In continuation of a study of the process of swarm formation in the Red Locust, Nomadacris septemfasciata (Serv.), to enable rational plans for control measures to be made, the population distribution of about 44½ million hoppers of the Red Locust was investigated in an observation area of 1,052 acres in the Iku outbreak area of the Rukwa Valley, Tanganyika Territory, from 18th January to 24th February 1957. to see if the hoppers showed a tendency to concentrate, which would have the effect of producing, immediately after the last moult, adult swarms from hoppers that were originally more scattered. From 25th January onwards, the estimated population remained constant in numbers. Densities over 50 per sq. yd. were unusual and, taking any continuous infestation over one per sq. yd. as a band, the mean density of hoppers in bands was 15 per sq. yd. There was a tendency for such bands to become larger by fusion and for the area quite free from locusts to increase slightly but the number of dispersed locusts increased. There would therefore have been no advantage in withholding insecticide control in the hope of attacking denser and more economical targets. Nevertheless, such populations have to be controlled.

In the Red Locust, under the conditions described, it seems probable that the behaviour of the young adults is most important in the formation of dense swarms, while in certain other species but not in the Red Locust, concentrated egg-laying and the behaviour of the hoppers are also important.

Investigations are required on more economical enumeration of patchy gregarious distributions.

Six types of habitat in papyrus (Cyperus papyrus) swamps in Uganda were studied with regard to the production of mosquito larvae. A classification, of the types is given, which was largely based on the lapse of time since temporary clearing by cutting or burning had been carried out.

Altogether a total of 5,781 larvae belonging to 17 species was studied. Culex (Culex) guiarti Blanch., C. (C.) univittatus Theo. and C. (Neoculex) rubinotus Theo. were the dominant species, comprising together 78 per cent. of the total number of larvae. Anopheles gambiae Giles was not recorded. Samples of larvae were taken at intervals between mid-January and early April 1957. The sampling method used was unsuitable for those species of which the larvae obtain air from roots or stems of submerged vegetation, and these were excluded from the present study.

There was considerable variation in species and numbers of larvae and in their frequency in the different types of habitat.

It is concluded that (a) peripheral zones, especially in natural untouched swamps, are much more productive than the interior, (b) where swamps have been altered by cutting and by burning of papyrus and other vegetation, burnt habitats, whether recently or after the lapse of up to four or five months, have a very low productivity, (c) of the six chemical factors investigated (pH, K, Na, absorbed oxygen, free and saline ammonia and albuminoid ammonia) only the quantity of soluble organic matter, indicated by absorbed oxygen, and albuminoid ammonia, showed any relation to productivity, the least productive habitats containing the smallest quantity of organic matter.

Other possible factors in swamp water, which were not investigated, are mentioned. These are (a) the nature of soluble oxidisable organic matter, (b) conductivity, (c) ferruginous surface films and (d) iron in solution.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is one of the main pests of fruit, worldwide, and the use of population suppression method with low environmental impact is an increasingly strong requirement of the consumer market. The aim of this study was to evaluate the effect of mineral and natural films on the physical–chemical properties of grapes (Vitis vinifera L.), cultivar Itália, and oviposition behaviour of C. capitata. Fruits were immersed in suspensions (100 and 200 g L−1) of mineral (kaolin Surround®WP, kaolin 607, kaolin 608, kaolin 611 and talc) and natural films (chitosan, cassava starch, potato starch and guar gum 5.0 g L−1) and distilled water (control). After drying, fruits were exposed to C. capitata pairs of males and females for 24 h in choice and non-choice tests; the number of punctures with and without eggs, eggs per fruit and behavioural response of fly to treated and untreated fruits were recorded. Results obtained in this study are promising, given the scientific evidence that films of mineral particles such as kaolin (Surround®, 607, 608 and 611) changed the firmness, luminosity, chroma and hue angle of grapes and reduced the oviposition of C. capitata. In addition, our results also showed that natural polymers do not deter C. capitata females, but rather seem to stimulate oviposition.

This paper presents the first report on the sublethal effect of an insect growth regulator (IGR), hexaflumuron, on the feeding behaviour of vector mosquitoes, Culex quinquefasciatus Say, Aedes aegypti (Linnaeus) and Anopheles stephensi Liston. Percentage engorgement and feeding behaviour of the adults of the three species emerged after sublethal exposures at the larval and pupal stages were markedly affected. Depression in blood feeding was significantly higher in Aedes aegypti with lower blood engorgement ratio. The proportion of females that failed to take a blood meal was higher in A. aegypti (30.2%) than in the other species when pupae had been exposed to 0.05 mg/1 hexaflumuron. Depression in blood feeding was probably due to abnormalities in the functioning of the mouth parts and feeding behaviour. No adverse effect on the feeding activity was noticed in the F1 generation of the treated species.

The history of the use of pyrethrum formulations to control Antestiopsis spp. on arabica coffee in Kenya is reviewed.

The material with which the present work was done comprised three distinct forms of Antestiopsis of doubtful taxonomic status; these were not observed to differ in their response to the insecticidal treatments used.

Laboratory experiments showed that Antestiopsis was highly susceptible to pyrethrum and that the addition of piperonyl butoxide, a pyrethrum synergist, did not affect this response.

Preliminary field experiments showed that concentrations of pyrethrins higher than those found effective in the laboratory were required. A hypothesis is advanced and established that this was due to a variable proportion of insects becoming paralysed and falling off the tree before acquiring a lethal dose.

These observations and experiments suggested a two-phase method of control, using pyrethrum as a non-persistent foliage spray at an economical but effective concentration of 0·005–0·006 per cent, pyrethrins, coupled with a 5 per cent. DDT or 0·5 per cent, dieldrin dust applied to the bole of the tree to form a persistent toxic barrier. The spray removed the bugs from the tree whilst the dust prevented the return of or killed those that had only received a sub-lethal dose of pyrethrum. It seemed unlikely that such a localised application of the persistent insecticide would have any appreciable effect on beneficial insects.

This two-phase treatment has been used successfully both in trials and in commercial practice for the control of Antestiopsis. When the initial population is in excess of 20 per tree, two spray applications and one dusting are necessary to effect control.

Studies were carried out to estimate and compare mortalities of larvae and pupae of Aedes (Stegomyia) simpsoni sensu lato breeding in axils of Colocasia esculenta, Xanthosoma sagittifolium (Araceae) and Musa spp. (Musaceae) in different locations in Uganda and also to ascertain whether there are any differences in their dynamics that could be used to separate the species. The probability of larvae surviving from one day to the next (40·5 – 99·8%), and the proportions dying in each instar (0·97 – 77·3%) and dying daily in all the four instars (3·9 – 46·3%) varied between seasons at each site and between sites and species of plants. Estimates of larval and pupal mortality were generally highest for fourth instar [52·4 ± 6·0% (mean ± SE)] and lowest for the second instar larvae (16·0 ± 2·6%). There was higher larval instar mortality in axils of X. sagittifolium (96·9%) and Musa spp. (82·2 – 96·5%) than in C. esculenta (47·1 – 88·4%).

Megaselia sandhui sp. n. is described from specimens of the adult male, female and pupa infesting cultivated mushrooms in India. It is closely related to the other species of Megaselia known to be pests of cultivated mushrooms.

The biting rates of Culicoides furens (Poey) and C. barbosai Wirth & Blanton on Florida Beach, Jamaica, were observed in 50 trials conducted 40–115 min after dawn from 5 February 1960 to 10 February 1961. The data were logarithmically transformed and non-zero biting rates standardised. Biting rates of both species varied markedly from week to week but monthly mean rates were significantly higher and lower for C. furens in September (111·4) and March (13·7), respectively. Monthly mean rates for C. barbosai fell into three groups, (i) March-June (15·3); (ii) November–December (9·1); (iii) January–February and July–October (3·1). These changes were negatively correlated with mean sea level. Biting rates of C. barbosai were highest at new moon (10·3) and lower but similar (4·3–5·2) for the other three phases of the moon. Those of C. furens were maximal at new moon (62·8), minimal at full moon (20·4) and intermediate (35·9, 39·5) at the quarters. The lunar effect is assumed to act through the tides. There were no significant differences between the standardised biting rates at different times after dawn. In a comparison of the quantitative effects of ten factors on the biting rates of C. furens, C. barbosai and Leptoconops becquaerti (Kieff.), most important were month of year and wind speed; of less importance were lunar cycle, temperature, collector and limb exposed; while site position, intensity of illumination, time after dawn, saturation deficit were of minor or no importance. It is concluded that the biting rate of L. becquaerti should be the least affected by changes in these factors, C. barbosai more affected and C. furens most affected.

External sexual characters are described for the larvae of Spodoptera littoralis (Boisd) and S. exempta (Wlk.). The characters on the female consist of two pairs of pits on the ventral surface of the eighth and ninth abdominal segments. These pits are visible under a light microscope and can therefore be used for the accurate sexing of live larvae from the third instar onwards. The first- and second-instar larvae of both species could not be sexed using external characters because of their small size. In the males of both species, there are no obvious external sexual characters until the last instar, and therefore the sexes are most easily separated by the presence or absence of the female characters. Third- to sixth-instar larvae of both species were examined for the presence or absence of the female pits and were then sexed by dissection. The accuracy of sexing using the external characters was 90–98% for S. littoralis and 100% in all cases for S. exempta. The histology of the female pits and their appearance under the scanning electron microscope is described. These pits in the female larvae give rise to the external openings of the adult reproductive system.

Autosterilizing devices, composed of 20×50 cm rectangles of white polyester cloth, baited with 50% w/v sucrose and impregnated with 10% suspension concentrate of the chitin synthesis inhibitor triflumuron, were suspended in two caged-layer poultry houses on a 6 ha farm near Bhubaneswar, Orissa Province, in north-east India. Populations of Musca domestica Linnaeus declined significantly over 6 weeks in houses in which the triflumuron-treated targets had been deployed. Following the removal of the targets from these houses, the M. domestica populations subsequently increased. No comparable changes were observed in a control poultry house in which an equal number of targets, dosed with 50% w/v sucrose only, were suspended. Laboratory evaluation of the sugar-baited triflumuron targets confirmed that exposure of the strain of M. domestica present in the poultry manure to triflumuron-treated targets reduced egg hatch to less than 1%. There was no decline in the quantity of triflumuron present on targets during their 6 week exposure in the poultry houses, as shown by gas chromatography. Furthermore, a laboratory bioassay demonstrated no decrease in the potency of the chemical over the exposure period. However, the quantity of sugar present on targets decreased significantly after only 3 weeks exposure. However, populations in the treatment houses were not eliminated and immigration from surrounding houses may have reduced the effectiveness of the technique. The results are discussed in relation to the use triflumuron-treated targets as a practical autoster-ilizing system for house fly control in livestock production systems.

The eggs of the three species of bot-flies discussed in this paper are distinguished by the fact of that of G. haemorrhoidalis being the only one stalked. It is also longer than those of the other two species, which are of about equal length. Further, it is brownish black in colour, that of G. intestinalis being whitish yellow and G. nasalis yellow. The egg of G. intestinalis adheres to the hair by clasping flanges, which run only two-thirds of its length, whilst the flanges of the G. nasalis egg run almost the entire length.

The egg of G. haemorrhoidalis is not inserted nor screwed into the skin of the host. The eggs of G. intestinalis are laid indiscriminately on the body of the host, but preferably on the long hairs investing the inside of the foreleg. G. nasalis lays its eggs on the hairs of the intermaxillary space, and G. haemorrhoidalis on the hairs of the lips, preferably the lower.

Field trials in British Somaliland and in the Anglo-Egyptian Sudan showed that dry bran bait can be used for complete destruction of Desert Locust hoppers (Schistocerca gregaha). Wet bait was never found to be completely effective when dry bait was ineffective.

Failures of dry baiting were found which were attributable to several causes : hoppers not feeding just before moulting ; ground too hot for hoppers to remain on it ; too low or too patchy a deposit of bait ; adult locusts probably not making contact with bait. None of these failures could be attributed to the bait being dry.

The main constituent of standard bait, wheat bran, should not be replaced by barley husks or peanut flour, but dom flour could be used and dura and maize flours could be tried instead of bran.

The use of dry bait makes it convenient and practical for locust scouts who use camels, vehicles, etc. to destroy small bands of hoppers as soon as they find them.

Dry baiting against marching bands and ring baiting can be done very conveniently and speedily by means of the Shendi Funnel, designed to be tied to the back of a vehicle.

Area baiting can be done rapidly by blowing dry bait up from a dusting machine, so that the wind spreads it. An area-dosage of 25 lb./acre is recommended, and a rate of ½-acre/minute should be readily achieved.

The amount of labour required is reduced to about 25% by the use of dry bait instead of wet. Dry baiting by machine uses only 10 per cent. of the labour required for dry-baiting by hand, but the cost would not fall as much as this, because higher wages would have to be paid for the greater skill necessary.

Adults can be killed by baiting, but it is much more difficult than with hoppers to ensure that the locusts make contact with the bait.

The insecticides already in use against the Desert Locust, arsenic and benzene hexachloride, can completely destroy hoppers when applied in bait. An insecticide is required with a long persistence like that of arsenic and a low mammalian toxicity like that of BHC.

Taxonomy and phylogeny of termites of the genus Reticulitermes in central and eastern Mediterranean lands are poorly understood, partly due to insufficient sampling. This study aims to contribute to the knowledge of east Mediterranean termites by presenting morphological and molecular data on Reticulitermes from Cyprus. Samples from 15 colonies were collected throughout the island. Qualitative and quantitative morphological characters were analyzed for alate and soldier castes. Partial sequences of the mitochondrial genes COII and 16S were used to evaluate genetic diversity of Cypriot colonies and to determine their phylogenetic relationships with taxa from central and eastern Mediterranean areas.

Cypriot alates have some morphological features in common with the Israeli R. clypeatus: an enlarged postclypeus and a wide unpigmented margin of the eye. They are larger than R. clypeatus but smaller than western European species, such as R. banyulensis, R. lucifugus corsicus and R. grassei. For Cypriot soldiers, two size groups were identified, possibly in relation with the age of their mother colonies.

Phylogenetic analysis shows that, contrary to what might be expected, the samples with the highest affinity with Cypriot samples are not those from the nearby mainland (south Turkey, Israel), but from north-eastern Greece. Comprehensive sampling in the nearby mainland is lacking, so the possibility that populations exist it that region with an affinity towards Cypriot Reticulitermes sp. cannot be ruled out. Together with samples from the Halkidiki peninsula, north-eastern Greece, northern Turkey and Crete, Cypriot Reticulitermes form a well-supported north-eastern Mediterranean clade.

Phlebotomus major, var. chinensis, var. n.

This variety differs from the description of P. major given by Annańdale by the relatively greater length of the proximal segment of the superior claspers, and, also in the male, in having the second, third, and fourth segments of the palpi of equal length. There are also slight colour differences in both sexes, but little importance can be attached to such a variable character.

Two major fruit fly pest species, Bactrocera dorsalis and B. umbrosa, are strongly attracted to methyl eugenol (ME) found in >450 plant species. They are, however, exclusive pollinators of certain daciniphilous (attracting Dacini fruit flies) Bulbophyllum orchids. A comparison between the recaptures of feral males after feeding ad libitum on 0.6 mg ME (simulating an average floral quantity of an orchid flower – Trial 1) and 480 mg in Trial 2 was investigated using the non-invasive capture-mark-release-recapture (CMRR) technique. Based on daily CMRR over a 16-day period, using a different colour enamel paint each day, percentages of B. dorsalis males recaptured in Trial 1 were significantly higher than those in Trial 2. However, for B. umbrosa, percentages of recaptures for different day-specific colours were highly variable due to low fly numbers captured/day. In Trial 1, of 756 B. dorsalis males released, 36.4% were recaptured once, 7.7 twice, 2.4 three times and 0.4 four times. While in Trial 2 of 1157 released males, 6% were recaptured once and 0.3% twice. Of 67 B. umbrosa males released, 28.4% were recaptured once and none more than once in Trial 1. Nevertheless, of 119 flies released in Trial 2, 25.2% were recaptured once and 3.3% twice. Overall, many marked males did return to a single ME-source to ‘refuel’ ME (a sex pheromone precursor). The results also show that a relatively high number of flies paid multi-visitations to a single 0.6 mg ME-source and indicate that the presence of natural ME-sources may impact area-wide IPM programmes.

The infestation of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Africa since 2016 has been a major threat to maize production. Previous studies in Togo and Ghana from 2016 to 2018 did not correlate FAW infestation to yield losses. Thus, the aim of this study which assesses the impact of FAW infestation by inspecting 150 maize farms throughout the five Agro-Ecological Zones (AEZs) of Togo for FAW plant damage, and third instar larvae were used to infest 10-day-old maize plants in netted plots under controlled conditions at an experiment station (Station d'Expérimentations Agronomiques de Lomé) in 2019 and 2020. As control plots at the experiment station, plots were both netted and treated with emamectin benzoate, simply netted, or open to natural infestation. The number of larvae, egg masses, percent damaged plants, and damage proportions of leaves and ears were scored until harvest. Infestations and damages on maize plant throughout Togo were similar between the two years but were higher in the southern part of the county (AEZ5). At the experiment station, the yield losses were significantly considerable and increased from 25% infestation. The losses were 0.37 t ha−1 for 25% infestation, 0.34 t ha−1 for 30%, 0.59 t ha−1 for the open plots, 0.70 t ha−1 for simple netted and 50% infestation, 1.03 t ha−1 for 75%, and 1.27 t ha−1 for 100% infestation. This current study suggested thorough inspection on maize farms to set off management practices from 25% of infestation.

The tettigoniid Barbitistes vicetinus Galvagni & Fontana was described in 1993 as an endemic and rare bush-cricket of north-east Italy. Since 2008, this species has become a pest, causing repeated outbreaks with severe defoliations in broadleaf forests and neighbouring crops. Few data are currently available on ecology and life-cycle of this species, in particular about how temperature regulates egg-diapause and hatching phenology. The present work reports a field study regarding hatching phenology of B. vicetinus, surveyed with 84 emergence traps over four consecutive years (2013–2016). Moreover, the effect of temperature on the hatching was tested in the laboratory, exposing eggs to different temperatures. Field observations showed that hatching occurred between the end of March and beginning of April. In warmer years, hatching started early in the spring and lasted longer, while in colder years, hatching started later and was concentrated in a few days. Moreover, a significant effect of both elevation and exposure on the hatching start was observed. Results obtained from laboratory suggested the ability of the species to develop in the post-final diapause in a wide range of thermal conditions. After the diapause (terminated by a prolonged common exposure to low temperature) B. vicetinus was able to hatch from 6 to 23°C although, due to prolonged post-diapause development, hatching took place progressively later at colder temperatures. To manage B. vicetinus outbreaks, forecasting the seasonal phenology of egg hatching and its duration is important for an effective pest control.

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.

The results of a general mosquito survey of the Liberian hinterland are presented together with the findings of previous workers in this country.

Liberia is almost entirely in the Upper Guinean Forest region with an annual rainfall from over 140 in. on the coast to about 80 in. in the hinterland.

A list is given of all species recorded from Liberia.

A brief account is given of the distribution, bionomics and relation to malaria of the Anophelini, with some taxonomie notes. Thirteen species or forms of Anophelines are listed, of which ten were found in the hinterland as well as on the coast.

A summary of the distribution and bionomics of the Megarhinini and Culicini of Liberia is given, with the writer's field notes and those of earlier workers, and some taxonomic notes. Seventy one or 72 species or forms are included, of which 59 were found in the hinterland. If the first mention of some species in the two previous papers in this series be included, 41 additions to the Liberian list, three of them new species, have been made.