Same-shape distribution model and rate summation approach are widely used to describe the insect developmental process. In this approach, by integrating a nonlinear deterministic developmental rate model and a probabilistic same-shape distribution model, the proportion of the cohort completing development is quantified as a function of accumulating developmental rates, which themselves are temperature dependent. This method is considered to be more accurate in modelling insect phenology because it can address a well-known biological fact, individual variability, that insect individual developmental rates respond to temperature differently, and because rate-summation essentially simulates developmental rates under variable temperatures instead of constant temperatures. By comparing insect development and reproduction with respect to their responses to temperatures, we argue for the extension of the same-shape and rate-summation approaches to modelling insect reproduction process under variable temperatures. We justify our arguments by the fact that individual variation universally exists in almost all biological characteristics, and the phenomenon that insect development and reproduction respond to temperature very similarly, which is supported by some endocrinological evidences reported in literature. In addition, the approach for testing the applicability of the original same-shape developmental modelling, experimentally verifying the sameness of the same-shape curves or that the shape of the curves is invariant with respect to the temperature regimes, equally applies to our extended version for reproduction modelling. We successfully tested the extension and its applicability with our experimental data of 1800 Russian wheat aphids' (RWA) (Diuraphis noxia (Mordvilko)) reproduction under various temperature and plant growth stage regimes. We also extended Taylor's (1981) nonlinear model for insect development to describe RWA mean (median) nymphal production under different temperatures and barley plant growth stages. Three same-shape distribution models, Weibull distribution, Stinner's model and logistic model, are used to construct the same-shape reproduction distribution models for RWA. The extensions performed in this paper contribute a new modelling approach for predicting insect reproduction under field variable temperatures and plant growth stages. The prediction model can be parameterized with data from typical laboratory demography experiments and further integrated into simulation models for insect population dynamics. Finally, we discussed why the sameness test of the same-shape distribution curves is sufficient in validating the approach and proposed a strategy for dealing with exceptional cases where the sameness test fails.

Diadegma semiclausum is an important parasitoid wasp and widely used in the biological control of the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous plants. Insect olfactory system is critical in guiding behaviors including feeding, mating, and oviposition, in which odorant binding proteins (OBPs) and odorant receptors (ORs) are two key components. However, limited attention has been paid to D. semiclausum olfactory genes. In this study, a transcriptome sequencing was performed on the RNA samples extracted from D. semiclausum male and female adult antennae. A total of 17 putative OBP and 67 OR genes were annotated and further compared to OBPs and ORs from P. xylostella, and other hemipteran parasitoid species. The expression patterns of D. semiclausum OBPs between male and female antennae were examined using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. Six OBPs (DsemOBP 6, 7, 8, 9, 10, and 14) demonstrated significantly higher expression levels in females than in males, which may assist in female D. semiclausum host-seeking and oviposition behaviors. This study advances our understanding of the olfactory system of D. semiclausum at the molecular level and paves the way for future functional studies aiming at increasing the efficacy to control P. xylostella by using D. semiclausum.

Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) are important pests of brassica crops, causing significant yield losses on cabbage in Ghana. To inform the development of ecologically sound and sustainable pest management strategies for these pests, their biological and population growth parameters were studied on three cabbage varieties (Oxylus, Fortune, and Leadercross). The study was conducted in a screen house under ambient conditions at 30 ± 1°C and 75 ± 5% RH and 12:12 h photoperiod from September to November 2020. The parameters of the preadult developmental period, survival rates, longevity, reproduction, and life table were evaluated following the female age-specific life table. There were significant differences in the nymphal developmental time, longevity, and fecundity on the cabbage varieties for both aphid species. The highest population growth parameters, net reproductive rate (R0), intrinsic rate of increase r, and finite rate of increase (λ) were recorded on Oxylus variety for both L. e. pseudobrassicae and M. persicae. The lowest was recorded on Leadercross variety for L.e pseudobrassicae and Fortune for M. persicae. The results from this study suggest that Leadercross is a less suitable host for L. e. pseudobrassicae and Fortune for M. persicae, thus, should be considered as less susceptible varieties for use in primary pest management by small-scale farmers or as a component of an integrated pest management strategy for these pests on cabbage.

The identity of Empoasca dolichi Paoli, a serious pest of beans and other crops in Africa, was confused. While processing a collection of leafhoppers from Malawi, E. dolichi was found mixed with other species. The identity of E. dolichi was established with reference to its type material, and two new species and a new subspecies of Empoasca from Malawi and two new species from Nigeria are described. New characters that might help specific identification and show the relationships of groups of species are also illustrated and described.

When fasting fifth-instar larvae of Rhodnius prolixus Stål were poisoned with a lethal dose of DDT, the rate of oxygen consumption increased from the onset of hyperactivity, reached a marked peak shortly after knockdown, and then declined. For some days after the peak the oxygen consumption was markedly in excess of that prior to poisoning with DDT. Eventually, the oxygen consumption fell below the pre-teatment value and continued at this low level for some days, although the insect was then undoubtedly dead and in one case had been bisected. There was no marked discontinuity in the declining phase of oxygen consumption and therefore there is no indication of when death occurred. It is concluded that the time of death in DDT-poisoned larvae of Rhodnius cannot be determined by measurements of oxygen consumption.

The total oxygen consumed from poisoning until death was always less than that consumed in the normal use of all metabolic reserves by the fasting insect, and these experiments do not support the hypothesis that death in DDT poisoning is due to total exhaustion of metabolic reserves. However, it is pointed out that, in Rhodnius, some of the metabolic reserves are contained in the undigested residue of the blood-meal and in the massive endocuticle and that there is no reason to think that either digestion of the remaining blood-meal or resorption of the endocuticle could be speeded up during DDT poisoning. Hence there is a strong possibility that, in DDT-killed Rhodnius, death is brought about by exhaustion of the available reserves.

The peak rate of oxygen consumption during poisoning was greatest in very recently fed larvae and decreased as the interval between moulting and DDT-treatment was increased. This suggests that knockdown occurs when the fuel demands of the DDT-induced activity exceed the rate at which the fuel can be mobilised from the metabolic reserves.

Observations were made in Sierra Leone from September 1949 to November 1951 on the incidence of trypanosomes in Glossina palpalis (R.-D.), in continuation of those previously reported that began in September 1948. Flies were dissected; trypanosomes found to be restricted to the proboscis were classed as Trypanosoma vivax and those found also or only in the mid-gut as T. congolense. None of the flies had infected labial glands. The whole data are presented for the sexes separately by months.

The existence of a marked seasonal variation in the incidence of T. vivax in G. palpalis is confirmed. The highest rates of infection occured in the months of heavy rain, and there was a significant inverse correlation between the monthly means of infection rate and of hours of sunshine. The cause is unknown, but possible explanations are discussed.

The older the fly, as judged by its appearance, the greater the rate of infection by both species of trypanosme; the virtual absence of infection in the youngest group of flies does not support the theory that they can only be infected when very young.

In the case of T. vivax, but not in that of T. congolense, females flies were more heavily infected than males. This may be due to larger food intake by the females, or to males, because of their more active life, appearing to be older than they are.

In our investigations on Smynthurus viridis, L., a study has been made of the population of this species, in an area of lucerne, at intervals of three and four days throughout the season.

The density of the population of the species in a favourable pasture is markedly affected by the relative abundance of certain food-plants, especially leguminous species and particularly clovers such as subterranean clover (Trifolium subterraneum) and lucerne (Medicago sativa).

The activity of the insect is intimately associated with the moisture of its environment, and the moisture content of the surface soil is one of the most important factors affecting the environmental conditions.

Considering the habits of the insect, it was felt that the sweeping method would not give a reliable record of the total population in a given area of pasture. A sample obtained by sweeping with a net does not include individuals on or near to the surface of the soil. The relative proportion of individuals situated on or near the soil surface and those situated further up the plants varies considerably from time to time, according to the meteorological conditions, the growth of the herbage and the moisture content of the surface soil. It was necessary therefore to devise a simple method by means of which a more accurate record of the total population in a given area could be obtained.

Some years ago the Entomological Department of the Swedish Forest Experiment Station was requested to undertake the investigation of the timber-destroying insects in Government buildings in Sweden. In order to obtain a preliminary survey of the amount of damage caused by these pests an illustrated leaflet containing short descriptions of the insects and their galleries was issued and, together with a detailed questionnaire and a circular letter, sent to about 7,000 persons. Altogether 2,148 reports were returned, 990 of which gave detailed information often accompanied by samples of wood for identification.

The examination of samples of Antestiopsis orbitalis (Westw.) from different parts of South Africa has shown complete intergradation between the colour patterns of the typical subspecies and that of the form facetus (Germ.), hitherto of indeterminate infraspecific status, and the latter name is suppressed. Additional localities of ocurrence are given for A. orbitalis, and Antestia rufovittata Dist. is redescribed and transferred to Antestiopsis.

The genus Sosylus includes important natural predators and parasites of ambrosia beetles (Platypodidae). Nine species of Sosylus are recorded from New Guinea (Papua New Guinea and Irian Jaya in Indonesia), and a key is provided for their identification. Five of the species, S. giluwe sp. n., S. hyweli sp. n., S. minusculus sp. n., S. morobensis sp. n. and S. reflexus sp. n., are described as new and one, S. erosus (Pasc.), is recognised as an extension to the known range of an existing species. New information is presented concerning the distribution and sexual dimorphism of the previously described species, and lectotypes are designated where necessary and feasible.

Collections recently received by the Imperial Bureau of Entomology, chiefly from Natal, have brought to light several interesting new forms in this group of flies, and their study has yielded certain unlooked for results which it appears desirable to place on record, together with descriptions of the new species, the types of which have been presented by the Bureau to the British Museum. The opportunity has been taken of publishing revised keys to the African species of Banksinetta and Taeniorhynchus.

A few larve of Tabanus fasciatus niloticus were obtained on 4th March 1925 near Renk, on the White Nile, their habitat being the Nile cabbage (Pistia stratiotes, Linn.). They were by no means common, a search of a couple of hours yielding but seven specimens. They were lying submerged in the water, supported on the bases of the lower leaves in such a position that their caudal respiratory siphons could be extended to reach the surface of the water, and never more than a single larva occurred on an individual plant. In appearance they were typical Tabanid larvae, except as regards colour ; the normal colour is white to yellowish, but the larvae in question were bright green, similar to the green of the leaves among which they were situated. They were placed in a glass jar with water, plant débris and some Nile cabbages, and taken to Khartoum, the journey occupying ten days. When the contents of the jar were examined in Khartoum two larvae were recovered and removed each to a test-tube containing a roll of filter-paper and water. They fed readily on earthworms.

In connection with his biological researches for the control of the coffee mealy-bugs in Africa, Mr. R. H. Le Pelley recently made a trip to the Far East in order to try to find some Oriental parasites of Pseudococcus lilacinus which could be introduced into Kenya Colony.

The type form of Aëdes (Stegomyia) aegypti (L.) is widespread in southwestern Nigeria, breeding in the basins of rotting tree stumps in the coastal mangrove swamp, in holes in living trees in the freshwater swamp zone and near Lagos and in domestic containers restricted to village clearings in the inland forest zone. Pot surveys were carried out in a rain forest village 50 miles north-west of Lagos and in the capital itself. Baked clay pots holding half a gallon of water were used in each case and were placed in three situations, inside houses, outside but in otherwise sheltered positions, and in fully exposed positions. The degree of larval infestation in both cases was greatest inside houses, but the behaviour pattern was less domestic in Lagos. Larvae were found in pots contaminated with decaying vegetable matter in Lagos but not in the village. Spraying tests indicated that houses and foliage afforded varying degrees of protection to the immature stages of the mosquito. Control of this species is made difficult by the localisation of the immature stages in relatively inaccessible sites and it is suggested that individual treatment of larval habitats by insecticidal pellets before the commencement of the rainy season would ensure a high mortality of first-generation larvae. The toxicity hazard to man is not considered to be great. The development of resistant and wild populations is discussed.

Oviposition was investigated in five strains of Aedes aegypti (L.), two being DDT-resistant (from Trinidad (STR) and Haiti) and three susceptible (two from West Africa and one (AS) from U.S.A.). Strains were compared with respect to their oviposition at sites illuminated at two levels (0·02 and 6·5 lumens per sq. ft.), each site being composed of a strip of moist white paper and an approximately equal area of open water set against a dark background.

Oviposition on the water surface was consistently less at the lower level of illumination. Generally the moist white paper was preferred by all strains, but oviposition on the water surface was practised more readily by strain AS than by the others, and differences between certain strains (including AS and STR) were significant.

Mass crosses and back-crosses were performed between strains AS and STR. The results were in close agreement with the hypothesis that laying on open-water surfaces is controlled by a genetic system in which there is no dominance.

The frequency of oviposition on an open-water surface was not correlated with two other characteristics (oviposition time and oviposition light preference) that have been investigated in these five strains, nor with DDT resistance.

Doses of 40, 80, 120, and 160 Gy were applied to 5-, 6-, 7-, and 8-day-old Anastrepha obliqua larvae, which were exposed to the Neotropical-native braconids Doryctobracon crawfordi and Utetes anastrephae and the Asian braconid Diachasmimorpha longicaudata. These tests were performed to know the effect of the increase in host radiation on the emergence of the aforementioned parasitoids and the related consequences of oviposition on the host. The study was based on the fact that higher radiation doses may cause a decrease in the host immune activity. There was a direct relationship between the increase in radiation dose and the parasitoid emergence. Both, the weight and the mortality of the host larvae were not affected by radiation. Although the larval weight of the larvae was lower and the mortality was higher in the younger larvae. Both, the number of scars and immature stages per host puparium originated from the younger larvae were lower than those from older larvae. Only U. anastrephae superparasitized more at lower radiation. Superparasitism by D. longicaudata was more frequent at 160 Gy. Qualitative measurements of melanin in the larvae parasitized showed that the levels were lower with increasing radiation. As radiation doses increased, the antagonistic response of the A. obliqua larva was reduced. Host larvae aged 5- and 6-day-old irradiated at 120–160 Gy significantly improve parasitoid emergence. This evidence is relevant for the mass production of the three tested parasitoid species.

The raspberry cane midge Resseliella theobaldi (Barnes) is one of the most important pests of cultivated red raspberry Rubus idaeus L. throughout Europe. For the last 50 years several studies have been made on the biology, life cycle and control of the pest. Some data can also be found on its natural enemies, but among these species only the chalcidoid Tetrastichus inunctus Nees turned out to be important in controlling raspberry cane midge populations. However, this species name is now ambiguous as the type is lost. In the present study, Aprostocetus epicharmus Walker was the chalcidoid species that parasitized the larvae of the raspberry cane midge, and its biology seems to be very similar to that of T. inunctus. It is therefore probable that the eulophid species earlier referred to as T. inunctus in the literature is A. epicharmus. Besides discussing this problem, particular consideration and detailed data are given on the biology and life cycle of A. epicharmus in relation to R. theobaldi. Different factors having effect on the population dynamics of both species are also discussed as results of a survey on several red raspberry cultivars, carried out in Hungary between 2002 and 2005.

Triatomine bugs carry the parasitic protozoa Trypanosoma cruzi, the causal agent of Chagas disease. It is known that both the parasite and entomopathogenic fungi can decrease bug survival, but the combined effect of both pathogens is not known, which is relevant for biological control purposes. Herein, the survival of the triatomine Meccus pallidipennis (Stal, 1872) was compared when it was coinfected with the fungus Metarhizium anisopliae (Metschnikoff) and T. cruzi, and when both pathogens acted separately. The immune response of the insect was also studied, using phenoloxidase activity in the bug gut and hemolymph, to understand our survival results. Contrary to expectations, triatomine survival was higher in multiple than in single challenges, even though the immune response was lower in cases of multiple infection. We postulate that T. cruzi exerts a protective effect and/or that the insect reduced the resources allocated to defend itself against both pathogens. Based on the present results, the use of M. anisopliae as a control agent should be re-considered.

The cereal rust mite, Abacarus hystrix, is one of the most notable among mites causing losses in cultivated grasslands. It is one of a few eriophyoid species for which a broad host range has been reported. Recent studies, however, have shown that host specialization is very likely in this species. For two populations of A. hystrix (one inhabiting perennial ryegrass, the second inhabiting quackgrass), host-associated differences correlated with strong host fidelity, distinct phenotypes and reproductive barriers have been found. In the present study, the ability of wheat colonization by quackgrass- and ryegrass-adapted cereal rust mite was studied. The hypothesis that the potential for wheat colonization by the quackgrass strain is more likely was tested by comparing the colonization performance (assessed by female survival and fecundity) of quackgrass- and ryegrass-associated A. hystrix on their familiar hosts and on wheat. The ryegrass population had no success in wheat colonization (expressed by extremely low fecundity and female survival). Fecundity and survival of quackgrass strain were similar on wheat and the familiar host, or even higher on wheat. Phylogenetic similarity of quackgrass and wheat is discussed as a possible factor that might influence such patterns of host colonization. Since A. hystrix is the only vector of the ryegrass mosaic virus (RgMV), the presented results may be helpful in explaining the inability of RgMV to successfully infest wheat. The conclusions are that (i) quackgrass- and ryegrass-adapted strains of the cereal rust mite have different physiological host ranges and (ii) phylogenetic relationships between host plant species appear to be drivers for host specialization in this mite species.

There are six strains of the complete genomic sequences of black queen cell virus (BQCV) published in the GenBank, including South Africa (AF183905), South Korea (JX149531), Hungary 10 (EF517515), Poland 4 (EF517519), Poland 5 (EF517520) and Poland 6 (EF517521). Based on the six BQCV strains published in the GenBank, ten pairs of primers were designed in the present study using reverse transcription polymerase chain reaction to obtain the first complete genome sequence of a BQCV strain in China, called the BQCV China-JL1 strain (KP119603). A phylogenetic tree was then built to analyse their genetic relationships. The BQCV China-JL1 strain showed 86–93% similarity with the six strains published in the GenBank. The BQCV China-JL1 strain consisted of 8358 nucleotides (nt). The 5′-proximal open reading frame (ORF1) initiated at nt position 546 and terminated at nt position 4676, ORF3 initiated at nt position 4891 and terminated at nt position 5433, and the 3′-proximal ORF (ORF2) was located between nt positions 5750 and 8203.