Aëdes (Stegomyia) polynesiensis Marks, Culex (Culex) pipiens fatigans Wiede-mann and Culex annulirostris Skuse were collected at Aitutaki, Southern Cook Islands, during a brief visit in 1958. Possible means of introduction of these mosquitos are discussed.

Methods have been developed for breeding continuous supplies of Lygus vosseleri in the laboratory. Adults readily oviposit in cotton seedlings, but tend to damage the tissues by feeding, so that the eggs fail to hatch. Portions of developing sorghum heads were found more satisfactory; grains in the milk stage stay fresh long enough for eggs laid in them to hatch, if the ratio of adults to grains is kept low.

The method used was to expose sorghum grains to adult Lygus for 3–4 days, afterwards removing the grains to hatching cages to await emergence of nymphs. On emergence, nymphs were transferred to rearing cages and fed immature sorghum grains, changed every two days. Hatching and rearing cages consisted of muslintopped, celluloid cylinders fitting on to shallow tins containing moist vermiculite covered by plaster of paris in which small holes received the sorghum stems.

At insectary temperatures the incubation period averaged 8·4 and the nymphal life 16·7 days; adult females survived up to 57 days and production of nymphs per female per day ranged up to 2·95. The mortalty in the egg stage is not yet known:the growth of fungi on the sorghum grains during incubation causes losses. Mortality in the nymphal stages averaged 44 per cent. and occurred chiefly in the first stage, probably due to handling. Improvements to reduce losses are described.

Difficulties in maintaining continuous supplies of sorghum grains, caused by attacks of Atherigona on sorghum seedlings and of Contarinia on sorghum heads, can be overcome, respectively by the use of insecticides and by bagging the emerging heads.

Syntomosphyrum glossinae Wtstn., a Chalcid parasite of the pupae of tsetse flies in East and West Africa, is recorded parasitising the oöthecae of Periplaneta americana (L.) at the West African Institute for Trypanosomiasis Research, Kaduna, Northern Nigeria.

The following species taken in London on imported bananas has been submitted recently for identification and has proved to be a new species of Dysmicoccus Ferris.

On checking some unidentified material in the British Museum (Natural History), the same species has come to light on imported bananas collected in London earlier. As some of these were labelled “from Canary bananas”, a check was made of all the material in the British Museum (N. H.) of mealybugs from the Canary Islands and it is evident that the species is widespread there but has been misidentified as Pseudococcus comstocki (Kuw.). Furthermore, it has been misidentified as this species on other occasions on imported bananas in England and Egypt and although some of the preparations concerned are labelled as from Canary bananas, it is not possible to determine whether all have come from this source.

In a sub-tropical city like Cairo it is most important that, so far as possible, the main streets be protected from the direct rays of a powerful sun by numerous and healthy shade-giving trees. For this purpose, the Lebbek (Albizzia lebbek) has been very extensively employed in Cairo, where it affords a welcome shade, as well as adding very considerably to the appearance of the streets. Until the summer of 1909, these trees have, on the whole, filled their parts quite satisfactorily. They had only one serious insect enemy to contend against, in the form of a longicorn beetle—Xystrocera globosa, Oliv. Hitherto this “borer” has been considered by far the most important pest of the lebbek, since its attacks, although comparatively slow in their effects on the life of the tree, are yet sure, and when extended over a period of years have caused no little mortality amongst the shade-trees of this city. During the past year the importance of this beetle has been, so far as Cairo is concerned, somewhat eclipsed by the depredations of a comparatively new pest—a mealy bug. This insect proves to be new to science, and is described for the first time in the appendix to this paper under the name of Dactylopius pertiiciosus, sp. n.

An apparatus for dispensing the eggs of cabbage root fly (Erioischia brassicae (Bch.)) is described. It consists of an ‘Agla’ micrometer syringe, a 2-ml pipette and a 20-mlsyringe connected together by a three-way valve. The eggs are dispensed volumetrically, the standard errors being < ±10% for batches ranging from 30 to 300 eggs. This degree of variation had no measurable effects on the uniformity of pupae from cabbage root fly cultures.

Mosquito-borne diseases have emerged in North Borneo in Malaysia due to rapid changes in the forest landscape, and mosquito surveillance is key to understanding disease transmission. However, surveillance programmes involving sampling and taxonomic identification require well-trained personnel, are time-consuming and labour-intensive. In this study, we aim to use a deep leaning model (DL) to develop an application capable of automatically detecting mosquito vectors collected from urban and suburban areas in North Borneo, Malaysia. Specifically, a DL model called MobileNetV2 was developed using a total of 4880 images of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus mosquitoes, which are widely distributed in Malaysia. More importantly, the model was deployed as an application that can be used in the field. The model was fine-tuned with hyperparameters of learning rate 0.0001, 0.0005, 0.001, 0.01 and the performance of the model was tested for accuracy, precision, recall and F1 score. Inference time was also considered during development to assess the feasibility of the model as an app in the real world. The model showed an accuracy of at least 97%, a precision of 96% and a recall of 97% on the test set. When used as an app in the field to detect mosquitoes with the elements of different background environments, the model was able to achieve an accuracy of 76% with an inference time of 47.33 ms. Our result demonstrates the practicality of computer vision and DL in the real world of vector and pest surveillance programmes. In the future, more image data and robust DL architecture can be explored to improve the prediction result.

Juvenile hormone (JH) plays a pivotal role in almost every aspect of insect development and reproduction. The chemical structure of the JH in heteropteran species has long remained elusive until methyl (2R,3S,10R)-2,3;10,11-bisepoxyfarnesoate, commonly named as juvenile hormone III skipped bisepoxide (JHSB3), was isolated from Plautia stali (Hemiptera: Heteroptera: Pentatomidae). Recently, several groups reported the presence of JHSB3 in other heteropteran species. However, most of the studies paid no attention to the determination of the relative and absolute structure of the JH. In this study, we investigated the JH of the cabbage bug Eurydema rugosa (Hemiptera: Heteroptera: Pentatomidae), known as a pest for wild and cultivated crucifers. JHSB3 was detected in the hexane extract from the corpus allatum (CA) product using a chiral ultraperformance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) which can inform the absolute stereochemistry of the JH. Its stereoisomers were not detected. Topical application of the synthetic JHSB3 to the last instar nymphs inhibited their metamorphosis and induced nymphal-type colouration of the dorsal abdomen in a dose-dependent manner. Additionally, the topical application of JHSB3 effectively terminated summer and winter diapauses in females. These results indicate that the JH of E. rugosa is JHSB3. Although individuals in summer and winter diapauses are physiologically distinct in E. rugosa, the results suggest that the physiological differences between these diapauses are based, not on the responsiveness to JH, but on the processes governing activation of the CA or on its upstream cascades.

The vector role of Aedes aegypti for viral diseases including dengue and dengue hemorrhagic fever makes it imperative for its proper control. Despite various adopted control strategies, genetic control measures have been recently focused against this vector. CRISPR Cas9 system is a recent and most efficient gene editing tool to target the sex determination pathway genes in Ae. aegypti. In the present study, CRISPR Cas9 system was used to knockout Ae. aegypti doublesex (Aaedsx) and Ae. aegypti sexlethal (AaeSxl) genes in Ae. aegypti embryos. The injection mixes with Cas9 protein (333 ng ul−1) and gRNAs (each at 100 ng ul−1) were injected into eggs. Injected eggs were allowed to hatch at 26 ± 1°C, 60 ± 10% RH. The survival and mortality rate was recorded in knockout Aaedsx and AaeSxl. The results revealed that knockout produced low survival and high mortality. A significant percentage of eggs (38.33%) did not hatch as compared to control groups (P value 0.00). Highest larval mortality (11.66%) was found in the knockout of Aaedsx female isoform, whereas, the emergence of only male adults also showed that the knockout of Aaedsx (female isoform) does not produce male lethality. The survival (3.33%) of knockout for AaeSxl eggs to the normal adults suggested further study to investigate AaeSxl as an efficient upstream of Aaedsx to target for sex transformation in Ae. aegypti mosquitoes.

The genus Obtusiclava, allied to Homoporus Thomson, is erected for the new species O. oryzae, a larval–pupal parasite of Pachydiplosis oryzae (Wood-Mason) in India and Ceylon.

An account is given detailing some aspects of the biology and economic importance of Psalydolytta pilipes Maklin in pearl millet (Pennisetum glaucum) fields in north-west Mali. Descriptions of the triungulin larval stage, together with drawings of larval development from the first grub stage to the coarctate larval stage, are given for two Psalydolytta species, P. pilipes and P. vestita Dufour. First grub phase larvae were successfully reared through to coarctates from eggs obtained from field captured adult beetles, on egg-pods obtained from a selection of commonly occurring grasshopper species. Yield losses resulting from cage trial experiments showed that whole millet candles can be destroyed during one night's feeding at densities approaching 12 beetles per head.

Similar increases in the height and aerial fresh weight of cowpeas compared with control plants were obtained when plants were sprayed with either 50 ppm a.i. (active ingredient) of the pyrethroid insecticide ‘Cymbush’® containing cypermethrin, or, the equivalent dilution of a blank formulation without the a.i. With broad beans, similar growth stimulation was obtained with the blank at the same or half dose, but not at a quarter dose. Testing the four formulation components separately showed that only the non-ionic emulsifier caused stimulation. A comparison of the stimulation of plant growth by the blank and the non-ionic emulsifier showed that plant height, shoot fresh weight, leaf fresh weight, leaf dry weight and leaf area were each equally increased by both treatments. The non-ionic emulsifier thus accounted for the entire stimulation caused by blank solution. Populations of Aphis fabae Scopoli (Homoptera: Aphididae) were twice as high on broad bean plants sprayed with the non-ionic emulsifier as on the controls. ‘Cymbush’ (the complete formulation) sprayed at 25 ppm a.i. was shown to increase the intrinsic rate of natural increase of the aphid through a 22% increase in fecundity; aphid development time was not affected. The results do, however, suggest that residual effects of cypermethrin may have partly counteracted the stimulatory effects of the non-ionic emulsifier. Nevertheless, it is possible that outbreaks of aphids and mites following pyrethroid application, and often assumed without evidence to have been due to natural enemy mortality, may at least in part reflect the plant stimulation caused by the non-ionic emulsifier in the formulation.

The association between insects and virus diseases of plants and the suspicion which at present rests on Jassidae, amongst others, may result in members of this family becoming of increased importance as potential vectors of virus diseases of crop plants. In America leaf-hoppers are already serious pests of cereals and of grape-vines, and in the cotton-growing area of Central and South Africa a Jassid forms one of the most important obstacles to the successful cultivation of this crop, so that in these countries a considerable amount of attention has been demanded by this group of insects. In this country, however, the leaf-hoppers have only been regarded as of minor importance, though in recent years increasing interest has been taken in certain species infesting potatoes and glasshouse crops. It was suggested to the writer that further knowledge of the biology of these insects was desirable, especially in view of the extreme importance of a nearly related species in many of the African cotton-growing areas, and it was accordingly decided to use the common species infesting glass-houses as a type for investigation with cotton as the food-plant.

The lac insects have, in recent years, been the object of extensive attention, partly on account of their economic importance, and partly on account of the biological interest that invests them. What the late Professor Lefroy had remarked about the Aphids in his “Indian Insect Life” may well have been said of these also but for the appearance of Chamberlin's Monograph (Bull. Ent. Res., xiv, 1923, pp. 147–122; xvi, 1925, pp. 31–42), which supplied a long-needed treatise on the subject. The weakness of this monograph, however, has seemed to me to be the insufficient treatment of the Indian forms, which was, evidently, due to lack of material, and it has therefore seemed desirable to undertake a study of the Indian lac insects in order to fill in the lacunae in this otherwise excellent monograph.

Several artificial media were tested in an attempt to eliminate the use of human faeces as oviposition and early larval habitats for breeding Musca sorbens Wied. in the laboratory. Eggs, laid on cotton-wool pads moistened with diluted milk or, preferably, on small quantities (10–15 g.) of human excrement, were transferred to the breeding medium. The best of those tested was a mixture of coarse wheat bran (120 g.) and diluted milk (240 g.), which yielded normal healthy larvae and adults. The average weight of a puparium produced in this medium was somewhat less than that of one produced in human excrement.

A review of the work carried out on mercury as a preservative against stored grain pests is given.

The influence of the duration of exposure to mercury vapour upon eggs of different stages of development is discussed.

Temperature and humidity within ordinary limits do not affect the efficiency of mercury.

Under airtight conditions this preservative is effective within a radius of three feet in receptables with or without grain.

Paper strips coated with mercury cannot be recommended for grain stored in bags and kept in piles because pressure and weight of the grain, or even shaking, will cause the mercury to be expelled from the strips.

Mercury dispersed in chalk cannot be used for grain destined for consumption. It is, however, quite suitable for preserving grain for seed.

Plastering the walls with mercury paste or afflxing slabs to the walls of godowns is not effective owing to the limited range of mercury vapour.

Application of mercury in various types of receptacles is discussed and advocated. Fumigation with mercury does not seem to be practicable.

During the early stages of the development of termite baits, dyed paper was placed in specified feeding stations to ascertain whether a slow-acting toxicant could be placed in a few bait stations to be delivered to the entire colony members of the Formosan subterranean termite, Coptotermes formosanus Shiraki. Feeding frequency data, as measured by the dye concentration in individual termites, suggested the absence of feeding site fidelity. However, these results were often misinterpreted as random movement of termites that were marked and released for population estimate studies, or the random search of food in soil by subterranean termites. A computer simulation program was constructed to re-examine this feeding frequency data, and confirmed the earlier conclusion that the lack of feeding site fidelity was the most likely explanation for the data.

Secondary metabolites are central to understanding the evolution of plant–animal interactions. Direct effects on phytophagous animals are well-known, but how secondary consumers adjust their behavioural and physiological responses to the herbivore's diet remains more scarcely explored for some metabolites. Caffeine is a neuroactive compound that affects both the behaviour and physiology of several animal species, from humans to insects. It is an alkaloid present in nectar, leaves and even sap of numerous species of plants where it plays a role in chemical defences against herbivores and pathogens. Caffeine effects have been overlooked in generalist herbivores that are not specialized in coffee or tea plants. Using a host–parasitoid system, we show that caffeine intake at a relatively low dose affects longevity and fecundity of the primary consumer, but also indirectly of the secondary one, suggesting that this alkaloid and/or its effects can be transmitted through trophic levels and persist in the food chain. Parasitism success was lowered by ≈16% on hosts fed with caffeine, and parasitoids of the next generation that have developed in hosts fed on caffeine showed a reduced longevity, but no differences in mass and size were found. This study helps at better understanding how plant secondary metabolites, such as caffeine involved in plant–animal interactions, could affect primary consumers, could have knock-on effects on upper trophic levels over generations, and could modify interspecific interactions in multitrophic systems.

Myzus persicae is a cosmopolitan aphid that is highly polyphagous and an important agricultural pest. The subspecies M. persicae nicotianae has been described for highly specialized phenotypes adapted to tobacco (Nicotiana tabacum). In Chile, the population of M. persicae nicotianae was originally composed of a single red genotype that did not possess insecticide resistance mutations. However, in the last decade, variation in the colour of tobacco aphids has been observed in the field. To determine whether this variation stems from the presence of new genotypes, sampling was carried out across the entire distribution of tobacco cultivation regions in Chile. The aphids collected were genotyped, and the frequency of kdr (L1014F), super-kdr (M918T), modification of acetylcholinesterase (MACE) and nicotinic acetylcholine receptor β subunit (nAChRβ) mutations associated with insecticide resistance was determined. A total of 16 new genotypes of M. persicae nicotianae were detected in Chile: four of them possessed the MACE mutation, and none of them possessed the kdr, super-kdr or nAChRβ mutation. The previously described red genotype was not detected in any of the sampled fields over two seasons. These results raise questions about the mechanisms underlying changes in the genetic structure of M. persicae nicotianae populations in Chile. Future research aimed at addressing these questions could provide new insight into aphid evolution and agricultural practices.

Glossina longipennis Corti was studied in Galana Ranch, Kenya over a four year period, in two areas (Tank E and Lali) where the species was abundant and other species were absent or scarce. There was active transmission of trypanosomiasis to cattle in both areas, the parasite species being Trypanosoma vivax Ziemann and T. congolense Broden. Mean infection rates of the G. longipenniswere 1.1% and 0.55% for T. vivax and T. congolenserespectively at Tank E, and 0.88% and 0.15% at Lali. Experimental transmission studies showed that cattle in fly-proof enclosures challenged with wild G. longipennis collected from Galana became infected with both trypanosome species. A tsetse control operation in one area (Tank E) using targets impregnated with deltamethrin in an oil formulation reduced the population of G. longipennisby 98% over one year, despite evidence of re-invasion. Populations of G. longipennis in the other area (Lali) were relatively stable over the whole study period. The effect of tsetse control on the incidence of cattle trypanosomiasis at Tank E was less clear than that on tsetse numbers, probably due to the lack of a sustained reduction in tsetse numbers. However, a significant relationship was demonstrated between fortnightly incidence measurements and electric net catches of G. longipennisat Tank E. A further significant predictor of incidence was rainfall in the previous four to seven weeks. This study confirms the importance of G. longipennisas a vector of bovine trypanosomiasis in areas where it is the predominant tsetse present.