A new species of scale insect from coconut trees in Trinidad is described and named Parlagena bennetti. The generic assignment is tentative. A key to the four known species of Parlagena is provided.

A photographic apparatus is described for obtaining a record of oviposition and larval eclosion at intervals through the night. By the use of electronic flash a negative silhouette image is produced and the method used does not appear to disturb the moths during oviposition. A second apparatus incorporating a moving pen is also described for studying and recording the times of emergence of moths from their pupae.

Length of body (one male), 2·3 mm.; length of wing, 1·6mm.; greatest breadth of wing, 0·5 to 0·6 mm. A large, dark brown species resembling C. nigripennis, C.I. & M.

The majority of plant viral disease is transmitted and spread by insect vectors in the field. The small brown planthopper, Laodelphax striatellus (Fallén), is the only efficient vector for rice black-streaked dwarf virus (RBSDV), a devastating plant virus that infects multiple grain crops, including rice, maize, and wheat. Adenosine triphosphate (ATP)-binding cassette (ABC) transporters participate in various biological processes. However, little is known about whether ABC transporters affect virus infection in insects. In this study, RBSDV accumulation was significantly reduced in L. striatellus after treatment with verapamil, an effective inhibitor of ABC transporters. Thirty-four ABC transporter genes were identified in L. striatellus and expression analysis showed that LsABCF2 and LsABCG9 were significantly upregulated and downregulated, respectively, after RBSDV infection. LsABCF2 and LsABCG9 were expressed during all developmental stages, and LsABCG9 was highly expressed in the midgut of L. striatellus. Knockdown of LsABCF2 promoted RBSDV accumulation, while knockdown of LsABCG9 suppressed RBSDV accumulation in L. striatellus. Our data showed that L. striatellus might upregulate the expression of LsABCF2 and downregulate LsABCG9 expression to suppress RBSDV infection. These results will contribute to understanding the effects of ABC transporters on virus transmission and provide theoretical basis for virus management in the field.

In the autumn of 1931 I received for determination from Dr. R. B. Jackson a small number of Culicine larvae collected in Hong Kong. These included two specimens of a Uranotaenia with very remarkable antennae, which seem well worth describing as a further example of the striking and unexpected deviations of structure which occur in various members of this genus. As the specimens sent were whole larvae and not skins, the identity of the species is somewhat uncertain, but an adult of U. testacea, Theo., was obtained by Dr. Jackson at the same time as the larvae, and it is most probable that the larvae belong to that species. Incidentally, U. testacea has not been recorded from Hong Kong before.

This summer I received for identification from the Entomological Department of the Experimental Station at Poltava one vial with 12 specimens (2 ♂♂, 10 ♀♀) of a new species of Scelio bred from eggs of Locusta migratoria ph. danica, collected by F. Lukjanovich, 12.viii.1925, at Priluky, Poltava province ; and later on Mr. B. P. Uvarov sent me two females of another species from Turkestan. All the representatives of the cosmopolitan genus Scelio, Latr., so far as we know, are egg-parasites of Acrididae. Some species have been bred from L. danica in Australia, but in Europe this is the first species of which the host has been recorded. Dr. J. J. Kieffer, in a posthumous monograph of the Scelionidae (Das Tierreich, Lief. 48, 1926), among other generic characters mentioned the four-jointed maxillary palpi. He further distinguished the Australian genus Neoscelio, Dodd, from Scelio by its having three-jointed maxillary palpi, besides the long metathoracic spine. Unfortunately Kieffer did not mention to which species of the genus Scelio his observation referred. I have dissected a few specimens of three species, S. vulgaris, Kieff., S. uvarovi, sp. n., and S. nikolskyi, sp. n., and can state that in both sexes of all these species the maxillary palpi are only three-jointed. The generic definition of the genus Scelio must therefore be corrected in this sense.

Insect crop pests are a major threat to food security in sub-Saharan Africa. Configuration of semi-natural habitat within agricultural landscapes has the potential to enhance biological pest control, helping to maintain yields whilst minimising the negative effects of pesticide use. Fall armyworm (Spodoptera frugiperda, J. E. Smith) is an increasingly important pest of maize in sub-Saharan Africa, with reports of yield loss between 12 and 45%. We investigated the patterns of fall armyworm leaf damage in maize crops in Ghana, and used pitfall traps and dummy caterpillars to assess the spatial distribution of potential fall armyworm predators. Crop damage from fall armyworm at our study sites increased significantly with distance from the field edge, by up to 4% per m. We found evidence that Araneae activity, richness and diversity correspondingly decreased with distance from semi-natural habitat, although Hymenoptera richness and diversity increased. Our preliminary findings suggest that modifying field configuration to increase the proximity of maize to semi-natural habitat may reduce fall armyworm damage and increase natural enemy activity within crops. Further research is required to determine the level of fall armyworm suppression achievable through natural enemies, and how effectively this could safeguard yields.

A quantitative survey of Wheat Bulb Fly (Leptohylemyia coarctata) was made in Yorkshire in 1945, and the distribution of the fly is discussed in relation to general observations and records in the years 1935–1946. The distribution is shown in themap (fig. 2).

One hundred and thirty-six fields on 86 farms were examined and Wheat Bulb Fly was present in over half of the farms and fields; in 8 fields (6 per cent.) it was present in moderately high numbers, and in 2 fields (1·5 per cent.) it was present in numbers sufficiently high to be likely to cause a failure in a bad wheat year. It was estimated that two or three thousand acres of wheat and rye in Yorkshire are likely to have a reduced crop as a result of Wheat Bulb Fly attack in an unfavourable season. Over half the dangerous area is near Selby. The only large area where Wheat Bulb Fly was virtually absent was the Yorkshire wolds.

Lateralisation is a well-established phenomenon observed in an increasing number of insect species. This study aims to obtain basic details on lateralisation in courtship and mating behaviour in Ostrinia furnacalis, the Asian corn borer. We conducted laboratory investigations to observe lateralisation in courtship and mating behaviours in adult O. furnacalis. Our goal was also to detect lateralised mating behaviour variations during sexual interactions and to elucidate how these variances might influence the mating success of males. Our findings reveal two distinct lateralised traits: male approaches from the right or left side of the female and the direction of male turning displays. Specifically, males approaching females from their right side predominantly exhibited left-biased 180° turning displays, while males approaching females from the left-side primarily displayed right-biased 180° turning displays. Notably, left-biased males, executing a 180° turn for end-to-end genital contact, initiated copulation with fewer attempts and began copulation earlier than their right-biased approaches with left-biased 180° turning displays. Furthermore, mating success was higher when males subsequently approached the right side of females during sexual encounters. Left-biased 180° turning males exhibited a higher number of successful mating interactions. These observations provide the first report on lateralisation in the reproductive behaviour of O. furnacalis under controlled laboratory conditions and hold promise for establishing reliable benchmarks for assessing and monitoring the quality of mass-produced individuals in pest control efforts.

Carboxylesterases (CarEs) is an important detoxification enzyme system in phase Ⅰ participating in insecticides resistance. In our previous study, SlCarE054, a CarEs gene from lepidoptera class, was screened out to be upregulated in a pyrethroids and organophosphates resistant population. Its overexpression was verified in two field-collected populations of Spodoptera litura (Lepidoptera: Noctuidae) resistant to pyrethroids and organophosphates by qRT-PCR. Spatiotemporal expression results showed that SlCarE054 was highly expressed in the pupae stage and the digestive tissue midgut. To further explore its role in pyrethroids and organophosphates resistance, its metabolism activity to insecticides was determined by UPLC. Its recombinant protein showed significant metabolism activity to cyhalothrin and fenvalerate, but not to phoxim or chlorpyrifos. The metabolic activity of SlCarE054 to β-cypermethrin showed stereoselectivity, with higher metabolic activity to θ-cypermethrin than the enantiomer α-cypermethrin. The metabolite of β-cypermethrin was identified as 3-phenoxybenzaldehyde. Further modelling and docking analysis indicated that β-cypermethrin, cyhalothrin and fenvalerate could bind with the catalytic triad of the 3D structure of SlCarE054. The interaction of β-cypermethrin with SlCarE054 also showed the lowest binding energy. Our work provides evidence that SlCarE054 play roles in β-cypermethrin resistance in S. litura.

The coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae), is a major destructive pest of Coffea arabica L. (Gentianales: Rubiaceae), widely planted in many Asian countries, including China. Quantitative real-time polymerase chain reaction (qRT-PCR) is a common method for quantitative analysis of gene transcription levels. To obtain accurate and reliable qRT-PCR results, it is necessary to select suitable reference genes to different experimental conditions for normalizing the target gene expression. However, the stability of the expression of reference genes in X. quadripes has rarely been studied. In this study, the expression stability of nine candidate reference genes were investigated under biotic and abiotic conditions for use in qRT-PCR's normalization. By integrating the results of four algorithms of NormFinder, BestKeeper, geNorm, and RefFinder, the optimal reference gene combinations in different experimental conditions were performed as follows: RPL10a and EIF3D were the optimal reference genes for developmental stage samples, EIF4E, RPL10a, and RPS27a for tissue samples, V-ATP and EF1α for the sex samples, EIF3D and V-ATP for temperature treatment, RPS27a and RPL10a for insecticide stress, and RPL10a, RPS27a, and EF1α for all the samples. This study will help to obtain the stable internal reference genes under biotic and abiotic conditions and lay the foundation for in-depth functional research of target genes or genomics on olfactory molecular mechanisms, temperature adaptability, and insecticide resistance in X. quadripes.

The general distribution of the Muscidae (other than Glossina) of medical interest in the Sudan is discussed, and brief notes are given on some Muscids in relation to trypanosmiasis.

Eighty-six species of some medical interest, belonging to 22 genera, are listed, with records of their distribution and notes on the habits of several of them.

During the past summer (1916) Mr. C. B. Williams has, on behalf of the Department of Agriculture, Trinidad, been engaged in investigating the natural enemies of Tomaspis and its allies, in the hopes of finding some effective means of controlling the froghopper, Tomaspis saccharina, Dist., which in recent years has caused considerable damage to the sugar plantations of Trinidad. With this object Mr. Williams has made collections of minute parasitic Hymenoptera in the Island and the adjacent mainland of British Guiana, and this material has from time to time been forwarded to me for study. Mr. Williams has from the first been fully alive to the importance of securing any specimens of the egg-destroying Paraphelinus, Perk., and I am glad to find species of this interesting genus in the gatherings from both Trinidad and British Guiana. The literature dealing with Paraphelinus is scattered and perhaps inaccessible to those to whom it is most likely to prove serviceable. I have therefore, in some introductory notes, recapitulated the main facts in the life-history and host attachment and added a bibliography to the present paper.

Specimens of seed bugs are recorded as pests of groundnuts, sorghum and cotton in Africa, usually under the name Aphanus apicalis Dall. or Rhyparochromus apicalis (Dall.). It is shown that these pests belong to the genus Naphius Stål and, further, that not all should be placed in the species N. apicalis (Dall.). A study of the genus Naphius shows that there are seven distinct species in the Ethiopian region. The true N. apicalis is shown to be the species that is known to cause damage to pumpkin in Rhodesia and sorghum in Nigeria: the pest of groundnuts in Senegal and Gambia is N. zavattarii (Mancini), not N. apicalis. To date, the other species of Naphius in Africa are not reported as pests. The known distribution of the two pest species is illustrated; N. apicalis occurs throughout tropical Africa, but N. zavattarii seems to be confined to the northern and eastern parts of Africa south of the Sahara, with the latter also present in the Canary Is, and cape Verde Is.

This subject has been discussed very fully by Dr. T. A. M. Nash and the writer in two recent papers (Bull. Ent. Res. 24, 1933, pp. 135, 475–477). There is, however, one point which it is felt should be made clear. Dr. Nash states that the writer, “working in the Western Kondoa fly-belt, finds the more normal type of obvious concentration. In the dry season tsetse become more numerous in Berlinia-Brachystegia woodland immediately surrounding ‘vleis.’ Owing to the small size of these ‘vleis,’ which are only about 75 yards across, the fly appears to an observer to be concentrated in them; in reality they are probably living in the shade of the surrounding weeds and fly out to attack the investigator. Passing through Berlinia woods in this country one finds fly more numerous on the edge of “vleis,” probably because the trees are almost non-deciduous owing to sub-soil water.”

The diurnal flight and biting activity patterns of Culicoides phlebotomus (Will.) were investigated during ten all-day (06·00–19·00 h) trapping sessions at Las Cuevas Bay, north Trinidad. A comparison was made of the results obtained by biting catches, paddle trapping (in which a piece of greased wire screen was swung in front of the collector's legs) and truck trapping. Biting activity persisted throughout the day, with peaks of activity one to two hours after sunrise and again at sunset. Truck trapping recorded little variation in flight activity of empty females during daylight hours, but that of engorged, half-gravid and gravid females was greater during the afternoon than in the morning. Male flight activity was high in the early morning and mid-afternoon but declined rapidly towards sunset. Paddle trapping alone recorded a substantial increase in the blood-seeking activity of parous females after sunset. The paddle-trapping technique was found to be a useful alternative to biting collections for the study of anthropophilic Culicoides.

While our knowledge of the effects of variation of the physical conditions of the environment upon mosquitos is, in some directions, fairly satisfactory, in the case of the effects of variation of temperature there is lamentably little known. So far as a fairly complete survey of the literature dealing with mosquitos has revealed, there is only one paper specifically dealing with this matter, by Macfie (1920), although incidental observations have been recorded by other workers. This present paper is an outcome of an attempt to fill, to a slight degree, this lacuna in our knowledge. The investigations were carried out while the writer was attached to the Department of Zoology at the University College of North Wales, Bangor, and he has to express his thanks to Dr. C. L. Walton, Adviser in Agricultural Zoology, Department of Agriculture, Bangor, for allowing him to carry out the experiments in the Agricultural Zoology Laboratory.

Chlorpyrifos was applied to field lucerne at a rate (0.3 kg/ha) recommended to control the weevil Sitona discoideus Gyllenhal. The fate of the weevil population and that of the immature stages of its parasitoid Microctonus aethiopoides Loan were examined by field sampling. A single application of chlorpyrifos reduced the weevil population by 96.2% 14 days after application. There was no significant decline in the control population between sampling intervals nor a change in the parasitism levels. However, in the insecticide-treated plots c. 88% of survivors (n=8) were parasitized. The effects of chlorpyrifos residues at 0.3 and 1.0 kg/ha were also examined. At the lower rate, residues produced c. 40–60% weevil mortality for up to 15 days after application although a significant decline in activity only occurred between days 1 and 3. At 1.0 kg/ha, the activity decay curve was much slower with no significant decline in weevil mortality for the first 15 days of the experiment. Weevil gender was shown to be a significant factor influencing mortality. Mortality of unparasitized weevils was also significantly greater than for parasitized hosts while the stage of parasitoid development had a significant effect on mortality. Where parasitoid development was sufficiently advanced, late-instar larva emerged and successfully pupated from cadavers up to 18 h following host mortality. The consequences of applying insecticide to control S. discoideus as they relate to the parasitoid and the success of biological control are discussed.

The fruit-fly damage in the Upper Jordan Valley is limited to the southern belt of Citrus plantations ; further north the fly's activity remains, so far, restricted. There is a permanent fluctuation in the fruit-fly's population density according to ecological conditions, which may change from year to year. This fluctuation is of an irregular character. In years of severe infestation the damage attains 10–15 per cent. of the total crop ; there are seasons, however, when the damage is practically negligible. There is constant danger in the fruit-fly situation, because this fly is able within a short time to increase immensely its population density, if environmental conditions are suitable.

The number of hosts is relatively small in the Jordan Valley ; the Citrus plantations supply sufficient food during 7–8 months, and there is a relatively long summer quiescent period (about 2 months) with an extremely low fruit-fly population ; during the remaining period figs, grapes and other occasional plants serve as hosts.

The fruit-fly is spread chiefly by mechanical agents (wind and transport of infested fruits).

There are 8 generations during the year in the Jordan Valley.

There are two peak infestation periods (October and April-May) and two quiescent periods (winter and late summer).

Fruit-fly control under present cultural conditions should be confined to peak infestation periods only, as unfavourable climatic conditions are responsible for an extremely high mortality of fly later in the winter and in summer.