. An opportunity was thus afforded of studying at length the control exerted by biotic factors on the prepupal stage of the host sawfly.

In 1932 on an expedition in Brazil, Dr. J. G. Myers, of the Imperial Institute of Entomology, while in search for suitable parasites for introduction into this and other colonies in the West Indian area, discovered the Tachinid fly Metagonistylum minense, Towns., known generally now as the Amazon fly, as an important parasite of Diatraea saccharalis, F., in the vicinity of Santarem on the Amazon, and as the result of his investigations there, formed the opinion that it would be a suitable parasite for introduction into British Guiana.

The adults of the Gregarious Guava Sawfly are relatively sluggish insects and can be readily captured on foliage (Pyenson 1938 b). They lay their eggs in single rows embedded in the tissue of the tips of young green twigs or along the midribs on the underside of the younger leaves.

The first Phlebotomus of the year 1936 observed in Corfu, Ionian Islands, Greece, was seen on 15th June. From that date these Diptera became rapidly more numerous (maximum towards the end of June and beginning of July) and disappeared fairly suddenly in the second half of September, not one being seen after the 21st of that month.

1. Serial examinations of the degree of infestation of thirty-five flocks during a nine-year period in Argyllshire, Perthshire, Selkirk and Northumberland, showed that tick incidence is greatest in spring and decreases markedly in early summer. Evidence is given of a similar periodicity in North Wales.

2. Evidence is given of the occurrence of a slight recrudescence of activity in autumn, and of the almost complete absence of activity in winter.

3. The spring curve of activity terminated in early May in Argyllshire, in the middle of May in Perthshire, and towards the end of May in the Borders and Northumberland.

4. The estimation of the relative annual infestation, e.g., in relation to the question of spread or increase of ticks, by single annual counts is shown to be quite unreliable.

5. No evidence was obtained of an increase in density of ticks in any area during the period of observation.

6. The seasonal periodicity in activity was found to bear no relation to the density of stocking of the ground by sheep.

7. The seasonal activity of ticks in Argyllshire, Perthshire, Selkirkshire and Northumberland, was found to be related to the air temperature, expressed as the weekly average of maximum temperatures. The limits of the air-temperature range corresponding to active tick infestation are 45°F. and 60°F. (average weekly maximum).

8. The curve of tick infestation during 1937 on a moor in North-east Scotland was found to differ markedly from the normal, and the possible explanations of the discrepancy are discussed.

The longevity and development of the eggs of Ornithodorus moubata, Murray, at different relative humidities between 6·2 per cent. and 80 per cent. were investigated. It was found that:—

(1) All stages investigated, i.e., egg, larva and 1st nymph, survived for a much longer period at high humidities than at low. The longevity snowed a steady gradation through the range of humidities used.

(2) Even at very low humidities a sufficient proportion of eggs developed to the 1st nymph stage to carry on the race.

(3) The 1st nymph is much more resistant to desiccation than the earlier stages.

This result does not agree with opinions expressed as the result of field observations, or with the only previous laboratory experiment it was possible to trace. Reasons for both these disagreements are suggested.

The Lygaeid bug described below has been well known as a pest of strawberries in Tasmania for a long time, both Thompson (1895) and Lea (1908) having given particulars of its activities under the name of the “Strawberry Bug.” Lea mentions that it also occurs in Victoria and New South Wales, but as it belongs to cosmopolitan genus with a world-wide distribution, it is possible that the Tasmanian species is distinct.

The grape vine (Vitis vinifera), which is a common fruit crop grown extensively in Mysore, has not been noticed till now to be subject to any very serious insect pests, though one occasionally comes across a Chrysomelid beetle (Scelodonta strigicoUis, Mot.), stray leaf-eating cockchafers (Adoretus spp.), twig-girdling Longicorn beetles (Sthenias grisator, F.), and stray scale-insects, which, however, have not done any very serious damage so far ; but recently substantial damage has been caused to the grape vine crop by an insect which appears to be quite a new record—at any rate for S. India. The insect concerned is a species of plume moth (Oxyptilus regulus, Meyr.), the larva of which bores into the ripening berries of the grape bunches and causes substantial injury. The grapes grown in the Mysore State belong to a local black variety, the fruits of which have a sub-acid taste and do not therefore fetch good prices at present because of the very large imports of sweet varieties from North India and elsewhere. The serious nature of the damage done by this new pest and the consequent menace to the grape crop, which is one of the oldest of the fruit plants to be raised in the State, and the likelihood of the insect extending its activities to the different varieties of this crop cultivated outside the State, prompted the author to attempt a fairly thorough study of the insect with a view to adopting control measures.