Tests of the acceptability of crushed dura (Sorghum millet) of various particle size composition suggested only small differences between any of them and wheaten bran. There seemed to be a slight advantage to dura passing a sieve of 20 meshes to the inch and stopped by 30, and a slight disadvantage to dura stopped by a 20-mesh sieve. There is certainly no reason to use wheaten bran in preference to crushed dura.

Maize bran containing 2·5 per cent. sodium arsenite was less acceptable than the other materials, but crushed maize was not. Nevertheless, this arsenic bait and also coarse dura with BHC produced a mortality apparently no lower than the most acceptable baits containing 0·5 per cent. BHC.

It is suggested that experiments with milling and separating machinery may produce a first-class dura bait and at the same time reserve the flour for human consumption.

Prolaelius glossinae, sp. nov.

♀. Nigra ; scapo apice, flagello articulo primo, tibiis tarsisque anticis brunneotestaceis ; alis medio late leviterque infuscatis ; basi et marginibus hyalinis.

Head as long as the greatest breadth, narrowed both in front of and behind the eyes ; opaque, very finely and shallowly reticulate, with sparse piliferous punctures. Eyes separated across the frons by twice the diameter of either and situated nearer to the base of the mandibles than to the posterior margin of the head ; ovate and smooth ; ocelli in an equilateral triangle, the posterior pair a little farther from each other than from the hind margin of the head. Antennae thirteen-jointed, as long as the thorax and propodeon together. Scape about twice the pedicel, the latter slightly exceeding the first funicular joint ; joints of the funicle subequal, no definite club ; the last joint and the fourth and fifth of the funicle longer, equalling the pedicel.

The highly oligophagous tephritid Chaetostomella cylindrica infests the flower heads of six genera and ten species of thistles in Lebanon. It predominantly utilizes two hosts occurring in sympatry, Notobasis syriaca and Onopordum illyricum. Previous work showed that adult flies emerging from N. syriaca fit more closely the description of the species, particularly with respect to the colour and pattern on the mesonotum; furthermore, significant differences were observed between the aculeus shape and length. This study investigates the biology of the immatures and compares adults from the two host races behaviourally and genetically. Larvae of both races fed in a similar way, with each larva destroying 3–10 achenes; however, the oviposition behaviour of females differed. Females of the Onopordum-associated flies laid an average of three eggs per head, and deposited the eggs glued to each others in a cluster, while females of the Notobasis-associated flies deposited their eggs unattached, usually with one egg per head. Subtle differences were also observed in the post-mating behaviour of adult males. DNA sequencing of an amplified fragment of the mitochondrial NADH-dehydrogenase subunit 1 gene revealed 44 single nucleotide polymorphisms in 622 base pairs. A PCR-RFLP method was developed to distinguish the two host-associated populations. Together with previously published morphometric studies, our data show that C. cylindrica consists of distinct host races, which seem to be reproductively isolated as two separate genetic lineages were observed.

A historical account of the Ox Warble Flies, Hypoderma lineatum and H. bovis, is given and the economic importance of the two species is discussed. Certain aspects of their biology and control have been studied over a period of several years in South Wales culminating in intensive investigations in the years 1945 and 1946.

The adults of H. lineatum emerge from their puparia in early May and those of H. bovis a month later. The adults of both species in their persistent endeavours to oviposit, worry cattle, whenever the weather is sunny and calm, from the end of May to early September but they tend to avoid the vicinity of water and shade.

The degree of incidence is high in Britain, at least in South Wales, judging by the larval populations present in the backs of cattle. Over 80 per cent. of the cattle included in the surveys conducted in 1945 and 1946 harboured infestations of varying intensity; in one case 152 larvae were recorded on a Shorthorn heifer.

The larvae spend, on an average basis, 42·5 days in the subcutaneous tissues of the backs of their hosts. They begin to depart in order to pupate much earlier than is normally assumed to be the case in Britain, more particularly in Worcestershire, where the proportion of larvae pupating prior to March 28th was as low as 1·4 per cent. compared with over 20 per cent. in the present studies.

The marked variations commonly observed in the seasonal incidence of the larvae in their final instars on cattle are correlated with the relative prevalence of the two species in different districts.

The incidence of both species, judging by the intensity of infestations, is associated with the topographical conditions of the locality. For instance, herds on upland pastures are generally less liable to severe attacks than those on lowland farms.

Cattle under three years old normally carry much heavier infestations of the larvae of both species than those exceeding this age when kept under identical conditions during the oviposition period.

Diphenyl-dichloro-trichlorethane and benzene hexachloride preparations are ineffective for destroying the larvae, at least in their final instars, but emulsions of the former insecticide when applied in the form of a spray to the legs and flanks of cattle during the period of oviposition proved highly promising and warrant further investigations.

When, early in the present year, Dr. A. Ingram sent in to the Entomological Research Committee his collection of larvae and bred adults of culicinae from Bole, Northern Territories, Gold Coast, the writer decided to describe these as soon as possible, and the opportunity seemed favourable to include a thorough revision of the known larvae of the African culicinae. The results of this work are given in the following tables. The difficulties of classification might have been considerable, but for the valuable pioneer work of Messrs. Dyar and Knab* in America, and the present author is glad to express his indebtedness to these writers, and would like to add his testimony, if any were needed, to the soundness of their general classification. The paper by Wesché† in this journal is also very important, as it is the only one devoted to a study of the larvae of African culicidae. Figures of most of the species not illustrated here will be found in it.

Several species of Dynastid beetles are serious pests of yam (Dioscorea) in Nigeria, the adults attacking the setts and new tubers underground. The base of the yam vine and the roots are not generally damaged. The most important species is Heteroligus meles (Billb.).

H. meles does not breed in the yam fields, and the adults fly to them from breeding grounds that are distinct, and to which they return later.

The cultivation and growth of the yam plant in Nigeria are briefly described. Small tubers, or cut pieces of tubers (setts) are planted. The earlier the date of planting and of emergence of the vine from the soil, the heavier the vine and the new tuber.

An account is given of observations on the infestation, in relation to crop growth, of a plot of yellow yams (D. cayenensis) planted near Benin, in Western Nigeria on 29th March 1958.

Adults of H. meles were taken, from 3rd April to 26th June and again from 8th to 21st November, between 7 and 9 p.m., at a light-trap placed at a distance of ¼ mile from the plot.

Beetles entered the soil of yam hills within six inches of the vine, usually before 7 a.m., on mornings following evening flights, the entry holes usually being identifiable. The first vines were seen in the experimental plot on 19th April. Beetles did not enter a yam hill unless the vine had emerged.

The longer the exposure to flying beetles, the more likely were plants to be attacked, and bigger vines attracted more beetles than did smaller ones. Later planting decreased beetle damage, but a lower yield resulted.

At first the beetles fed on the sett, making and increasing the size of fewer lesions than later on the new yam. About the time that the flying period ended, the setts were starting to rot, and the beetles left the immediate vicinity of the yam plant, as no acceptable food was available. Most moved deeper into the soil, but a few left the plant altogether and flew away. After the new tubers had begun to develop, the beetles returned in early August from their positions deeper in the soil to feed on them, constantly making new lesions, more numerous but smaller than those made in the setts, averaging about 4 g. of yam eaten.

During late August and again in late September, a few beetles moved underground from the original plants attacked to others. In mid-November, the beetles left the yam fields altogether, presumably returning to the breeding area.

The reasons why the beetles fly away from the yam fields remain uncertain, but they may include the seasonal decline in rainfall, the maturation of the yam tuber and the development of the gonads.

Factors that can affect the rate of attack are the dates of planting and harvesting in relation to the period during which the beetles fly, the method of cultivation and the variety of yam planted.

This paper reports the data for the uncommon Anopheles spp. from 24-h man-baited catches mainly in the Semliki Forest, Uganda, but also from the Zika and Mpanga Forests Anopheles (Cellia) nili (Theo.), A. (C.) marshallii (Theo.), A. (C.) demeilloni Evans, A. (C.) squamosus Theo., A. (A.) coustani Lav. s. str. and A. (A.) tenebrosus (Dön.) were rarely caught. A. (A.) obscurus (Grünb.), A. (C.) moucheti Evans and A. (C.) keniensis Evans were also scarce, but the numbers did indicate nocturnal and ground-haunting habits. Comparison of catches of the less uncommon species (A. (A.) ziemanni Grünb., A. (A.) paludis Theo., A. (A.) implexus (Theo.), A. (C.) funestus Giles, A. (C.) hargreavesi Evans and A. (C.) pharoensis Theo.) with those obtained by other workers showed them to be primarily ground haunting and nocturnal but with wide variation in their temporal distribution patterns.

The effect of host movement on multiple feeding by Aedes aegypti (L.) was observed in a laboratory experiment and the value of techniques developed to measure multiple meals was assessed. Multiple feeding on the arms of two human volunteers was significantly increased when both hosts moved their arms. If only one host was moving, a slight increase in multiple feeds over the level obtained with no movement was noted, although in such cases the majority of meals were taken from the stationary host. Statistical analyses of the results showed that the association between host movement and multiple feeding was highly significant.

Experiments were carried out to determine whether Oryzaephilus surinamensis (L.) was attracted to water on a wick suspended in an arena. When insects were preconditioned at 25, 50, 75 or 100% RH, they were attracted to the water source. Those preconditioned at 50% RH gave the greatest response and those preconditioned at 100% RH, the least. Measurement of the humidity changes in the arena caused by adding a wick containing 5 Μ1 of water showed that the gradient between the edge and centre was steepest at the start of an experiment when insect activity was also greatest. About 30 min after a wick had been placed in the arena, virtually all the water (about 94%) had evaporated, the humidity had equalised over the arena and the insects were no longer attracted to the wick. This behavioural response is discussed in relation to the insects' environment.

The importance of finding the effect of defoliation on the reproductive capacity of Cordia macrostachya is explained in view of the proposed introduction of two species of leaf-eating beetles from Trinidad into Mauritius for the control of this weed.

An account is given of experiments in which the production of inflorescences and fruits was compared in defoliated and control plants.

The results show that defoliation has a significant effect in reducing the reproductive capacity of the plant.

Africanized honeybees are presently expanding their geographic range within the USA and are considered undesirable due to their substantial defensive behaviour. Africanized honeybees can be differentiated from honeybees of European ancestry using discriminant analysis of morphological characters, based on a minimum of ten intact specimens per colony. In this paper we report a PCR-based method suitable for the identification of African or European mtDNA from sting remnants, such as typically remain on victims following a stinging incident. We experimentally simulated collection and shipment conditions with dried and alcohol preservation of stings, and also report that the method was suitable for sting remnants stored with a victim sample for over one year in alcohol. The determination of mtDNA haplotypes from stinger remnants must be tempered by the constraints inherent in interpretation of mtDNA haplotype data. Such data do not provide any information regarding the genetic contribution of the paternal lineage. However, in geographic areas where baseline information regarding European haplotype frequencies is known, the detection of a different mtDNA haplotype in stingers from a victim, especially when associated with observations of extreme defensive behaviour, would certainly be suggestive of Africanization.

Following the discovery of Lydella jaliscosp. n. (from Jalisco, Mexico), a parasite of the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Pyralidae), the limits of the genus Lydella Robineau-Desvoidy have been widened to include Diatraeophaga Townsend syn. n., Metoposisyrops Townsend syn. n., and Metagonistylum Townsend syn. n. All species regarded as belonging to Lydella are listed, with L. minense (Townsend) comb. n., L. oryzae (Townsend) comb. n., L. scirpophagae (Chao & Shi) comb. n., L. sesamiae (Mesnil) comb. n., and L. striatalis (Townsend) comb. n.

This paper deals with seven Indian species and one African variety belonging to the subfamilies Spathiinae and Doryctinae. Four of the species are important parasites of the cotton stem weevil, Pempheres affinis, Fst., and are described as new in compliance with an urgent request for their names.

A species of Dioryctria reared from Pinus kesiya (= khasya) at Shillong, Assam, where it is found in association with D. abietella (Schiff.) and D. sylvestrella (Ratz.), is described as new and is named D. castanea sp.n. The distinctive purplish or reddish chestnut brown coloration of the forewings is considered to distinguish this species from others in the genus. Illustrations are given of the adult and of the male and female genitalia.

Three egg parasites, Sozites kerichoensis Kerrich (Ichneumonidae), Oligositoides semicinctium De Santis (Trichogrammatidae), and Platystasius benjamini Nixon (Scelionidae) were reared from egg-masses of two closely related Entypotrachelus species indigenous in the tropical rain forest of Kenya. E. meyeri Kolbe occurs west of the Rift Valley, and E. micans Hust. occurs in the foot-hills south and west of Mt. Kenya, east of the Rift Valley. When the forests are cleared, both species transfer from forest trees, weeds and shrubs to newly planted tea and Cinchona spp. where the larvae feed on the roots and the adults feed and oviposit on the leaves.

The object of the present paper is to place on record a number of observations made by the writer in the Ibadan district of Southern Nigeria in the years 1922 to 1925, in the hope that they may be of some interest to other workers in Africa.

The writer wishes to acknowledge his indebtedness to Dr. G. A. K. Marshall and the specialists of the Department of Entomology in the British Museum for identifying the insects mentioned, and to Dr. A. W. Hill, Director of the Royal Botanic Gardens, for determining the majority of the plants.

Studies conducted in Zika Forest, Uganda, on the breeding interactions between Aedes africanus (Theo.) and two mosquito predators, Toxorhynchites brevipalpis conradti Grünb. and T. kaimosi (van Som.), revealed a significant reduction in the numbers of A. africanus larvae and pupae in tree holes that were also inhabited by the predator larvae. There was a tendency for seasonal peaks in numbers of A. africanus to be followed two months later by peaks in Toxorhynchites spp. Cannibalism appeared to play an important role in the regulation of the population size of the two species of Toxorhynchites. The implications of these results in relation to the possible use of Toxorhynchites mosquitoes for biological control of A. africanus and other mosquitoes breeding in tree holes are discussed.

The figitid Ganaspis pelleranoi and the braconid Doryctobracon areolatus (Hym: Braconidae, Opiinae) are wide-ranging (from Florida, USA to Argentina) fruit fly parasitoids with tropical and subtropical distribution with a wet and temperate climate. In Argentina, both parasitoid species are thought to be restricted to the subtropical rainforests of the northwest and northeast, locally known as ‘Yungas’ and ‘Paranaense’ forests, respectively. However, these species recently have been recorded at the Monte and Thistle of the Prepuna eco-region, an arid region of central-western Argentina. Despite the extreme environmental conditions, anthropic artificial irrigation seems to be playing a fundamental role in fostering the presence and persistence of these species. Maximum Entropy (MaxEnt) models were developed to assess the suitability of these areas to harbor both species. The present work is a first approach to identify suitable areas for the distribution of these two fruit fly biological control agents in the American continent; based on 19 bioclimatic variables. Furthermore, the models resulting from including the new records in the ‘Monte’ eco-region suggest that local populations may become adapted to particular micro-environmental conditions generated by artificial irrigation. Models revealed that these artificial oases are suitable for G. pelleranoi but seem to be unsuitable for D. areolatus. This first and new approach to the area suitability of these species invites to produce models that reflect actual distribution including more records of presence in oases with similar conditions, thus decreasing the bias of the model generated by over reliance on areas with higher humidity (forest), which correspond to the distribution known before the inclusion of the new records.

The mechanical conveyance of germs by flies and other insects is of importance not only to the sanitary officer, but to the agriculturist and even to the merchant, for the more the matter is enquired into, the more numerous become the cases in which the origin of fermentation or disease in plants and animals can be traced primarily to this agency. Whatever may be the significance of this question in temperate climates, it is obviously of far greater importance in the tropics, where insects are present in greater profusion throughout all seasons of the year. The subject certainly merits more attention than has yet been bestowed upon it.

In a study of the incidence of damage to coconut palms in Madagascar and the Comores Archipelage caused by species of Oryctes (Scarabaeidae) it was found that attack is heaviest in localities where there are abundant breeding sites for the beetle, and that tall palms are more often attacked than short ones. The most important larval breeding sites are dead standing coconut palms and decaving coconut trunks and stumps. Larvae also breed in decaying satra trunks (Medemia sp.), wood of Albizia in coffee plantations, decaying Raphia trunks, and occasionally in rubbish heaps and manure, but are only rarely encountered in decaying wood in forests. Coconut palms are important feeding sites for O. gigas, O. blucheaui and O. simiar. O. pyrrhus attacks coconut seedlings and young oil palms. Forest palms are occasionally attacked. O. ranavaloattacks bamboo on the east coast. Banana plants are occasionally attacked by O. simiar.

Scoliid parasites of the larvae of Oryctes are widely distributed but not commonly found. Gregarines in larvae are also widespread but of rare occurrence. Oxyurid nematodes were often found in the fermantation chamber at the gut of Oryctes and Cetonid larvae. The fungus Cordyceps sp. was found at only one locality where it was attacking 56 per cent. of the larvae of Oryctes. Examples of infection by the fungus Metarrhizium were rarely encountered. Namatodes often occurred in the aedeagus of adult males of O. gigas and in the bursa copulatrix and colleterial glands of adult females, as well as under the elytra. They were less common in the other species of Oryctes examined. Mermithid nematodes were found in adults of Oryctes on rare occasions. No insect parasites of the adult stage of Oryctes were found. Elaterid larvae, possibly predacious on those of Oryctes were occasionally found but did not appear to be of much importance.

It is concluded that the major factor limiting Oryctes populations in Madagascar and the Comores is the number of suitable breeding sites.