We examined the life history consequences of cornicle secretion by Aphis fabae Scopoli in second and fourth instars, and its effects on host suitability for its parasitoid, Lysiphlebus fabarum (Marshall). Cornicle secretion did not affect aphid fecundity, but secretion in the second instar enhanced life table parameters, whereas secretion in the fourth instar affected them negatively, suggesting a higher cost of secretion in later instars. Secretion in either instar improved host suitability for L. fabarum. Although control and treated aphids were parasitized at similar rates, and with similar success, wasps developed faster and emerged as larger adults in aphids that had secreted, regardless of instar. Transgenerational effects were also evident. Progeny emergence was higher when parental wasps developed in fourth instars than in seconds, whether aphids secreted or not, and progeny were larger when parental hosts secreted in the second instar, but not in the fourth. Secreting fourth instars were preferred to controls by L. fabarum females in choice tests, but not secreting second instars, and fourth-instar secretion improved wasp emergence. When control aphids were attacked, second instars were more likely to secrete than fourth instars, whereas the latter were more likely to kick the parasitoid. Cornicle secretion reduced the probability of subsequent secretion events and the frequency of other aphid defensive behaviors, indicating energetic tradeoffs among defensive tactics. Overall, our results revealed that cornicle secretion by immature A. fabae exacts both physiological and behavioral costs and results in improved host suitability for its parasitoid.

The genus Pseudodoniella was proposed by China & Carvalho (1951) for the species pacifica from Keravat, New Britain. Recently two more species have come to hand, from Lae, New Guinea and Popondetta, Papua. They are new and are described and figured here. It has been found that in the genus Parabryocoropsis China & Carvalho (1951), two of the species then described, cheesmanae from Kokoda, Papua and duni from Keravat, New Britain, were incorrectly placed and should have been assigned to Pseudodoniella.

The biology of Rhyssa persuasoria, L., and of Ibalia leucospoides, Hochenw., has already been sketched in a preliminary paper published in this Bulletin (xix, pp. 67–77, pl. iii, 1928) in collaboration with Mr. R. N. Chrystal, of the Imperial Forestry Institute. The following observations were made by the writer chiefly at the Farnham House Laboratory, during the spring and summer of 1928, and are gathered together in view of his departure from England. The work of collecting and rearing supplies of Rhyssa and Ibalia for shipment to New Zealand, for the biological control of Sirex nodilio (juvencus), has been continued on a larger scale. The present notes were made incidentally during this work and are arranged under nearly the same headings as in the previous paper, to which they are supplementary. One error needs correcting. It was stated (on p. 75) that the larch (Larix europaea, D.C.) is indigenous, though actually planted in the Oxford locality mentioned. As a matter of fact, of course, larch, though Palaearctic, is not indigenous to Britain.

Fourth instar larvae of a new strain of Culex quinquefasciatus Say from Tanzania (TANGA) were tested for insecticide resistance. Initially, the resistance ratio (RR) to chlorpyrifos was 41.8, to temephos 30.8, to propoxur 3.7. After 2–3 years of laboratory culture, resistance to chlorpyrifos and propoxur had declined (chlorpyrifos 5.7, 3.8; propoxur 1.9, permethrin 1.9). Significant synergism was found between s, s, s-tributyl trithiophosphate (DEF) and chlorphyrifos, reducing the RR from 8.0 to 2.5. Synergism between piperonyl butoxide and permethrin was less than in a susceptible control strain. Twelve esterase isozymes of different relative mobilities (Rm) on polyacrylamide gel electrophoresis were identified, ten of which remained when the strain was reinvestigated two years (approximately 32 generations) later. Null activity for all but one of these bands was observed in some larvae. Four esterase bands (Rm 0.25, 0.27, 0.31, 0.34, designated A2, A3, B2, B3) showed polymorphism in activity, with very intense bands in some larvae. The mean frequency of bands with activity greater than standard, declined as organophosphorus (OP) resistance declined, but resistance was unconnected with the frequency of nulls at these positions. In mass larval assays of in vitro sensitivity of acetylcholinesterase (AChE) to propoxur, the I50 exceeded 10x10−4M, compared with 0.1x10−4M in a reverted resistant strain (RANGOON). Single larvel assays revealed heterogeneity, which was interpreted on the basis of an AChE resistance allele (AceR) with a frequency of 0.23.

Among a number of insects sent in for identification by Dr. J. J. H. Szent-Ivany, of the Department of Agriculture, New Guinea, were several species of weevils that are reported as causing serious injury to cacao and coffee plants. Four of these are described below, and the types have been deposited in the British Museum (Natural History).

Some types of joint action of insecticides described by previous authors are discussed, and experiments described on the joint action on Periplaneta americana (L.) of the γ and δ isomers, and of the γ and α isomers, of benzene hexachloride. The values of the mortalities obtained are given in tables and compared with calculations of those that would be expected according to several models of joint action in which no interaction occurs. From statistical evidence it is concluded that only one of these models, namely, independent action with a strong positive correlation of the susceptibilities to the two poisons, can give an appropriate explanation of the results. These results, however, can also be explained by suggesting that antagonistic effects play a part in the joint action of the BHC isomers investigated.

Effective, statistically robust sampling and surveillance strategies form an integral component of large agricultural industries such as the grains industry. Intensive in-storage sampling is essential for pest detection, integrated pest management (IPM), to determine grain quality and to satisfy importing nation's biosecurity concerns, while surveillance over broad geographic regions ensures that biosecurity risks can be excluded, monitored, eradicated or contained within an area. In the grains industry, a number of qualitative and quantitative methodologies for surveillance and in-storage sampling have been considered. Primarily, research has focussed on developing statistical methodologies for in-storage sampling strategies concentrating on detection of pest insects within a grain bulk; however, the need for effective and statistically defensible surveillance strategies has also been recognised. Interestingly, although surveillance and in-storage sampling have typically been considered independently, many techniques and concepts are common between the two fields of research. This review aims to consider the development of statistically based in-storage sampling and surveillance strategies and to identify methods that may be useful for both surveillance and in-storage sampling. We discuss the utility of new quantitative and qualitative approaches, such as Bayesian statistics, fault trees and more traditional probabilistic methods and show how these methods may be used in both surveillance and in-storage sampling systems.

During recent years a great deal of research work has been carried out in connection with the control of the black currant gall mite Eriophyes ribis (Westw.) Nal. This work has necessarily included the very careful study of the mites themselves, in order that the life-cycle might be fully understood, with the final object of trying to exterminate the mites at a period when they offered least resistance and were not living within the buds, which afford them adequate protection.

While examining some black currant bushes in the late spring and summer months of 1923, in order to locate the position and determine the habits of the mites during that season, a rather peculiar form of mite was noticed to be present in small numbers. This new mite, when examined in the field, appeared to be very much stouter and of a darker colour than the familiar black currant gall mite. However, for some time it was regarded as being an immature stage of the common species. After some months this mite turned up again in greater numbers, and it was decided to examine it in detail in the Laboratory. The species proved to be a new one belonging to the genus Phyllocoptes.

Most studies on riverine ground beetle assemblages last 1–2 years, and studies on carabids from lowland stream ecosystems are rare. In 1999, a 16-year study was launched to gain insight into the structure and diversity of carabid assemblages in a cross-section of four habitats located beside a 5 m wide stream: Meadow (wet meadow), Clumps (meadow scattered with birch and willow clumps farther from the river), Birch (birch stand), and Pine (pine stand located the farthest from the stream). The total number of 14, 216 individuals representing 118 carabid species were collected. Eleven functional carabid groups have been analysed. Principal response curve analysis showed significant differences existing during the whole study period among carabid assemblages from the four habitats. Generalised Linear Mixed Models analysis revealed a dependence of Chao2 estimator performance on temperature and ground water level, whereas life traits of carabids depended solely on the latter factor, affecting species composition (i.e., proportions of autumn and spring breeders, large and small zoophages, hemizoophages, forest, generalists and open area species, wingless species, hygrophilous, mesophilous and xerophilous species). The lower the ground water level, the higher was the proportion of late-successional species. Both Chao2 value and the proportion of late-successional species were growing with the increasing distance from the stream, peaking in the Pine habitat. Early-successional fauna dominated in streamside assemblages. IndVal analysis identified 1–9 characteristic species for each habitat type, mostly non-recurrent during the study period. Thus, species composition of riverine carabid assemblages should be studied for longer periods than 1–2 years to avoid accidental observations.

A method for fumigation experiments has been worked out, and preliminary tests on 21 substances are reported. The dosage-mortality relationships of about 10 of these arc being worked out in some detail, while six have been chosen for practical tests. It is hoped to make reports on these two aspects later.

Wind tunnel studies were conducted on the influence of pheromone dose and wind speed on the response behaviour of the larger grain borer, Prostephanus truncatus Horn to its male-produced aggregation pheromone. The pheromone did not increase the proportion flying and non-optimal dosages reduced flight initiation. Beetles flew at progressively lower airspeed and net upwind velocity as the pheromone dose was increased from 0.02 mg to 4 mg. Also, at the higher doses, the latency of take-off was longer. However, at the intermediate dose of 0.2 mg, take-off latency was significantly shorter, and the proportion of beetles exhibiting phototaxis at this dose was at a minimum. Wind was necessary for the beetles' orientation to pheromone, supporting the pheromone-induced anemotaxis hypothesis. Flying beetles increased their airspeed and net upwind velocity and therefore flew faster at the higher wind speeds. These results suggest that pheromone dose and wind speed are major influences on the flight behaviour of P. truncatus, and the implications of this on the interpretation of field pheromone-baited trap catch data are discussed.

The natural areas of the Coastal Plain of Rio Grande do Sul (CPRS) have suffered fragmentation due to anthropic action. The faunal surveys offer a low-cost method to quickly evaluate environmental alterations, and Syrphidae flies are often used as models in this kind of study. We aimed to ascertain the diversity of Syrphidae in the South region of Brazil by estimating its species’ richness, and to use this data to identify new areas for conservation. In this survey Malaise traps were installed for 8 days in the CPRS, which was divided into five regions. Each region was subdivided into seven collecting areas and each of those areas received four traps, totaling 140 traps. A total of 456 Syrphidae individuals from 18 genera and 49 species were collected. In Region 1, there were nine exclusive species; in Region 2, there were three; in Region 3, there were 13, ten of which came from Estação Ecológica do Taim (ESEC Taim). In the Individual-based rarefaction analysis, Region 1 possessed the largest number of expected species out of the regions in the CPRS; we found 97% of these species. This insect collection effort, as one of the first in the CPRS, has broadened the known geographic distributions of 11 species of Syrphidae, and also indicated areas to be conserved. Additionally, it gave support for expanding ESEC Taim and creating new areas of conservation in Region 1, in Arroio Pelotas and Arroio Corrientes.

The larvae of three species of bark beetle, Scolytus scolytus (F.), S. multistriatus (Marsham) and Pteleobius vittatus(F.) are described and figured. The larva of S. scolytus resembles most closely that of S. triarmatus (Eggers) but the species appear to be distinct. The larva of S. multistriatus is clearly separated from all other Scolytus larvae so far described. The larva of P. vittatus is most closely related to those of the genera Hylesinus and Leperisinus. The characters of the larvae largely support classifications based on adult morphology and anatomy.

The progress of applied Entomology is mainly visible in the discovery of practical means for the destruction of insects injurious to cultivated plants, and in the minute determination of the various stages of the growth and development of such insects. More recently the parasites of insect pests, both of vegetable and animal origin, have also largely attracted attention. But physiological research, so far as injurious insects are concerned, has almost entirely been overlooked and neglected; although this line of enquiry affords obvious opportunities for arriving at tbe very essence of the whole matter, and should indeed be made one of the main starting points in the study of insect pests.

Mites or Acari belong to the class Arachnoidea, which also contains the Scorpions, the Spiders, the minute False-Scorpions, the long-legged Field Spiders and some other curious eight-legged creatures. They are at present considered as a degenerating branch of the Arachnoid trunk. Their larvse are six-legged, their nymphs eight-legged, but deprived of genital apertures.

Apart from the Ticks (Ixodoidea), mites have been generally very much neglected by collectors and systematists alike; but seeing that they comprise a considerable number of species of undoubted economic importance, it has seemed desirable to call attention to them by this brief account of some of the more striking forms. A fuller investigation of their habits and lifehistories, especially as regards tropical species, is certain to yield much information that is likely to be of both practical value and scientific interest.

The mode of inheritance of dieldrin-resistance in Cimex lectularius L. and Pediculus h. humanus L. was investigated. The method involved the determination of dosage/mortality regression lines by exposing batches of insects to a range of dieldrin concentrations. Reciprocal crosses were made between normal (N) and resistant (R) strains of each insect, and the F1 and F2 progeny were examined for susceptibility levels over a wide range of concentrations of dieldrin. Back-crosses were made from the F1 generation to N and R strains, and the progeny were examined in the same way. In some cases, further back-crosses were made after elimination of susceptible individuals from the progeny of the first back-cross.

All the results with C. lectularius were consistent with monofactorial inheritance of dieldrin-resistance through a gene of intermediate dominance. With P. h. humanus, the results were complicated by an apparent maternal effect which caused the F1 and F2 generations from a N ♀ × R ♂ cross to be less resistant than those from a R ♀ × N ♂ cross. In general, however, the results indicated genetic segregation consistent with the same type of monofactorial inheritance as that found in C. lectularius.

Radioactive (32P) and genetic (recessive eye-colour mutation) markers were used to estimate egg to pupal survival of Musca vetustissima Walker. Both marking techniques provided similar survival estimates under laboratory and field conditions in Australia. Egg to pupal survival rarely exceeded 10% in samples at intervals during spring and summer. Abiotic (dung quality and weather) and biotic (other dung fauna) mortality agents were both important in limiting the breeding success of M. vetustissima, being jointly responsible for a seasonal mean mortality of 93·8%.

This work was commenced in 1919 and continued in 1920 and 1923. The writer's thanks are due to Prof. H. Maxwell Lefroy, who provided facilities for the carrying out of the work at Westbrook House, Heston, and showed great interest in its progress. Publication of the results has been delayed in the hope that further experiment could be made in the near future.

During recent years the number of described species of Australian Tabanidae, or March-flies, as they are almost universally called in this country, has been increased very considerably, and with this increase there has come a wider knowledge of the distribution of the various genera and species. While advancement has taken place in this direction, little progress appears to have been made towards acquiring an accurate knowledge of the life-history and habits of any of these flies, and, up to the present time, no precise information has been published concerning oviposition, larval development, feeding habits and pupation of any of our numerous species.