CUF 101, a resistant cultivar of alfalfa, was exposed to 15 clones of Acyrthosiphon pisum Harris collected from alfalfa fields in three regions of France (east, south, central west) to determine whether the level of resistance varied across the different clones. The survival of alfalfa seedlings infested at the cotyledon stage was assessed using a standardized method. Although no difference in seedling mortality was detected between clones grouped by region, there was a significant variation among the 15 pea aphid clones. In particular, two clones of southern origin were more aggressive. In addition, the different pea aphid clones were characterized using allozyme and RAPD-PCR markers. Among the 15 clones, seven allozyme genotypes (plus one when adding colour polymorphism) and 12 RAPD-PCR genotypes were distinguished. The two southern clones differing by their aggressiveness on the resistant alfalfa belonged to the same allozyme and RAPD genotype which was distinct from the other pea aphid clones. Our results reinforce the need to take into account aphid genetic diversity in breeding programmes for resistance in cultivated plants.

Mangoma spinidorsum gen. et sp. n. reared from the galls of Procontarinia matteiana Kieffer & Cecconi at Bangalore, Karnataka, India, on mango leaves is described.

Larothrips dentipes gen. et sp.n., possibly a pollinating agent of yam flowers in Nigeria, is described. The genus Thrips is defined and compared with the closely related monobasic genera Microcephalothrips and Larothrips.

The specimens which form the basis of the following notes and descriptions were received by the writer from Mr. T. H. Colebrook Taylor, Assistant Entomologist, Fiji Islands, and were reared by him in the course of investigations looking to the introduction into the Fijis of parasites of Coccidae for the purpose of controlling the scale pests of coconut. One genus, two species and a variety are described as new.

Wheat of three moisture contents was fumigated with ethylene oxide, methyl bromide and hydrogen cyanide. Both chemical and biological assays were used to follow the changing distribution of the fumigant when applied with sustained vacuum, in a vacuum fumigation with simultaneous admission of air and fumigant, or at atmospheric pressure.

As these various factors were altered, in a multifactorial experiment, the changes in the fumigant distribution were also recorded chemically, and then analysed statistically. Changes in the mortality of both species of Calandra, either buried in a one-cwt sack of wheat or in the free-space, were estimated so that that part of the changes which was associated with the altered fumigant distribution was segregated by a covariance analysis and the remainder formed an estimate of the direct influence of the experimental Conditions on the susceptibility of the weevils to the fumigants.

When either ethylene oxide or methyl bromide is used as a fumigant for wheat, vacuum fumigation with simultaneous admission of air and fumigant gives results, in terms of the control of Calandra spp., which are almost indistinguishable from those obtained at atmospheric pressure under comparable conditions. When hydrogen cyanide is the fumigant, atmospheric fumigation is superior, quite apart from the capital expense and other practical disadvantages of fumigations at reduced pressures.

Pyrethrum-oil films were tested in various forms on plaster substrata against the tick, Ornithodorus moubata. The insecticide was most effective if applied :—

1. Concentrated rather than dilute.

2. In a medium rather than a light petroleum oil.

3. As an emulsion in Lanette Wax Solution rather than in oil alone.

4. With an irritant (such as 4-chlor-2-methyl-phenol) present in the solution.

Some account of work on the egg-parasites of the coffee bug in Kenya Colony has already been published in a bulletin of the Department of Agriculture of that country.

The egg parasitoid Trissolcus vassilievi (Mayr) (Hymenoptera: Scelionidae) is a significant natural enemy of the sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), the most important pest of wheat in Iran. This study examined the developmental time and egg-to-adult survival of two geographically separate populations of T. vassilievi on two corresponding host populations at five constant temperatures ranging from 15.0 to 35.0±1°C. No wasps of either population emerged at 15.0°C and the temperature threshold for development was similar between populations, ranging from 13.1±0.3 to 13.8±0.4°C for males and 12.2±0.1 to 12.6±0.1°C for females, but the thermal constant varied with gender and parasitoid population. Development of wasps from the colder Tabriz location was slower, with thermal constants for males and females of 172.6±3.1 and 204.1±1.2 degree-days, respectively, compared to Varamin wasps with 164.7±3.0 and 195.6±1.3 degree-days, respectively. Based on genetic inheritance patterns, reciprocal crosses between the two populations were expected to result in females with thermal phenotypes intermediate to their parental populations, and males that resembled their mothers. However, female progeny of crosses more closely resembled their maternal population, indicating a maternal effect on thermal phenotype. Furthermore, the magnitude of the maternal effect on the thermal constant was asymmetric and was more strongly expressed by Varmin than Tabriz females. These results suggest the possibility of using selective crosses between wasp populations, in combination with artificial selection in the laboratory, to tune the thermal phenotype of parasitoids to specific regions prior to augmentative releases.

The attractiveness of various colours, colour combinations and sizes of sticky traps of the 3-dimensional trap (3DT), cross-shaped target (XT), rectangular screen (RT) and monopanels were evaluated for their efficacy to capture Glossina austeni Newstead and G. brevipalpis Newstead in north-eastern KwaZulu-Natal, South Africa. The 3-dimensional shapes of the XT and 3DT in light blue (l.blue) and white were significantly (ca. 3.1–6.9 times) better than the RT for G. austeni. On bicoloured XTs, G. austeni landed preferentially on electric blue (e.blue) (58%) and black (63%) surfaces when used with white; while for G. brevipalpis, significantly more landed on e.blue (60–66%) surfaces when used with l.blue, black or white surfaces. Increased trap size increased the catches of G. brevipalpis females and both sexes of G. austeni significantly. Temoocid and polybutene sticky materials were equally effective and remained durable for 2–3 weeks. The glossy shine of trap surfaces did not have any significant effect on the attraction and landing responses of the two species. The overall trap efficiency of the e.blue/l.blue XT was 23% for G. brevipalpis and 28% for G. austeni, and that of the e.blue/black XT was 16% for G. brevipalpis and 51% for G. austeni. Larger monopanels, painted e.blue/black on both sides, increased the catches of G. austeni females significantly by up to four times compared to the standard e.blue/black XT. This monopanel would be recommended for use as a simple and cost effective survey tool for both species in South Africa.

In 1956 and 1957, tests were made in the Sudan Eepublic of four methods of applying insecticides for the control of heavy infestations of midges, particularly Tanytarsus lewisi Freeman, which breed in the Blue Nile. During the winter season the adults occur in myriads in areas adjacent to the river in Khartoum and similar localities, resting in trees and shrubs by day and being attracted to artificial lights after dusk

An emulsion containing 0·4 per cent. DDT applied from the ground to shadetrees in Khartoum at the rate of 0·5·1·0 lb. DDT per tree achieved local control of the midges for three days and detectable reduction for 10 days. An emulsion containing 12·5 per cent. DDT applied from an aircraft to the wooded riverfrontage at Khartoum at 2·1 lb. per acre reduced the numbers of adult midges for the next 15 days, but subsequent applications under conditions of greater air turbulence were ineffective.

The application of DDT as a larvicide in oil solution from aircraft to the river 10 miles above Khartoum, at a concentration approximately equivalent to 0·1 p.p.m. in 2 hours' riverflow, did not appear to reduce the numbers of adults or immature stages at Khartoum, and was followed by some mortality of fish.

The previous paper on the nomenclature of Australian Tabanidae (Ferguson, 1924) was unfortunately despatched for publication long before Enderlein's paper “ Ein neues Tabaniden-system ” (Enderlein 1922) became available in Sydney. Hence certain alterations are necessary to statements which appear in my former paper.

Following an evaluation of the anatomical characters and habits of the Scolytini, four genera are recognised, namely Scolytus Geoffroy, Scolytopsis Blandford, Camptocerus Dejean, and Cnemonyx Eichhoff (=Loganius Chapuis, Ceratolepis Chapuis, Coptosomus Schedl, syn. n.). Two South American species, Camptocerus aquilus and C. rectus, having an ambrosial habit, are described as new.

Mr. H. Hargreaves, Government Entomologist, Uganda, has sent me identified, larvae of several species of beetles. I now describe those which are of economic importance.

Although parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

The eastern larch beetle (Dendroctonus simplex Le Conte) is recognized as a serious destructive forest pest in the upper part of North America. Under epidemic conditions, this beetle can attack healthy trees, causing severe damages to larch stands. Dendroctonus species are considered as holobionts, as they engage in multipartite interactions with microorganisms, such as bacteria, filamentous fungi, and yeasts, which are implicated in physiological processes of the insect, such as nutrition. They also play a key role in the beetle's attack, as they are responsible for the detoxification of the subcortical environment and weaken the tree's defense mechanisms. The eastern larch beetle is associated with bacteria and fungi, but their implication in the success of the beetle remains unknown. Here, we investigated the bacterial and fungal microbiota of this beetle pest throughout its ontogeny (pioneer adults, larvae and pupae) by high-throughput sequencing. A successional microbial assemblage was identified throughout the beetle developmental stages, reflecting the beetle's requirements. These results indicate that a symbiotic association between the eastern larch beetle and some of these microorganisms takes place and that this D. simplex symbiotic complex is helping the insect to colonize its host tree and survive the conditions encountered.

The introduction of flowering plants into orchards can increase functional biodiversity in pome fruit cultivation. Plants provide nectar, pollen and prey resources supporting pollinators and natural enemies. However, pests may also benefit from floral diets and a careful selection of plants is necessary to reduce any risk of pest proliferation. The codling moth Cydia pomonella is a major pest in apple growing worldwide and adults are known to consume sugars. The impact of floral diets (parsnip, wild carrot, coriander, red clover) on longevity, fecundity and fertility of adult codling moth was examined under laboratory conditions. In general, male moths lived longer than females, regardless of dietary treatments. Moths survived longest when supplied with parsnip flowers as a floral diet. Contrary to carrot, coriander resulted in higher longevity of adult C. pomonella compared to moths provided with red clover as a negative control. Adult nutrition on floral diets did not affect fecundity substantially. As expected, the majority of eggs were laid within the first week. Prolongation of moths’ lifespan by floral diets did not significantly increase the total number of eggs laid in contrast to a diet with 25% sucrose solution. According to these results, the risk of inadvertently promoting codling moth when growing selected flowering plants in the orchard will be rather low, because the fitness of the moths and especially the reproduction of the females will not be substantially enhanced.

The object of this paper is to give taxonomic consideration and status to the ‘white-clubbed’ parasite of tsetse flies that was studied by Dr. D. S. Saunders in the foregoing paper. Since the biological evidence in conjunction with the distribution suggests that it is specifically distinct from Syntomosphyrum glossinae Waterston it is described as a new species, although the morphological separation is weak.

Leaving Karonga, at the northern end of Lake Nyasa, on July 15th, I reached Katumbi on the Luwumbu River, the chief tributary of the Upper Luangwa, about a week later. I had made this river my objective, as I had already examined, in 1908, a considerable portion of the Luangwa above its junction with the Luwumbu. After following the Luwumbu down to this point, the Luangwa itself was followed for a considerable distance, chiefly on the left bank.

Reasons for the large day-to-day variations in the numbers of nymphs and adults of the Coreid bug, Pseudotheraptus wayi Brown, taken in the crowns of coconut palms in Zanzibar by the searching technique over a period of six years were investigated in 1957–58. Data are given showing the results of searches (each occupying less than 20 minutes) carried out on two young palms at different times of day and night and in different weather conditions. For each successive 2-hour period between 6.0 a.m. and 2.0 p.m. (in the case of nymphs) or 4.0 p.m. (in the case of adults) the proportion of searches in which P. wayi was observed was significantly greater on dull days than on bright, sunny days, but there were no such differences that were significant in respect of any other 2-hour period for which comparisons could be made, except 4.0 to 6.0 p.m., when the proportion of searches disclosing nymphs was greater on bright days. During the hours of bright sunlight, the adults and nymphs hide in crevices and in the debris found in the leaf axils, but both remain in the open from dusk to dawn. During heavy rain they take shelter in dry crevices and niches.

It is pointed out that this behaviour must be taken into consideration if the searching technique is used to assess the result of an application of insecticide.