The dispersion and density of brood galleries of the wood-boring ambrosia beetle, Xyleborus fornicatus Eichh., in the tea plant depends on the type of branch (primary, secondary and tertiary) and not on the total available length of branch nor on branch thickness. Within the different branch types, branch lengths and the numbers of galleries contained in them are directly related. Significantly more galleries are formed in the primary branches than in the secondaries, which themselves carry more than the tertiaries. For precise estimation of Xyleborus population density, a stratified sampling system, representing the different branch classes, will be required.

Acclimation had a beneficial effect on Scottish clones of Aulacorthum solani (Kaltenbach) as seen in enhanced reproduction and development at 5°C, compared with non-acclimated clones at this temperature. In contrast, not all Myzus persicae (Sulzer) clones tested benefited. When reared at 5°C for a second generation, both species had slower nymphal development and M. persicae also had less efficient adult reproduction (a longer pre-reproductive period and reduced fecundity) compared with the first generation. Both species demonstrated a high capacity for recovery from low temperatures, A. solani being the better of the two. In general however, the ability of clones to survive, reproduce and develop at low temperatures or upon transfer to high temperatures, was variable and was not related to annual cycle, origin or organophosphorus resistance. These differing responses support previous results and are suggested as being an efficient means of ensuring variability in aphid populations surviving after winter.

Following examination of Cicadelloidea off potato, castor, millets and berseem from Simla, India, and of some of Distant's type specimens, the genera Jilinga, Pseudosubhimalus and Sarejuia are described as new, and new combinations and synonymies given ; two new species are also described under Aconurella Ribaut and Sarejuia. Dio Distant, Erythridea Ribaut and Erythria Fieber are considered to be distinct, and a key to these genera is given.

An account is given of the life-history of Agrilus acutus (Thnb.) (Buprestidae), a pest of ‘mesta’ (Hibiscus cannabinus) in india. The eggs are ovate and scale like, and are laid singly on the stem, usually near a leaf scar, and when kept at 31°C. and 73 per cent. relative humidity hatched on average in 12.4 days. The larva bores through the lower surface of the egg directly into the stem and feeds under the bark forming a sprial tunnel. A raised weal develops on the surface of the stem overlying the tunnel. Before each moult, the larva bores into the wood and makes a vertical chamber in which moulting occurs. There are normally three moults in the active feeding stages, but exceptionally four, and a prepupal moult. The rate of tunnelling is at first about 56 mm. per day and later eaches about 107 mm. The larval stage lests 26 days. The fully grown larva is 21 mm. long and bores into the wood to pupate, making a pupal chamber 11 mm. long into which it fits itself by adopting an asymmetrical U-shaped posture. After a prepupal stage of 2.5 days it pupates. The pupal period occupies about 11.7 days and a further seven days are spent by the adult in the pupal chamber. The adult female mates within a day of emergence from the stem. but does not oviposit until at least seven days have elapsed.

Two types of municipal solid waste (MSW), newly arrived and 2 weeks old, were sampled from a sanitary landfill in Pulau Pinang, Malaysia at a fortnightly interval and kept under field conditions for 2 weeks. A total of 480 kg of each type of MSW was sampled to study species composition and impact of delays in cover soil applications on filth fly emergence. Out of 960 kg of MSW sampled, 9.2 ± 0.5 flies emerged per kilogram. Weekly adult fly emergence rates of newly arrived and 2-week-old waste did not differ significantly and MSW remained suitable for fly breeding for up to 1 month. Eight species of flies emerged from the MSW: namely, Musca domestica, Musca sorbens, Synthesiomyia nudiseta, Hydrotaea chalcogaster, Chrysomya megacephala, Lucilia cuprina, Hemipyrellia ligurriens and Sarcophaga sp. Newly arrived waste was determined to be the main source for M. domestica, C. megacephala and L. cuprina in the landfill owing to significantly higher mean emergence compared with 2-week-old waste. Musca sorbens was found in newly arrived waste but not in 2-week-old waste, suggesting that the species was able to survive transportation to landfill but unable to survive landfill conditions. Hemipyrellia ligurriens, H. chalcogaster and S. nudiseta were not imported into the landfill with MSW and pre-existing flies in and around the landfill itself may be their source. The results show that landfills can be a major source of fly breeding if cover soil or temporary cover is not applied daily or on a regular schedule.

Lygus Hahn plant bugs (Hemiptera: Miridae) are serious pests of a wide variety of economically important crops in North America. European Peristenus digoneutis Loan and P. relictus Ruthe (Hymenoptera: Braconidae) are being considered for release in Canada as part of a classical biological control program for Lygus. The attractiveness of different host plants to European Peristenus has not been addressed, but may be an important consideration prior to parasitoid release. Lygus rugulipennis Poppius nymphs were collected in the Northern Temperate Atlantic (NTA) ecoregion on red clover (Trifolium pratense L.; Fabaceae) and chamomile (Matricaria recutita L.; Asteraceae), and in the Western European Broadleaf Forest (WEBF) ecoregion on red clover and alfalfa (Medicago sativa L.; Fabaceae). Parasitism levels and parasitoid species were determined using a multiplex PCR assay for P. digoneutis, P. relictus, and P. pallipes Curtis. Mean parasitism levels in L. rugulipennis were 45–49% in the NTA ecoregion and 25–32% in the WEBF ecoregion. However, in neither ecoregion were parasitism levels and parasitoid species compositions significantly different in nymphs from different host plant species. Furthermore, multiparasitism was low despite the fact that P. digoneutis and P. relictus share the same host species.

1. At 27°C. the life-cycle of Dysdercus howardi occupies approximately 32 days.

2. Copulation (at 27°C.) takes place approximately 2·8 days after the last moult of the female insect.

3. At 27°C. oviposition begins about 8 days after the last moult of the female, and 5–6 days after mating.

4. The average number of eggs laid by one female is 141·9 and the average number of batches is two.

5. Mortality appears to be highest among the 5th stage nymphs.

6. The ratio of females to males is 1: 1·27.

7. The average length of adult life in the female Dysdercus howardi is eleven days.

8. A table comparing D. howardi with other species of the genus Dysdercus is given.

Dengue is a fast-spreading mosquito-borne viral disease in the world. The primary vector of the disease is Aedes aegypti of the family Culicidae. It is a container breeder. Since a vaccine or a drug has not been developed against dengue, vector control appears to be the best method so far to control dengue. The current study was conducted to determine the effect of delayed mating on fecundity, fertility, life-history parameters, and longevity of Ae. aegypti, because such information can help formulate integrated vector control strategies involving the release of sub-fertile males into the environment. During this study, mating was delayed by 0, 2, 5, and 8 days after emergence. Males and females were separated by hand at the pupal stage using the apparent size difference of the sexes. The separated pupae were kept in separate cages until emergence. When mating was delayed for 8 days, the number of eggs laid by the female declined by 38%, and the percentage number of eggs that hatched reduced by 24%. However, the percentage of larval mortality, duration of the larval and pupal periods, and adult longevity were not significantly affected. The current results indicate that delayed mating has a negative effect on the reproductive performance of vector mosquitoes.

A mosquito survey, having as its object an enquiry into the distribution and prevalence in certain Far Eastern Ports of Stegomyia fasciata, the known carrier of yellow fever, was begun, on behalf of the Imperial Bureau of Entomology, by Dr. A. T. Stanton, whose report was published in the Bulletin of Entomological Research (Vol. x, pt. 3). As it seemed unlikely that he would be at leisure to complete the observations by a survey of the ports of China and Japan, as had been planned, the writer was instructed, in April 1921, by the Government of the Federated Malay States, at the suggestion of the Imperial Bureau, to complete the enquiry.

Anoplolepis gracilipes is one of the six most widespread and pestiferous invasive ant species. Populations of this invader in Arnhem Land, Australia have been observed to decline, but the reasons behind these declines are not known. We investigated if there is evidence of a pathogen that could be responsible for killing ant queens or affecting their reproductive output. We measured queen number per nest, fecundity and fat content of queens from A. gracilipes populations in various stages of decline or expansion. We found no significant difference in any of these variables among populations. However, 23% of queens were found to have melanized nodules, a cellular immune response, in their ovaries and fat bodies. The melanized nodules found in dissected queens are highly likely to indicate the presence of pathogens or parasites capable of infecting A. gracilipes. Queens with nodules had significantly fewer oocytes in their ovaries, but nodule presence was not associated with low ant population abundances. Although the microorganism responsible for the nodules is as yet unidentified, this is the first evidence of the presence of a pathogenic microorganism in the invasive ant A. gracilipes that may be affecting reproduction.

Ceratovacuna lanigera Zehntner is a major leaf pest of sugarcane. Widely distributed, it affects both the yield and quality of sugarcane in China. This study aimed to assess real yield and sugar yield losses, and the effect of C. lanigera damage on emergence of newly planted and ratoon cane under current production levels. Field experiments were carried out from 2014 to 2016 in Yunnan Province China. At maturity, plants were harvested and weighed to determine yield, and the effect on sugarcane quality and sucrose content analyzed. Real yield decreased by average of 46,185 kg hm−2 (range: 37,545–61,845 kg hm−2) in damaged versus undamaged areas, with an average yield loss rate of 35.9% (28.5–45.7%). Juice yield decreased by an average of 3.01% (2.4–4.13%) and sucrose content by 6.38% (5.48–8.16%). Juice brix decreased by an average of 7.66°BX (6.95–9.05°BX) and juice gravity purity by 12.35% (8.43–19.97%). In contrast, the reducing sugar content increased by an average of 1.21% (1.01–1.3%). Emergence rates of newly planted cane decreased by an average of 26.0% (24.7–27.3%). The emergence number of ratoon cane decreased by 66,834 hm2 (57,429–76,238 hm−2) and relative emergence loss rates of ratoon cane decreased by an average of 57.8% (57.6–58.0%). These findings confirm that C. lanigera damage severely affects sugarcane yield and quality in Yunnan Province. The results will help the implementation of effective control measures, thereby supporting sustainable development of the Chinese sugar industry.

The following is a report on the distribution of the tsetse-flies, Glossina palpalis, R. D., and G. morsitans, Westw., in the Lado District, through which I travelled during the first six months of 1911, together with some brief notes on their bionomics. My route and the localities in which the tsetse-flies were seen are shown approximately on the attached map, and owing to the impossibility of showing them accurately—most of the khors and villages over and through which I passed are not marked on the map—a route report is also appended. From December 30th, when I left Shambe, till March 8th, when I reached Meredi, I travelled in company with El Bimb. C. M. Drew, M.C., and from May 2nd, when I arrived at Kajo Kaji till July 2nd, when I reached Rejaf, I was with El Bimb. C. H. Stigand, Inspector of the Rejaf and southern portion of the Lado District, to whom I am indebted for much valuable assistance.

Morphology of male genitalia of culicids is generally species-specific and often used as a taxonomic marker. However, some characters of the male genitalia vary intraspecifically and are not taxonomically diagnostic. This might be the case of Aedes scapularis, a Neotropical culicid with vector competence for arboviruses and filarial worms. Males of this species may or not present a retrorse process (RP) in the genitalic claspette filaments, which led authors to suspect that this variance might be indicative of population divergence or incipient speciation process. This suspicion has not been investigated hitherto and it is not known if there are variable patterns of RPs. We hypothesized that the presence of the RP varies intraspecifically in Ae. scapularis and then we statistically evaluated the variability of this character in a single population. To this study the genitalia of 73 males of Ae. scapularis were prepared, and their RPs were meristically quantified and categorized according to the phenotypes observed. We noted that the presence or RPs is a polymorphic character because it varied inter and intra-individually. The presence of a single RP on each claspette filament was the predominant pattern (77%), but absent or multiple RPs in each filament were also found either in bilateral symmetry or asymmetry. Thus, we conclude that the presence of RPs owing to its high variability is not indicative of populational divergence or diagnostic of species complex within Ae. scapularis.

For several years the Farnham House Laboratory of the Imperial Institute of Entomology has been making a study of the parasites of Diprion spp., in order to acclimatise the most important of them in Canada. Dr. K. R. S. Morris has been specially engaged on this investigation in Czechoslovakia and Hungary, and this year (1935) has discovered some parasitised eggs of Diprion sertifer, Geoffr. Almost at the same time, other eggs of the same host, sent from Sweden, were found to be parasitised by some Chalcids, but belonging to another species. Experiments are actually being made to breed and acclimatise these two species in Canada. Both are Chalcids belonging to the family Eulophidae, sub-family Entedoninae. As very little is known about these egg-parasites of sawflies, we are giving notes and descriptions of these two species, of which one proved to be new.

Since the publication of my 1931 revision of the genus Diatraea, Guilding, in which 48 American species were treated, a considerable number of additional specimens of these moths has reached me from various sources. This material forms the foundation of the present paper, but I am also taking advantage of this opportunity to add certain references to the systematics which have come to my notice recently, as well as new locality and host records and descriptions of the early stages of some of the species ; the larval and pupal descriptions, however, are given primarily for the use of field workers, and should not be interpreted as technical diagnoses.

This study focuses on the regulation of synchronization between the life cycle of the oligophagous whitefly, Trialeurodes lauri (Signoret), and its evergreen host tree Arbutus andrachne in Mediterranean chaparral. Whitefly infestations vary considerably among trees. The adults of the univoltine (one generation per year) whitefly emerge en masse during April and May and oviposit on the new spring foliage. Following approximately one month of development to the early fourth instar, the nymphs enter nine-month diapauses, terminating in February. This diapause is induced and maintained by the plant and can be experimentally avoided (in the case of developing young nymphs) or terminated (in the case of diapausing fourth instars), if whitefly-bearing branches are severed from the tree and placed in water under laboratory conditions. This study is the first report of a whitefly diapausing through both summer and winter seasons. The role of the host plant in the process is discussed.

An insecticide impregnated fabric (IIF) trap was developed at the Vector Control Research Centre, India. The mosquito sampling efficiency of this new trap, relative to hand catches of indoor resting mosquitoes, was evaluated in human dwellings and cattle sheds in a filariasis endemic area. The predominant species collected in human dwellings was Culex quinquefasciatus Say, a vector of bancroftian filariasis; whereas mosquitoes of the Culex vishnui group Theobald and Anopheles subpictus Grassi were caught in relatively greater numbers in cattle sheds. The numbers of mosquitoes in the trap were significantly correlated with the numbers caught in hand catches, and the numbers of mosquitoes collected per two traps per day in the three habitats during the study period were 1.79, 0.95 and 2.27x those collected by hand-catches. The number of occasions on which mosquitoes were detected by both methods was comparable. There was no evidence for a systematic difference in the age-structure and parasite distribution between the two sampling methods, suggesting that the trap is able to monitor both insect vectors and parasite infections. Therefore, the calculation of infection and infectivity rates necessary to monitor filariasis transmission should be possible from the IIF trap in filariasis endemic areas where control measures are being taken.

Most of the species of Leiognathus are parasitic on small mammals (bats, rodents, etc.), others occur on birds and a few also on reptiles. A number of the species of this genus have been described under the name Liponyssus, butpersonally I do not think that Liponyssus setosus, Kolenati (the type and first described species of the genus Liponyssus) falls into the same natural genus as the species described by recent authors under that generic name or under the name Leiognathus. On the other hand, Kolenati's genera Ischoronyssus, Macronyssus, Lepronyssus, Steatonyssus and Pimelonyssus certainly seem to me to be congeneric with Leiognathus, Cn., and ultimately one of these names will have to replace Canestrini's.

Highly resistant and extremely resistant clones (R2 and R3) of Myzus persicae (Sulzer) exhibited a significantly lower mortality and developed a deleterious dark stomach deposit less frequently on sugarbeet than a susceptible (S) clone. After allowing equal populations of four resistant clones to develop together on sugarbeet for four weeks, approximately half of the aphids recovered were from the moderately resistant (R1) clone, suggesting that this clone had a significantly greater reproductive rate than the others. There was no significant difference in the propensity of any clone to produce alates on sugarbeet, although none of the clones produced very many. It is suggested that, even in the absence of insecticides on sugarbeet, resistant clones may become dominant due to their higher fecundity (R1 clones) and lower mortality (R2 and R3 clones) than susceptible clones.

The northern house mosquito (Culex pipiens pipiens L.) is a vector of several important pathogens and comprises two epidemiologically distinct ecotypes (molestus Forskål and pipiens). The delimitation of its ecotypes is a crucial, yet controversial step in vector surveillance due to varying diagnostic values of different characters. Therefore, we reviewed the success of a diagnostic assay based on the mitochondrial cytochrome c oxidase subunit I locus (COI) by analyzing previously published sequences of molestus and pipiens sampled in different geographical areas. Next, by genotyping individuals from Northern Serbia at this locus, we additionally assessed whether genetic structure of urban and rural Cx. p. pipiens ecotypes corresponded to the admixture pattern. Finally, to account for the different susceptibility of genetic markers to introgression, we also analyzed genetic structuring based on the ribosomal internal transcribed spacer 2 (ITS2). No latitude-dependent differentiation of Cx. p. pipiens ecotypes was found at a global level, with the COI assay further failing to accurately identify molestus and pipiens ecotypes. Likewise, both individual- (BAPS) and population-based (analysis of molecular variance and FST estimates) methods showed no significant urban/rural genetic differentiation in Serbia, indicating unhindered gene flow between different Cx. p. pipiens habitat types. The findings challenge the previous instances of Cx. p. pipiens ecotype identification, while also spotlighting the vectorial capacity of their hybrid offspring.