Rhembastus pomorum, sp. n. (fig. l).

Oblong-ovate, metallic dark blue ; clypeus, antennae and legs fulvous ; prothorax finely and remotely punctured ; elytra finely punctate-striate, with the interstices glabrous. Length, 4 mm.

In the autumn of 1928 Dr. J. Schwetz forwarded to the writer, from Stanleyville, a small collection of blood-sucking Diptera, the majority of which had been obtained by him in the region of the Lower Lomami River. The material sent included specimens of four species of Glossina, the determination of three of which (G. palpalis, Rob.-Desv., G. fusca, Walk., and G. tabaniformis, Westw.) presented no difficulty. The fourth species, however, which had evidently attracted the special attention of the sender, since specimens of it were received labelled “ ? G. pallicera,” proves to be new and is accordingly described below. Dr. Schwetz, who is already well known by reason of entomological investigations in Belgian Congo extending over a long series of years, is to be congratulated upon a discovery which brings the number of recognised species of Glossina up to twenty.

At the request of the Imperial Bureau of Entomology I have had pleasure in studying the forms described below. In the alcoholic material examined some adult forms were accompanied by larvae ; I am thus afforded another opportunity of publishing further notes on the anatomy of Chrysomelid larvae. The drawings are by Mr. A. J. E. Terzi.

For the last few months I have been using a beech tree-hole in Epping Forest as a source of supply of Anopheles plumbeus; and it has been our custom to collect larvae from the hole and transfer them to the laboratory at Sandwich, where the development is continued under artificial conditions. In this way we have been able to obtain large numbers of Anopheles plumbeus and Ochlerotatus geniculatus, together with the recently discovered Orthopodomyia albionensis as an associate. Not long after finding the Orthopodomyia, I was surprised to find yet another species from the same tree-hole, two male Stegomyia fasciata, emerging from the tank containing the mixed larvae from Epping Forest. The speciemens were of normal size, and we now have them preserved in our collection here.

It is confirmed that the scutellaris-growp mosquito of the Tokelau and Ellice Islands is Aëdes (Stegomyia) polynesiensis Marks. No other mosquitos are known from the former Group, but Culex (Culex). annulirostris Skuse, A. (Aëdimorphus) vexans nocturnus (Theo.) and A. (Stegomyia) aegypti (L.) are also recorded from Funafuti, Ellice Islands. C. annulirostris and A. vexans nocturnus are listed—apparently for the first time—from Tarawa, Gilbert Islands. Reference is made to the microfilaria rate at Nukunono in the Tokelau Group, and to some potential mosquito larval habitats, as yet unutilised, in all three Groups.

There are several possible causes of aggregated nesting in solitary Aculeata, one being joint defense against parasites. We tested whether females prefer nesting in aggregations, even if they consist of heterospecifics. We compared the colonization and nesting parasitism of trap-nests with and without a red mason bee aggregation. The results did not support our hypothesis that females prefer nesting in aggregations. The numbers of wild Aculeata nests did not differ between trap-nests with and without an aggregation. Unexpectedly, parasitism rates were higher in trap-nests with aggregations. When analyzing only nests of wild insects (mostly wasps), the differences in parasitism disappeared. Natural nesting sites may be such a limited resource that females nested in the first trap-nest they encountered and did not discriminate between our treatments, or wasps might share too few parasites species with bees to benefit from joint nest defense.

The ability to insert foreign genes into arthropod genomes has led to a diverse set of potential applications for transgenic arthropods, many of which are designed to advance public health or improve agricultural production. New techniques for expressing foreign genes in arthropods have now been successfully used in at least 18 different genera. However, advances in field biology are lagging far behind those in the laboratory, and considerable work is needed before deployment in nature can be a reality. A mechanism to drive the gene of interest though a natural population must be developed and thoroughly evaluated before any field release, but progress in this area has been limited. Likewise, serious consideration of potential risks associated with deployment in nature has been lacking. This review gives an overview of the most promising techniques for expressing foreign genes in arthropods, considers the potential risks associated with their deployment, and highlights the areas of research that are most urgently needed for the field to advance out of the laboratory and into practice.

Glossina vanhoofi Henrard has been found at the I.R.S.A.C. field station at Irangi in the Belgian Congo in dense rain-forest. The fly does not normally attack man and was collected only by looking for it in its resting places. The fly rests on small saplings, head down, at an average height of about 133 cm. A three-months' survey on a fly-round transecting three valleys and two hill-tops showed that the resting density (defined as the total number of resting flies observed per 10,000 metres of path) was correlated with the profile of the transect, the hill-tops yielding more flies than the valleys. The fly-round was worked three times a day and showed the highest density during early morning in all three months; in two of them there was little difference between midday and evening catches. The resting height varied in much the same way in all the sections of the fly-round and the average height remained virtually constant during the three months of the survey. There was a slight difference between the sexes as regards average resting height, the females perching somewhat lower than the males. The sex ratio of about 1:1 was very constant throughout the day and the period of the observations.

There is some evidence which seems to indicate that this species is strongly attracted to possible host-animals by a sense of smell.

Puparia have been found in “classical” sites, but the proportion containing living pupae was small. The duration of the pupal period is about 35 days under laboratory conditions at 26°C. and 90 per cent. relative humidity.

G. vanhoofi in captivity feeds readily on the porcupine, Atherurus africanus.

Previous work in Britain has shown that insecticides, even systemic ones, fail to protect brassica plants in the seed-bed from virus diseases transmitted by aphids, and an explanation was sought through experiments carried out at Rothamsted. Observations on the effect on apterae and alates of Myzus persicae (Sulz.) of contact with leaves detached from cauliflower plants previously treated with a 0·2 per cent. DDT emulsion spray showed that exposure for up to 30 min. was insufficient to kill the majority of those tested, although many were temporarily incapacitated; alatae of Brevicoryne brassicae (L.) were even less affected.

In cage experiments using infected and healthy cauliflower seedlings, apterae of M. persicae were able to transmit cauliflower mosaic virus (ClMV) and cabbage black ring spot virus (CBRSV) from infected to healthy seedlings when no spray was used, but failed to do so when the infected plants were sprayed with DDT; when alates were used in similar tests using only CBRSV, only low rates of transmission were obtained. In similar experiments using turnip seedlings and ClMV, transmission by apterae of M. persicae was high on untreated plants when the infector plant was itself untreated, but distinctly lower when it was sprayed with DDT; alates of M. persicae were found to transmit ClMV from a DDT-treated infector to untreated plants but not to a treated plant. Virus spread was thus reduced but not prevented by the use of DDT sprays. It is considered that these results lend support to the hypothesis that increase of virus within a seed-bed is preponderantly the result of the arrival, in succession, of many individual viruliferous alates from outside.

The effect of a single flood irrigation cycle on the number of adults of Musca vetustissima Wlk. emerging from cattle dung was examined in the field in south-western Australia. Sets of fresh dung pads were exposed to natural oviposition on the day after a flooding and then every three days until the next flooding, 21 days later. The emergence of flies was compared with that from equivalent sets of dung pads in an adjacent unflooded but otherwise similar pasture. The age-stages most susceptible to drowning were post-feeding larvae and pre-emergent puparia. Reduced fly emergence from dung placed in the irrigated pasture one day after the first irrigation was attributed to suppression of oviposition by the wet conditions. Overall, there was a reduction of 57% in the number of flies emerging in the irrigated pasture compared with the unflooded control.

The genus Podagrica occurs in very large numbers in Africa, both as regards species and specimens, and from the records we already have, at least twelve are recorded as doing damage to cotton, Hibiscus and other plants. A list of these is given and also a list of described African species, there being at present no up-to-date catalogue of the Halticinae.

Weise, in Naturgeschichte der Insecten Deutschlands, 26, 1886, p. 681, sinks the genus Nisotra, Baly, 1864, to Podagrica, Foudras, 1860, quite rightly. There are already 39 described African species, to which I now add eight new ones. There can be no doubt that the whole genus will prove to be destructive to various crops. It ranges from Europe to Australia, but does not occur in North or South America. The species are very difficult to define, almost as much so as the genus Haltica ; the species having the prothorax fulvous and the elytra blue form the largest group ; another group is entirely flavous or fulvous, and a third small group has spots or slight markings.

Les parasites suivants ont été recueillis par Mr. J. G. Myers à Versailles, France, en juillet et août 1925, de la Cécidomyie des poires, Perrisia pyri, Bch. Le matériel obtenu comprend les 10 espèces dont les noms suivent, avec indication de leurs dates d'éclosion, mais seuls les deux Platygasterines et le Torymus peuvent être considérés comme ayant une importance dans la destruction de la Cécidomyie, les autres espèces n'ayant été obtenues qu'en trés petit nombre ou n'étant probablement pas parasites de ce petit Diptère.

Little is still known about the distribution of mosquitos in Abyssinia. The first record appears to be that of Theobald (1904) who described specimens collected by Balfour along the banks of the Baro and Pibor Rivers, which flow from Western Abyssinia into the Sobat, a tributary of the White Nile. Scott (1927) reported 13 species which he collected from Central Abyssinia, and he refers to two other species previously found by the Mission to Lake Tana (1925).

At the request of Dr. W. R. Thompson, Superintendent, Farnham House Laboratory, The Imperial Institute of Entomology, England, arrangements were made in 1936 to collect and furnish to him larvae of the predacious Elaterid Pyrophorus luminosus, Illiger, indigenous to Puerto Rico. These beetles were for liberation in Mauritius to aid in the control of the white grub, Phytalus smithi, Arrow. Shipments were sent by steamer from Puerto Rico to New York and then to England for repacking and shipment to Mauritius. The Mauritius government appropriated the sum of 85 pounds sterling to defray the expense of collection, packing and shipment.

In the Revista Industrial y Agrícola de Tucumán of November 1923 to January 1924, 4th year, numbers 6–8, Arthur H. Rosenfeld & T. C. Barber published an interesting article on the sugar-cane moth borer, known in Tucumán as the “ gusano chupador de la caña de azucar,” in which they detail the different effects of the said moth borer (Diatraea saccharalis).

Last year, Dr. William E. Cross, Director of the Estación Industrial y Agrícola de Tucumán, was good enough to entrust me with the study of some Diatraea parasites, the identification of which had, so far, only been effected generically.

My best thanks are due to Dr. Cross for having supplied me with material for this investigation, which I consider very interesting, owing to the daily increasing importance of the biological control of agricultural pests.

There is no doubt but that by continuing these investigations other parasites will be discovered ; this is as yet only the first step on the road which may lead to very important results.

In biological control, successful establishment of a natural enemy species depends on its adaptability in the introduced range including its ability to re-establish desired ecological interactions with the pest. These are affected by genetic parameters hitherto largely unresolved in biological control. The larger grain borer (LGB), Prostephanus truncatus, an invasive species from meso-America, is the most important post-harvest pest of maize in Africa. We studied the genetic structure of Teretrius nigrescens, a predatory beetle previously released for the control of the pest in Africa, to test the hypothesis that establishment patterns were a result of ecotype–environment mismatch and to follow up on our earlier reports of distinct lineages of the predator. We studied 13 populations of T. nigrescens, using 16 polymorphic microsatellite markers. Five genetic populations with a hierarchical structure and significant isolation by distance were detected. The most diverse population was found in southern Mexico, consistent with earlier lineage coexistence observations. Populations introduced to Africa maintained genetic similarity to local geographic populations of their area of origin. The more successful Benin releases were also more genetically diverse. Loss of rare alleles and a higher frequency of existing private alleles in some populations indicated population expansions following bottleneck events. Sustainable biological control should accommodate pest and natural enemy species, and monitor genetic changes associated with introduction and release.

This is the first report of Bactra bactrana (Kennel, 1901) (Lepidoptera: Tortricidae) attacking a major solanaceous crop, sweet pepper Capsicum annuum L. The infestation was detected in two greenhouses at the area of Tympaki (Southern Crete, Greece). The moth larvae caused typical symptoms of a fruit borer with numerous small holes on the surface of the peppers and extensive damage on the inside of the fruit as a result of the feeding activity. Unknown factors facilitated this major shift in host range since B. bactrana is typically a stem borer of sedges. In addition, the pest status of B. bactrana is currently under question, as in both cases the infestations by the moth were associated with significant yield losses. B. bactrana was moderately controlled with chemicals registered for Lepidoptera management in sweet pepper due to the boring nature of the infestation. Some comparative taxonomic notes are provided to facilitate accurate pest discrimination of related Bactra species. Finally, biological attributes of the species are summarized and are discussed from pest control and ecological perspectives. Because Bactra species have been used in augmentative releases for the control of sage, the implications of our findings on the release of biocontrol agents are placed in perspective.

When a promising natural enemy of a key pest exists locally, it is a common practice in biological control (BC) to rear and release it for supplementary control in the targeted agroecosystem even though significant knowledge gaps concerning pre/post release may still exist. Incorporating genetic information into BC research fills some of these gaps. Habrobracon hebetor, a parasitoid of many economically important moths that infest stored and field crops worldwide is commonly used, particularly against the millet head miner (MHM), a key pest of millet in Sahelian countries. To advance our knowledge on how H. hebetor that occurs naturally in open-field cropping systems and grain stores as well as being mass-produced and released for MHM control, performs in millet agroecosystems in Niger we evaluated its population genetics using two mitochondrial and 21 microsatellite markers. The field samples were genetically more diverse and displayed heterozygote excess. Very few field samples had faced significant recent demographic bottlenecks. The mating system (i.e. nonrandom mating with complementary sex determination) of this species may be the major driver of these findings rather than bottlenecks caused by the small number of individuals released and the scarcity of hosts during the longlasting dry season in Niger. H. hebetor population structure was represented by several small patches and genetically distinct individuals. Gene flow occurred at local and regional scales through human-mediated and natural short-distance dispersal. These findings highlight the importance of the mating system in the genetic diversity and structure of H. hebetor populations, and contribute to our understanding of its reported efficacy against MHM in pearl millet fields.

Predictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5°C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (±13 SEM) days at 9.7°C. Physiological age survival curves constructed with developmental base temperature (7.2°C) did not correspond to those constructed with a senescence base temperature (5.9°C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9–24.9°C).