In a study of the incidence of funnel ants (Aphaenogaster spp.) on the Atherton and Evelyn Tablelands of northern Queensland in 1959–61, 422 farms were surveyed, totalling over 98,000 acres of pasture, of which 10.8 per cent. proved to be infested with A. pythia Forel. The ants damage the introduced pasture grasses (Paspalum dilatatum and Pennisetum clandestinum) by removing soil from around their roots to from loose mounds, which smother the closely-grazedsward. Inferior species of grass and deep-rooted weeds are thus encouraged and affected areas become useless for dairying.

The natural habitat of A. pythia is wet sclerophyll forest which occurs in narrow belts fringing the rain forest and in pockets within it; the rain forest does not harbour the ant, but following its clearance and its replacement by pastures, A. pythia has spread out and colonised the latter. In areas of lower annual rainfall (under 50 in.) occupied dry sclerophyll forest and Eucalyptus woodland, A. pythia is replaced by A. longiceps F. Smith. Improved pastures have not been established here, but in the relatively restricted areas of infestation by this species, the large funnel-shaped orifices of its mounds create a hazard to stock.

Two new genera and species of Phycitinae found with Hypsipyla robusta (Moore) attacking Meliaceae in Nigeria are described. The three genera and species are differentiated, and the genus Hypsipyla is briefly reviewed. Illustrations of the wing venation and wing pattern of the adult male and of the genitalia of both sexes are given for the two species described as new, Catopyla dysorphnaea and Gyroptera robertsi, and also for H. robusta.

Bathycoelia thalassina (H.-S.), of which the developmental stages and life history are described, is responsible for premature ripening of cocoa pods in Ghana. Experiments conducted at Tafo to determine the nature of the damage to pods showed that the insect feeds directly on the beans, and that beans so attacked turn brown and subsequently die: only the empty shell of the bean remains.

The saliva of the insect kills any tissue of the pod that it penetrates and within four days the injured areas cease to grow and become yellow, then brown, and finally black.

The symptom most characteristic of damage is the change in colour. The pod may become completely yellow, or yellow in the basal or distal half only (usually the latter) or yellow in spots, depending on the size of the pod, the site of attack, and the duration of feeding at each site.

The insect usually attacks pods of the Amazon varieties, 10–17 cm. long. The incision made by the stylets is microscopic, and is covered by a jelly-like substance, and no evident lesions develop on the surface as in damage caused by cocoa mirids or coreids.

Damage caused by B. thalassina on young pods resembles cherelle wilt of physiological origin, and the two can be distinguished only by slicing the pods, whereupon the former can be recognised by the presence of injured beans.

According to the survey of damage caused by B. thalassina in Ghana, this species seems to be an economic pest on some Amazon and hybrid types of cocoa, whereas Amelonado cocoa usually suffers little.

Newly emerged and 3-day-old house-flies (Musca domestica L.) of a diazinin-susceptible and a diazinon-resistant strain were treated topically with diazinon or diazoxon and examined for symptoms of poisoning and recovery at intervals up to 5 hours and at 24 hours after treatment. The effects of the poisons varied with the age and strain of the flies and with the poison used. Most of the flies that became paralysed died, but some recovered, even after appearing to be dead. Of flies treated when newly emerged, more of the resistant than of the susceptible strain recovered from paralysis, and more recovered from diazoxon than from diazinon treatment. Recoveries were fewer amongst flies treated when three days old and occurred in appreciable numbers only amongst those of the resistant strain treated with diazoxon.

Histochemical tests on flies, treated with diazoxon showed a close correlation between inhibition of cholinesterase activity in the thoracic ganglion and the external symptoms of poisoning. Inhibition was slight in apparently unaffected flies, more extensive in severely affected flies, and total or nearly so in completely paralysed flies. Inhibition first appeared at the periphery of the ganglion and spread inwards to the centre. Flies that recovered from paralysis had normal or almost normal cholinesterase activity, partially recovered flies showed activity only in the central parts of the ganglion. Recovery of cholinesterase activity seems to occur from the centre of the ganglion outwards.

A Tortricid moth belonging to the Olethreutinae, bred from larvae feeding on the parasitic dodder Cuscuta reflexa in West Pakistan, is described as new and is named Herpystis cuscutae sp.n. The species is differentiated from the closely related H. jejuna Meyr., which occurs in India, and also from the two other Indian species of this genus, H. pallidula Meyr. and H. tinctoria Meyr. The status of the three specimens comprising the original type series of H. jejuna is re-evaluated, and one of them is considered to be probably conspecific with H. cuscutae.

From obsevations on larvae from laboratory-reared females of Glossina morsitans orientalis Vanderplank, six stages were recognised between the time of deposition (signalled in these experiments by a simple automatic device) and completion of puparium formation, each characterised by an associated pattern of behaviour. They are termed crawling (during which there is a stron phot-negative response), circling and reversing, head retraction, barrelling (the assumption of the puparial shape), hardening, and darkening. In choice-chamber experiments, crawling larvae markedly preferred moist to dry air but showed no response to gravity. In daylight at 26°C., larvae introduced into translucent plastic tubing travelled up to 65 in. before pupating; under bettwe conditions for locomotion they would probably go further. The interval before pupation was longer the earlier in the day birth occurred and was greater in light (average 108 min.) than in darkness (average 40 min.) and least, perhaps because of the contact stimulation, in sand in darkness. When bodily contact was minimised by suspending larvae by a thread tied round or stuck to the polypneustic lobes, pupation was accelerated; this possible reflected the mechanical stimulation of the handling, for pinching the larva with forceps produced a similar acceleration.

A Phycitine Pyralid associated with Sorghum cultivars (Kaffir corn, dura or Indian millet) in Uganda, Tanzania and Sudan, and also known from one example from Northern Nigeria, is described as new and is named Salebria mesozonella sp.n. Illustrations are given of the adults and genitalia of both sexes.

The effects of temperature and humidity on the development of Oligonychus coffeae (Nietner) were studied by exposing the various stages of the mite to air in equilibrium with saturated solutions of appropriate salts in containers within thermostatically controlled cabinets. Adults and early stages were maintained on fresh tea shoots.

The pre-oviposition, oviposition and post-oviposition periods of adult females at 75–80% relative varied inversely with temperature, and averaged, respectively, 0.8, 5.9 and 1.4 days at 32° and 2.3, 30.6 and 2.0 days at 20°C. The mean number of eggs laid per female likewise varied inversely with temperature, from 12.0 at 32°C at 32° to 107.3 at 20°C.

No eggs hatched when incubated at 34°C., irrespective of humidity, or at 17% R.H., irrespective of temperature. Optimum conditions for incubation (those affording over 90% hatch) were provied by a combination of temperatures and relative humidities within the ranges 20–30°C. and 49–94%. When eggs were exposed daily for five days to temperatures of 37 or 40° for six hours at 72–94% R.H. and then transferred to room conditions (24–32°C., 64–88% R.H.), the percentage of eggs hatching was reduced from 94.7 (room conditions) to about 75 or 5–12, respectively.

The mean incubation period of eggs varied from 3.9 days at 32° to 10.8 at 20°C., and the mean duratio of the combined larval and nymphal stages from 4.9 days at 30° to 8.7 at 20°C. At 32°C., larval mortality was very high.

In 1960–65, six field trials were carried out on tea estates in Ceylon to assess the effect on yield, and on the response of the crop to fertilizer, of dieldrin sprays applied after pruning to control shot-hole borer (Xyleborus fornicatus Eichh.). Periodic sampling was carried out to assess the numbers of borers and their galleries. Yields were recorded by weekly or fortnightly weighings of the green leaf plucked, over pruning cycles of two to four years.

The pattern of the yield increases on the sprayed plots was related to the difference in attack between the sprayed and unsprayed plots. Increases were, in general, small in the first year and much larger in the second year, reaching peak values of 32–58 per cent. (on the yields of successive three-monthly periods recorded) in the late second year, and declining thereafter through the third year as the difference in attack declined. Over the first two years there were marked yield increases in eight of the nine pruning cycles, and these ranged from 11·7 per cent, to 26·3 per cent. There was significant regression (P<0·001) of the percentage increase in yield on the maximum difference in gallery counts. Yield increases in the third year of pruning cycles were also considerable and the results evidence a prolonged effect of the heavy borer attack occurring in the second year.

In one trial there was a significant interaction between the effects of dieldrin spraying and of nitrogen supplied. Control of the borer greatly improved the crop response to nitrogen. Nitrogen application increased the yield but resulted also in a proportionately larger loss of crop from borer attack. There was a small but significant increase in the number of borer galleries on the plots receiving nitrogen.

The evidence on the size and pattern of crop losses caused by the borer suggests that these occur both from shoot breakages and from the direct effect of galleries on the growth of stems.

The significance of the results in relation to estate practice, and the economics of spraying, are briefly discussed.

A new species of thrips is described which is predatory on Tetranychid mites on apple trees in Iraq. It bears a superficial resemblance to species of Scolothrips, but in view of the undivided tarsi and the chaetotaxy of teh head and pronotum it is placed in a new genus as Parascolothrips priesneri sp.n.

A mathematical treatment is proposed, utilising the methods and notation of matrix algebra, for evaluating the theroetical effects on the growth and structure of a population of the removal of individuals in particular age groups or stages in the life history. Formulae are derived to establish what proportions of given age groups or stages, individually or in combination, can be withdraw from the population whilst permitting its maintenance at a constant level. It is pointed out that these methods, appropriate to the situtation in which the population is exploited by a cropping procedure, can be extened to the special case of population control, in which it is desired to minimise or eliminate the population. The methods are illustated by numerical examples based on census observations on a growing population of Lasioderma serricorne (F.).

Anjeerodiplosis peshawarensis Mani is a serious pest in North India of the fruit of the country fig (Ficus carica), which is its only known host. The midges are abundant, hovering under the host tree in the mornings and at dusk, and breed throughout the year, except in the summer from April until the July rains. In this period newly formed fruits are not infested, but in other months scarcely 30 per cent, of the fruits remain free from attack.

Eggs are laid in fruits when they one week old, succulent, and of the size of a pea. The eggs are minute, hyaline, unsculptured, oval and pedicellate and occur in bundles of 16. Incubation takes three days in September and March and five days in December and January. In laboratory tests, average viability in January was found to be about 83 per cent.

The entire larval period is passed inside the figs, each of which may contain 200–300 larvae. There are four larval instars, which differ in size according to Dyar's law and in morphology. The first-instar larva is devoid of cuticular outgrowths and does not show spiracles; the second and third instars have nine pairs of spiracles and possess characteristic spines, warts and tubercles; the fourth instar develops the sternal spatula. The entire larval period lasts three weeks from the middle of August to October and four weeks in January and February. From the middle of April until the July rains, fourth-instar larvae remain inside the figs. When the larval period is three weeks, the first and second instars together and the third and fourth instars separately last about a week.

Full-grown fourth-instar larvae bore out of the fruit and drop to the ground, where they jump for some time with the aid of their sternal spatula. They finally pupate in the soil without forming a cocoon but become covered in a protective case composed of soil particles that adhere to the larval skin. Early fourth-instar larvae, which do not have a sternal spatula, if taken from the fruits, may also successfully pupate, and the pupal period is normal. This period is 10–15 days between July and November and 25–26 days in January and February. It is shortest (10 days) in the rainy season, when both temperature and humidity are high.

The pupa is obtect, creamy white and bears poorly developed cephalic horns and bristles, well developed thoracic horns and many spines and cuticular outgrowths. Mortality in the pupal stage is between 15 and 30 per cent.

Emergence of the adults invariably occurs in the early hours of the day. Two or three days before emergence, the protective case becomes detached piecemeal. Males emerge before females. The ratio of males to females on the day of emergence is 1:2 between March and December and 2:3 in January and February. Copulation starts soon after emergence and lasts from 60 to 90 seconds.

There is considerable overlapping of generations. On the basis of the time required for completion of the life-cycle in different months, it is calculated that seven generations are completed in a year.

A diet previously described for rearing Pieris brassicae (L.) was found to be very successful for rearing Mamestra brassicae (L.). Less than 5 per cent. of the pupae that formed entered diapause. The larvae can be much more quickly counted, examined and looked after when kept on the diet than when kept on cabbage leaves.

It has been shown that adults of Glossina morsitans Westw. that have fed from a bait ox in their natural environment digest their blood meals more rapidly than others that have emerged and been fed in the laboratory, even when both are maintained under identical environmental conditions after feeding.

In further experiments with G. morsitans in Rhodesia, flies caught in the field and fed in the laboratory were found to lose their ability to digest their meals rapidly. Measurements, made throughout three hunger cycles, of the rate of digestion, as reflected in the rate of excretion, of blood meals by field-caught flies fed on guineapigs in the laboratory showed that this was not significantly different from that of the normal, flied-fed flies during the first two hunger cycles but that during the third it fell to a level comparable to that of flise that emerged and were fed in the laboratory.

It is concluded that whatever may be the events that condition the field flies to digest their meals rapidly in the natural environment, these are repeated with the ingestion of each meal, and that laboratory conditions cause a rapid loss of this greater digestive capability.

The genus Nephotettix in Africa and Madagascar has been found to be represented by two species: one of them is N. modulatus Melich., the other is described as new and named N. afer sp.n. Both species are widely distributed in Africa, and a map is presented showing the countries in which each has so far been recorded.

The insecticidal Potencies of DDT, dieldrin, isobenzan, malathion, diazinon and arprocarb were assessed both by topical application of oil solutions to test insects any by exposing the latter to residues on glass, using young male and non-pregnant female adults of Glossina morsitans submorsitans Newst., G. austebi Newst., and Chrysomya putoria (Wied.).

By topical application, dieldrin and isobenzan were 10–23 times as potent as DDT, but their residues were on ly 2.2–6.3 times as effective; arprocarb was likewise more effective by topical application than as a residue, being, respectively, 9 and 3.5 times as effective as DDT. In contrast, diazinon, and, especially, malathion tended to be more efficient, relative to DDT, as residues than might be expected from application tests.

It is presumed that the difference between the ralative potency of an insecticide as a reesidue and as applied topically reflects the physical factors affecting contamination and penetration of the insect, but these matters have nor been stuided with tsetse flies.

The humidity responses of Trogoderma granarium Events were tested in humidity gradients set up in choice-chambers, each comprising a petri-dish with the lower half divided diametrically into two compartments containing sulphuric-acid soluctions affording different relative humidities and surmounted by a copper-gauze platform on which the insects, released centrally, could move about. Counts of the numbers in either half of the arena were made at 15–minute intervals over two hours.

In a gradient of 20–80 per cent. relative humidity, at 20°C., the average count was significantly greater on the drier side than on the moister one for larvae and adults tested in groups and for larvae and adult males, but not females, tested singly; the response was greater when the insects were tested in groups. Antennectomised adults, tested at 25°C. in a gradient of 20–100 per cent. relative humidity, showed no response, although intact control beetles showed a significant perference for the drier side. When adults were tested in groups at 25°C. in a range of gradients, from 20–10 to 20–100 per cent, a preference for the drier side was invariably shown, the response tending to be greater and to occur more rapidly in larvae than in adults, and as the humidity gradient steepened.

Further evidence is provided to show that the head of the desert locust is the most vulnerable body region to the toxic action of malathion (and malaoxon). The circulatory system is shown to play an important part in determining the toxicity of the insecticide by taking it towards or away from the sensitive areas. The rates of absorption, distribution and excretion of 3H-malathion for different applications are given.

Late in 1962, Heteronychus licas (Klug) was recorded causing damage to sugar-cane for the first time in Nigeria. It had previously been known there only as an inhabitant of grassland and a negligible pest of yams (Dioscorea spp.). The damage to sugar-cane, which was first noted at an early stage in the development of a large commercial sugar-growing estate (the first in the country) in Nothern Nigeria, resmbles that caused by Lepidopterous stem borers; the young shoots and tillers are eaten away around soil level by the larvae and adults and are eventually killed (‘deadhearts’). The adults sometimes tunnel in the pith of older canes, but seldom kill them. Surveys on the estate in 1963–64 showed that damage by the beetle was becoming increasingly important. In anticipation that this might happen, field and laboratory investigations into the habits and life-historv of H. licas were carried out in the same two years, and the initial results are reported.

There is one generation a year. Oviposition took place in moist soil near the bases of cane plants from late October to December. In the laboratory, the average female laid 60–75 eggs over a period of 1–3 weeks, hatching occurred after 9–16 days and the three instars lasted successively 14–19, 15–24 and 20–25 days. Larvae were found in the field from November to March, but occured in large numbers only during January and early February, mostly within a depth of 1 ft. in the soil; only those in the second and third instars fed on the canes. Puation took place in a cell 112–3 ft. below the surface; the prepupal and pupal stages together lasted 23–31 days in the laboratory. In the field, pupae were most numerous in February and March and adults, which began to emerge early in March, reached their greatest numbers between then and May.

Evening catches at a light-source showed that H. licas had two flight seasons each year, a subsidiary (post-teneral) one in April-June and a main (pre-reproductive) one in October-November, separated by a period of inactivity. Egg laying follows the second, and the adults die. Factors influencing the behaviour of the adults are discussed.

There were marked seasonal fluctuations in the incidence of ‘deadhearts’ caused by H. licas; it was highest in March-June each year, lowest during the period of adult inactivity, and again high during October-November.

Larvae kept together in the laboratory inflicted mutual injuries, mostly ending in death, but the extent to which this occured in nature could not be determined. Five Carabid species were found preying on the larvae in the field, and one on the adults as well. The importance of these and other possible predators and of parasites for the control of H. licas is discussed.

Measures that could be adopted for control are reviewed the literature.