Two field experiments examined the effect of dung fauna on the breeding success of Haematobia irritans exigua DeMeijere at Rockhampton, Australia, and Haematobia thirouxi potans (Bezzi) at Hluhluwe Game Reserve, Republic of South Africa. Dung pads naturally infested with Haematobia eggs were produced by cattle at Rockhampton and by Cape buffalo at Hluhluwe. Pads were either exposed to, or protected from, all dung fauna for various periods up to four days. The effect of dung fauna on the immature stages of Haematobia spp. was estimated from differences in the numbers and size of flies that emerged from treated and control pads. In the first experiment, pads produced during the morning and afternoon were exposed for one, two or four days on seven different occasions. At Rockhampton, fauna-induced mortality was substantial but did not increase significantly after the pads had been exposed for one day. At Hluhluwe, in pads produced during the morning, fauna-induced mortality rose substantially with duration of exposure; in afternoon pads the increase was not statistically significant. Fly size, indicated by the mean headcapsule width of surviving females, decreased as exposure of pads to dung fauna increased from zero to four days, except in the afternoon pads at Rockhampton. In the second experiment, pads produced in the afternoon were exposed in the field for four days on 16 occasions at Rockhampton, and on 17 at Hluhluwe. Fauna-induced mortality averaged 79% and 84%, respectively. The activities of the dung fauna reduced the headcapsule widths of surviving flies by an average 2% at Rockhampton and by 7% at Hluhluwe, despite similar levels of dung dispersal. The dung fauna associated with the highest mortality of H. irriatans exigua at Rockhampton were Scarabaeinae and Macrocheles spp., while there were no significant associations between fly mortality and particular fauna in the Hluhluwe data.

The theory that the larger wild mammals, commonly called “big game,” are solely and entirely responsible for the presence of tsetse-flies, has become so firmly fixed in the mind of the average “man in the street” in South Africa, that no amount of contrary argument or even proof, were such forthcoming, could ever have much effect in altering his opinion. The newcomer quickly assimilates the same idea, and after a time begins to voice it as assertively as his mentor. It is thus most difficult to obtain really reliable data. An investigator, beginning an enquiry with an open mind, finds himself flooded with such a mass of apparently well substantiated statements, provided by experienced and obviously sincere persons, that he can with difficulty keep his mind free from a certain amount of bias. Starting from the assumption that the presence of fly depends upon that of game, arguments against the continued existence of the latter quickly multiply in the public mind. I was talking to a friend the other day, and he mentioned that he had been replying to some questions upon this very subject. He was no partisan of the anti-game movement, but regretfully expressed his conviction that in order to get rid of tsetse-fly it would be necessary to abolish the larger animals. I ventured, to ask for some clear instance of this interdependence. He was unable to quote any first-hand evidence which might not have been explained away, and his main contention, in short, was, “Of course the fly is dependent upon the game, everyone with any experience knows that; ask any old hunter or native.” This, I think, about sums up the ideas of the majority of people, and, if further argument is deemed necessary, the assumed general disappearance of the fly after rinderpest is pointed to as affording conclusive proof. The presumption is, of course, that the fly, deprived of its means of subsistence, died of starvation. An acquaintance with some of the districts visited by the epidemic would however by no means indicate that this was the real cause of the phenomenon, where it occurred. A study of the effect of rinderpest upon the relations between fly and game, might indeed, were it possible always to obtain accurate data, shed some new and interesting light upon the whole subject.

Using a deterministic model of a tsetse population, theoretical calculations have been made of the effect of repeated applications of a non-persistent insecticide upon a natural population. It has been assumed that the insecticidal applications instantaneously reduce the adult population, and that there is no residual effect.

For the numerical work it has been assumed a female fly has a pupal period of four weeks and an average expectation of life of six weeks and produces her first larva three weeks after emergence, and subsequent ones at intervals of one-and-a-half weeks.

Results have been calculated for kills of females varying from 50 per cent, to 95 per cent, per application, for series of up to eight successive applications, and for intervals between successive applications of from one to six weeks and also for the case when the population is allowed to become stable between applications.

During recent years in Sweden much time and work has been devoted to the devising of accurate and withal time-saving methods of estimating the number of bark-beetles breeding in a trunk as well as the total number of bark-beetles per hectare in a given instance. The results achieved by the methods finally adopted seem to us so satisfactory that we venture to think that the methods in question may be used to advantage even in other countries, when similar problems arise.

Milionia isodoxa Prout is a serious defoliator of planted hoop pine, Araucaria cunninghamii, in the Highlands of Papua New Guinea. The insect has been found in seven mainland districts, and larvae have been collected from naturally occurring hoop pine in the Madang and Southern Highlands Districts. M. isodoxa is multivoltine, the life-cycle taking approximately eight weeks. The durations of the five larval instars are 4, 4, 4, 5 and 10 days, respectively, and of the pupal period approximately two weeks. The males feed primarily on organic solutes, the females on nectar, so that the sex ratio of adult M. isodoxa in the hoop pine plantations at Bulolo varies with the time of day and locality. Pupae may be attacked by two species of Ichneumonidae and one of Braconidae, and the ants Anoplolepis longipes (Jerd.) and Oecophylla smaragdina (F.) are particularly effective larval predators in the Bulolo plantations; some adults are killed by spiders. The fungus Beauveria bassiana is responsible for high pupal mortality in the Highlands. Frass-drop frequency studies of M. isodoxa larvae in the laboratory showed that feeding activity is greatest in the early instars, and is greater at night for all instars. Larvae reared at 21°C required 14 days more for development than did those reared under the normal daily fluctuation, 19–31°C.

The persistence and toxicity of DDT crystals on thin layers of plant wax were studied. Deposits of crystalline DDT at rates of 2 to 8 microgm. per sq. cm. were applied to glass plates, plain or coated with a 0·5 μ layer of wax obtained from leaves of sisal or cabbage. The plates were stored for various periods at 18°C. and at 43°C. (representing temperature and tropical leaf-temperatures). DDT remaining after storage was estimated biologically by means of its contact action on adult Tribolium castaneum (Hbst.), and chemically by a modification of the Schechter-Haller method. At 18°C, there was no significant change in any of the deposits when estimated chemically. But biological estimation showed that, although the toxicity of the deposits on waxed plates was unchanged, that on glass plates was doubled after storage for eight days. The reason for this change was not discovered. At 43°C., the amount of DDT, estimated both chemically and biologically, diminished rapidly and was negligible after 26 days. The loss of toxicity at 43°C. was shown to be accompanied by loss of weight of the deposits. Loss at 43°C. from plain glass plates could be much reduced by storing them in an atmosphere saturated with DDT vapour. It appeared, therefore, that loss of toxicity at the higher temperature was due to volatilisation of DDT and not to decomposition.

European farms at Abercorn had been suffering from bovine trypanosomiasis carried by Glossina morsitans Westw., and the Tanganyika Department of Tsetse Research were asked in 1935 to advise.

Fly-pickets were established in 1936 to prevent carriage of flies on to the farms, and a belt of country was protected from fire, with the object of thickening the woody vegetation so as to make it unfavourable to G. morsitans. The fire-protected area was extended and continued until 1946; serious escape fires occurred in 1938 and 1941. During these first five years the reduction in catches at the pickets was only about one-third.

An intensive survey of the area was made in 1941, as the result of which concentrations of flies were identified in certain shallow valleys forming the headwaters of small tributary streams. Several of these were cleared of trees, with the result that the apparent density of G. morsitans was at once depressed not only in the valleys themselves but over wide areas of untouched woodland round about.

In 1942 and the following years these clearings were extended to new valley sites as they were discovered, both inside and outside the fire-excluded area, and always with striking effects. The last clearing of all was done in 1952.

Field studies on the biting habits of Culicoides barbosai Wirth & Blanton were made near Montego Bay, Jamaica, during 1959 and 1960. Females of C. barbosai were collected in sufficient numbers for analysis in. seven experiments, six from Florida beach and one from Beading. Four positions were marked out on each site. Begular meteorological observations were made in the middle of the catching positions. An experiment consisted of four trials held on different days, each trial being composed of four collecting periods of 15 min. separated by 5-min. intervals. In each period four individuals collected, two exposing an arm each and two a leg. Individuals collected in a different position in each period of a trial.

Catches were logarithmically transformed for analysis and tests of significance. The experiments were designed to provide correction factors for limbs, positions on Florida beach, and collectors, for use in other experiments. Correction factors are given as logarithms for application to transformed catches.

More C. barbosai were collected from arms than legs, and catches in position IV were significantly higher than those in positions I, II and III. Five collectors (C, D, K, L and S) were compared. The ratio between leg/arm catches from D, who collected in only two experiments, was significantly different from those of C, L and S. The differences between the catches of C, K and L were insignificant, but all three caught significantly more than S. The catches from L were smaller after sea bathing and, compared to C and S, L’s catches increased significantly immediately after sunset. For this reason and to avoid inhibiting winds, quantitative studies on females of C. barbosai are best conducted in the early morning (dawn + 40 min.).

The experimental errors (residual variances) were homogeneous with probabilities of 0.1 (C. barbosai—7 experiments) and 0.4 (C. furens (Poey)—8 experiments).

Understanding the biology of the housefly (Musca domestica L.) is crucial for the development of mass-rearing protocols in order to use this insect as a degradation agent for livestock waste. In this study, the biological and genetic differences between different laboratory strains of M. domestica were analysed. Additionally, hybrids were obtained by mixing the strains and their biological parameters were also measured. The three strains of M. domestica presented differences in their biological and morphological parameters, the main differences were: size, egg production and developmental time. The strain A (specimens from Central Europe) had the best qualities to be used in mass-rearing conditions: it produced the largest quantities of eggs (5.77±0.38 eggs per female per day), the individuals were larger (12.62±0.22 mg) and its developmental time was shorter (15.22±0.21 days). However, the strain C (specimens from SW Europe) produced the fewest eggs (3.15±0.42 eggs per female per day) and needed 18.16±0.49 days to develop from larva to adult, whilst the females from strain B (from South America) produced 4.25±0.47 eggs per day and needed 17.11±0.36 days to complete its development. Genetic analysis of the original laboratory strains showed four different mtDNA cytochrome c oxidase subunit I haplotypes. Statistical parsimony network analysis showed that the SW Europe and South-American strains shared haplotypes, whereas the Central Europe strain did not. Upon hybridizing the strains, variations in egg production and in developmental time were observed in between hybrids and pure strains, and when mixing Central European and South-American strains only males were obtained.

Larvae of aphidophagous ladybirds leave a cue in their tracks that deters oviposition. The influence of relatedness on this behaviour is for the first time explored in this paper. Two-spot ladybird females (Adalia bipunctata L.) under different conditions (young and naive, young and experienced, and old and naive) were exposed either to (i) clean filter paper, (ii) filter paper contaminated with unrelated larval tracks or (iii) filter paper contaminated with related larval tracks from their offspring. Oviposition time was recorded during nine hours. Oviposition was inhibited by larval tracks, and was more so by related than unrelated ones. Experienced females showed the same behaviour but with lower intensity. With old females, response was not significant with any type of larval tracks. This is the first report of the effect of relatedness on a ladybird's response to larval tracks.

Five sampling methods were evaluated for efficiency in estimating field populations of Megalurothrips sjostedti (Trybom) on cowpeas in Nigeria. The methods (sticky traps, water traps, sweep netting, shaking plants and the collection of whole plant samples) were judged on the basis of low sample variance, low cost and fidelity to absolute population trends. Shaking plants and water traps were the best sampling techniques on the basis of sample variance and cost. Shaking plants also showed the closest correlation with absolute population trends and is therefore recommended for rapid estimation of field populations of thrips. The performance of the usual alcohol method of sampling M. sjostedti on cowpeas (collecting racemes and flowers in alcohol) was not comparable with those of shaking plants and water traps, but was considered important because it sampled the infested structures, eliminating more transient visitors which might also be sampled by shaking plants.

A controlled technique is described, whereby the comparative protective values of various dips and sprays used in sheep maggot fly control can be accurately assessed.

In order to determine the exact mode of action of the agents under test, each is examined from the point of view of its power to inhibit oviposition by the adult fly and also for its larvicidal properties.

The “anti-adult” test involves the weekly exposure of treated groups of sheep to an active and dense fly population, maintained in a closed chamber under controlled conditions of temperature and light.

The larvicide test is a modification of a former method of larval implantation, and is applied to the sheep when the “anti-adult” protection, indicated by the previous test, is found to have failed.

In the second part of the paper, a number of results are presented which serve to illustrate the working of the technique, and demonstrate the comparative value of several methods of maggot fly control which are in current use.

A dip containing 0·5 per cent. DDT in water suspension was found to give the most satisfactory protection, and to achieve this result purely by its action against the adult fly. A 0·5 per cent. DDT benzene emulsion dip was less satisfactory, as alsowas spraying as a method of applying the insecticide. In general, spraying has given about half the protection of dipping, whilst on sheep in full fleece, the application of half a gallon of spray was found to be inadequate. Protection was again found to be poor when the fleece was carefully dressed with half a pound of a dry powder containing 5 per cent. DDT.

In contrast to DDT, BHC and arsenic were shown to possess virtually no “antiadult” properties at the concentrations tested. BHC and arsenic both acted as efficient larvicides and provided a valuable and similar degree of protection against the sheep maggot fly, as an incidental effect, when they were tested at the concentrations normally used for their primary function of sheep scab control.

The seasonal abundance, biting cycle, age composition and survival of females of Aedes polynesiensis Marks and A. samoanus (Grünberg), the major vectors of subperiodic bancroftian filariasis, were studied in Samoa. A. polynesiensis density was low during the high rainfall months and increased immediately following them. A. samoanus density showed no clear relation to rainfall. A. polynesiensis was active throughout the day, with peaks indoors and out at 08.00–09.00 h and 16.00–18.00 h. The nulliparous and parous populations showed similar patterns of activity. The biting cycles of 2-parous and 3- plus 4-parous females were asymmetric with time. A. samoanus was active throughout the night, with highest activity at 23.00– 01.00 h. A minor peak at 19.00–20.00 h was more pronounced among older females than among younger ones. Night biting by A. polynesiensis and day biting by A. samoanus were rare. The parous proportion of A. polynesiensis ranged from 36·3 to 59·5% and the epidemiologically significant 3- plus 4-parous proportion ranged from 1·0 to 6·7%. The parous proportion of A. samoanus was 37·9–49·7% and the 3- plus 4-parous proportion 1·4–2·6%. The proportions found to be parous in both vectors were generally higher in the cool than the warm season, suggesting higher daily survival during that period.

The present study investigated the patterns of microorganisms in an artificial larval diet during Dacus ciliatus (Diptera; Tephritidae) larval development. Microbial population contents in the diet of total heterotrophic bacteria, yeast and molds, coliform and lactobacilli, and their dynamics during development, were monitored. Initially, the microbial composition in diet trays failing to produce viable pupae and in trays successfully producing pupae and adult flies was characterized. The failing diet trays contained large populations of lactobacilli that increased during larval development, and low populations of coliforms. In contrast, the successful diet showed an increasing population of coliforms and a low, or undetected, population of lactobacilli. To study the hypothesis that lactobacilli affect D. ciliatus larval development, we conducted controlled inoculation experiments in which Lactobacillus plantarum was added into fresh diet at the time of egg seeding. L. plantarum inoculated trays showed no production of D. ciliatus. Control trays without lactobacilli inoculation showed variable results. One tray successfully produced viable pupae and adults, and showed a slight and slow increase in the indigenous populations of lactobacilli. The second tray, however, failed to produce pupae and showed a fast increase of the indigenous lactobacilli to very high levels. Monitored pH trends in L. plantarum-inoculated diet showed a sharp pH decrease during the first 4 days of larval development from 5 to less than 4 units, while successful diet, producing viable D. ciliatus pupae and adults, showed a moderate pH drop during most of the larval development period. The paper discusses the possible ecological interactions between D. ciliatus larvae, the microbial content of the diet and the physical properties of the diet. The discussion also points out at the usefulness of this approach in understanding and managing mass production parameters of tephritid fruit flies industrial diets used for Sterile Insect Technique.

The males of Heliothrips haemorrhoidalis (Bouché) are very rare and the species is thelytokous. Mutation of genes controlling male characteristics will therefore not be subject to selection, and so structural variation in these males is of no taxonomic significance. It is concluded that haemorrhoidalis and ceylonicus Schmutz represent one species in which the females vary in size, sculpture and colour throughout the tropics.

Examination of the polytene chromosomes and cross-breeding data confirmed the specific status of Anopheles dirusPeyton & Harrison within the complex of A. balabacensis Baisas. The data also strongly suggested that A. dirus itself is a complex of at least two species, one of which, a hitherto unrecognized species, provisionally designated A. dirus species B, previously known as the Perlis form, occurs in northern Peninsular Malaysia. A distinct population from Thailand was designated A. dirus species A. The mosquitoes studied also include material from natural populations in Sabah, here provisionally designated A. balabacensis s.s., and may represent the first genetic analysis of this species. The Sabah material is distinct from either of the A. dirus forms. Hybrid males from crosses of A. balabacensis × A. dirus species A and of A. dirus species B females × A. dirus species A males were sterile. Chromosome studies also showed that reproductive isolation was accompanied by genetic changes in both the autosomesand X chromosome in the hybrid larvae.

A molecular phylogenetic study of the Drepanoidea based on the EF-1α sequences and combined EF-1α and COI sequences was carried out in order to infer higher classification at and above the subfamily level. The sample contained 14 taxa representing 13 genera recognized in the Drepanoidea. The results revealed that the Drepaninae, Thyatirinae and Cyclidiinae respectively form monophyletic groups. The sister relationship between the Drepaninae and the Thyatirinae was validated. The monophyly of the Cyclidiinae with the Drepaninae+Thyatirinae was supported robustly. Hypsomadius insignis and Oreta vatama within the traditional definition of the Drepaninae formed an individual clade with robust support (100%) and constitutes a sister relationship to a clade containing the rest of the Drepaninae in all the topologies, which means that the subfamily Oretinae of the Drepanidae should be restored. The family Drepanidae is divided into four subfamilies: Drepaninae, Oretinae, Thyatirinae and Cyclidiinae in this work. The family Epicopeiidae formed a monophyly with high bootstrap values. The result of combined analysis of EF-1α and COI showed that the Epicopeiidae have a closer phylogenetic relationship with the Geometridae than with the Drepanidae and belong to neither the Drepanoidea nor the Geometroidea.

The effects of the chitin synthesis inhibitor triflumuron, 2-chloro-N-[[[4-(trifluoromethoxy)phenyl]amino]carbonyl]benzamide, on the housefly, Musca domestica Linnaeus were examined in the laboratory. A dose of 1 μg of triflumuron applied topically to adult females of M. domestica resulted in egg hatch inhibition greater than 95%. At doses below 1 μg applied topically to adult females, subsequent hatched larvae were also highly sensitive to triflumuron; 0.5 μg applied topically produced 25% inhibition of egg hatch, but of the larvae that eclosed, only 20% survived to pupation. Hence, a dose of 0.5 μg applied to adults gave a total mortality of 85%. The effects of a single topical application of triflumuron declined over time in a dose dependent manner. After a dose of 1 μg, <5% of the first egg batch hatched, however, after 14 days egg hatch had risen to >90%. Topically applied triflumuron was most effective in inhibiting egg hatch when applied to females less than 3 days old. After 60 min tarsal contact with 20% triflumuron suspension concentrate on poly cotton cloth, 100% egg hatch inhibition was maintained for up to 1 week. Lower contact times, or triflumuron concentrations, gave lower percentage mortalities. The results suggest that triflumuron has considerable potential as a control agent for incorporation into autosterilizing devices for housefly control. However, further work is required to develop delivery systems capable of transferring an effective dose to females under field conditions.

Various substances have been used by different workers as substrata for breeding the house-fly under laboratory conditions. Horse manure was recommended by Hutchison (1916), Glaser (1924), Grady (1928), Derbeneva (1935) and Kusina (1936). A mixture of horse manure and hog manure was used by Hockenyos (1931). Feldman-Muhsam (1944) obtained the best breeding results by using cow dung. Pig dung was preferred by Lörincz & Makara (1935). Lodge (1918) reared house-flies on a mixture of casein, bread, water and banana. Richardson (1932) used another mixture of wheat bran, alfalfa meal, diamalt, yeast and water. Kobayashi (1935) used a by-product of soya beans. Basden (1947) in his large scale experiments, necessitating about 2,500 flies daily, used a mixture of middlings, grass meal, tap water, dry malt extract and dried yeast.

Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya are pests of the timber tree Triplochiton scleroxylon in Nigeria. The egg and five nymphal instars are described and illustrated. Under laboratory conditions the life-cycle (egg-egg) of D. eastopi was completed in 18½ days, and mated fed females had a life span of 15 days. The sex ratio in the field was 1:1. Nymphs feed near the veins of mature leaves, causing premature leaf fall; adults feed on leaves of any age and cause no symptoms. Fecundity averaged 502 eggs, with a daily oviposition rate of 38; most eggs are laid in batches along the veins of mature leaves. The life-cycle of D. harrisoni was 16 days; mated and fed females lived 10 days. The feeding of firstinstar nymphs near the margins of young leaves causes leaf tunnels to form, inside which the nymphs complete their development; adults feed only from young leaves. In the field the female:male ratio was 2:3. Fecundity averaged 131, with a daily oviposition rate of 31. Fertility improved with multiple matings. The eggs are laid singly, partially embedded in the epidermis, and only on young leaves.