The new species described in this paper was received from Richard Le Pelley, Government Entomologist, Kenya Colony, British East Africa, for identification. A new genus Eurymyiocnema is erected for its reception. This genus is most closely related to Myiocnema Ashmead, which was placed by its author in the “Aphelininae”, although subsequent authors have regarded Myiocnema as belonging to the Elasmidae. Eurymyiocnema is placed in the Aphelinidae, and the opinion is expressed that Myiocnema, as well as Euryischia Riley, are out of place in the Elasmidae, since both of these genera resemble Aphelinus Dalman much more closely than they do Elasmus Westwood.

To evaluate the effectiveness of the introduced Hymenopterous parasites Apanteles circumscriptus (Nees) and Enaysma splendens Delucchi in the control of Phyllonorycter messaniella (Zell.) samples of leaves were taken from infested oaks during 1969–70. In Christchurch there were three generations of P. messaniella per year with spring, summer, and autumn emergence periods. Infestation on deciduous oaks was negligible in some areas but was 6.3 mines/leaf in the lower crown of oaks close to evergreen oaks on which P. messaniella overwinters. On deciduous oaks total parasitism ranged from 30% to 80%. Apanteles was the most abundant parasite but Enaysma assumed almost equal importance on oaks with low infestations. Pnigalio pectinicornis (L.), a self-introduced parasite, has been almost completely displaced by the other two parasites since their introduction in 1957. The infestation intensity recorded in Nelson (2.3 mines/leaf) was much lower than the level reported before the release of the parasites (40+ mines/leaf), but still much higher than levels in Europe.

White peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) (Homiptera: Diaspididae), was a serious pest of mulberry until it was the subject of a successful biological control programme in Italy at the turn of the century. Since the 1950s it has returned as a sporadic pest of commercial peach and, more recently, kiwi fruit orchards. We sampled white peach scale in an unmanaged mulberry orchard in coastal Campania over a 17 month period to measure the impact, relative abundance, and interactions of the parasitoids in the absence of pesticides. Sampled scales were dissected, and the immature stages of the parasitoids identified. Mean densities of white peach scale varied with month from 3–15/9 cm2 on primary (interior) branches and 15–100/1.5–2 m secondary (exterior) branch. The generalist ectoparasitoid Aphytis proclia (Walker) was most abundant, followed by two specialist endoparasitoids, Encarsia berlesei (Howard) and Pteroptrix orientalis (Silvestri) (all Hymenoptera: Aphelinidae). Primary parasitism also varied with month from 25–85% on primary branches and 20–90% on secondary branches. Parasitism on primary branches was inversely density-dependent, but was densityindependent on secondary branches. Low levels of superparasitism were generally observed in E. berlesei and P. orientalis (0–6%), but were higher in A. proclia (0–21%). Multiple parasitism of hosts by E. berlesei and A. proclia was fairly common (up to 24% of E. berlesei immatures were found sharing a host with A. proclia), and A. proclia was the probable winner of within-host competitions. The hyperparasitoid Azotus perspeciosus (Girault) (Hymenoptera: Aphelinidae) parasitized late pre-imaginal instars of all three primary parasitoid species. There was no significant difference in hyperparasitism of the three primary parasitoid species, but the rate of hyperparasitism was inversely related to the total density of primary parasitoids.

Grasshoppers host a number of parasitoids, but little is known about their impact on grasshopper life history attributes or how those impacts may vary with land use. Here, we report on a three-year survey of nine grasshopper species in a tallgrass prairie managed with fire and bison grazing treatments. We measured parasitoid prevalence and the impact of parasitoid infection on grasshopper fecundity to determine if grasshopper-parasitoid interactions varied with management treatment. Adult female grasshoppers were collected every three weeks from eight watersheds managed with different prescribed burning and grazing treatments. Grasshopper fecundity with and without parasitoids was estimated through dissections of reproductive tracts. Dipteran parasitoids from two families (Nemestrinidae and Tachinidae) were observed infecting grasshoppers. We found significant effects of grazing treatment, but not burn interval, on grasshopper-parasitoid interactions. Parasitoids were three times more abundant in watersheds with bison grazing than in ungrazed watersheds, and the relative abundance of nemestrinid and tachinid flies varied with grazing treatment. Parasitoid prevalence varied among grasshopper species from <0.01% infected (Mermiria bivittata) to 17% infected (Hypochlora alba). Parasitoid infection reduced individual grasshopper fecundity, with stronger effects on current reproduction than on past reproduction. Furthermore, current fecundity in parasitized grasshoppers was lower in grazed watersheds compared to ungrazed watersheds. Nemestrinid parasitoids generally had stronger impacts on grasshopper fecundity than tachinid parasitoids, the effects of which were more variable.

The control of Anastrepha obliqua includes the sterilization of mass-reared insects grown in isolation in a constantly controlled environment. Through time, laboratory mass-reared colonies may produce flies with lower field performance. To recover the genetic variation and aptitude of mass-reared populations, wild insects are introduced into mass-reared colonies. Our aim in this study was to determine whether the host species from two localities influence the life history traits of A. obliqua. We collected flies as larvae from infested fruits of Spondias purpurea, S. mombin, Mangifera indica cv. ‘piña’, and M. indica cv. ‘coche’ from two localities in Chiapas, Mexico. There were significant differences in the mating competitiveness of males collected from mango cv. ‘coche’ compared with mass-reared males. There were no differences in the mating propensity between flies from the two localities, even in the number of matings, when weight was considered as a covariable. The mass-reared strain showed the earliest age at first oviposition. The locality affected the longevity and oviposition period, and these influenced the birth rate, intrinsic rate of increase, finite rate of population increase, mean generation time, and doubling time. According to the demographic parameters, the population of S. mombin would allow artificial colonization in less time, considering that it has a high reproduction rate starting at an early age. Even in the propensity test, it had the highest number of matings. However, males with greater sexual competitiveness and longevity for colonization corresponded to those collected from S. purpurea.

It is known that there is a high mortality in puparia of Glossina submorsitans and tachinoides if they are kept in air which is far from saturation; it seems anomalous that there is no evidence of mortality among puparia in nature at the end of the dry season when the soil in the thickets appears to be quite dry.

Experiments are described, showing that the soil of the thickets (unlike the more sandy soil of the open country) will take up large quantities of water; as its colloid content is high, this soil must also possess great power of retaining the water. Moreover even when the soil seems quite dry (water content 4 per cent.) the atmosphere in the soil spaces is very nearly saturated.

An ecological study of summer populations of Metopolophium dirhodum (Walker) on winter wheat, was carried out near Bedford, UK, in 1978–80. Alate production (as percentages of alatiform fourth-instar nymphs) followed a consistent and synchronous three-phase pattern: with increases to 50% in early June in 1978–80 and 90% in late July in 1978–79. The proportions of winged offspring deposited by apterous parents also showed a similar increase, changing from 5% on 14–20 June to 91% on 5–11 July. Alate parents deposited mostly (75%) wingless offspring. Frequency distributions for nymph batch sizes were obtained for both morphs in 1979. Alate deposition was bimodally distributed. For apterous aphids, the fourth instar was the main dispersal stage. The numbers of adult apterae expressed as proportions of the total population were generally lower in 1979 than in 1978. The numbers of colonies increased sharply between 19 and 21 June in 1978 and 1979, and remained at similar levels to each other until at least 5 July. Colony and population numbers were highly significantly correlated over certain periods in 1978 and 1979. Colonies with >20 aphids increased sharply in numbers after 6 July, probably as a result of changing aptera dispersiveness. An estimate of mean colony size in 1979 showed a well-defined 14-day plateau phase. Changes in population alate production and changes in the proportions of winged offspring (from apterous parents) are discussed in relation to colony development. It is considered that increases in colony size produce colony-specific patterns of alate production.

Ten non-organochlorine insecticides which had shown promise in laboratory tests as formicides, because of their delayed toxic action, were field-tested in Brazil in experimental leaf-cutting ant baits and were compared with a mirex bait. Seven of these gave good control (similar to mirex) against Atta sexdens (L.) colonies. Several showed some success, at the concentrations used, against the larger Atta cephalotes (L.) colonies, but were not as good as mirex.

By microencapsulating some quick-acting and very potent insecticides it was shown that useful formicides could be produced, presumably because encapsulation delayed the toxic action.

Substituting vermiculite plus orange juice in place of dried citrus pulp as an attractive bait matrix gave successful results.

Blood-meals of two species of haematophagous insects, Glossina morsitans Westw. and Aedes (Stegomyia) aegypti (L.), have been ‘ marked ’ by allowing groups of adults to feed on an ox to which an aqueous solution containing 4 g. of trypan blue had previously been administered intravenously. The dyestuff is detected by a paper chromatographic procedure in which the blood-meal, mixed with 0·1N NaOH, is applied to a narrow strip of Whatman No. 1 chromatographic filter paper and the chromatogram is developed in 0·1N NaOH. Under these conditions, trypan blue remains at the origin, whereas the other coloured components of the blood-meal move away from the point of application. The duration of the mark in the ox and in the insects has been examined. The trypan blue was detected in four out of six fresh blood-meals of Glossina taken 38 days after injection of the dye into the ox, in six out of six examples of Glossina examined two days after blood-meals taken 24 days after the injection, in four out of six examples of Glossina examined eight days after blood-meals taken immediately following the injection, in six out of six examples of Aedes one day after blood-meals taken 14 days after the injection and in six out of six examples of Aedes two days after blood-meals taken immediately following the injection.

The taxonomic status of Phylacteophaga Froggatt is re-evaluated using the independent techniques of allozyme electrophoresis and detailed morphological comparison. Analysis of 45 scorable loci showed highly significant fixed differences (46–51%) among two currently recognized subspecies, P. eucalypti eucalypti Froggatt P. e. froggatti Riek, and a previously unrecognized taxon from Tasmania, demonstrating that they are different species. In addition to colour, significant variation is revealed among P. e. occidens Benson, P. rubida Riek and the three electrophoretically defined species, in body size, structure of the antennae, the shape of the crest, dorsal spines and saw teeth of the ovipositor, and in male genitalia. Based on these results there is substantial justification in recognizing P. occidens and P. rubida as separate species, distinct from P. eucalypti, P. froggatti, and P. amygdalinisp. n. Further, comparison of the holotype of P. e. tasmanica Riek shows it to be conspecific with the lectotype of P. eucalypti (designated here) so that the former species is considered a junior synonym. The distribution of P. eucalypti and P. froggatti is extended to include Tasmania, and a key is presented to distinguish the males and females of all five species. The biology and host plant relations of the species concerned are discussed, along with their pest status and potential to spread to other regions of the world where eucalypts are grown.

Three species of Mesoclanis flies that attack the developing seeds of Chrysanthemoides monilifera in South Africa are being assessed for their potential as biological control agents of C. monilifera in Australia. Surveys in South Africa indicated that M. polana Munro is restricted to C. m. rotundata along the subtropical northern coast, M. magnipalpis Bezzi and M. dubia Walker occur on all three subspecies sampled (C. m. rotundata, C. m. monilifera, C. m. pisifera), although M. dubia is less abundant and has a more restricted distribution than M. magnipalpis. Mesoclanis eggs are laid into a wide range of flowerhead stages of C. m. rotundata over a period of approximately 12–14 days, from very small flowerheads with involucral bracts still completely closed, to flowerheads with the laminae of ray florets (petals) starting to elongate. Levels of oviposition by M. magnipalpis into C. m. pisifera are low in very young flowerheads, possibly as a consequence of a heavy layer of indumentum on young C. m. pisifera flowerheads. The pattern and location of feeding and pupation within flowerheads differs slightly for the three Mesoclanis species, but none of the species is associated with the formation of gall tissue. The effect of Mesoclanis activity on ovule development was assessed on four occasions. Mesoclanis destroyed all the ovules in some capitula, and the maximum level of ovule destruction recorded for a site was 64%.

Different Shin-Etsu twist-tie rope formulations, containing either the cotton bollworm, Helicoverpa armigera (Hübner) pheromone or pink bollworm, Pectinophora gossypiella (Saunders) pheromone, or both, in the same rope, were tested in Israel for mating disruption. The success of mating disruption was evaluated by the mating table technique, comparing the percentage of mating of virgin sentinel females in pheromone-treated and control plots. Two variants of this technique were evaluated, one with two mating tables per plot, each containing five to seven females, and the other with six to eight mating tables per plot, with only one female per table. The latter method was more sensitive than the former, particularly at low population densities. Two tests were conducted in 1995 in order to compare a blend of five components of H. armigera pheromone with a blend of two components for mating disruption. The application consisted of 2000 ropes/ha, each with 80 mg pheromone. Evaluation by the two mating table methods showed clearly that the formulation containing two components was superior to the five-component blend for mating disruption, suppressing mating almost completely for 49 days. A new combined formulation, HPROPE, containing 175 mg of the H. armigera two component blend and 65 mg of P. gossypiella pheromone was tested in 1996 for mating disruption of both pests. Application of 625 ropes/ha caused a high level of suppression of mating of H. armigera females for at least 94 days and that of P. gossypiella females for 161 days. The pheromone release rates were c. 625 mg/day/ha for H. armigera and 162 mg/day/ha for P. gossypiella. A ‘long-life’ formulation of P. gossypiella pheromone, PBW rope LR, applied at 125 ropes/ha releasing 137 mg/day/ha achieved complete suppression of mating over 75 days. This release rate of P. gossypiella pheromone was much lower than that currently used in Israel (275 mg/day/ha). The present study indicates that mating of females of two moth pests with different pheromones can be disrupted by one combined formulation.

Megaplatypus mutatus (=Platypus sulcatus Chapuis) is an Ambrosia beetle native to South America, which was recently introduced in Italy and its presence there is causing severe damage to the local poplar plantations. The male M. mutatus pheromone is composed of (S)-(+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone) and 3-pentanol. A series of field trials testing dose, blend and enantiomer composition performed in Argentina and Italy evaluated attraction and found that the optimal release rate of pheromone components as baits in cross vane baited traps (CIPEIN-CV) was 6, 6 and 30 mg day−1 of sulcatone, (+)-sulcatol and 3-pentanol, respectively. It was also determined that racemic sulcatol is as effective as the pure (+)-isomer for the purpose of beetle catch, due to the inert nature of the (−)-isomer allowing the usage of low cost racemic sulcatol instead of highly expensive (+)-sulcatol. The results of our work contribute to the development of pheromone-based local technologies with low environmental impact and low cost for control or monitoring of an important pest.

Arthropod communities in the tropics are increasingly impacted by rapid changes in land use. Because species showing distinct seasonal patterns of activity are thought to be at higher risk of climate-related extirpation, global warming is generally considered a lower threat to arthropod biodiversity in the tropics than in temperate regions. To examine changes associated with land use and weather variables in tropical arthropod communities, we deployed Malaise traps at three major anthropogenic forests (secondary reserve forest, oil palm forest, and urban ornamental forest (UOF)) in Peninsular Malaysia and collected arthropods continuously for 12 months. We used metabarcoding protocols to characterize the diversity within weekly samples. We found that changes in the composition of arthropod communities were significantly associated with maximum temperature in all the three forests, but shifts were reversed in the UOF compared with the other forests. This suggests arthropods in forests in Peninsular Malaysia face a double threat: community shifts and biodiversity loss due to exploitation and disturbance of forests which consequently put species at further risk related to global warming. We highlight the positive feedback mechanism of land use and temperature, which pose threats to the arthropod communities and further implicates ecosystem functioning and human well-being. Consequently, conservation and mitigation plans are urgently needed.

Oryctes monoceros is a serious coconut pest, causing up to 40% damage in tropical Africa. Synthetic aggregation pheromone, ethyl 4-methyloctanoate, has been used to lure adults to traps. Traps with pheromone plus decaying palm material captured a high proportion of males. This raises the question whether individuals, which damage palms are receptive to the pheromone. We studied the sex ratio of the insects feeding on coconuts and those attracted to pheromone traps. Sixty two percent of adults from feeding galleries on living coconut palms were females. Pheromone with rotting palm material lured 43% females. To investigate the reasons for this difference, we compared the reproductive system of females lured to the odour traps or feeding in coconut galleries, or present in old rotting stems. Ninety six percent of the females trapped by pheromone had mated, and were sexually mature. In the galleries on living palms, 46% of females were immature, and 24% had not mated. In old rotting stems where eggs are laid and larvae develop, a mixture of 52% mated and 48% virgin females was found. Therefore, the pheromone together with the odour of rotting coconut stems signals a reproduction site to beetles, particularly mature females. In practice, the pheromone-baited traps will help in reducing the dissemination of gravid females, but will not affect directly the numbers of immature ones attacking palms. Our results show that when using pheromones for monitoring or controlling insects, the physiological status of the insects may have unexpected effects on the outcome.

Mosquitos continue to enter occupied, untreated native huts throughout the night, with peak periods of entry at dusk and dawn. Early morning mosquito catches do not give a true picture of the numbers entering and leaving huts during the night.

In a series of catches 63 per cent. of 5,576 mosquitos and 79 per cent. of 506 Anopheles gambiae were caught resting on the underside of the thatch roof.

By using five traps inserted in apertures one foot below the top of the wall, the numbers of mosquitos attempting to leave a hut were determined. Of 1,014 mosquitos entering huts before 10 p.m., 63 per cent. remained inside until 6.30 a.m., that is for 8½ hours. Catches to estimate numbers entering and leaving at different times during the night were also made.

Treatment of huts with DDT wettable powder and DDT-kerosene solution did not interfere with the normal behaviour of mosquitos as far as entry was concerned. Biting occurred in the treated huts.

The DDT wettable powder appeared to be more effective than the DDT-kerosene solution.

Some mosquitos entered the treated huts, fed and then left before acquiring a lethal dose. After making contact with treated surfaces mosquitos became restless but, under the conditions existing in the huts during the experiments, activation did not result in more leaving the treated huts than the untreated one. Unfortunately there were few A. gambiae and the predominant species entering the huts was Taeniorhynchus fuscopennatus.

Some of the female A. gambiae released into unoccupied DDT-treated huts escaped into the traps before acquiring a lethal dose. Although there was a tendency for more to enter the traps of a DDT-treated hut than those of an untreated hut, the data are insufficient to show a significant difference.

The majority of mosquitos entering the traps did so within one hour of their release.

No mosquitos were still alive 12 hours after their release in huts treated 17 weeks previously with DDT wettable powder or DDT-kerosene solution, or in the hut treated 12 weeks previously with "“Gammexane” wettable powder.

The identity of Culicoides habereri, Becker, with C. grahamii, Austen, is conclusively established as the result of a comparison of the typical series of the former with the type and para-types of the latter, which are preserved in the British Museum (Natural History). For the opportunity of making this comparison and thus proving the synonymy given above, the present writer is indebted to Dr. Kurt Lampert, of the Königl. Naturaliensammlung, Stuttgart, where the original material of C. habereri is preserved; with the most obliging courtesy Dr. Lampert not only forwarded for comparison the typical series described by Becker, but also presented three para-types of C. habereri to our National Collection.

Helicoverpa gelotopoeon, the South American bollworm, is a polyphagous pest of the Heliothinae complex that causes damage to soybean, cotton, and chickpea crops. Some species within this complex have developed resistance to genetically modified crops and insecticides, which has led to increased interest in their genetic diversity and population structure. The objective of this study was to characterize biological and reproductive parameters of two populations of H. gelotopoeon collected in two different provinces of Argentina. Intra- and inter-population crosses revealed that H. gelotopoeon populations from both regions of Argentina did not present evidence of pre-zygotic and post-zygotic incompatibility, suggesting that Tucumán and Córdoba populations of H. gelotopoeon belong to a single wide-ranging species. Our data support the occurrence of substantial gene flow between H. gelotopoeon populations, probably due to the widely documented, long-range migratory capacity of Heliothinae species.

The ‘paddy paradox’, the occurrence of large populations of vectors but low amounts of malaria transmission where irrigated rice is grown, was investigated in a village in Ghana where M form Anopheles gambiae are common. Peridomestic and indoor host-seeking mosquitoes were collected in tent traps and light traps over 21 consecutive nights at the start of the rainy season in June 2009 when the population increased exponentially from less than 100 per night to over 1000. Infection rates in the overall mosquito population were 0.3% and in the estimated parous population were 1.9%. Numbers of An. gambiae in the tent trap peaked between midnight and 02:40 am. The majority of insects were taking their first blood meal, as virgins or shortly after mating. More than expected were collected in the light trap during a rainstorm at the start of the rains but overall numbers were not affected. Fewer than expected were collected after a subsequent storm. Recruitment to the adult population decreased over the following days. It is hypothesised that the ‘paddy paradox’ is due to young pre-gravid insects dispersing more widely than gravid ones, not necessarily to low survival in the mosquito.

Wheat bulb fly (WBF, Delia coarctata, Fallén, Diptera: Anthomyiidae) is a pest of commercial importance in wheat, barley and rye, with attacked crops failing to produce full potential yields. Females do not oviposit in association with a host-plant; therefore, prompt location of a suitable host is critical to the survival of the newly hatched larvae. The objective of this study was to conduct choice test bioassays to assess the attraction of WBF larvae to specific chemical constituents of WBF host-plant root exudates, the hydroxamic acids DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and MBOA (6-methoxy-benzoxazolin-2-one). The larval response to four concentrations of each test compound was assessed in arena bioassays. Analysis using a Rayleigh test of uniformity of the final resting positions of larvae in response to these chemicals indicated attraction. These results go some way to explaining the mechanisms by which WBF larvae locate host plants, giving the potential to develop semiochemical based control strategies.