A new species of sandfly, Psychodopygus lainsoni, is described from specimens captured in ‘ terra firme ’ rain forest at km 46 Altamira-Itaituba on the Transamazônica highway. In many respects the male resembles those of the squamiventris group, and the female is similar to those of other groups.

An account is given of the life-history of Pseudendaphis maculans Barnes, a common and widely distributed endoparsite of Aphids, especially of Toxoptera aurantii (Boy.), in Trinidad. Alates are parasitised to a much smaller extent than apterae : it is thought that this is due to the parasite larva inhibiting wing development. Nymphs appear to be attacked usually during the first stadium; the parasite larva is fully fed after 6 to 7 days. Shortly before the larve leaves its host the latter assumes a characteristic spotty appearance, due to numerous granules of dark matter that are readily visible through the integument, which has become paler and more transparent than normal. Pupation takes place in the soil: 9–10 days after leaving the host the adult emerges, invaribaly during the early afternoon.

Insects inducing galls. Adult female apparently without limbs or antennae. Mouth-parts obscure. Spiracles large and conspicuous ; two pairs, occupying a position close to the posterior extremity. Anal orifice minute, setiferous. Genital orifice sharply defined. Spiracles, anal and genital orifices all included in a densely chitinous area. This dense deposition of chitin renders the interpretation of the characters difficult and prevents any accurate definition of the genus.

A survey of the distribution of Aëdes aegypti and other Culicine mosquitos was made during the dry season of 1942, between 31st March and 15th May. The position of Eritrea gives it a particular interest in relation to the possible spread of yellow fever from Africa to the East. In the west it borders on the Anglo-Egyptian Sudan, in parts of which yellow fever is endemic, and it has a Red Sea coast line of some 600 miles, near the centre of which is the port of Massawa. The Culicines hitherto found include six that are known to be potential vectors of yellow fever.

The topography and climate of Eritrea have been described by Lega, Raffaele and Canalis (1937). The country may be divided into four areas, the eastern and western plains, the mountain slopes and the plateau. The latter, on which lie several of the towns, is from about 1,900 to 2,500 metres (some 6,200 to 8,200 feet) above sea level.

The following notes are based on a small collection of Coccidæ recently received by the Entomological Research Committee from Mr. C. C. Gowdey, the Government Entomologist in Uganda.

For purposes of mass-rearing fruit flies, nutrient intake through artificial diets is a challenge, artificial food content and processing should promote sufficient absorption and availability to ensure fly fitness. Bulking agents play an essential role in creating a quality diet, but its physical characteristics, such as particle size, may establish a better microenvironment for feeding and development. Currently, there is a lack of information about protein metabolism in mass-reared fruit flies. Therefore, we evaluated whether the particle size of the bulking agent affects the absorption and excretion of the proteins, as well as their effect on the life-history traits of Anastrepha obliqua. We determined the protein content of hemolymph and feces, as well as the presence of nitrogen end-products as indicators of their level of absorption in a diet elaborated with coarse and fine corn cob particles as a bulking agent. The bromatological composition showed that coarse particles increased the bioavailability and content of crude, digestible, and soluble protein for the diet and hemolymph protein of larvae alike. We found an inverse relationship between the protein content of the hemolymph and feces of the larvae. Ammonium was determined to be a product of the catabolism of proteins. Also, A. obliqua improved its development (yield and pupal weight) and fitness (adult emergence and flight ability) when larvae were reared on a coarse particle diet. In conclusion, a diet elaborated with a coarse bulking agent features increased protein bioavailability and nutritional quality, which, in turn, increases the life-history traits of A. obliqua.

During a survey for whitegrub parasites, six Thynnid species were found in parts of western Patagonia and studied in varying degrees of detail.

Definite host records are established for Elaphroptera scoliaeformis (Hal.), E. (Paralycus) sp. near nigripennis (Smith) and Pseudelaphroptera brevipilosa Durán, which are solitary external parasites of the mature larvae of Aulacopalpus pilicollis (Fairm.) (Rutelinae), Macrosoma glacialis (F.) (Melolonthinae) and Adioristus acuminatus Hust. (Curculionidae), respectively.

No adult feeding was observed during the mating flight of E. scoliaeformis and E. sp. near nigripennis, but pairs of P. brevipilosa and Ornepetes semicincta Turner fed extensively on flower heads of Umbelliferae. Some evidence is presented suggesting that at the conclusion of the mating flight the winged males tend to return the apterous females to the sites where they picked them up.

Hosts are permanently paralysed and malaxated before eggs are laid on them. The eggs of the two Elaphroptera species are placed parallel to the longitudinal axis of the host, on the mid-ventral line of abdominal segments two to seven. In the case of P. brevipilosa, the egg is lightly cemented by its caudal end at an angle of about 45 degrees to the host surface, the attachment being near the spiracular line of the host and between the third thoracic and sixth abdominal segments.

There are five larval instars. The larvae do not normally move over the host surface. In the first four instars feeding is by suction, but the fifth-instar larva tears a hole in the host in the region of the earlier feeding punctures. The film of liquid with which the larva is bathed is produced from its posterior extremity and is not exuded from the feeding puncture. Cocoons of two types may be recognised, corresponding to the sexes, the female type being the shorter and of more rigid construction.

E. scoliaeformis, E. sp. near nigripennis, and P. brevipilosa have a single generation a year. The period from egg deposition to cocoon formation is generally covered in three weeks, and at least nine months are spent in the cocoon as a mature larva or prepupa. Adults probably live up to two months.

The only natural enemies observed were a Bombyliid of the genus Acrophthalmyda and a Carabid predator, Cnemacanthus sp., attacking the cocoon stages of E. sp. near nigripennis. The adult of this Thynnid is also attacked by a mimicking Asilid fly, Lycomya germainii Big.

The function of the mating flight and the economic value of members of the Thynnidae as controlling agents for Scarabaeid pests are briefly discussed.

The effects of sublethal doses of insecticides and unrelated environmental stresses on Dysdercus fasciatus Sign, were studied in the laboratory. Dieldrin applied topically to fifth-instar nymphs at 02–0·6 μg/individual increased egg production, at 0·8–60 μg/individual decreased egg production, and at 0·6–60 μg/individual decreased fertility. Applied to adults, dieldrin at 2–4 μg/individual reduced egg production, and at 0·02–0 08 μg/individual (males) and 0·2–0·8 μg/individual (females) shortened the life span. In a separate experiment, dieldrin at 0·2 μg/individual reduced egg production when applied to fourth-instar nymphs, but had no effect on fifth-instar nymphs or adults. p.p'DDT at 6 μg/individual applied topically to unmated females increased egg production. Exposure of all life stages to 0·06 mg DDT/ litre for two generations was followed by increased egg production and fertility: shorter exposure at 1 mg DDT/litre had no effect, and at 6–20 mg/litre egg production and fertility were reduced. Rearing on boiled cotton seed resulted in small adults with low gg production and fertility, the eggs being longer than normal. Crowding nymphs (24 individuals/200-ml cage) had the same effect on the size of the resultant adults. Starvation caused low egg production and fertility. Fluttering of males during a free fall (a measure of activity) was increased by crowding (maximum at 2 individuals/cage), by topically applied dieldrin at 0·04–0·08 μg/individual and DDT at 3–5 μg/individual, by two-generation exposure to 0·06 mg DDT/litre, but not by feeding on boiled cotton seed.

The effects of crowding and photoperiod during rearing of Mythimna convecta (Walker) on oocyte development in adult females were measured in the laboratory and field. Most larvae reared under isolated conditions in a Light 12 h: Dark 12 h photoperiod had mature oocytes within 72–84 h of eclosion. Females were slower to mature when reared under longer daylengths. The mean oocyte width in 3–10 days old females was significantly lower for moths reared under long (Light 16 h: Dark 8 h) than equal (Light 12 h: Dark 12 h) daylengths. Crowding of larvae also prolonged the pre-reproductive period. In the laboratory, 47% of females had arrested oocyte development of 3–6 days after eclosion and, in the field during late winter/spring, 48% of females required 3–9 days to mature. Larvae were collected from late spring/summer populations and caged under high and low density conditions. All females emerging from both treatments had arrested oocyte development of at least seven days. In catches from baited moth traps run over the same period, the proportion of immature female M. convecta was lower during spring (18–30%), than in summer (60%) and, in both seasons, mating commenced before oocytes had matured, but after oocyte arrest. Long daylength appears to be only one of several contributing factors causing delays in ovarian development during summer. Delays in achieving reproductive maturity, induced by either crowding or summer conditions, may assist M. convecta to emigrate from unfavourable habitats. This is particularly relevant in the winter rainfall areas of south-eastern Australia where most food plants senesce in summer and suitable habitats are usually confined to the coast.

The larva of Hylemya arambourgi Séguy is an important pest of barley in Kenya; it attacks the shoots, causing death of the central leaf. Three to four shoots are destroyed by each larva, and an early, heavy infestation, under conditions of drought, may cause complete loss of the crop. Where a crop is obtained, the effect of an infestation on yield is difficult to assess, because climatic factors play a major part in determining ultimate figures.

The life-cycle is briefly described.

Trials with various methods of chemical control showed that only seed treatments were consistently effective. Other forms of pre-sowing treatment were ineffective at economic rates of application, while a spray applied after an attack had developed was of little value. Sprays applied prior to the development of an attack gave variable results but were usually ineffective.

The most satisfactory chemicals used as seed treatments were dieldrin and heptachlor. Aldrin and endrin were sometimes effective, while γ BHC, carbaryl, dimethoate and thiometon were ineffective. A formulation of chlordane was also ineffective, but this failure may have been due to poor dispersion on the seed. It is probable that the insecticide acted mainly as a systemic poison, since larvae rarely enter the soil before the time of pupation.

Both dieldrin and heptachlor were initially used at rates of 4·6–5·0 oz. of active ingredient per 100 lb. seed, but usually gave as good results at rates of 3·5 and 3·2 oz., respectively. Dieldrin gave a measure of control at even lower rates.

The prospects for cultural methods of control appeared slight. No evidence of varietal resistance was obtained, while the possibility of control by restrictions on the sowing season is ruled out by the lack of evidence of diapause and the probability that Pennisetum clandestinum and other Gramineae, such as Chloris gayanaand Setariasp., serve as alternative hosts. For the same reasons, it is considered unlikely that any change in the position of barley in the seven-year rotation would have any effect on the level of infestation.

On 12th September 1919, while watching at a pool near Kotakota, Lake Nyasa, the emergence of mosquitos from their pupae, which in the case of this particular species takes place mostly between 4.30 p.m. and dusk (about 6.30 at that time of year), the writer saw at rest on some scum on the surface of the water, an Anthomyiid fly of the genus Lispa, which after a few minutes made a sudden rush at a mosquito just emerging from its pupa-case. The mosquito with its wings still unexpanded and part of its legs and the hinder segments of its abdomen still within the pupa-case was absolutely at its mercy. The fly grappling it from behind with its front legs proceeded to thrust its proboscis into the thorax. The fly was by no means timid, and it was possible to lean over and approach one’s head to watch the proceedings so closely that it was even possible to determine by its antennae the sex of the unlucky mosquito ; it was a male. The fly was captured before it had finished its meal, lest it should suddenly fly up and escape.

From trials with cotton (variety Stoneville 7A) grown on the Ord River Irrigation Area of Western Australia, the results of delaying insecticide protection of crops against Heliothis attack by four and eight weeks were re-examined. With each delay the crop set later when temperatures were cooler, the plants older and larger, and the accumulated insect damage greater. Yet there was no significant difference in the final number of bolls produced in each crop. The growth of cotton and the compensatory mechanisms of the plant indicated by the data were simulated by a simple computer model. A modification of the model to simulate the response of a cotton plant to attack by Heliothis larvae was also developed. Output from the model suggests that, under the conditions of the experiment, there is a theoretical maximum number of bolls produced by this cotton variety. To produce this maximum crop requires complete protection from Heliothis larvae, but the period of protection can be minimised.

The “ North Block ” at Kikore, Central Province, Tanganyika, was treated with insecticide dispersed from an Anson 1 aircraft during the period 23rd January to 4th May 1951. The area consisted of some 4,000 acres of mixed bush, including about 230 acres of miombo, infested by two species of tsetse fly, Glossina morsitans Westw. and swynnertoni Aust.

The insecticide used was equivalent to a 19·4 per cent. solution of technical BHC (equal to 2·45 per cent. γ isomer) in 50 per cent. diesel oil, 50 per cent. power kerosene. The solution was dispensed through a boom and nozzles under pressure as a coarse aerosol (mass median diam. 70 microns), at a nominal mean dose of 0·25 lb. technical BHC per acre per application. Eight applications were planned and seven completed.

The first application was relatively ineffective, and for the second and subsequent cycles the emission rate was increased and over part of the block the swathe width was reduced. The result was a much improved kill but neither species of tsetse was exterminated.

Owing to the number of factors involved, it is not possible to give any principal reason why this experiment was less successful than previous ones, but many of the difficulties encountered are inherent in rainy-season operations in East Africa.

Head with the integument rather light yellowish, especially when viewed from in front. Erect scales mostly brown, a small area of white ones in the middle towards the front, and in front of these a few long, narrow recumbent scales, not forming a definite frontal tuft. Many light brown bristles between the eyes; border bristles dark. Antennae with the basal joint yellow; in female with a few small scales on the second joint; male plumes light brown. Female palpi very slightly longer than the proboscis, thin, with appressed scales; narrow whitish rings at the tips of the first three joints, just extending on to the bases of the succeeding joints; tip of last joint dark. Second joint slightly longer than the first, slightly shorter than the third and fourth together; fourth joint less than half as long as the third. [Male palpi missing.\ Proboscis dark, except for the labella.

Studies examining and using pattern variation in insects for identification and characterization of individuals and populations have been limited by the methods available for quantifying wing patterns objectively. In this paper, differences in wing pattern are demonstrated statistically using moment invariant data sets generated automatically from digitized images of the speckled wood butterfly, Pararge aegeria (Linnaeus). Studies with other biological subjects have already shown moment invariants to work well with outline shapes and silhouettes. A pilot study with replicated monochrome photographs of a single butterfly showed the method could detect pattern differences between wing surfaces, even in the presence of simulated wing fading and damage. In a further study of the wings of 228 specimens, multivariate analyses of variance using the moment data reliably detected differences between groups of butterflies according to sex, geographical origin and culture history. Potential applications and future improvements of the moment methodology are considered.

In this study, the question of whether Childers canegrub, Antitrogus parvulus (Britton) overwinters in the subsoil was addressed. Irrigated fields of sugarcane were sampled during a 2-year period near Bundaberg in southern Queensland. Antitrogus parvulus overwintered as second and third instars at each of three sites. During autumn and winter third instars of different allochronic (separated in age by 12 months) populations occurred together and could not be readily separated. Field-collected third instars were reared on ryegrass and separated into two age groups based on the date of pupation. Third instars in the first year of their life cycle (young third instars) remained at shallow depth (100–200 mm) and did not overwinter in the subsoil as once thought. Minimum temperatures during winter were 13–16°C and did not prevent young third instars from feeding and gaining weight. Third instars in their second and final year moved downwards from late summer and pupated in the subsoil at 293–425 mm in spring. General phenology was as previously reported with first instar larvae occurring from January until April, second instars from January until November and third instar larvae throughout the year. Prepupae and pupae were found between October and December and adults occurred in soil during November and January. Batches of eggs occurred at a mean depth of 350 mm. First and second instars occurred predominantly at relatively shallow (100–200 mm) depths in the soil profile. All stages tended to be most common under rows of sugarcane rather than in the interrow.

The stem borer, Chilo aleniellus (Strand) (Lepidoptera, Pyralidae) is recorded for the first time as a pest of maize in the western part of the forest area of Côte d'lvoire. Descriptions are given of the larva (including chaetotaxy), the pupa, and adult genitalia. The geographical distribution of this species is presented, and its importance as a pest in Côte d'Ivoire is discussed.

A careful measure of fitness represents a crucial target in crop pest management and becomes fundamental considering extremely prolific insects. In the present paper, we describe a standardized rearing protocol and a bioinformatics tool to calculate aphid fitness indices and invasiveness starting from life table data. We tested the protocol and the bioinformatic tool using six Myzus persicae (Sulzer) asexual lineages in order to investigate if karyotype rearrangements and ecotype could influence their reproductive performances. The tool showed that different karyotypes do not influence adaptive success and put in evidence a marked invasive potential of the M. persicae lineage 64. The presence of a similar fitness rate of 33H and 7GK asexual lineages (both possessing intra-individual karyotype variations) in respect to the asexual lineage 1 (with a standard karyotype) represents an important demonstration of the potentiality of holocentric chromosomes to reduce the effects of chromosome rearrangements.

The rather numerous Ethiopian species of Dacus (s.l.) are very homogeneousowing to their reduced chaetotaxy and the very simple pattern of the wings; they have no praescutellar bristles, only a scutellar pair, and very often only twosupra-alar bristles, the anterior one being wanting. There are no species with astalked abdomen, or with spinose femora, or with elongated antennae, or withbanded wings.

It was long ago recognised by students of the biology of mosquitos that differences in certain larval characters could be employed for the separation of the CULICIDAE into groups and even for the recognition of individual species. Present-day know-ledge of this subject in relation to the Anopheline group is largely based on the work of Grassi in Italy and James and Christophers in India.