Apanteles carposinae, sp. n.

♀. Black; the front legs entirely (save for the black feet and for some occasional slight darkening on femora above and below, on tibiae above, and on coxae and tarsi), middle legs entirely (save for the black feet and for femora darkened above and below and for some occasional slight darkening on tibiae and coxae), hind coxae at apex below, hind trochanters and trochantines, hind femora (save above and below extensively), hind tibiae, hind tarsi (save for black feet and some darkening), and palpi, red testaceous; tibial spurs pale; wings infumated evenly throughout and the setae coloured; stigma, metacarp, and all veins, brown; stigma uniformly opaque.

♂. Black; front coxae (save at base), front trochanters and trochantines, front femora (save for darkening above and below, which is sometimes strong), front tibiae (save for strong darkening above), front tarsi (save for some darkening and the black feet), middle coxae (save at base or even basal half), middle trochanters and trochantines largely, middle femora (save for extensive strong darkening above and below), hind coxae at apex below to some extent in the lighter but not in the darker examples, hind femora (save for extensive strong darkening above and below), and palpi, red testaceous; the four posterior tibiae and tarsi, and the hind trochanters and trochantines, largely darkened throughout save perhaps in an occasional lighter example; tibial spurs pale; wings infumated evenly throughout and the setae coloured; stigma, metacarp, and all veins, brown; stigma uniformly opaque.

The two species of thrips described in the following pages have been found on tea in sufficient numbers as to be regarded as pests, and they should therefore be made known to economic biologists. A member of the sub-order Tubulifera (Haplothrips sp.) was also found both by Prof. Maxwell Lefroy and Mr. Andrews on tea, but it seems to occur also on other plants; I have not yet had the opportunity of studying it.

P. lefroyi is a strongly characterised species both in structure and coloration; whilst P. setiventris, when both sexes are taken, should be easily recognised by the black “ tail ” of the ♂. The former species may ultimately be removed from the genus Physothrips, with advantage.

Only a very strong dose of 0·5 mg of hempa caused necrosis in testes of Locusta migratoria (L.). The apical cells, spermatogonia and primary spermatocytes became pycnotic and the germ cells were disorganised. Multinucleated cells also developed, due to failure of spindle formation, and a few hypertrophied spermatids occurred. In ovaries the chromatin of the follicular epithelial cell nuclei was abnormally fragmented; nuclei of the follicular epithelial cells became pycnotic; germinal vesicle was badly damaged; cytoplasm of the follicular epithelial cells was drawn into the peripheral empty space formed by the contraction of the ooplasm; the follicular epithelium degenerated later; and yolk formation was inhibited. With increased doses and post-treatment periods necrosis became more marked. Hempa was more effective in the ovary than in the testes of L. migratoria.

The construction of an inexpensive, simple, hand-drawn fumigator for field plots is described. The general principle employed is the injection of liquid nicotine under pressure into the exhaust system of a two-stroke engine, close to the port. The liquid is vaporised by the heat of the exhaust stream and distributed by it below a drag sheet at the rear of the machine.

The machine is of simple and robust construction, utilising standard plumbing fittings, angle iron, strip iron and second-hand motor-cycle parts and can, therefore, be made where only limited facilities are available.

The machine is self-contained and easily transportable as it can be towed behind a car from one locality to another. It is suitable for use on a wide variety of crops since the track is variable between 43 in. and 67 in. and the clearance between 16 in. and 34 in. With the 18 ft. long sheet used it can fumigate, in good conditions, one acre in about five hours. It is pointed out that the use of a lightweight sheet about 54 ft. long would decrease the time required per acre to about if hours and would enable the machine to be drawn by a tractor if desired; these suggestions have not, however, been tried.

The machine has been in use since 1941 for controlling aphis infestation in connection with work on virus yellows of sugar beet and has given most satisfactory results. Tests showed that a kill of 88–99 per cent, of Aphids was obtained.

Limewashes containing DDT or “Gammexane” were tested for insecticidal action on mosquitos (Aëdes aegypti) by confining the latter in cages with treated walls and ceilings. Only about 60 per cent, of the total internal surface of the cages were treated but the mosquitos were averse to settling on the floor, window, etc., which constituted a large part (28 per cent.) of the untreated area.

Limewashes containing 160 mg. DDT per square foot gave a high kill of mosquitos after two hours' exposure in the cage; and 8 mg. per square foot of the active principle of “Gammexane” gave a high kill with a one hour exposure.

Both treatments remained effective for 6–8 weeks under temperate conditions.

The pineapple plantations of Mauritius have sustained since 1937 severe attacks of mealybugs (Pseudococcus spp.) which threatened to ruin the whole crop in certain localities. These attacks result in a wilting of the plants, which may be due to a toxin secreted by the bugs during their process of feeding.

On the basis of specimens from New Guinea and New Britain, the genus Dynamenais Kirkaldy (Pyrrhocoridae) is re-defined, four species and one subspecies are described in the new subgenus Syncrotus (Syncrotellus) (Pyrrhocoridae), and two species are described for the new genus Goilalaka (Pentatomidae). S. (S.) similis sp.n. was recorded from cacao, and S. (S.) madanganus sp.n. and G. rubroruga sp.n. from Solanum spp.

The following notes and descriptions are based on material received by the Entomological Research Committee, who have kindly presented the types of the new species to the National Collection.

Site and time effects are important factors determining trap catches of tsetse flies. These factors may interact significantly and therefore confound interpretation of time series data used for population monitoring. We therefore investigated the magnitude and importance of site × time interactions in trap catches of Glossina pallidipes Austen and G. longipennis Corti using a 2200 trap-days (400 trap-months) data set. The interaction was found to be siginificant (p<0.05) in 46–100% of the combinations of different numbers of months and sites between 2 and 12. The mean percent variance due to the interaction ranged between 4% and 28% for G. pallidipes and 12% and 36% for G.longipennis. The interaction was usually less important than the effect of site alone but more important than the effect of time alone. These results suggest that tsetse researchers should examine critically the adequacy of existing approaches to population monitoring with traps and to testing new traps and odour baits.

A revised key is given to the Enicospilus antefurcalis (Szépl.) species-group, some species of which are parasites of Lepidoptera of economic importance, of the Afrotropical region. One Oriental species, E. laqueatus (End.), is recorded for the first time from Africa and two species, E. watshami sp. n. and E. polemus sp. n., are described.

A method is described by which candidate repellents can be rapidly screened and evaluated by comparing them with a standard repellent or with each other. Mosquitos are confined in a petri dish, of which the top is covered with mosquito gauze and the bottom lined with two semicircular filter papers, one of which is treated with a standard repellent, the other with candidate repellent. The dish is placed in an apparatus through which passes a slow stream of air of standard temperature and humidity. Counts of mosquitos are taken every half minute on and above the two halves of the petri dish, which is jarred after every second count to change the position of the mosquitos. A total of 40 counts is taken, the dish being rotated through 180° after the 20th count. The index of reaction is determined as the mean excess of position records for the candidate repellent over those for the standard one.

The initial effectiveness and the persistence of various repellents have been compared. In tests against Aedes aegypti (L.), the repellency of N, N-diethyl-m-toluamide and of O-chloro-N, N-diethyl benzamide did not differ, but each significantly exceeded that of dimethyl phthalate (DMP). The loss of repellency of DMP with time was approximately linear.

Attention is drawn to various aspects and applications of the method, and to its advantages, particularly for rapid screening of repellents.

The types of the new forms described in this paper are deposited in the collections of the Zoological Survey of India, Kaiser Castle, Benares.

Crop phenological studies are vital in the formulation of effective integrated pest management packages. A 2-year phenological study spanning 2017–2019 was conducted in eight mango orchards in the transition zone of Ghana, to determine the relationship between the aggregation of culprit fruit fly species and the phenology of the mango crop. A total of 160 shoots were tagged and observed weekly for the plant's developmental processes using the Biologische Bundesantalt, Bundessortenamt and Chemische Industrie mango phenological scale as a guide. Fruit fly monitoring was conducted with two para pheromone attractants (methyl eugenol and terpinyl acetate) in 32 improvised traps. Host fruits sampled at colour break and ripe stages were incubated to identify culprit species. Significant infestation levels were assessed with one way analysis of variance. Three culprit species (Bactrocera dorsalis, Ceratitis cosyra and Ceratitis ditissima) emerged from incubated fruits. Co-infestation between B. dorsalis and C. cosyra was observed mostly at colour break. A residual population of B. dorsalis was observed throughout the crop cycle but peaked at the colour break phenological stage in May and early June, and dropped in August (at post-harvest). The interaction among fruit fly species, season, fruit source and phenological stage of the fruit was significant (P = 0.016). C. cosyra appeared at the beginning of anthesis, increased during flowering to fruit set and peaked in April when fruits were nearing maturity and green. It is therefore important that management practices are implemented throughout the phenological cycle of the crop but intensified from anthesis to post-harvest to reduce pest populations and damage.

Changes in environmental conditions influence the performance of organisms in every aspect of their life. Being capable of accurately sensing these changes allow organisms to better adapt. The detection of environmental conditions involves different sensory modalities. There are many studies on the morphology of different sensory structures but not so many studies showing their function. Here we studied the morphology of different sensory structures in the larva of a dipteran parasitoid. We occluded the putative sensory structures coupling the morphology with their function. First, we could develop a non-invasive method in which we occluded the putative sensorial structures annulling their function temporarily. Regarding their functionality, we found that larvae of Mallophora ruficauda require simultaneously of the sensilla found both in the antennae and those of the maxillary palps in order to orient to its host. When either both antennae or both maxillary palps were occluded, no orientation to the host was observed. We also found that these structures are not involved in the acceptance of the host because high and similar proportion of parasitized hosts was found in host acceptance experiments. We propose that other sensilla could be involved in host acceptance and discuss how the different sensilla in the antennae and maxillary palps complement each other to provide larvae with the information for locating its host.

Hypotheses about the worldwide colonization routes of the melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae), are mainly based on sparse historical records. Here we aim at reconstructing the colonization history of the African continent based on an improved description of the population structure of Z. cucurbitae and approximate Bayesian analyses. Individuals of Z. cucurbitae were sampled in 17 localities from East, West and Central Africa and genotyped at 19 microsatellite markers. Bayesian analyses showed intracontinental population structuring with populations from Uganda diverging from those of Tanzania and populations from Burundi and Kenya showing traces of admixture with West African samples. Approximate Bayesian Computation provided support to the hypothesis of a single introduction Z. cucurbitae into East Africa and subsequent expansion to West Africa, each colonization event was followed by a bottleneck that promoted population divergence within Africa. Parameter estimates suggested that these events are roughly compatible with the historical records of Z. cucurbitae presence in sub-Saharan Africa (viz. 1936 in East Africa and 1999 in West Africa) and allow excluding alternative hypotheses on older or multiple introductions of Z. cucurbitae.

Culex quinquefasciatus Say is the major vector of the filarial parasite Wuchereria bancrofti (Cobbold) which causes lymphatic filariasis in humans. A repetitive DNA sequence from the genome of C. quinquefasciatus has been cloned and completely sequenced. The 693 bp cloned fragment had an A+T content of 72%. Dot matrix analysis of the fragment did not reveal any direct or inverted repeats within it. Southern blot analysis using a variety of restriction enzymes appeared to indicate that the cloned fragment was interspersed within the genome with a copy number of approximately 30,000. A search of the GenBank database did not reveal significant homologies to any previously cloned sequences. Although the probe was sensitive enough to detect picogram quantities of DNA, it was not specific for C. quinquefasciatus, as it hybridized with DNA from other mosquito species, Culex pseudovishnui Colless, Culex gelidus Theobald, Culex tritaeniorhynchusGiles, Anopheles vagus Dönitz and Mansonia uniformis (Theobald). However PCR primers derived from the cloned sequence, IpC, were found to be specific and amplified only C. quinquefasciatus DNA. The optimized PCR assay was found to be very sensitive and was capable of detecting DNA from all stages of C. quinquefasciatusthus making it an ideal diagnostic tool.

The costs and benefits of polyandry are still not well understood. We studied the effects of multiple mating on the reproductive performance of female Brontispa longissima (Coleoptera: Chrysomelidae), one of the most serious pests of the coconut palm, by using three experimental treatments: (1) singly-mated females (single treatment); (2) females that mated 10 times with the same male (repetition treatment); and (3) females that mated once with each of 10 different males (polyandry treatment). Both multiple mating treatments resulted in significantly greater total egg production and the proportion of eggs that successfully hatched (hatching success) than with the single mating treatment. Furthermore, the polyandry treatment resulted in greater total egg production and hatching success than with the repetition treatment. Thus, mate diversity may affect the direct and indirect benefits of multiple mating. Female longevity, the length of the preoviposition period, the length of the period from emergence to termination of oviposition, and the length of the ovipositing period did not differ among treatments. The pronounced fecundity and fertility benefits that females gain from multiple mating, coupled with a lack of longevity costs, apparently explain the extreme polyandry in B. longissima.

The use of chemical insecticides is the main control method for Blattella germanica worldwide. The prolonged and frequent use of insecticides produced the selection of insecticide-resistant individuals. The German cockroach is one of the most widespread urban pests in Argentina. In the last decades, resistance monitoring studies in this country demonstrated that there is a high prevalence of pyrethroid-resistant populations of B. germanica in the field. In this work, we studied the resistance mechanisms of a field-collected strain of B. germanica at toxicological, enzymatic, and molecular levels. A resistance ratio of 100 was obtained for the resistant strain when it was exposed to β-cypermethrin. The pretreatment with specific synergists (piperonyl butoxide and triphenyl phosphate) led to a significant increase in the toxicity of the pyrethroid, suggesting an involvement of oxidases and esterases in the detoxification of this insecticide. Moreover, esterase and oxidase activities in the resistant strain were 1.5-fold and 2-fold higher respectively, compared to the susceptible individuals. On the other hand, the voltage-gated sodium channel gene of the resistant cockroaches did not show nucleotidic substitutions in the domain II which are associated to knockdown resistance in this species. These results suggest that the main mechanism of resistance of the studied cockroaches' strain is metabolic, mainly due to an increase in the activity of oxidase and esterase enzymes. The results of this work in addition to other reports found in literature show that the extended use of a single active principle for cockroach control promotes the development of resistance leading to control failure in the field. In contrast, integrated pest management strategies include the use of different control tools in addition to chemical insecticides, which delay the appearance of resistance increasing the efficacy of pest control.

A large collection of mosquitos made in five atolls of the Maldive Islands has revealed the presence of 15 species. These are listed and notes of taxonomic interest on seven of them are given.

This marked genus appears to be intermediate between Atheroides, Haliday, and Sipha, Passerini.