1. To determine the percentage hatch of Calandra granaria eggs, the grain containing them should be kept for 6–10 days at 25°C. after a two-day oviposition period.

2. Pretreatment of grain with mercury vapour makes no difference to the fertility of eggs afterwards laid in it.

3. At 25°C. 99 per cent. of the eggs are sterilised in 24 hours and 87 per cent. in 8 hours, using what probably approaches the saturated vapour.

4. At 10°C., the sterilisation for periods of 24, 48, and 72 hours is 44, 87 and 93 per cent. respectively.

5. At 25°C., mercury vapour will penetrate at least 30 cm. of grain in 2 days. At 12°C., mercury vapour will penetrate at least 90 cm. of grain in 7 days.

Four species of Haemagogus have been found in Brazil, the commonest and most widely distributed being H. spegazzinii.

Keys and diagrams are given to facilitate the identification of the Haemagogus of this country.

Two of the proven vectors of sylvan yellow fever, H. capricornii and H. spegazzinii, can be distinguished one from another only by their male terminalia.

Traps designed to capture insects during normal movement/dispersal, or via attraction to non-specific (plant) volatile lures, yield by-catch that carries valuable information about patterns of community diversity and composition. In order to identify potential native/introduced pests and detect predictors of colonization of non-native pines, we examined beetle assemblages captured in intercept panel traps baited with kairomone lures used during a national monitoring of the woodwasp, Sirex noctilio, in Southern Africa. We identified 50 families and 436 morphospecies of beetles from nine sites sampled in both 2008 and 2009 and six areas in 2007 (trap catch pooled by region) across a latitudinal and elevational gradient. The most diverse groups were mainly those strongly associated with trees, known to include damaging pests. While native species dominated the samples in terms of richness, the dominant species was the introduced bark beetle Orthotomicus erosus (Curculionidae: Scolytinae) (22 ± 34 individuals/site). Four Scolytinae species without previous records in South Africa, namely Coccotrypes niger, Hypocryphalus robustus (formerly Hypocryphalus mangiferae), Hypothenemus birmanus and Xyleborus perforans, were captured in low abundances. Communities showed temporal stability within sites and strong biogeographic patterns across the landscape. The strongest single predictors of community composition were potential evaporation, latitude and maximum relative humidity, while the strongest multifactor model contained elevation, potential evaporation and maximum relative humidity. Temperature, land use variables and distance to natural areas did not significantly correlate with community composition. Non-phytophagous beetles were also captured and were highly diverse (32 families) perhaps representing important beneficial insects.

The situation following different degrees of discriminative clearing against G. morsitans Westw. was examined in eastern Ankole District, Uganda. In one area, where the treatment had been more intensive, the fly density was low, and it seemed that the population might be maintained by immigration from an adjacent area to the west, where treatment had been less intensive and in parts of which fly density was relatively high. The application of more intensive discriminative clearing of the fly's concentration sites to the western area, together with completion of the treatment of the eastern, failed to result in any marked effect on the tsetse population except as regards its distribution. Before this intensive clearing, concentrations of G. morsitans occurred in a double-storey vegetation type, the chief component of the upper storey of which consisted of Acacia gerrardii. After the upper-storey trees in this were felled, concentrations were found in groups of tall Acacia hockii, 12–18 ft. high, which had appeared to be of little importance to the fly before clearing. A year after the treatment of the western area there was no apparent reduction in fly density. The feeding habits and rate of utilisation of reserves of the flies showed no significant change as a result of clearing.

It seems that the failure of the discriminative clearing régime applied in this area, compared with the effect produced by less intensive clearing elsewhere in Ankole, is due to the presence in this area alone of the groups of tall A. hockii.

Insect-borne plant viruses usually alter the interactions between host plant and insect vector in ways conducive to their transmission (‘host manipulation hypothesis’). Most studies have tested this hypothesis with persistently and non-persistently transmitted viruses, while few have examined semi-persistently transmitted viruses. The crinivirus Tomato chlorosis virus (ToCV) is semi-persistently transmitted virus by whiteflies, and has been recently reported infecting potato plants in Brazil, where Bemisia tabaci Middle East Asia Minor 1 (MEAM1) is a competent vector. We investigated how ToCV infection modifies the interaction between potato plants and B. tabaci in ways that increase the likelihood of ToCV transmission, in two clones, one susceptible (‘Agata’) and the other moderately resistant (Bach-4) to B. tabaci. Whiteflies alighted and laid more eggs on ToCV-infected plants than mock-inoculated plants of Bach-4. When non-viruliferous whiteflies were released on ToCV-infected plants near mock-inoculated plants, adults moved more intensely towards non-infected plants than in the reverse condition for both clones. Feeding on ToCV-infected plants reduced egg-incubation period in both clones, but the egg–adult cycle was similar for whiteflies fed on ToCV-infected and mock-inoculated plants. Our results demonstrated that ToCV infection in potato plants alters B. tabaci behaviour and development in distinct ways depending on the host clone, with potential implications for ToCV spread.

In 1932, Clark investigated the exotic and indigenous insect relationships with Pinus radiata in New Zealand, recording six species in the former group and 19 in the latter. Three previously unrecorded insect associations are now added to this list.

In the form of the head this genus is allied to the Acidia-Pseudospheniscus group, but is distinguished by the very short antennae, by the bare third vein, by the dc. bristles being placed on the line of the a. sa., by the peculiar coloration of the head, and by the wing-pattern of the Aciura type. Only one as yet undescribed species from Abyssinia, Br. kovácsi, Bezzi.

The material on which this paper is based was bred from Nacoleia octasema (Meyr.) in New Guinea. The species of the new genus, herein described, was found to be an important primary parasite of the larva. The Tyndarichus species is a hyperparasite.

The new genus is close to Copidosoma and Litomastix, and very closely resembles the other genera of this group in both structure and habits. In the species described below the male is not unlike the males of some species of Copidosoma, and the female resembles Litomastix; the species appears to be polyembryonic. In the present state of the systematics of the ENcyrtidae it is deemed advisable to describe this species under a new genus.

I am grateful to Dr. J. Ghesquière, who consented to examine material of this genus and was generous in his advice and assistance.

(a). G. morsitans had been found in banana plantations and it was feared that it might in time establish itself. However, most of these flies had been caught in plantations which were reverting back to natural types of vegetation.

(b). It was shown by the release of marked flies that G. morsitans was repelled by the plantations which were still being cultivated.

(c). Only one G. morsitans was taken by the writer in cultivated plantations. It was demonstrated that flies found in these situations might easily have been transported thither by man or animals.

(d). The temperature in the banana plantations was slightly higher, and the range of the humidity greater, than in the adjacent vegetation. The difference between these physical factors of the two localities is insufficient to account for the flies' preference for natural types of vegetation as opposed to plantations.

During 1955 and 1956 two attempts were made to eradicate Glossina, palpalis (R.-D.) and G. tachinoides Westw. from 8¼ miles of heavily forested perennial river in Benue Province of the Northern Kegion of Nigeria by using DDT.

Descriptions of the rivers and the means employed in applying the DDT using knapsack sprayers are given, together with the effect of the insecticide on the fly population.

It was found that it was possible to eliminate G. palpalis from this type of habitat, where the forest is largely restricted to the immediate vicinity of the rivers, but that isolation must be carefully undertaken to prevent reinvasion, which would appear to be more extensive than had been expected. G. palpalis was completely absent for 18 weeks.

G. tachinoides, which was present in much smaller numbers, also disappeared on the treated river, but because of a similar disappearance on the control river it is not possible to attribute this to the insecticidal treatment.

The cost of spraying was about half the cost of clearing by normal current methods.

In the Transactions of the Entomological Society of London, 1929, in the introduction to my revision of the Indo-Australian and Ethiopian species of Microgaster, I stated my intention of writing subsequently for the related genus Microplitis a revision of the species from the same area. This I have done in the present paper, the slight alteration of title being necessary as no species of Microplitis have yet been described from the Ethiopian region.

Samples of water containing mosquito larvae are collected at Accra by the Sanitary Inspectors, and are sent regularly to the Laboratory for identification. The number of samples submitted in this way is never very large, and varies considerably from time to time; but, recently, a careful examination has been made of all the specimens received during a complete year, and it is proposed to analyse in this paper the materials thus collected. In 1910–1911 Graham made a similar study of the larvae found in native water-receptacles at Lagos, and it will therefore be interesting to compare our results with those obtained by him.

Accra, the capital of the Gold Coast Colony, is situated on the coast a few miles west of the meridian of Greenwich and about 330 miles north of the Equator. The town itself is divided into three portions, Accra proper to the west, Christiansborg where the Governor resides to the east, and the official residential area Victoriaborg between these two. The surrounding country is level for some miles, but the actual site of the town slopes slightly upwards as it recedes from the sea. Accra is a very dry and dusty town, almost completely denuded of vegetation. The rainfall is low ; during the twelve months under consideration, December 1914 to November 1915, 21·75 inches of rain fell. During the same period the maximum shade temperature averaged 85·39°, the minimum 73·83°, and the relative humidity 72·46°. The physical features and climatic conditions of Accra differ therefore greatly from those of Lagos, a low-lying town surrounded by swamps with an average rainfall of about 70 inches.

To obtain dietary information for the laboratory rearing of Planococcoides njalensis (Laing) the bark tissue of cocoa shoots and mealybug honeydew were analysed for their free sugar and amino acid contents. Paper chromatographic analysis showed the bark tissue to contain mainly sucrose, with smaller amounts of glucose, fructose and raffinose. The proportions of sucrose and glucose+fructose in the honeydew were 24–27% and 24–35%, respectively, with the bulk of the 80% ethanol fraction composed of ketose oligosaccharides. The latter compounds may result from the glycosyltransferase action of mealybug invertase which has been partially characterised. Of the free nitrogenous substances, ethanolamine, asparagine, cysteine, lysine and γ-aminobutyric acid, alanine and glutamic acid are preferentially absorbed. It is concluded that these are important mealybug metabolites, which may be supplied with small amounts of sugar in future liquid-diet trials. Their approximate physiological concentrations were estimated by a semi-quantitative method.

LD50 doses of chloropicrin, ethylene oxide, ethylene dibromide, acrylonitrile plus 8% carbon dioxide, and acrylonitrile plus ethylene dibromide were found to decrease the productivity of adults of Sitophilus oryzae (L.) and Tribolium castaneum (Hbst.). Acrylonitrile, acrylonitrile plus methyl iodide and phosphine caused a reduction in productivity in S. oryzae but not in T. castaneum. Carbon dioxide decreased the productivity of T. castaneum. Carbon tetrachloride, methylene chloride, methyl bromide, methyl iodide, acrylonitrile plus carbon tetrachloride and acrylonitrile plus methylene chloride had little influence on the productivity. The productivity of T. castaneum exposed to trichloroethylene and acrylonitrile plus trichloroethylene was higher than in control batches. After exposure to acrylonitrile, reduced productivity was noted in adults of Callosobruchus chinensis (L.) that had been exposed as adults or pupae, and in T. castaneum but not S. oryzae that had been exposed as pupae.

Microencapsulated gossyplure or its component Z,Z-isomer were applied to 0·04-ha field plots in Arizona for disruption of sexual communication in adults of Pectinophora gossypiella (Saund.). In an initial efficacy test, the materials were placed on cotton plants in 50-μl drops by hand at a rate of 3·7 g a.i./ha (24 690 drops/ha). Trap catches were reduced by averages of 92 and 81% for the Z,Z-isomer or gossyplure treatments, respectively, during a one-week test period. Mating in mini-mating stations was reduced by 100 and 91% for Z,Z-isomer and gossyplure treatments, respectively. In a further test, sprays were applied using a Micron Herbi 77 hand-held spinning disc applicator that was calibrated to deliver 1·97 × 108 spray droplets/ha (about 250 μm in diameter and 0·01 μl/drop). The spray and drop methods were used to apply rates of 2·5 or 12·3 g a.i./ha of both materials to 0·04-ha field plots. The 12·3 g/ha rate of microencapsulated materials was necessary to give about 90% reductions in trap catches for the 9–12–day test periods. Gossyplure and its Z,Z-isomer gave similar reductions in catches when the same rates and method of application were used. However, comparisons of results for 50-μl drops vs. spray indicated that the drops generally resulted in significantly lower trap catches than sprays at the 2·5 g/ha dose rate. The results indicate that spray application of microencapsulated gossyplure or its Z,Z-isomer have potential for communication disruption of P. gossypiella.

Using a high-throughput 454 pyrosequencing approach a novel set of microsatellite markers was developed for one of the key grapevine insect pests, the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae). 20 primer pairs flanking a microsatellite motif were designed based on the sequences obtained and were subsequently evaluated in a sample of 14 L. botrana populations from Europe and the Middle East. 11 markers showed stable and reproducible amplification patterns; however, one of the 11 markers was monomorphic in all L. botrana populations analysed. Estimated frequencies of null alleles of more than 20% were evident for two of the markers tested, but varied substantially depending on the respective L. botrana population. In 12 of the 14 L. botrana populations observed heterozygosities were lower to those expected under Hardy–Weinberg equilibrium, indicating a deficiency of heterozygotes in the respective populations. The overall FST value of 0.075 suggested a moderate but significant genetic differentiation between the L. botrana populations included in this study. In addition, a clear geographic structure was detected in the set of samples, evident through a significant isolation by distance and through results from structure analysis. In structure analysis, L. botrana populations were grouped in two clearly separated clusters according to their European (Spain, Italy, Germany) or Middle Eastern (Israel, Syria, Turkey) origin. This novel set of microsatellite markers can now be applied to study the evolutionary ecology of this species including host shifts and host adaptation as well as spread of individuals across worldwide viticulture.

For over a century, scientists from industrialized countries as well as from developing countries have appropriated natural enemies from different regions of the world. These actions have been conducted thus far without compensation to the donor countries for such ‘biological services’. This unrecompensed extraction has been predicated on the basis that biodiversity (including natural enemies) are ‘humankind's common heritage’ (Kloppenburg & Kleinman, 1987). Such a view has been challenged by some social scientists as well as representatives from some developing countries who now question the inequity of global patterns of exchange of and access to plant genetic resources. At issue is the substantial ‘genetic debt’ that the industrialized countries have procured from developing countries and which has remained uncompensated (Fowler & Mooney, 1990). In fact, the agricultures of industrialized countries are characterized by extreme dependence on ‘introduced’ genetic materials from developing countries. Much of this germplasm has been utilized by seed companies from industrialized countries to develop new, high-yielding varieties, often sold back to developing countries at considerable profit. The contradiction in the status of developing countries crop genetic resources as freely available ‘common heritage’ and the status of seed companies’ commercial varieties as ‘private property’ available by purchase has fueled a major geopolitical controversy. This dispute is bound to expand to other activities involving interregional exchange of biological resources. Concern about global environmental changes, the levels of responsibility of industrialized and developing countries in relation to these changes, and the fact that many developing countries are major repositories of biodiversity which play major biospheric roles, are all issues that fuel the controversy.

An in vitro test, based on the molasses sandwich-bait test, for mass screening of new compounds for general insect repellency is described. This is followed by a detailed account of a laboratory technique for comparing the initial potency of contact repellents for the stable fly Stomoxys calcitrans (L.).

Methods for rearing S. calcitrans of standardised aggressiveness and making comparative assessments of contact repellents against this fly are described. For initial potency, a standard area of the treated close-clipped abdominal skin of mice lying outside the cage was exposed through an orifice to standardised flies. A treated 0·5-cm-wide screen was incorporated as a border round the exposed area of treated skin so that flies biting the mouse were obliged to make tarsal contact with repellent. Using this method, and the organdie bag x human hand method for determining persistence on an inert substrate, each of the following repellents was compared with butyl 3-methylcinchoninate, a new repellent for S. calcitrans:

dimethylphthalate; 2-ethyl-1, 3-hexanediol; butoxypolypropylene glycol; dibutyl succinate; N,N-diethyl-m-toluamide; di-n-propyl isocinchomeronate; 2,3,4,5-bis (Δ2-butenylene)-tetrahydrofurfural; 2-hydroxyethyl n-octyl sulphide and N-benzoyl piperidine.

In each case butyl 3-methylcinchoninate was found to be superior. In the initial potency tests, the 50% repellency application rate was found to lie between 0·002 and 0·007 mg/cm2, while on organdie, rates of 0·2, 0·4, 0·8 mg/cm2 gave mean protection periods of 9, 19 and 34 days, respectively.

Through the kindness of Professor E. O. Essig, of the University of California, I have been enabled to examine a collection of Coccidae from Formosa, made by M. Maki and S. Inamura, and also a small amount of material from Foochow, China, collected by Mr. C. R. Kellogg. It is upon this material that the present paper is for the most part based. In addition to this, I am taking advantage of the opportunity to rectify certain errors that have been made in the identification of a few species from Japan.