In this article is recorded the finding of eggs of Ficalbia (Ficalbia) minima, Theo., which were hitherto unknown. A description of these eggs is given and they are compared with eggs of Mansonioides which occur in a similar situation.

The range of the moth Zeiraphera diniana Guénée and the regions where high population densities are infrequent and unpredictable are thought to be determined by high temperatures during egg pre-diapause. Exposure of eggs to incubation temperatures known to be optimal for Z. diniana elsewhere resulted in a pre-diapause mortality of 13% which corresponds to known rates of egg mortality in British forests. Evidence suggests that high temperature and its duration are both important determinants of pre-diapause egg mortality which, if experienced in forest conditions, may prevent populations from reaching outbreak levels. Historical records of outbreaks were associated with lower than average August temperature. However, high temperatures on their own are unlikely to determine the range of the insect in Britain since a high proportion of eggs survives extremes; more than 70% of British eggs survived 24 h exposure to a temperature of 30°C. Variations in egg mortality among families of moths suggests a genetic basis for differences in thermal tolerance. Furthermore, there may be selection for thermally-tolerant eggs in British forest environments and this could be connected with other forms of genetic differentiation in budmoth populations.

(1) Up to 35 per cent, of adult Dysdercus nigrofasciatus from a heavily infested late cotton crop at Barberton were found to be parasitised by Tachinid larvae at the end of the season.

(2) The predominant Tachinid species was Alophora nasalis; Bogosilla fasciata was present in smaller numbers, and appears to be more common in regions of higher rainfall.

(3) The development of the Tachinid larva within the stainer was a protracted process under local winter conditions, the larval period of A. nasalis being of the order of 2–3 months, and parasitised stainers were correspondingly long-lived.

(4) The possible economic significance of the parasites is discussed.

The following paper is the result of the study of material recently received by the Entomological Research Committee, by which the types of two of the species described below have been presented to the British Museum (Natural History): the type of Chrysops centurionis has been handed over to the National Collection by its discoverer, Captain A. D. Fraser, R.A.M.C.

A correction is made to a paper by Nash (1955) in which Syntomosphyrum glossinae Wtstn., a Chalcid parasite of the pupae of tsetse flies, was wrongly recorded as parasitising the oöthecae of Periplaneta americana (L.). The parasite in question was almost certainly the very similar Tetrastichua hagenowii (Ratz.)which is a world-wide parasite of P. americana. There is no evidence that eitherparasite can attack both P. americana and Glossina palpalis (R.-D.).

With the exception of a few isolated records nothing is known of the Coccidae of Southern Rhodesia. Dr. Brain has made a study of the family in the Union of South Africa, the results of which are to be found in his excellent Monograph,* and Prof. Newstead has described many interesting and hitherto unknown forms from Central Africa in the earlier volumes of this Bulletin.

It has been proposed that the existing Organisation Internationale de Lutte Biologique (a mainly western European and Mediterranean body) should be enlarged and restructured to form a world-wide International Organisation for Biological Control. IOBC would be open to individual as well as institutional members, and would have largely autonomous regional sections in different parts of the world. IOBC is expected to come into being early in 1971.

Dermatodes cinchonae, sp. n.

♂♀. Derm black or piceous, with uniform dense brown scaling above, becoming paler laterally and beneath.

Twelve species of termites occurring in the British Solomon Islands Protectorate are listed, and an illustrated key to their soldier castes is provided. An analysis of the 114 records has been made in order to indicate, in a general way, the relative abundance of the various species. Notes are given on distribution within the islands, on habitats and nests, and on the occurrence of termites on coconut palms and in buildings. Damage to buildings is discussed and suggestions made for control measures applicable to local conditions.

Survival of Musca vetustissima Walker from egg to adult in nutritious cattle dung from pasture irrigated during the dry south-western Australian summer was measured in the field. When drowning was prevented by placing dung on a low embankment, survival was high for only the first two months of the fly season, which included the first month of the five-month irrigation period. Substantial emergence of wild M. vetustissima adults from naturally- infested dung occurred only around that time. Survival was so low during the last four months of irrigation, even in the absence of mortality caused by drowning, that irrigated pasture areas in south-western Australia are unlikely to have significantly greater potential for breeding of M. vetustissima than non-irrigated pastures during most of the summer.

Understanding the blood-feeding patterns of mosquitoes is essential for evaluating their potential as disease vectors, especially in urban areas where mosquitoes coexist with humans, domestic animals and wildlife. This study aimed to bridge a substantial gap in regional knowledge by identifying the blood meal sources of field-collected mosquitoes in domestic and open green environments from two urbanisations of temperate Argentina, the Área Metropolitana de Buenos Aires (AMBA) and Tandil, using molecular techniques. Female mosquitoes were collected from November 2019 to March 2020 and April–May 2021. A bipartite network analysis was performed for each environment and urbanisation. A total of 103 blood meals from Aedes (2 species) and Culex (7 species) were identified. Among these, five mammal and 18 bird species were recognised as hosts. Aedes mosquitoes exclusively fed on mammals, while Culex mosquitoes exhibited a broader host range including both birds and mammals. In AMBA, the open green environments were composed by more mosquito species than the domestic environments, while both presented similar numbers of vertebrate species. In contrast, in open green environments from Tandil only blood-fed Aedes albifasciatus were collected. For open green environments of AMBA and domestic environments of Tandil, results suggested some degree of host selection. For the three main vectors of diseases in the region, Aedes aegypti, Ae. albifasciatus and Culex pipiens molestus, we present the first molecular evidence of human blood meals in South America. Epidemiological significance of the present findings is discussed.

Drosophila suzukii is a pest of global concern due to its great impact on several crops. The entomopathogenic nematode Steinernema carpocapsae was highly virulent to the larvae of the fly although some immune mechanisms were triggered along the infection course. Thus, to understand the gene activation profile we performed a comparative transcriptome of D. suzukii larvae infected with S. carpocapsae and Xenorhabdus nematophila to map the differentially expressed genes involved in the defence response. The analysis exposed the induction of genes involved in the humoral response such as the antimicrobial peptides and pattern-recognition receptors while there was a suppression of the cellular defence. Besides, genes involved in melanisation, and clot formation were downregulated hindering the encapsulation response and wound healing. After the infection, larvae were in a stress condition with an enrichment of metabolic and transport functionalities. Concerning the stress response, we observed variations of the heat-shock proteins, detoxification, and peroxidase enzymes. These findings set a genetical comprehensive knowledge of the host-pathogen relation of D. suzukii challenged with S. carpocapsae which could support further comparative studies with entomopathogenic nematodes.

The interplay between the host plant of an insect herbivore and an insect predator (here two-spot ladybird beetles; Adalia bipunctata (L).; Coleoptera: Coccinellidae), feeding upon such a herbivore was examined in the laboratory as factors possibly determining the differential abundance and success of green and red host races of pea aphid, Acyrthosiphon pisum Harris. The experiment comprised three treatments: two host plants (bean and clover), two treatment levels (control and predation) and three colour morph levels (green alone, red alone and green and red in mixture). Green morphs had higher fitness on the general host plant, bean Vicia faba, than on the derived host, clover (Trifolium pratense), in the absence of predation. Although green morph fitness was reduced by predation when infesting bean together with reds, there was no observable net fitness loss due to predation on clover in mixed colonies with red morphs. Red morphs exhibited fitness loss alone on both bean and clover, while clover plants seemingly prevented fitness loss in the presence of predation when red morphs were mixed with green ones. According to this scenario, when colour morphs existed as a mixed colony, the net fitness of either pea aphid morph was not influenced by predation on clover. Predators had significant effects only on red morphs on broad bean either when alone or were mixed together with green morphs. Thus, only red morphs experienced the benefits of switching from the general to the derived host red clover in the presence of predation. For green morphs, there was no apparent cost of switching host plants when they faced predation. Hence, the co-existence of green-red colour polymorphism of pea aphids on single host plants appears to be maintained by the morph gaining fitness on the derived host due to a host plant– and predation–reduction effect. These findings have important implications for understanding the ecology and evolution of host switching by different colour-plant host adapted races of pea aphids.

Parasitoids are an important group of insects because their species number is among the highest. Multiple studies have addressed the relationships between forest successional age and insect diversity by focusing on herbivorous organisms, but changes in diversity of parasitoids are still poorly known. This work analyses the diversity of parasitoids in tropical forests representing three successional stages. A total of 30 traps were placed, ten in each forest successional stages. We estimated true diversity of Ichneumonidae species and guilds and explored the relationship between their diversity and the abundance of plant species using an Indicator Species Analysis; the relationship between parasitoid species and plant richness and abundance was tested using a Redundancy Analysis. A total of 1522 individuals and 168 morpho-species were captured in four months. Species richness showed no differences; however, parasitoid abundance was higher in young forest, while intermediate forest had the highest true diversity values (1D) with 71.6 effective species. According to insect guilds, richness, abundance, and diversity were similar in the three vegetation successional stages. This finding may be explained based on the intermediate disturbance hypothesis, which postulates that moderate disturbance levels favor the highest diversity. In conclusion, successional age matters, i.e., diversity is the highest in intermediate stages, while the old forests harbors guilds unique to that successional stage, such as parasitoids of melitophagous larvae of bees. Other successional stages were characterized by a single species of parasitoid, belonging to the genera Eiphosoma and Anomalon, which may indicate altered and preserved forests, respectively.

The writer some years ago described a mosquito under the name of Dixomyia elegans, the type of which remained unique until May, 1927, when a few adults, larvae and pupae were collected. The larvae and pupae were found in hoof-holes made by cattle on the edge of a swamp. The water in these holes contained a considerable amount of decaying vegetable matter and was comparatively clear. It was not examined for algae, except that both Nitella and Chara were noted as being absent. The B. D. H. Universal Indicator gave a colour change of greenish-yellow (7·0–7·5) in all samples of water tested for pH.

The species of Sesiidae reared from larvae feeding in the vines and tubers of sweet potato (Ipomoea batatas) in Kenya are described as new and named Synanthedon leptosceles and S. dasysceles, respectively. Illustrations are given of the adults and male and female genitalia of both species. S. leptosceles is differentiated from the superficially similar East African species S. erythromma Hmps., which also is associated with sweet potato. Aegeria pyrostoma Meyr. is synonymised under S. erythromma following the examination of type material. S. dasysceles is noted to be readily distinguishable from these and other known species of Synanthedon by the rough scaling and white markings of the legs.

Experiments were conducted in Bangladesh in April–July and July–December to study the effectiveness of three methods of insecticide application to three varieties of rice against the stem-borers Scirpophaga incertulas (Wlk.) and Chilo polychrysus (Meyr.). In April–July, seedlings of the varieties IR8 and Dacca-14 were uprooted when 22 days old and treated individually with 0·0375%, 0·075%, 0·15% or 0·3% diazinon (as Diazinon 60 EC), dicrotophos (as Bidrin 85 EC) or carbaryl (as Sevin 85 SP) or 0·3% γ-BHC dust for 12, followed by dipping for 12 h in fresh water and then transplantation. In July–December, the same treatments were applied by controlled irrigation to the seedbeds of the varieties IR8 and Dacca-25 and for 40 h when the seedlings were 24 days old. In another experiment in July–December, granular formulations of diazinon (as Diazinon 5G), dicrotophos (as Bidrin 5G) and Sevidol (a mixed formulation of carbaryl 8G plus γ-BHC 8G) were also applied to the transplanted field at an interval of 20 days. Insecticides applied to uprooted seedlings reduced borer populations more in the case of variety IR8 than in Dacca–14. Diazinon applied at 0·3% to the variety IR8 and Dacca–25 effectively reduced the borer population to 4–8 and 10·5%, respectively, for up to 41 days; γ-BHC applied to the seedbed did not show much response. Dicrotophos was not highly effective in controlling the borers. Granular formulations of Sevidol at 1–5, 2 and 2–5 kg a.i./ ha and diazinon at 2–5 kg a.i./ha controlled stem-borers more effectively in variety IR8 than in Dacca-25. Variety IR8 was found more susceptible to the stem-borers than Dacca-25 and Dacca-14.