Cixiid planthoppers are considered of major economic importance, as they can transmit phytoplasmas responsible for many plant diseases. While thorougly studied in vineyards, the epidemiology of stolbur phytoplasma, transmitted by Hyalesthes obsoletus Signoret, was rarely investigated on minor crops as lavender, where it leads to ‘yellow decline’ disease and large economic losses. The objective of this paper is to understand the effect of the local landscape characteristics on the presence and density of H. obsoletus in the ‘Plateau de Valensole’, southern France. Potential host plants of H. obsoletus were surveyed in three contrasted zones (in terms of crops and disease intensity), by uprooting plants and capturing adults in emergence traps. The localization and potential movements of H. obsoletus from the host plants towards lavandin (infertile hybrid of lavender) were determined using yellow sticky traps. Clary sage plants were found as major hosts of H. obsoletus. Flying insects were also caught in fields of lavandin, although emergence traps and plant uprooting did not confirm this crop as a winter host, i.e., as a reservoir for the insect. Based on one zone, we showed that attractiveness may depend on crop (clary sage or lavandin) and on its age, as well as on the distance to the supposed source field. These results suggest that clary sage could be an important host of H. obsoletus, whose density largely varies between zones. Genetic studies would be required to confirm the role of clary sage in the dissemination of yellow decline of lavandin.

The Pentatomid bug, Scotinophara lurida (Burm.), is a serious pest of the rice crop in certain areas of Ceylon. Five or six generations develop on the two annual rice crops, and that which attains the adult stage at the time of harvest of either crop ‘aestivates’ and does not become sexually mature until later. The generations that become adult earlier in each crop season become sexually mature forthwith, and mate and oviposit.

In 1952, laboratory experiments to ascertain the susceptibility of adults of S. lurida to a range of modern organic insecticides, and field experiments on insecticidal control, were initiated. The insecticides tested were DDT, BHC, endrin, dieldrin, malathion, Chlorthion, Guthion, Dipterex, diazinon and parathion.

In the laboratory, freshly emerged, sexually mature and aestivating bugs were tested separately by topical application on the abdomen, and it was found that the insecticides could be arranged in the following descending order of toxicity, based on the LD50, against the sexually mature adult:— γ BHC, endrin, dieldrin, parathion, Dipterex, Chlorthion, diazinon, Guthion, malathion, DDT. The adults of the aestivating generations, at least prior to becoming sexually mature, were markedly more resistant to all the insecticides tested than were sexually mature bugs of uninterrupted development, the resistance ranging from two-fold to nineteen-fold that of the latter.

There is some indication that tolerance to every insecticide does not necessarily increase with increasing age and sexual maturity of the normal adult bug. Thus, whereas with the organophosphorus insecticides increasing sexual maturity is associated with an increase in tolerance, with DDT and endrin the bugs appear to become more susceptible with increasing sexual maturity, while with γ BHC and dieldrin there is little change.

The chlorinated hydrocarbon insecticides DDT, toxaphene, chlordane, aldrin, dieldrin, endrin, isodrin and γ BHC and the organophosphorus insecticides malathion, diazinon, Dipterex, Chlorthion, Guthion and parathion have been tested as emulsion sprays against S. lurida in the field. DDT and toxaphene gave the poorest results with about 85 per cent, control of the pest in 24 hours when applied at and above a concentration of 0·045 per cent, active ingredient. The other insecticides are arranged thus in descending order of efficacy against the pest considering the minimum dosage required to give 100 per cent, or near 100 per cent, control within 24 hours of application of the treatment: —parathion 0·02 per cent.→ endrin 0·03 per cent. = Chlorthion 0·03 per cent.→ Dipterex 0·03–0·04 per cent.=Guthion 0·02 per cent.→ dieldrin 0·06 per cent.= malathion 0·06 per cent.= γ BHC 0·06 per cent. → diazinon 0·07 per cent. Aldrin and isodrin were of about equal effectiveness giving about 90 per cent, control of the pest within 24 hours when applied at a concentration of 0·06 per cent, active ingredient.

Of the dusts tested, both γ BHC at 1·3 per cent, and dieldrin at 2·5 per cent, gave 100 per cent, control of the pest in 24 hours when applied under still and dewy conditions obtaining in the morning. Under dry, windy conditions however, γ BHC at 1·3 per cent, and 3 per cent, gave better control of the pest than did dieldrin or aldrin dusts.

Parathion, dieldrin, endrin, Metasystox and Ekatin were tested for residual action against S. lurida on the rice crop. Parathion was the most effective residually for a period of two days with dieldrin coming next in order of residual effectiveness.

Metasystox and Ekatin were tested for their systemic action against S. lurida on three-week-old and ten-week-old rice plants as foliar sprays and as root treatments. Systemic action of a low order of effectiveness against the pest was demonstrated in all cases but the poor results achieved and the high rates of application involved did not warrant their consideration for practical field use.

An investigation of the “ fly-belts ” in the Ol Orokuti area of the Masai Reserve was carried out early in April 1934, in response to a request from the European farmers of the Sotik district.

Nymph and adult populations of Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya were counted weekly on 3- or 4-year-old trees, Triplochiton scleroxylon, in Nigeria during 1966–71. D. eastopi showed successively larger peaks in late January or early February, mid-August, and early or mid-September; the smallest populations were in mid or late March. D. harrisoni showed peaks in February, late July or early August, and late October or early November, the second peak being the largest. Multiple regression analysis of Diclidophlebia populations against rainfall, saturation deficit, temperature and time showed that temperature had the greatest, although slight, effect on D. eastopi, while saturation deficit, through the host-plant, had a marked effect on D. harrisoni. D. harrisoni populations were dependent on the availability of young leaves. It is concluded that, to avoid attack by Diclidophlebia, transplanting of Triplochiton seedlings should be in late February or early March.

During the months of May and June 1921 I investigated the cause of the serious losses that had occurred among the rose-trees (especially Rosa damascena, Mill.) which are extensively grown in Bulgaria for making attar of roses. The conclusion arrived at is that the cause of the general decline in rose culture is inadequate nourishment of the plants, owing to an insufficient amount of humus and nitrogen in the soil, aggravated by the entire neglect of manuring by the growers. But the immediate cause of the death of thousands of rose-bushes has proved to be certain galls that are to be found on the stems, reaching 2–3 cm. in length and sometimes twice as thick as the normal stem.

For the last few months I have been using a beech tree-hole in Epping Forest as a source of supply of Anopheles plumbeus; and it has been our custom to collect larvae from the hole and transfer them to the laboratory at Sandwich, where the development is continued under artificial conditions. In this way we have been able to obtain large numbers of Anopheles plumbeus and Ochlerotatus geniculatus, together with the recently discovered Orthopodomyia albionensis as an associate. Not long after finding the Orthopodomyia, I was surprised to find yet another species from the same tree-hole, two male Stegomyia fasciata, emerging from the tank containing the mixed larvae from Epping Forest. The speciemens were of normal size, and we now have them preserved in our collection here.

The object of this paper is to place on record, with as much detail as possible, a scientific and official account of this year's locust invasion and also to describe methods of control which were found to be, or thought likely to prove, efficacious. Thus in future years reliable information may not be lacking with regard to these very important points. It should be added that the paucity of previous scientific records concerning locust invasions of Palestine during earlier periods has proved a not inconsiderable handicap from a number of different points of view.

In Vol. 29 (March, 1938) of this journal a short summary was given of the results achieved during an investigation of the wood-destroying insects in public buildings in the southern part of Sweden, Götaland. This survey has since that time been continued in Svealand, the middle part of Sweden, and in the following a short summary of the results will be given.

Experiments were carried out in Syria with parathion dusts for the control of Eurygaster integriceps Put. on wheat to ascertain the best time to apply the dust and the most suitable rate of application using a 6 h.p. dusting machine mounted on a “ jeep ”.

A field experiment is described in which a dust containing 0·75 per cent. parathion was applied under a drag-sheet to three plots of wheat at rates of 40, 20 and 10 kg. per hectare, respectively. The insects onthe wheat were mostly in the first three instars and the population was assessed by making 100 hand sweeps with a net at both 60 hours and 70 hours after treatment on each plot. The effect of treatment when compared with a control plot was to reduce the insect population in the three plots by 98·4 per cent., 83 per cent. and 65 per cent., respectively.

A further field experiment on a larger scale was carried out in an area in which plots of wheat were interplanted with plots of barley. In this case, the great majority of the insects were fourth-stage nymphs or adults. Five plots of wheat were treated with a dust containing 0·8 per cent. parathion at a rate of 35 kg. per hectare without using a drag-sheet. In two of the plots which were dusted in calm weather, about 89 per cent. control was obtained, in the other plots the effectiveness of the dusting was appreciably reduced by wind.

A cage containing 1,406 live specimens was placed, prior to dusting, in one of the plots of the latter experiment (dusted under calm conditions) and 6¾ hours after treatment all were dead. In the control only two specimens out of a total of 239 originally caged were found dead 24 hours later.

In 1923, under the name Oscinis pallipes, C. G. Lamb described a tiny black fly from Khartoum, Sudan. In the accompanying notes by Cottam (1923), this fly was said to swarm in immense numbers on ceilings and upper parts of rooms and verandahs in September to December. The swarms were said to be larger than those frequently recorded in Europe for “Chloropisca circumdata Meigen” which is now known as Thaumatomyia notata (Meigen). While it is not primarily an eye gnat, as are the Hippelates flies in the Americas, Cottam noted that the flies “are attracted to artificial light at night, and constitute a nuisance by swarming round lamps or on dinner tables and getting into people's eyes”.

Results are given of laboratory trials of insecticides, carried out in Kenya, against two pests of agricultural crops in East Africa. Against Epilachna hirta (Thnb.) (Col., COCCINELLIDAE), the adults and larvae of which feed on the foliage of wheat and other crops, dusts containing 0·5 or 2 per cent, parathion, applied at rates to give 0·74 to 2·97 mg. active ingredient per sq. ft., were the most rapidly effective against the adults. A 5 per cent. DDT dust, at rates giving 0·36 to 5·82 mg. technical DDT per sq. ft., was less rapid in action but produced very good results by the end of three days. A proprietary BHC dust, used at rates giving deposits of from 0·23 to 1·04 mg. γ isomer per sq. ft., was less effective and, at the highest rate used, only reached 100 per cent, mortality after eight days.

Several insecticides were tested in emulsified solutions against Cylas puncticollis Boh. (Col., CURCULIONIDAE), one of the important sweet-potato weevils of East Africa. All the insecticides were applied at concentrations of 0·02, 0·1 and 0·5 per cent, active ingredient, and at a deposit rate of 0·813 mg. of spray per sq. cm. DDT was the most effective after 18 hours, but γ BHC was only slightly inferior.

The egg, five larval instars and pupa of Milionia isodoxa Prout are described, and the adult is redescribed. Setal maps for the first and fifth larval instars are presented.

During initial screening of the synthetic pyrethroid lamdacyhalothrin (PP 321) at a concentration of 44 and 22 mg/l and applied as a 30 ml drench over each plant against third to fourth instar cutworms, Agrotis segetum (Denis & Schiffermüller) in microplots, few died but they did not damage the plants. Reducing the concentrations to 11 and 5.5 mg/l increased mortality and plant damage. When A. segetum were confined on soil treated with the insecticide at concentrations of 22, 11 and 5.5 mg/l and sprayed at an equivalent rate of 500 l/ha, they all died within one day. The higher concentrations appeared to have a repellent and/or antifeedant effect, and it has been possible to reduce the concentration of lamdacyhalothrin to 12.5 mg/l (≡5.6g a.i./ha) for the drench treatment without risking economic plant damage. For insecticides that have repellent and/or antifeedant properties, it should be possible to balance lower concentrations with adequate protection of plants from pest damage.

Closely allied to Ceratitis, MacLeay, and agreeing therewith in thoracic chætotaxy† and, venation : differing in general facies of body, in shape of scutellum, and in that of ovipositor, the first segment of which, instead of being flattened and truncate triangular in shape, is thickened and tubular, resembling that of Urophora.

At the request of Dr. W. R. Thompson, Superintendent, Farnham House Laboratory, The Imperial Institute of Entomology, England, arrangements were made in 1936 to collect and furnish to him larvae of the predacious Elaterid Pyrophorus luminosus, Illiger, indigenous to Puerto Rico. These beetles were for liberation in Mauritius to aid in the control of the white grub, Phytalus smithi, Arrow. Shipments were sent by steamer from Puerto Rico to New York and then to England for repacking and shipment to Mauritius. The Mauritius government appropriated the sum of 85 pounds sterling to defray the expense of collection, packing and shipment.

Les parasites suivants ont été recueillis par Mr. J. G. Myers à Versailles, France, en juillet et août 1925, de la Cécidomyie des poires, Perrisia pyri, Bch. Le matériel obtenu comprend les 10 espèces dont les noms suivent, avec indication de leurs dates d'éclosion, mais seuls les deux Platygasterines et le Torymus peuvent être considérés comme ayant une importance dans la destruction de la Cécidomyie, les autres espèces n'ayant été obtenues qu'en trés petit nombre ou n'étant probablement pas parasites de ce petit Diptère.

Understanding the development and reproduction of insects surviving controlled atmosphere treatment may help in developing sound pest management strategies. The developmental duration, survival percentage, and oviposition of Plodia interpunctella and its F1 generation were determined after the fifth instar larvae (the last-stage larvae) were exposed to 98% N2 for different exposure times. The survival percentage of the last-stage larvae treated with 98% N2 for 6, 4, 1.5, and 0 day was 70, 80, 91, and 100%, respectively when measured 24 h after treatment. The survival percentage of the last-stage larvae that developed to pupae was 37, 55, 73, and 96%, corresponding to the different exposure times. The developmental time needed to pass from pupa to adult emergence of specimens treated as the last-stage larvae were 8, 7, 6, and 6 days corresponding respectively to high N2 treatment after 6, 4, 1.5, and 0 day of exposure. The mean number of eggs laid by the subsequent females developed from the treated last-stage larvae was 35, 66, 81, and 123, respectively. The oviposition inhibition ratio of the F1 generation decreased by more than 33% compared with that of the parental generation. When the last-stage larvae were exposed to 98% N2 for longer than 4 days, the immature developmental time of surviving individuals in the F1 generation was delayed more than 6 days due to slower egg hatching and longer development of the first and second instar larvae stages. The population trend index of the F1 generation was lower when raised from the treated last-stage larvae than those from untreated controls.

The oriental armyworm Mythimna separata (Walker) (Lepidoptera: Noctuidae) is a major migratory pest of cereal crops in East Asia, South Asia and Australia. To comprehensively understand the ecological tolerance of M. separata, we collected life table data of individuals from four consecutive generations reared under outdoor natural fluctuating temperatures from 15 April to 17 October 2018 in Yangling, Shaanxi, China. The results showed that the immature stage in early summer and summer were shorter than in spring and autumn. High mortality in late larval instar and pupal stages was observed in the summer generation. The adult pre-oviposition period in autumn was longer than the other seasons. The population in the earlier two seasons had heavier pupae and higher fecundity than the population in the latter two seasons. The intrinsic rate of increase and the finite rate of increase was the highest in early summer (r = 0.1292 day−1, λ = 1.1391 day−1), followed by spring (r = 0.1102 day−1, λ = 1.1165 day−1), and was the lowest in summer (r = 0.0281 day−1, λ = 1.0293 day−1). The results of this study would be useful to predict the population dynamics of M. separata and deepen our standing of the adaptiveness of this migratory pest in natural fluctuating ambient environments.

There are several possible causes of aggregated nesting in solitary Aculeata, one being joint defense against parasites. We tested whether females prefer nesting in aggregations, even if they consist of heterospecifics. We compared the colonization and nesting parasitism of trap-nests with and without a red mason bee aggregation. The results did not support our hypothesis that females prefer nesting in aggregations. The numbers of wild Aculeata nests did not differ between trap-nests with and without an aggregation. Unexpectedly, parasitism rates were higher in trap-nests with aggregations. When analyzing only nests of wild insects (mostly wasps), the differences in parasitism disappeared. Natural nesting sites may be such a limited resource that females nested in the first trap-nest they encountered and did not discriminate between our treatments, or wasps might share too few parasites species with bees to benefit from joint nest defense.