The following new species was reared from the eggs of a Pentatomid bug, Tectocoris lineola, F. (banksi, Don.), which attacks cotton. It occurred in company with Hadronotus nigricornis, Dodd, and was more abundant than that species.

A chalcidoid wasp, Torymus apiomyiae sp. n., is described from material reared in southern Yugoslavia. The host is Apiomyia bergenstammi (Wachtl), a gall midge galling young fruit-bearing twigs of pear trees, which is locally a serious pest.

In connection with further experiments concerned with the significance of the pH of natural and other waters and the relative suitability or unsuitability to the development of the larvae of certain mosquito species, electric currents have been used to alter the pH readings, thus avoiding the necessity of adding extraneous acids or alkalis to bring about this alteration.

Populations of the red locust, Nomadacris septemfasciata (Serv.), can build up to large numbers in certain of the grass plains of south-central Africa. Adult populations are always under-dispersed, and estimates of their size can be made economically only by counting the locusts flushed on line traverses of considerable length. It is necessary, in such traverses, to determine the width of the strip swept, the proportion of the locusts in it that are flushed, and the accuracy with which these are counted. Investigations into the use of a three-seat Hiller helicopter for this purpose were carried out in south-west Tanzania in 1964–65. It proved possible to cause virtually all the locusts in a strip the width of the rotor blades to rise ahead of the machine, provided it was flown at a height of about 10 ft. and at less than 10 m.p.h. and neither in the early morning nor in the late evening. A comparison of estimates of the size of the population in a 1-sq.-mile plot made by Land-Rover traverses with those made by helicopter, both when the traverse strip was marked on the ground and when it was assessed from within the helicopter, showed no evidence of systematic errors in estimating from the helicopter either the number of locusts flushed or the width of strip. Further, two observers simultaneously counting locusts rising from one strip achieved very similar results. Thus, estimation of the size of a complete outbreak-area population by means of a helicopter is clearly possible.

In a previous paper, “ On the use of experimental plots when studying forest insects ” (Bull. Ent. Res. x, pt. 2, Jan. 1920), the author emphasised the necessity of using every effort in order to obtain accurate records of the degree of infestation and amount of injury of forest trees. During recent years the author has developed a method of recording and graphically illustrating the part played by different insects in killing a tree. This method having yielded very good results, he proposes here to bring it to the notice of other entomologists, especially those interested in forest insects.

The material, upon which these observations were made is contained in the collection of the “Centraal Militair Geneeskundig Laboratorium” in Weltevreden (Java). To complete my observations many specimens in the collection of the British Museum were studied and compared.

The following note records the Ceratopogoninae found in two collections of small insects made by Dr. J. F. Corson at Dar-es-Salaam, Tanganyika Territory, East Africa, 1st to 20th September 1925. All the insects were taken between 5.30 p.m. and 6.30 p.m. on the windows of either the Bacteriological Laboratory or of a bungalow. We have pleasure in dedicating to the collector the single new species found.

In 1941 Edwards listed nine species from British Somaliland, comprising one Anopheline and eight Culicines. These were the specimens collected by R. E. Drake-Brockman in 1913 and by T.H. Twigg in 1930, but there appears to have been no datailed mosquito survey of the terrtory.

The present notes are based on a small collection made by the writer in January 1942, as a result of a brief survey in a limited area of the Protectorate, augmented by notes and material, mostly larvae, made by Dr. D. G. MacInnes from March to June 1942. Although only a few places were visited, the survey has added a further thirteen species to the list for the territory. Owing to circumstances, the restricted area investigated was confined to the region along the roads Boramo-Hargeisa to Berbera and Berbera to Burao, the altitude range being from sea-level to 5,000 feet.

In the American continent, the sugarcane borer Diatraea saccharalis (F.) is the main pest in sugarcane producing areas. The objective of this study was to assess the effect of crop residue management on damage by D. saccharalis, its egg parasitoids and the ants associated with sugarcane. The study was carried out during 2011–2012, 2012–2013 and 2013–2014 crop cycles, in three commercial fields located in different regions of Tucumán state, Argentina. Two types of crop residue management (= treatments) were compared: conservation of trash at the soil surface (CT) and trash burning (TB). In ‘trash conservation’ treatment, crop residue was allowed to remain over the soil surface during the whole sugarcane growing season, while the second treatment consisted of complete burning of trash blanket approximately 2 weeks after harvest. The injury level was measured by recording the number of stalks bored and internodes bored. Parasitism was estimated by counting the total number of eggs and number of black eggs (which indicates the occurrence of egg parasitoids). Ants (Formicidae) richness was calculated by two estimators; abundance-based coverage estimator and incidence-based coverage estimator, using the non-parametric richness estimators: Chao 2 and Jackknife. Finally, the indicator value was estimated through the measurement of specificity and fidelity. In all the parameters studied no significant difference was found between TB and CT treatments.

Since the publication of my previous paper on the Ethiopian fruit-flies of the genus Dacus, I have received some additional species, the descriptions of which are given in the following pages, with the purpose of completing our knowledge of this very important genus of Diptera. For the material here illustrated I am indebted to Dr. Guy A. K. Marshall, Director of the Imperial Bureau of Entomology, and to Dr. Alberto Mochi, of Ghinda, Erythraea: to whom I have to offer my best thanks.

The writer some years ago described a mosquito under the name of Dixomyia elegans, the type of which remained unique until May, 1927, when a few adults, larvae and pupae were collected. The larvae and pupae were found in hoof-holes made by cattle on the edge of a swamp. The water in these holes contained a considerable amount of decaying vegetable matter and was comparatively clear. It was not examined for algae, except that both Nitella and Chara were noted as being absent. The B. D. H. Universal Indicator gave a colour change of greenish-yellow (7·0–7·5) in all samples of water tested for pH.

Eurycoccus cuniculorum sp. n. and E. tamariscus sp. n., are described from Pakistan. They were collected on species of Tamarix during a survey of insect pests by the Commonwealth Institute of Biological Control for possible natural enemies of Tamarix spp. that have become undesirable plants in the USA. The mealybugs live under the bark or in tunnels caused by other organisms and both species have unusual characters in the positions of the thoracic spiracles.

The association of esterase (EST) activity with resistance to the organophosphorus (OP) insecticide methidathion was investigated in field-collected populations of whitefly (Bemisia tabaci (Gennadius)) in Israel. The inheritance of EST activity was studied by controlled crosses in the laboratory. Among-family variance of EST activity was highly significant although all families were maintained in the same rearing room. This indicates that genetic or common environmental effects due to rearing each family on a different caged plant must have been important. Heritability estimated from son-mother regression was h2=0.98, but this estimate seems to be unrealistically high. Daughter-mother and daughter-mid-parent regressions produced lower heritability estimates (as expected). None of the regression coefficients of daughters on mother, however, were significantly different from zero and the regression on parent explained only very small amounts of the activity variation in the offspring. Estimates obtained from intraclass correlations among offspring were higher and outside the acceptable range, reflecting the variance component due to the common environment. The predictive value of the heritability estimates appears to be very low. The frequency distribution of activity among individuals sampled from one insecticide treated site (AM) was skewed to the right, as previously reported. But samples from another site (TZ) showed a symmetrical distribution, unlike the previous pattern. When field collected individuals from AM were released on clean plants in the laboratory, samples taken from the plants one or more days later showed symmetrical EST distribution. Electro-phoretic paterns of field and laboratory samples were the same, but band intensity was stronger in samples from laboratory populations. Differences in mean EST activity between populations and sampling years were unrelated to methidathion resistance.

The present list of the mosquitos of south Thailand makes certain corrections to a list previously published and adds Anopheles barbumbrosus Strickl. & Chowd. and Anopheles letifer Sandosham to the list.

Taxonomic notes are given on eight species and a description of the larva of Uranotaenia bimaculiala Leic., previously undescribed, is included. The characters by which U. bimaculiala can be separated from the closely allied U. micans Leic. and U. edwardsi Barraud are detailed.

A description is given of the detection of an active breeding place of A. mauritianus in the Kurdani River, near Acre. This species was first reported by Barraud in 1920 as breeding in the swamps of the Kishon and Auja. Since that time neither Buxton nor the other workers in Palestine have been able to find this species. It is conceivable that the reason for the failure is due to the fact that the larvae closely resemble those of A. hyrcanus and that like it, the adult is a swamp feeder and not a house visitor.

The use of pesticides impairs biological control in the agroecosystems and thus compromises the effectiveness of natural enemies against populations of pest species. The concerns over pesticides should expand beyond mortality and encompass their sublethal effects and their consequences to the target insect species and natural enemies to aid in our understanding of the potential and consequential use of these compounds. The present study aimed to determine the effects of an insecticide mixture on life-history and demographic parameters of the cotton aphid Aphis gossypii Glover (Hemiptera: Aphididae) and two of its main parasitoids – Aphidius flaviventris Kurdjumov (Hymenoptera: Aphelinidae) and Aphidius colemani Viereck (Hymenoptera: Braconidae). Based on the obtained results, thiacloprid + deltamethrin in its lethal concentration dose 20% of the pest population (LC20) significantly affected the cotton aphid for two generations, increasing developmental time and demographic parameters. The LC20 manifested changes in many demographic parameters of the parasitoid A. flaviventris. This concentration also increased preadult and female longevity, total pre-ovipositional period, and mean generation time (T) of A. colemani, but no other demographic parameters were affected. Nonetheless, the insecticide mixture did not affect the parasitism rate of A. colemani. Thus, the thiacloprid + deltamethrin mixture significantly impaired the cotton aphid population and its parasitoid A. flaviventris. Therefore, the use of thiacloprid + deltamethrin is not encouraged for controlling the parasitoid A. flaviventris, but it is a relatively safe compound for A. colemani.

Large numbers of the bat, Nycteris hispida, Schreber, have been observed at dusk flying out of the residual forest islands at Gadau. Some have been captured and placed in a large cage containing Glossina morsitans and G. tachinoides. The sleeping bats, hanging head downwards, are perfect complacent hosts; both species of tsetse have been seen to attack and feed on them on many occasions, and to experience no difficulty in becoming fully gorged.