Analysis by gas-liquid chromatography showed that flowers open at the time of the first generation of cabbage root flies, Erioischia brassicae (Bch.), contained nectars composed almost entirely of sucrose and fructose whereas those open during the second generation secreted fructose and glucose. There were qualitative as well as quantitative differences in the sugar composition of all the nectars analysed. In both generations, the most highly nutritive sources of nectars, 94% and 86% sugar solutions, were available from the umbellifers Anthriscus sylvestris and Heracleum sphondylium, respectively. Fructose and glucose were also the main sugars on pollen and anthers at the time of the second generation but, in addition, pollen samples contained large quantities of the sugar alcohol inositol. The surfaces of the pollen of the grasses Dactylis glomerata, Holcus lanatus and Arrhenatherum elatius all contained sufficient nutritive carbohydrates for maturation of the first batch of cabbage root fly eggs. One or more of the chemicals found only in water extracts of Arrhenatherum pollen was probably toxic to the flies. To obtain sufficient carbohydrates to mature the first batch of eggs, flies had to probe at least 1–2 mg of grass pollen each day, equivalent to the pollen produced daily by two flowering heads of Dactylis.

Females of Glossina palpalis (R.-D.) were dissected and examined for pregnancy at the Ugbobigha field station of the West African Institute for Trypanosomiasis Research in southern Nigeria between January 1958 and October 1959. Of 2,490 females dissected, 46 (2%) were virgin; 764 (31%) had an egg in utero and 221 (9%) a larva in utero. Highest pregnancy rates were found in months with heaviest rainfall and lowest mean temperature, saturation deficit and evaporation rate.

The pregnancy rate in G. palpalis near Kaduna, in Northern Nigeria, was nearly twice that found at Ugbobigha, the major difference being in the number of females with a larva in utero. It is suggested that in the Ugbobigha area an adverse factor operates in the late egg or early larval stage, causing abortion; this is probably not a direct effect of climate or of insufficient food but may partly be related to the possible inability of females to obtain a blood-meal at just the right stage in gestation. Low pregnancy rates may, at least in part, explain the low densities of G. palpalis commonly found in the forest belt of West Africa, despite the wide distribution of the species in such areas.

Further tests of insecticides, mainly carbaryl, endosulfan, endrin and DDT, for possible use against pests of cotton in Central Africa are described. In laboratory tests in Rhodesia, carbaryl was the most effective against first-instar larvae of Diparopsis castanea Hmps. exposed on leaves, stems and bracts of effective against second-instar larvae of Heliothis armigera (Hb.), to which the insecticides were applied directly, and carbaryl the least.

When adults of Dysdercus intermedius Dist. and D. fasciatus Sign. were caged with treated bolls, carbaryl was the most effective, endrin the next and (against the former sp. only) endosulfan the least. Deposits on leaves from 0.5 per cent. sprays of carbaryl, DDT and endosulfan remained effective in dry conditions for two weeks, but application of 0.05–1.0 in of simulated rain reduced their effectiveness immediately, especially that of carbaryl. The effectiveness of deposits was also reduced by plant growth and was affected by plant habit; on a hairy variety the deposits persisted longer than on a glabrous one, partly because the hairs retained them and partly because they made movement of the larvae more difficult.

The spectral sensitivity of the compound eye of the cabbage root fly, Delia radicum (Linnaeus), was measured using the electroretinogram (ERG) technique, at fifteen selected wavelengths between 340 nm and 670 nm. The form of the ERG was found to be diphasic in nature. A primary peak of spectral sensitivity in the UV (340–350 nm), and a smaller secondary peak in the blue-green region (460–546 nm) were found, together with a shoulder of sensitivity, representing a ‘pseudo-peak’ as reported for other Diptera, in the red region (630 nm). No significant differences were found between the dorsal and ventral regions of the eye. The peak response in the green region (546 nm) agrees well with existing behavioural data on colour attraction and visual discrimination of host plants by the cabbage root fly.

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.

Polyacrylamide gel electrophoresis of enzymes (carboxylesterases) was used for the first time to monitor rates of parasitism in airborne alate (winged) grain aphid, Sitobion avenae (F.) population samples collected by suction trapping in Hertfordshire, UK. Using previously described electrophoretic ‘keys’, the species of hymenopterous parasitoids present in individual aphids were identified and found to be Aphidius ervi (Haliday) and/or Aphidius rhopalosiphi (De Stephani Perez) (Braconidae). Entomophthoralean fungal infection was also detected using this approach. Aphidiid wasp parasitism was detected from early June to mid-August and fungal infection from late June to late July. The results are discussed in relation to parasitoid population structure and dynamics, especially (i) the fact that winged aphids passively transport the early stages of their braconid parasitoids and fungal pathogens, potentially to newly-founded colonies, which may directly impact on the dual aphid-parasitoid populations genetics; and (ii) the approach used to collect and assay parasitised and fungal infected aphids involving both suction trapping and electrophoretic testing may have potential in assessing the level and efficacy of these biological control agents in integrated pest management (IPM) schemes to combat cereal aphid outbreaks.

In mature Valencia orange trees at three sites in the Transvaal lowveld, there was a variable differential between levels of Aonidiella aurantii (Maskell) in the upper and lower parts of the trees. At one site there were high scale levels in the crowns of the trees as a result of past poor chemical spray procedure. In recent years, pest management has maximized on the use of natural enemies, especially Aphytis spp. However, the natural enemies have not been able to ameliorate the crown problem. At generally high levels of Aonidiella aurantii, the natural enemies were ableonly, more or less, to maintain the average overall level of the scale from one year to the next; they could not bring it down. This arose each year from too many scales escaping parasitism and reaching the relatively invincible adult stage early in the season. As the behaviour of the parasitoids was inversely density-dependent at these relatively high scale levels, this led to a greater increase in scale numbers, leading eventually to up to 90% of the population (excluding crawlers) being composed of adult females. The inverse density dependence was also partly because the majority of single scales escaped parasitoid attack. In the lowveld, it is a prerequisite that the density of A. aurantii first be lowered by an introduced natural enemy (e.g. the coccinellid Chilocorus nigritus (F.)) that attacks the adult stage and/ or by chemical means before maximal use is made of the regulatory influence of the existing natural enemies, particularly Aphytis spp.

Adult behaviour and oviposition patterns of Cacoecimorpha pronubana (Hb.), Phlogophora meticulosa (L.), Autographa gamma (L.), Mamestra brassicae (L.) and Lacanobia oleracea (L.) were studied by introducing laboratory reared pupae into glasshouses. Adults emerging from these pupae were located by direct visual searching of chrysanthemum plants and of the greenhouse structures for up to three weeks after emergence.

In small houses (2·9×3·3×2·5 m), 49 adults of C. pronubana emerged. At least 15 stayed inside the house and laid 1 750 eggs. With P. meticulosa, A. gamma and L. oleracea, 262 adults emerged and escaped from the houses without laying eggs inside.

In a large glasshouse (9·8×13·1×5·1 m) with automatic ventilators, 840 adults of P. meticulosa, A. gamma and M. brassicae emerged and many were prevented from escaping when the ventilators were closed during the moths' flight period. Moths were inactive in daytime and most were found on the highest parts of the aluminium framework, mainly on the sides which received most external light overnight. None were found on the glass. Only 27·3% of the P. meticulosa were found on the plants. Moth distributions probably result from moths flying until they reach a barrier, which they then tend to follow, with directional responses to gravity, light, settling site, food plant and oviposition site superimposed in varying degrees on this basic pattern. About 30 470 eggs were laid, more in outer than in inner beds and more in the outer than in the inner rows of a bed. P. meticulosa and A. gamma laid eggs only on plants. M. brassicae laid about 1 854 eggs on the undersides of leaves and 2 972 on glass and framework, mainly in the direction of external light.

All five species can cause serious damage to crops. Initial infestations can be controlled by sprays of chemical insecticides or Bacillus thurin-giensis. Usually a few larvae survive a single spray and, in the absence of further control measures, they may produce a troublesome second generation, although in certain circumstances further control measures may not be required. If biological control of other tomato pests becomes widespread, steps should be taken to prevent L. oleracea again becoming an important pest.

Tephritid pests controlled through the sterile insect technique (SIT) are mass-reared and subsequently released in affected areas. Several quality parameters are currently used to test adults, but none take into account interactions with a predator. When sterile males are released in the field, they will need to avoid predators until they reach sexual maturity and survive long enough to mate with wild females. Spiders are one of the most common predators that flies may encounter in release sites. In this study, we evaluated the antipredator behavior of a mass-reared sterile unisexual strain (‘Tapachula-7’) of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae) against their spider predators. We sampled spiders in citrus trees to determine which families could be more common. We established the baseline activity rates of sterile Tapachula-7 (Tap-7) flies in comparison with wild flies. We also tested the behavior of the fertile and sterile bisexual strain and wild flies against hunting spiders (Family Salticidae) and orb building spiders (Family Tetragnathidae). We recorded 18 spider families, with Salticidae being the most dominant. Tap-7 flies diminished their activity in comparison with wild males at 1800 h but showed similar activity levels earlier in the day. When exposed to orb-web spiders (Leucauge venusta), Tap-7, fertile and sterile males from the bisexual strain had similar rates of survival, but Tap-7 males showed lower survival than wild males. Against hunting spiders (Phidippus audax), wild males had higher probability of defensive wing displays, but there was no difference in spider attack rates. In general, sterile Tap -7 males performed as well as males from the bisexual strain, although they had lower survival than wild males. This could be due to either mass-rearing and/or irradiation effects. We recommend the use of the defensive wing display behavior as a quality parameter and propose a rapid and effective method to evaluate fly activity. The efficiency of SIT will be improved if released sterile males have the same antipredator repertoire as their wild counterparts.

The biology and population fluctuations of the non-biting Muscid Hydrotaea irritans (Fall.) were studied in two contrasting areas of Surrey using a standardised catching technique at selected sites, by analysing catches and by dissecting the collected flies. Following the first appearance of adults in early June, catches reached a maximum in late July, the males having fallen to a small proportion by early July. During August catches gradually fell, remaining at a relatively low level for the rest of the summer. The complete life-cycle, starting with eggs from caged fly colonies, took 295 days under sheltered outdoor conditions. The fly is univoltine, with three larval instars; larvae leave the egg in the second instar which is a brief, saprophagous stage, while the third, principal stage is predatory on other insect larvae. Overwintering normally occurs as a late-stage larva. Flies collected from sheep-grazing areas in Northumberland were shown, using serological methods, to have fed predominantly on cattle blood protein.

These notes are intended as a summary of the early investigations into the habits of Glossina morsitans carried out in connection with the Luangwa Sleeping Sickness Commission. The part of the valley that has been examined is that lying between 12° S. and 13° 50' S., but it has been practicable to make only one journey to the eastern side of the river. This journey was undertaken in September and consisted of an examination of the Rukususi and Rukusi Rivers from the Luangwa almost to the Nyasaland boundaries. Hence these remarks apply mainly to the district immediately surrounding Nawalia, the headquarters of the Commission. The observations have been made during the period from August 1911 to the beginning of March 1912.

The biodiversity of the European termite Kalotermes flavicollis is here studied through the analysis of mitochondrial (303 bp of control region and 912 bp of COI/tRNALeu/COII) and nuclear (five microsatellite and 20 Inter-SINE loci) markers on 18 colonies collected in Southern France, Corsica, Sardinia, peninsular Italy, the Balkans and Greece. Different statistical analyses (Bayesian phylogenetic analysis, parsimony network, F-statistics, PCA) were performed. Mitochondrial sequences produced an unresolved polytomy including samples from peninsular Italy, Balkans and Greece, and three main clades: southern France, Corsica-Sardinia and Portoscuso (SW Sardinia). Nuclear markers confirm these data, further highlighting a more significant divergence at the regional scale. The results obtained for the peri-Tyrrhenian area agree with major paleogeographic and paleoclimatic events that shaped the biodiversity of the local fauna. K. flavicollis biodiversity and its phylogeographic pattern are also evaluated in the light of the data available for the other native European termite taxon (genus Reticulitermes), in order to produce a more complete scenario of the Mediterranean. In the area comprised between southern France and Italy, the degree of diversity is similar; however, in the eastern area, while K. flavicollis is differentiated only at the population level, the genus Reticulitermes comprises at least six entities of specific and/or subspecific level. This discrepancy may be explained by taking into account the different evolutionary histories of the two taxa.

Female. Dorsum nude and densely chitinised. Marsupium occupying practically the whole of the interior. Venter (sternites) remaining attached to the food-plant. Legs and antennae present. Cephalic margin with a strongly developed clypeus, lying prone over the mentum. Abdominal stigmata present.

The Enemy Release Hypothesis (ERH) predicts that introduced plant species can escape herbivory and therefore have a competitive advantage over native plants, which are exposed to both generalist and specialist natural enemies. In this study, the ERH was explored using the invasive alien species, Arundo donax and two native tall-statured grasses, the cosmopolitan Phragmites australis and African endemic Phragmites mauritianus in South Africa. It was predicted that A. donax would have reduced species richness of herbivores compared with the native Phragmites spp., that it would be devoid of specialist herbivores and would thus be experiencing enemy escape in the adventive range. The herbivore assemblages were determined from both field surveys and a literature review. The assumptions of the ERH were for the most part not met; 13 herbivores were found on A. donax compared with 17 on P. australis and 20 on P. mauritianus. Arundo donax had two specialist herbivores from its native range, and shared native herbivores with Phragmites spp. Although A. donax had reduced species richness and diversity compared with that found in the native distribution, it has partially re-acquired a herbivore assemblage which is similar to that found on analogous native species. This suggests that enemy release may not fully explain the invasive success of A. donax in South Africa.

Leaf-cutter ant species (Atta spp.) are key pests of cultivated crops in the Neotropics, and recent studies have demonstrated that workers of Atta spp., particularly of Atta sexdens rubropilosa, exhibit aggressive behavior among nestmates when in contact with the sesquiterpene β-eudesmol, found in leaves of Eucalyptus maculata. However, the underlying mechanism sparking this behavior pattern has yet to be investigated. This work aimed to elucidate the mechanism by which this substance elicits aggression in workers of A. sexdens rubropilosa. The results, thus obtained, showed that β-eudesmol is able to modify the chemical composition of the workers cuticle, impairing nestmate recognition, triggering alarm behavior and leading to nestmate aggression.

The question of the effect of poisons on the blood of insects is a new one in entomo-toxicological literature. In a series of works by Metalnikov (1908, 1924, 1927) we have a study of the reaction of the blood of the larva of the Wax Moth (Galleria mellonella) in consequence of an injection into the body cavity of various substances and morbiferous microbes. The paper by Mrs. Tareeva and Nenyukov (1931) describes, very briefly and in general features, the picture of the blood of Calliptamus italicus in the case of poisoning by means of sodium arsenate or sodium fluoride.

A detailed study was conducted on the mating behaviour of Bactrocera cacuminata (Hering) (Diptera: Tephritidae) in nature. Plant tissues from Solanum mauritianum Scopoli, the primary larval host for B. cacuminata, were also analysed for methyl eugenol content. In the field, over a 15 month period, 44,171 observations of adult B. cacuminata individuals were made including 1109 mating pairs on S. mauritianum. Calling behaviour consisting of wing fanning and anus beating by males was also consistently observed on the underside of leaves of S. mauritianum after sunset. Female flies that arrived into these groups of 10–15 calling males were mated and often remained coupled until dawn. No methyl eugenol was detected from the analysis of leaves, flowers and fruits of S. mauritianum. Thus, B. cacuminata does not need to aggregate at sites where methyl eugenol is present and the hypothesis that this chemical plays a role in the selection of mating sites by B. cacuminata is not supported by the current study. It is concluded that S. mauritianum is the primary site of mating for B. cacuminata in nature and that the concept that the larval host plant is the centre of activity for dacine fruit flies remains robust, being fully supported by the results of this study.

Musca fergusoni J. & B. is an indigenous Australian fly that infests livestock, feeding on sweat and other body secretions and breeding in cow and horse dung. The fly is larviparous, developing a single larva at a time and depositing it at the end of the first instar. The ovaries comprise two ovarioles each, and the single ovulations alternate between ovaries and between ovarioles within an ovary. Abnormalities of development shown by unfertilised females are described, including the accumulation of fluid around unhatched eggs in the uterus which suggests that there is intrauterine secretion of nourishment for the larva. Descriptions are given of the immature stages. The egg is adapted for life in utero by having the respiratory plastron confined to the posterior end, oriented towards the genital aperture of the mother. The puparium is whitish, and is hardened by calcification instead of tanning. The durations of development at 16, 20, 27 and 32°C are given: from larval deposition to moult to third instar takes 58, 38, 19 and 15 h, respectively; from larval deposition to pupariation 11·5, 7·5, 3·5–4 and 3–3·5 days, respectively; and from larval deposition to adult emergence 53–57, 31–33, 15·5–16·5, and 10–11 days, respectively.

Field experiments have been conducted in Uganda to investigate the use of the insecticides DDT and Benzene Hexachioride for the control of tsetse. Since the Tsetse Research Department of Shinyanga has developed a line of investigation into the possibility of using cattle sprayed with DDT as poison bait for tsetses, it was considered that the alternative method of attack, i.e., treatment of vegetation, should be tried. The preliminarywork has been against Glossina palpalis, R.-D. Results of experiments against this species should provide a basis for work against other species. Experiments have been carried out as far as possible on small islands and headlandson Lake Victoria where the flies exist in isolated communities and where results are nottherefore influenced by infiltration of flies from surrounding bush.

Breeding of Simulium damnosum Theobald s.1., the vector of Onchocerca volvulus, had been eliminated by 1977 from about 654 000 km2 of the Onchocerciasis Control Programme in the Volta River Basin Area (OCP) of West Africa. Nevertheless, migrating adult females continually invaded the controlled area, being blown on the prevailing south-westerly winds from uncontrolled breeding sites beyond the south-western border of the OCP area. Graphs of numbers of females caught per man per day (the daily biting rate) throughout the wet season, March to October, at 16 sites in 1977 within the OCP controlled area were remarkably similar in pattern from site to site over a range of about 500 km downwind. In 1978, only seven sites within the OCP area were similarly monitored, and the graphs were different in pattern from those in 1977, when they each consisted of three or four well-defined waves or cycles of daily biting rate which could be easily identified and traced across country, their times of occurrence lagging increasingly as the distance of the site from the south-western border of the OCP area increased. Four methods were used to demonstrate and estimate the lag: visual comparison of seasonal graphs; comparison of the mean dates of cycles at different sites and the regression of these dates on distance from the south-western border; the dates when particular cumulative percentages of the total season's catch occurred at each site and their regression on distance; and principal coordinate analysis of the data and its relation to distance from the south-western border. Statistically significant lags were demonstrated and averaged one day for every 10–30 km from the border in 1977, which indicated an average speed of migration across country. In 1978, a rate of one day per 7–35 km was indicated. Where some graphs at outlying sites were anomalous, possible alternative sources of immigrant flies are considered. The possible behaviour of flies in causing the lag is discussed.