Theresia (Procris) ampelophaga, Bayle, a moth of the family Anthroceridae (Zygaenidae) is one of the most important pests of the vine in various countries, but the existing accounts of its bionomics are very contradictory and not free from inaccuracies.

Very nearly allied to B. scutellaris, Bezzi (Memoirs of the Indian Museum, iii, 1913, p. 98, pl. viii, fig. 10), but differing in its smaller size, black face, differently coloured scutellum and unicolorous wings. This last character distinguishes it at once from any other Oriental species of this genus at present known.

The Imperial Bureau of Entomology have received the following six species of Rhynchota from Colombia, forwarded by Mr. M. T. Dawe, the Director of Agriculture, who reports two of them Trichocentrus sp., and Collaria oleosa as injurious to rice plantations, and the remaining four, Monalonion atratum, M. illustris, M. megiston, and M. collaris as damaging cacao pods. Of these Monalonions, two are here described as new species.

Two Lepidopterous leafminers have been observed on sweet potato at Koronivia, Fiji. The Gracillariid Acrocercops prosacta Meyr. is the more abundant species in most areas but populations of a Lyonetiid, Bedellia ipomoeae Bradley, reach damaging levels in fields sprayed with dieldrin for control of weevils (Cylas formicarius elegantulus (Summers) and Euscepes postfasciatus (Fairm.)). Such treatment is shown to reduce parasitisation of B. ipomoeae by a species of Apanteles near A. tapatapaoanus Fullaway and of A. prosacta, by another Braconid, a species of Mesocoelus near M. acrocercopsis Mues. However, outbreaks of B. ipomoeae could not be attributed to such reduction. Elimination of ant predation by the dieldrin sprays was more likely to have initiated the outbreaks.

Sprays containing malathion, diazinon, or dieldrin killed larvae, but not pupae, of B. ipomoeae. Outbreaks of B. ipomoeae can probably be prevented by relying on cultural methods to control weevils or by intensifying insecticide applications to control both B. ipomoeae and the weevils.

The effect of water currents on the dispersion of the larvae of Aedes aegypti (L.) and Anopheles stephensi List, were examined in the laboratory. The larvae represent two distinct respiratory positions, and on the basis of their amount of movement were termed active and inactive, respectively. While active larvae resist water currents, and tend to disperse evenly in a field system, inactive larvae tend to be washed away but also to accumulate in loci of minimal water movement. These findings could be applied to detection of larval populations, control by irrigation and spot chemical treatments in rice fields.

Kumasi is a rapidly expanding township of about 80,000 inhabitants. This has led to an extensive building programme which has followed the ridges in the vicinity of the town, leaving the valleys in between potentially dangerous isolated habitats of Glossina. The danger from these isolated habitats is enhanced by the large numbers of itinerant labourers.

The topography of the town and its surroundings is hilly; the vegetation is of semi-deciduous rain forest type, but with very thick secondary bush along most of the valleys in which the farms had been abandoned.

The climate is remarkably equable with the rainfall showing periodicity but the percentage relative humidity is high and even throughout the year.

The experimental clearing of an isolated habitat of Glossina in the Dechem valley was commenced in July 1950 and finished in March 1951. The clearing was of a discriminative nature, with cutting, stumping and burning of a strip of bush up to 20 ft. high and 250–300 yards wide along the stream, and a high reduction of fly population was achieved. This reduction was such that further clearings were planned.

The reduction in fly population was assessed from fly-boy catches and from trap catches. These records showed that rainfall affected the catches.

At the time of writing, about a sixth of the protective clearings planned around Kumasi have been completed, the fly population being reduced between about 80 per cent. and complete eradication.

Nesodiprion biremis (Konow) is a potential pest of pine nurseries and plantations in northern Thailand, attacking both native and exotic species. The eggs are laid in an aggregated pattern on fairly young or mature needles. There are normally six larval instars in both sexes. The larvae feed almost entirely on mature foliage unless food is short, and show little preference for particular species of pine. They are not markedly gregarious. Larval defence mechanisms are discussed. Cocoons are spun among the bases of living needles close to the stem. The life-cycle takes at least six weeks at 25–30°C, and there are probably 5–6 broadly overlapping generations each year. Egg mortality is normally low, but mortality of first-instar larvae due to inability to initiate a feeding site is high. Two parasites attack the larvae and at least four more species the cocoons. Shortage of food leads to the production of smaller adults with a reduced fecundity. Possible control strategies are discussed.

In connection with investigations into the life-history, etc., of Glossina morsitans in Northern Rhodesia, special efforts have recently been made to secure parasitesof the fly. As a result, a considerable number of Chalcidoids have been bred frompuparia collected between August and December of last year at Kashitu (LI. Lloyd)and Mwengwa (R. A. F. Eminson). These interesting Hymenoptera have now beenforwarded to the Imperial Bureau of Entomology by Mr. Lloyd, Chief Entomologistin Northern Rhodesia, with the parasitised puparia and some relevant notes. Onthis material the present report is based. The collection contains three species, representing as many widely separated groups in the superfamily Chalcidoidea.Two believed to be new are described below, the types being deposited in the British Museum.

There appear to be two main causes of “ blight,” namely, the attacks of the froghoppers (Tomaspis saccharina) and the attacks of root fungi (Marasmius and Odontia).

The susceptibility of the cane to the attacks of these root fungi has been shown to be largely due to unsatisfactory conditions as regards the health of the plant and particularly to conditions of drought—physiological or actual. Moreover, this root disease tends to intensify the effect of the water-shortage. It is suggested that a careful analysis of the evidence might also show that the susceptibility to froghopper attack is due to causes which disturb the water balance of the cane, a disturbance which would be even more marked where root disease was present.

The balance in the water content is dependent upon the simultaneous working of the absorption that takes place through the roots and the transpiration that takes place through the leaves ; if transpiration is excessive the plant makes too great a demand upon the supply of available water in the soil. The humid climate of Trinidad is, therefore, particularly favourable to the growth of the sugar-cane. A favourable climate can, however, be offset by unfavourable soil conditions. The distribution of the rainfall, the conditions of the soil, the degree of atmospheric humidity, the effect of the disturbance of the water-balance upon the nature of the cell-sap, etc., all need to be taken into account. As regards rainfall and blight, it would appear that : (1) Prolonged periods of drought, or of excessive rainfall ; and (2) periods of drought following on spells of excessive wet weather, are both particularly harmful.

In view of the part played by root absorption in the maintenance of the water-balance, a detailed consideration of the root system of the sugar-cane in connection with blight might possibly throw fresh light upon the subject.

A disturbance of the water-balance may also affect the cane's susceptibility to the attacks of insects through its effect upon the physiology of the cane. Is it possible that drought (physiological or actual) or other unfavourable climatic and soil conditions may affect the concentration or constitution of the sugars in the sap in such a way as to render them more attractive to sap-feeding insects ?

The problem is extremely complex. We have seen that root disease is dependant upon the weakness and debility of the cane, resulting from unfavourable environmental conditions and from shortage of water ; that the root disease thus caused intensifies the effect of this water-shortage by lowering the plant's capacity for root absorption ; that the plant, susceptible in any case to attacks of froghoppers as the result of any disturbance in the water-balance, is rendered even more susceptible as a result of root disease. On the other hand, root disease is said to be due to a lack of vitality in the plant ; a plant attacked by froghopper is greatly reduced in vitality, and thus the tendency to root disease is increased.

We have considered the interrelation between the absorption of water by the roots and the transpiration of water through the leaves, and the effect of the water content on the physiology of the plant. We must also consider the interrelation between the attacking froghopper and root fungus, and the cane which is attacked.

Can we decrease the number of attacking organisms, or is it more feasible to increase the cane's resistance to their attack ? In the past the economic entomologist has directed his attention almost entirely to answering the first question ; it is now realised that an answer to the second question is quite as, perhaps even more, urgently demanded. Unhealthy canes are undoubtedly more susceptible to attack than healthy canes, that is, if we use the term “ health ” in its rightful sense as denoting vigour and the capacity to resist adverse environmental conditions, and not merely luxuriant growth.

Diparopsis watersi (Roths.) is the principal pest of cotton in the Abyan Delta, West Aden Protectorate, an almost rainless area where the crop is sown in August–September on floodland watered by seasonal streams rising on the Yemen plateau. From December onwards, a large proportion of the pupae formed exhibit a facultative diapause, and adults emerging from these are responsible for infesting the following season's crop, the size of the initial population in which depends upon the extent to which this moth flight is intercepted by cotton in a suitable stage for breeding. When initial populations are low, most of the crop is set before the population has greatly increased by short-cycle breeding, shedding of flower buds and young bolls following attack by D. watersi is slight in relation to natural shedding, and little crop loss is attributable to this boll-worm. When a large part of the moth flight is intercepted, initial populations are high, heavy shedding is caused, and varying degrees of loss ranging up to virtual crop failure can result.

Investigations show that, when land is watered, emergence from diapause pupae is almost completed within six weeks; it is thought that watering reduces soil temperature below the high level that appears to inhibit diapause development throughout the summer. The resulting moth flight is largely spent before flower buds become available and the initial population in the crop is low. When land that was under cotton the previous year is not watered, soil temperatures remain high, and this is thought to account for a delay in emergence until temperatures fall, giving rise to a moth flight extending from November to January. Much of this is intercepted by cotton in a condition suitable for breeding by D. watersi, the initial population is high and heavy losses can result. The annual variation in the volume of the floods results in corresponding fluctuations in cotton acreage, a varying proportion of the previous year's cotton land remaining unwatered. The histories of the four cotton crops 1958–59 to 1960–61 indicate the extent to which infestation of the crop depends on this factor. In a year of poor floods following a large acreage in the previous year, infestations tend to be severe, and, conversely, a large crop following a smaller one the year before is normally lightly attacked. Failure to observe a close season may also promote heavy infestation, since it results in the provision of a food supply for the offspring of the main emergence from diapause pupae, which otherwise would not survive.

Endrin has proved very effective in the control of D. watersi, and Sevin also shows promise, but several applications over the two months following the first flower buds are necessary and it is doubtful whether these could be economic. A close season is essential, and the effects of its violation have been seen in recent years. The available flood water should be used more economically, using a system of area rotation of crops whereby cotton would be followed by another crop and that in turn by a dry fallow. The spring floods, which normally run to waste, could thus be utilised, and this would reduce the incidence of unwatered cotton land.

During 1963–69 the United States Department of Agriculture sponsored investigations on scale insects and their natural enemies in West Pakistan.* In the course of the survey Lepidosaphes conchiformis (Gmel.)† was collected from several localities. It occurred sporadically, but infestations were heavy on most of the plants on which it was found. In the hills it was commonly parasitised by Aphytis maculicornis (Masi). The potential importance of the scale and its parasite merited laboratory studies at Rawalpindi.

Wesché employed the relative length of the trumpets to the length of the thorax and the shape of the openings of the trumpets in drawing up a Key to the Pupae of West African Culicidae (Bull. Ent. Res., i, pp. 18–19). Howard, Dyar and Knab in their valuable monograph “ The Mosquitoes of North and Central America and the West Indies ” (Vol. i, pp. 102–103) state that in their experience too much has been made of the difference between the pupal trumpets of Anopheles and Culex; the variations in the shape, size, and length of the breathing trumpets between different species are numerous, they say, but “ furnish no characteristics which are diagnostic of genera or larger groups.” They consider that there are intermediate forms and that differences between species are frequently more striking than between genera themselves. They remark also that this may equally well apply to the differences in shape of the pupal paddles, admitting, however, that “ there is a striking difference between the two tribes Culicini and Sabethini ” as regards the paddles for “ In the Culicini the paddles are large, broad and rounded in outline; they are strengthened by a stout longitudinal midrib which bears a spine or seta apically.

Elongate, subcylindrical, black, clothed with yellowish-brown and whitish scales with antennae and legs fulvous, the legs with whitish scales.

The following Aphids were collected by Professor Guido Paoli, of Chiavari in Italian Somaliland and in Eritrea.

In the Esmeraldas focus of onchocerciasis in Ecuador, the larvae of the primary vector Simulium exiguum Roubaud are found in sympatry with the non-vector S. gonzalezi Vargas & Díaz Nájera. Distinguishing the pre-ultimate stage larvae of these two species usually relies on the pattern of markings on the cephalic apotome. These patterns appear either as dark spots against a pale cuticle (positive head pattern) or as pale spots within a darkened area of the cuticle (negative head pattern). Larvae of S. exiguum s.l. usually exhibit positive or no head patterns whilst those of S. gonzalezi usually have negative head patterns. The purpose of this paper was to investigate head pattern variation (scored in one of six categories) in (polytene) chromosomally identified larvae of the two species and cytotypes of S. exiguum from three collection sites in Ecuador (including one in the onchocerciasis focus). The head patterns of a total of 1183 larvae were studied. Chromosomal identification of penultimate instar larvae revealed only the presence of the Cayapa and Quevedo cytotypes of S. exiguum (n=208). Both cytotypes exhibited a wide range of head patterns from positive to negative. The results indicate that negative head patterns cannot be used to reliably distinguish between larvae of S. exiguum s.l. and S. gonzalezi. All except one larva with negative head patterns were females (n=53), suggesting that head pattern in this species complex might be a sex-linked character.

1. The Algerian race of Locusta migratoria, L., although never known to occur in the gregarious phase in nature can be transformed into almost typical ph. gregaria by breeding in crowded cages.

2. Biometric characters of such individuals indicate a relationship of the Algerian race to the subsp. migratoria, but the data are insufficient for a final decision on this point.

3. The rate of embryonic and hopper development in the Algerian race is the same as in the tropical African subsp. migratorioides when bred at the same temperature and relative humidity.

4. The rate of sexual maturation is very much slower in the Algerian race than in the tropical one bred under the same conditions.

The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that overwinters at pupal stage. Under optimum overwintering conditions pupae will develop into adults the next spring. Shorter or longer than optimum chilling periods induce prolonged pupae dormancy. Pupae that enter prolonged dormancy due to a short chilling period exhibit high emergence rates after a second cycle of cold/warm periods. Adults found to be larger and less fecund compared to their counterparts from pupae with annual diapause. On the other hand, extreme long chilling periods at pupal stage results in high mortality rates. However, for one Greek population, a substantial number of adults emerged following prolonged chilling of pupae (ca. 18 consecutive months). In this study, we used three R. cerasi populations in order to address possible geographical variation in fitness cost of adults from pupae with prolonged dormancy. In addition, the fitness traits of these adults emerging after prolonged pupae chilling were compared with that of their counterparts from pupae with annual diapause or prolonged dormancy. Our results reveal no population-specific variation in fitness cost of adults from pupae with prolonged dormancy. Within a population, lifetime fecundity did not differ between adults emerged from pupae with prolonged dormancy and those emerged after prolonged pupae chilling. Adults emerged from pupae exposed to prolonged chilling suffer an additional reduction in adult longevity compared to adults from pupae with prolonged dormancy. Hence, fitness of R. cerasi adults is regulated by diapause regimes of pupae.

The coffee leaf-miner Leucoptera meyricki Ghesq. is the most serious insect pest of Coffea arabica in Kenya. Until recently, sprays containing parathion, methyl-parathion or diazinon have been recommended for its control.

Field trials were carried out there during 1962 with these three insecticides and two others, fenthion and fenitrothion, that had shown promise in laboratory trials described in an earlier paper. The greater part of the investigation was carried out on the larval stage. Single-tree plots were used, arranged in randomised blocks, and sprays were in most cases applied by knapsack machines. Spraying in all trials was timed to coincide with the presence of large numbers of half-grown larvae. Suitable dates could be forecast because the generations of L. meyricki follow a denned cycle with a single stage dominant at any one time. Mortalities of larvae were assessed, four days after application of the insecticide, by dissecting freshly mined leaves selected at random. Where necessary, a spray of coarse droplets of a poison bait was applied before a trial in order to reduce populations of parasites and mortality due to them to a low level.

At a concentration of 0·02 per cent., a spray of parathion gave a. significantly higher kill than one of methyl-parathion. Diazinon, fenthion and fenitrothion were available as emulsifiable concentrates containing 60, 55 and 50 per cent, active ingredient (w/v), respectively. These were tested at equivalent dilutions. At a dilution of 1¼ pints concentrate in 100 gal. water (affording concentrations of 0·094, 0·086 and 0·078 per cent, active ingredient, respectively), which was the volume per acre required to give full cover, fenitrothion gave a significantly higher kill than fenthion or diazinon, there being no significant difference between mortalities achieved by the latter two insecticides. The addition of a supplementary wetting agent to sprays of fenitrothion increased kill significantly, as did a reduction in spray volume with fenitrothion and parathion. The possible reasons for this are discussed.

The field trials described generally confirm the results obtained in earlier laboratory tests and support the view that any insecticide which shows promise in the laboratory will also give good results in the field.

A small-scale trial on potted seedling coffee plants was carried out to test by the dipping technique the ovicidal properties of concentrations of parathion, diazinon, fenthion and fenitrothion equal to one-half or two-thirds those necessary to give satisfactory field control of mining larvae. Mortality of eggs varied with their age, but in all tests with the first three insecticides it exceeded 90 per cent. In a comparison between fenthion and fenitrothion, the former was significantly more toxic than the latter, which killed only 38·1 and 82·1 per cent., respectively, of eggs ½ and 5½ days old.

The correct timing of sprays against Leucoptera is very important and should follow about seven days after the peak of moth numbers.

The insecticides used in these experiments are considered in the light of the characteristics, which are listed, that are desirable in those to be recommended for the control of Leucoptera on coffee. Those recommended, with rates (Ib. per acre), are parathion (0·4), fenitrothion (0·9) and fenthion (1·0). Diazinon and methyl-parathion are no longer recommended.