Following successful small-scale trials, an attempt was made, by aircraft application of insecticide, to eradicate Glossina morsitans Westw. and G. pallidipes Aust. from an isolated block of savannah woodland, approximately 11 sq. miles in extent, at Chungai in the Central Province of Tanganyika between July 1958 and January 1959. A single-engined aircraft, fitted with two belt-driven rotary-cage atomisers, was used to apply a 5 per cent, solution of γ BHC in power kerosene at a nominal dosage of 0·08 gal. per acre (0.04 lb. γ BHC per acre). Seven applications were made at approximately 28-day intervals, the time taken to complete an application varying from five to eight days. The operation failed to control the flies. Although each of the first two applications reduced the apparent density of G. morsitans by about 90 per cent, and that of G. pallidipes by a lesser, although still considerable, factor, later applications gave varying and often low mortalities, and the populations increased slowly for some time, the insecticide applications causing only temporary depressions in numbers. Numbers fell towards the end of the operation, but final reductions were only about 50 per cent, or less. Kills of female flies were low, and this undoubtedly led to the eventual failure.

The low volume-dosage, a drop spectrum that possibly contained too few droplets of the required size, meteorological conditions, and biological factors that apparently favoured the survival of female flies are suggested as contributory elements to the low mortalities.

Operational costs were considerably lower than in previous work.

In social insects such as the honey bee, the quality of drones at the time of their emergence can affect their maintenance in the colony until maturity. Body mass, wing size and wing asymmetry of emerging honey bee drones were measured and correlated with their life span in the colony and compared between individuals reaching maturity or not. The life span of drones differed among colonies in which they were maintained after emergence but not between colonies in which they were reared. More drones heavier at emergence reached sexual maturity at 15 days and had a longer life span compared with light-weight drones of lower mass. The size and symmetry of drone forewings was not correlated with their life span. Our results suggest that body mass at emergence is a good predictor of drone survival in the colony.

Effective early detection, monitoring and management methods are critical for reducing the impacts of insect pests in agriculture and forestry. Combining host plant volatiles with sex pheromones could enhance trapping methodologies, whilst the use of non-host volatiles could improve the effectiveness of pest management through repellency effects. In this meta-analysis approach, we analysed 51 studies that used electroantennograms (EAG), wind tunnels and/or field traps to evaluate the antennal and behavioural responses of Lepidoptera to sex pheromones combined with attractant or repellent plant volatiles. Proposed attractant plant volatiles had a positive association with female Lepidoptera responses to sex pheromone, but effects on males were highly variable, with unexpected repellency reported in some studies. Proposed repellent plant volatiles were significantly or near-significantly negatively associated with male attraction to sex pheromones but were scarcely studied. Sub-group analysis identified that male responses to sex pheromone were reduced when the dose of attractant plant volatile relative to sex pheromone was increased. Green-leaf volatiles were associated with the strongest positive effects for males in field traps. Multiple-compound attractant plant volatile blends were less effective than single compounds in field studies. Our analysis demonstrates, (i) the potential value of combining host plant volatiles with sex pheromones to capture females rather than only males, (ii) the importance of identifying appropriate host plant volatiles and optimal relative doses, and (iii) the potential for non-host plant volatile use in pest management strategies.

A new species of Scirtothrips found damaging tea in Kenya is described and named S. kenyensis, and a note is given on damage caused by members of this genus. The name Heliothrips minutissimus Bagn. is suppressed as a synonym of Scirtothrips dorsalis Hood, and S. sweetmani Bianchi and S. tilschacki Ananthakrishnan are suppressed as synonyms of S. bispinosus (Bagn.), a combination that is here restored.

Most of this paper is occupied with the description of a method for evaluating the influence ol temperature, recorded in the field, on the rate of development of the eggs of a grasshopper (Austroicetes cruciata). When the conventional methods of temperature summation were used, important errors were introduced because:—

(a) The temperature in the environment of the insect may be different from the temperature in the meteorological screen.

(b) The arithmetic mean of the maximum and minimum temperature may not be an adequate estimate of the true mean temperature for the day.

(c) The relationship between temperature and the rate of development of the organism over the range of temperature used, was not linear.

(d) Development may proceed for less than 24 hours of each day.

Temelucha minuta (Morl.), a common parasite of Phthorimaea operculella (Zell.), is redescribed with emphasis on features enabling it to be separated from other species of Temelucha. T. clausa Kerrich is placed as a junior synonym of T. minuta. The known geographical range of the parasite is expanded to include Cyprus, Australia and India. A provisional key is given to the Australian species of Temelucha, and notes are given on their distribution and hosts. T. verimaculata (Cam.) is placed as a junior synonym of T. australiensis (Szépl.).

Climate change has affected the geographical distributions of most species worldwide; in particular, insects of economic importance inhabiting tropical regions have been impacted. Current and future predictions of change in geographic distribution are frequently included in species distribution models (SDMs). The potential spatial distributions of the fruit fly Anastrepha striata Schiner, the main species of agricultural importance in guava crops, under current and possible future scenarios in Colombia were modeled, and the establishment risk was assessed for each guava-producing municipality in the country. SDMs were developed using 221 geographical records in conjunction with nine scenopoetic variables. The model for current climate conditions indicated an extensive suitable area for the establishment of A. striata in the Andean region, smaller areas in the Caribbean and Pacific, and almost no areas in the Orinoquia and Amazonian regions. A brief discussion regarding the area's suitability for the fly is offered. According to the results, altitude is one of the main factors that direct the distribution of A. striata in the tropics. The Colombian guava-producing municipalities were classified according to the degree of vulnerability to fly establishment as follows: 42 were high risk, 16 were intermediate risk, and 17 were low risk. The implementation of future integrated management plans must include optimal spatial data and must consider environmental aspects, such as those suggested by the models presented here. Control decisions should aim to mitigate the positive relationship between global warming and the increase in the dispersal area of the fruit fly.

Cold storage effects on the female predatory thrips Scolothrips longicornis Priesner (Thysanoptera: Thripidae) fed on Tetranychus urticae Koch eggs for different time periods (5, 10, 20 and, 30 days) at 5 or 25 °C (control) on development and life table parameters were examined. Female adult duration and female total longevity were not influenced by the period of cold storage. The minimum mean female total longevity (28.1 ± 0.32 day) was observed in the 30-day treatment. The oviposition period decreased with increasing cold storage duration. All life table parameters of S. longicornis demonstrated a significant difference across treatments. Our results demonstrated that the female adult of S. longicornis could be maintained at 5 °C for 5-days with minimal reduction in the life-history process. This would be beneficial in the storage and mass production of S. longicornis in biocontrol programs involving T. urticae.

A translocation homozygous strain (TT) of Delia antiqua (Mg) was released into a field cage in Wageningen, The Netherlands, together with a standard laboratory strain (++). During the course of the season, the fecundity and fertility of the adults were measured together with the karyotype frequencies (TT+; T+; ++) of the F1 progeny. No selective disadvantage of the translocation karyotypes was observed. However, only four F1 adults emerged in the field cage; therefore a sample of pupae was removed from the cage, and it was shown that nearly 100% of the surviving pupae had entered diapause. This figure was confirmed from the remainder of the pupae. The fertility of eggs from the emerging adults was reduced to 54%, compared with the standard fertility of nearly 90%, but because of the diapause response of the strains used, the effect of this reduced fertility in the field-cage population could not be followed. The reasons for the change in diapause response of the laboratory strains are discussed and suggestions made as to how this could be prevented. The report highlights the importance of quality in control techniques involving translocations.

The genus Subhimalus is erected for the new species S. melanus on potato and S. fuscus on clover; Balclutha versicoloroides from clover is described as new.

Zanjoneura kenyana gen. et sp.n. is described from specimens collected on Caesalpinia spinosa in Kenya, and two species are transferred to Zanjoneura from Frutioidia. A key is given to the 18 genera of the Erythroneurini found in Africa.

In the foregoing pages the following tentative views have been put forward in the hope that they may receive either confirmation or criticism from other investigators :(1). The latter part of the dry season is probably, in general, the most favourable portion of the year to the fly.(2). The later the onset of the rains the greater the capacity for increase.(3). Seasons of unusually heavy rainfall are inimical, at least in certain areas.(4).A series of years of lew rainfall is favourable.(5).Regions where the fly commonly attains the greatest concentration of numbers are the regions where it is most liable to be reduced or to die out,namely, parts of the infested areas where first-grade foci predominate.(6).In Southern Khodesia the passage of grass fires has, as a rule, no appreciable effect on the numbers of the fly.(7).Mopani belts are probably of considerable value to the fly in providing limited areas attractive to game in the wet season, where the grass remains short; they possibly also afford a convenient refuge from grass fires in the dry season.(8).The fly does not migrate under the stimulus of hunger or in company with game.(9).The fly as a whole does not follow game about infested areas.(10).The maximum distance at which a hungry fly readily detects its hosts is a short one, possibly less than 100 yards.(11).The maximum following distance of the females remains to be determined ; the writer is not yet convinced that the females seek animals and humanbeings only for the purpose of feeding, though this appears probable.

A simple X-ray method for detecting sorghum midge (Contarinia sorghicola (Coq.)) larvae and pupae in infested spikelets of grain sorghum (Sorghum vulgare) is described and illustrated. Undamaged ovaries were easily and accurately detected in the radiographs, but the detection of spikelets that had been attacked by midge was less accurate. Diapause larvae showed up clearly in the radiographs but pupae often produced indistinct images, possibly because they were dead. X-ray examination therefore tended to underestimate midge infestation. It is concluded that this radiographic technique is less accurate than dissection, but might be used for rapid general field surveys and for in vivo observations of larval development within infested spikelets.

We studied the occurrence, morphology and phenology of Dendroctonus micans in Lithuania and the fungi associated with the beetle at different developmental stages. The occurrence of D. micans was assessed in 19 seed orchards (at least 40 years old) of Picea abies (L. Karst.) situated in different parts of the country. Bark beetle phenology was studied in two sites: a seed orchard of P. abies and a plantation of Picea pungens (Engelm.). D. micans morphology was assessed under the dissection microscope using individuals at different developmental stages that were sampled during phenology observations. Communities of fungi associated with D. micans were studied using both fungal culturing methods and direct high-throughput sequencing from D. micans. Results showed that the incidence D. micans was relatively rare and D. micans was mainly detected in central and eastern Lithuania. The life cycle included the following stages: adult, egg, I–V developmental stage larvae and pupa. However, development of D. micans was quicker and its nests larger under the bark of P. pungens than of P. abies, indicating the effect of the host species. Fungal culturing and direct high-throughput sequencing revealed that D. micans associated fungi communities were species rich and dominated by yeasts from a class Saccharomycetes. In total, 319 fungal taxa were sequenced, among which Peterozyma toletana (37.5% of all fungal sequences), Yamadazyma scolyti (30.0%) and Kuraishia capsulate (17.7%) were the most common. Plant pathogens and blue stain fungi were also detected suggesting their potentially negative effects to both tree health and timber quality.

Losses from Pink Bollworm (Platyedra gossypiella) and from Spiny Bollworm (Earias insulana) were studied in the American Upland cotton crop grown on Zeidab pump irrigation scheme in the Northern Province of the Sudan. In 1948, a year of normal attack, 12·9 per cent. of the estimated potential yield was destroyed by bollworms. Pink Bollworm was responsible for 10·7 per cent. or a loss of 135 pounds of seed cotton per acre. Spiny Bollworm damaged 2·2 per cent. or 28 pounds per acre.

Four-fifths of the total yield is derived from the bottom crop which is harvested before the end of September and consists of high grade seed cotton. The other fifth is produced as a top crop and consists of low grade seed cotton ripening in October and November. Only 3·5 per cent. of the bottom crop is lost on account of Pink Bollworm as against 33·3 per cent. of the top crop. The corresponding figures for Spiny Bollworm are 1·6 per cent. and 4·1 per cent.

Some factors influencing the extent of pink bollworm attack are outlined. The Zeidab crop escapes serious damage through rapid maturity and even growth. Correct agricultural management is of great importance. Attack by Laphygma exigua in the seedling stage may result in increased damage by Pink Bollworm in the ripening crop.

The origin of the initial pink bollworm infestation is discussed. Available evidence, which is not conclusive, suggests that local carry over of the dead season may not be sufficient to account for the initial infestations observed in the crop.

Atmospheric water vapour saturation deficit appears to influence the duration of larval diapause in Pink Bollworm in the northern Sudan. Maximum emergence of moths from resting larvae in three areas occurs at or near the lowest saturation deficit of the year. The possibility is discussed that the degree of fixity of the diapause may be related to the gradient of the saturation deficit curve during the development of the resting larvae in the crop, a rising curve being associated with a well fixed diapause which lasts until the saturation deficit falls, and a falling curve being associated with a poorly fixed diapause which does not last but begins to break at once.

The turnover of the radioisotope 137Cs is shown to be of a one-component nature and to be positively correlated with temperature for males of both Glossina morsitans Westw. and G. pallidipes Aust. A direct correlation with oxygen consumption is also demonstrated, and the relation for both species may be described by the same regression line. The feasibility of using 137Cs as a metabolic label for tsetse is therefore confirmed, and it is suggested that the predictive nature of the relationship between radioisotope turnover and metabolism may extend beyond closely related species.

Blaesoxipha atlanis (Aldrich) is a common parasitic fly of agriculturally important grasshoppers in Canada. The suitability of Camnula pellucida (Scudder), Melanoplus bivittatus (Say), Melanoplus packardii Scudder, and Melanoplus sanguinipes (Fabricius) as hosts was studied in the laboratory. Grasshoppers were singly-parasitized or left unparasitized and reared for 9 days. Melanoplus bivittatus and M. packardii did not support parasite development, i.e. were non-permissive hosts. In both species, parasite larvae were melanized and encapsulated, but development proceeded further in M. packardii. Melanoplus sanguinipes and C. pellucida were permissive host species with, respectively, 70% and 35% of the implanted larvae emerging from their hosts of which 86% and 50% developed into adults. Parasite development time was longer in C. pellucida. Adult B. atlanis dry mass varied with host species and host mass at parasitism, but not with host sex. Parasites developing in M. sanguinipes were larger in terms of dry mass than counterparts developing in C. pellucida. In permissive species, unparasitized grasshoppers gained in body mass while parasitized insects lost mass during the 9-day observation period. In non-permissive species, all insects gained in body mass, but parasitized females gained less mass than unparasitized conspecifics. All unparasitized grasshoppers survived while 75–95% of permissive and 30–40% of non-permissive hosts died. Variation in the intensity of field parasitism among grasshopper species may be explained, at least in part, by qualitative differences in suitability between potential host species. Novel pest management strategies emphasize preservation of a small proportion of the pest population for natural enemies. Consideration of the outcome of specific host-parasite interactions should improve the understanding of grasshopper population dynamics and increase the predictive value of models that assess potential crop losses.

An undesirable effect of using a dust containing 0·4 per cent, lindane for the control of Pseudotheraptus wayi Brown on coconut palms is the eradication of Oecophylla longinoda (Latr.), a species of ant inimical to this Coreid, and in the search for a more suitable preparation, formulations were tested in Zanzibar that contained DDT, with synthetic resins to prevent its absorption through the treated surface of the palm. One such formulation, prepared by dissolving 23·5 lb. of a proprietary coumarone indene resin and then 235 lb. 80 per cent. p,p′DDT in a mixture of 100 gal. power kerosene and 100 gal. diesoline, heated to 40–45°C., is here termed 10 DRDK and its properties described.

When 10 DRDK was applied by pneumatic hand-sprayers to the centres of palm crowns, small species of ants (Pheidole spp., Crematogaster spp., Paratrechina longicornis (Latr.)) and Anoplolepis longipes (Jerd.) were eradicated from such sites, whereas O. longinoda increased in numbers and other large species (Camponotus spp., Polyrhachis spp., etc.) were unaffected. Although 10 DRDK was lethal to all species when applied as an aerosol in the laboratory, the residual deposit from it killed only the smaller species, apparently because their bodies make contact with the DDT crystals whereas those of the larger species (except A. longipes) are held clear. Under Zanzibar conditions, this deposit, which is at first gummy, gives rise within 2–3 weeks, or following mechanical disturbance, to needle-like crystals of DDT, 10–120 μ long × 2–10 μ wide projecting from the sprayed surface and forming clumps up to 1·5 mm. high.

In field tests, paper bands dipped in 10 DRDK and attached round palm trunks prevented the passage of A. longipes for six months, and of Pheidole for nine months, despite heavy rain; that of the larger species of ants was unaffected. Determinations of the deposit on a sample band selected each week at random showed great variability but fell from 392–478 μg. DDT per sq. cm. initially to 92–176 μg. after 31 weeks. In concurrent tests of similar bands exposed in the laboratory, the deposit fell only to 282 μg. per sq. cm. over approximately the same period.

In tests of 10 DRDK applied topically to the dorsum of Pseudotheraptus wayi, complete mortality of adults was obtained within 48 hours with droplets 85 μ in diameter (containing 0·31 μg. DDT) and the size required diminished progressively, the earlier the stage treated. When individuals of P. wayi were allowed to walk for one minute on glass plates bearing known deposits from 10 DRDK, complete mortality of all stages, from 2nd-instar nymphs to adults, followed within 24 hours of exposure to 2·7 mg. DDT per sq. ft., but not to 1·6 mg., except in the case of recently moulted adults, 5th- or 4th-instar nymphs.

Two experimental areas totalling some 1,000 palms, of which 10 per cent, had Oecophylla nesting in them in October 1952, were sprayed with a commercial formulation containing DDT from November 1952 to June 1953, and the percentage fell to 2·5; the areas were then treated with 10 DRDK by hand-sprayer until January 1954 and by machine for the rest of 1954. The percentage of palms having Oecophylla, in October 1953, October 1954 and February 1955 increased to 7, 15 and 38, respectively. In a control area one mile away, the percentage rose from 23·5 to 36 over the same period. In a third area, 12 applications of 10 DRDK totalling 10 gal. per acre were made by machine during 1953, 12 totalling 33 gal. in 1954 and 9 totalling 30 in 1955, and the percentage of palms colonised by Oecophylla rose from nil to 21·7 in 1953, to 26·1 by March 1955 and to 30 by April 1956, while the percentage colonised by A. longipes fell over the same period from 90 to 1.5. In the control areas, A. longipes remained dominant and no Oecophylla became established.

The addition of lindane to 10 DRDK to give concentrations of 0·1, 0·5 or 1·0 per cent, adversely affected the selective properties of the formulation, and although the highest strength gave a good kill of P. wayi and other insects, apart from Coccids, which increased considerably, it reduced Oecophylla to a greater extent than it did other species of ants. No advantages are obtained by the addition of dieldrin, endrin, pyrethrins or rotenone.

Much progress has been made in understanding the environmental and hormonal systems regulating winter diapause. However, transcriptional regulation of summer diapause is still largely unknown, making it difficult to understand an all-around regulation profile of seasonal adaptation. To bridge this gap, comparison RNA-seq to profile the transcriptome and to examine differential gene expression profiles between non-diapause, summer diapause, and winter diapause groups were performed. A total number of 113 million reads were generated and assembled into 79,117 unigenes, with 37,492 unigenes categorized into 58 functional gene ontology groups, 25 clusters of orthologous group categories, and 256 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. KEGG analysis mapped 2108 differentially expressed genes to 48 and 67 pathways for summer and winter diapauses, respectively. Enrichment statistics showed that 11 identical pathways similarly overlapped in the top 20 enriched functional groups both related to summer and winter diapauses. We also identified 35 key candidate genes for universal and differential functions related to summer and winter diapause preparation. Furthermore, we identified some genes involved in the signaling and metabolic pathways that may be the key drivers to integrate environmental signals into the summer and winter diapause preparation. The current study provided valuable insights into global molecular mechanisms underpinning diapause preparation.

The genus Diparopsis Hmps. is confined to Africa. During the present century, an insect always identified hitherto as Diparopsis castanea Hmps. has become a serious pest as a bollworm of cotton in many parts of that continent. Until recently, the genus was thought to consist of only two species, D. castanea Hmps. and D. tephragramma B.-Bkr., but differences in the structure of the frontal process of the adult suggested that the former comprised two or more distinct sub-species or species. The present study was undertaken to determine the status of these different forms. It is based on the material in the collections of the British Museum (Natural History) and on additional material obtained through the courtesy of the Government Entomologist, Anglo-Egyptian Sudan, and the Commonwealth Institute of Entomology.