Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) develops in chestnut buds that remain asymptomatic from oviposition (June–July) until budburst; it is, thus, easily spread by plant material used in propagation. Therefore, it is particularly interesting to identify infested plant batches before their movement. Unfortunately, a non-destructive method for checking buds has not yet been developed, and the only technique available is the screening of a bud sample. The visual investigation is long and requires highly skilled and trained staff. The purpose of this work was to set up an effective and fast method able to identify the presence of first instar larvae of D. kuriphilus in a large number of chestnut buds by PCR. Four primer pairs were designed on nuclear and mitochondrial sequences of a set of seven gall wasp taxa and tested on five different cynipid's DNA. Nested diagnostic PCR was carried out on DNA extracted from samples of 2 g buds simulating four levels of infestation (larvae were added to uninfested buds); 320 bp amplicon of 28S sequence was chosen as a marker to detect one larva out of 2 g buds. The method showed a potential efficiency of 5000 to 15,000 buds per week, depending on bud size.

Implementation of the sterile insect technique for tsetse (Glossina spp.) requires that only sterile male insects be released; thus, at some stage of the fly production process the females have to be removed. A further constraint in the use of the sterile insect technique for tsetse is that the females are needed for colony production and hence, a non-destructive method of sex separation is required. In most tsetse sterile insect technique programmes thus far, females have been eliminated from the released material by hand-separation of chilled adults. Using near-infrared (NIR) spectroscopy, significant differences have been found between the spectra for the pupae of male and female G. pallidipes Austen. Significantly, the differences appear to be maximized 4–5 days before emergence of the adults. Tsetse fly pupae up to five days before emergence can be sexed with accuracies that generally range from 80 to 100%. This system, when refined, will enable effective separation of male and female pupae to be carried out, with emerged females being returned to the colony and males being irradiated and released. If separation can be achieved five days before emergence, this will also enable irradiated male pupae to be shipped to other destinations as required. Other Diptera were evaluated using this system but had lower classification accuracies of 50–74%. This may be due to the difference in reproductive physiology between these different fly groups.

Estimations have been made of the weight of material accumulated by adults of Phormia (Protophormia) terraenovae R.-D. from deposits of DDT and other lipophilic particles on different types of substrate on which the flies were exposed.

Uptake of dry DDT particles is shown to be similar to that of dry lipophilic dye particles of similar size so that conclusions on the contamination of insects by dry lipophilic dyestuff may be extended to contamination by DDT dust.

The presence of oil greatly reduces the uptake of DDT particles from a fibrous substrate, the uptake decreasing logarithmically with increase in the amount of oil applied to the substrate. The viscosity of the oil has no more than a very small effect on the uptake of lipophilic particles from oily deposits and the solubility of the particles in the oil has no significant effect.

A reduction in the uptake of dry lipophilic particles from filter paper and from a hard, waxy substrate occurs when a wetting agent solution is applied immediately before the particles. When the particles are applied after the drying of the wetting agent on the substrate, a reduction in uptake also occurs on the non-absorbent, waxy surface, but is not so large as when the particles are applied before drying of the wetting agent. No reduction in uptake occurs on the absorbent substrate under these conditions.

On the basis of the experimental results the variations in the adhesion of lipophilic particles to substrates are discussed.

While differences in the affinity of particles for substrates of different types cause variations in adhesion, the physical structure of the surface may be more important in determining the amount picked up from it. The presence of oil or wetting agent on the surface increases adhesion, probably by increasing both the affinity of the lipophilic particles for the substrate and the area of contact between the particles and the substrate.

Adults of Zonocerus variegatus (L.) collected in southern Nigeria in January to May 1963 were found to be parasitised by larvae of Blaesoxipha filipjevi Rohd. Of 1,691 adults of Z. variegatus dissected, 43 contained from one to six larvae of B. filipjevi, but none was found in 167 nymphs dissected mostly in January and February. No parasites were found in 155 examples of 11 other locally occurring species of Orthoptera. Full-grown larva left their hosts through the cervical membrane; they pupated within 48 hours, probably in the soil in natural conditions, and the adult Sarcophagid emerged 9–10 days later. No larva was observed to undergo diapause. The presence of the parasite restricted the ovarian development of the female host, but the species is considered to be of negligible importance in the control of Z. variegatus because of its low incidence.

Forty five species, two subspecies and one variety of Culex occur in the Sudan.

Taxonomic notes are given on a few species, and new localities, mainly for the subgenus Culex, are recorded. The known distribution of all species of this subgenus is shown on maps.

Several aspects of distribution are discussed, and there is a short section on practical importance.

The spatial dispersion patterns of larvae of the Palaearctic mosquito Aedes cantans (Meigen) were studied in two temporary woodland pools in England, between 1988 and 1990. Variance to mean ratios indicated that all larval instars were aggregated, but the degree of aggregation differed between ponds and between years, depending on the population density. The negative binomial model was found to fit the majority of the data, and the values for the parameter k varied between 0.05 and 0.96. Taylor's power law gave a good fit to the data with values of b, an index of aggregation, varying between 1.42 and 1.91. Iwao's patchiness regression yielded values for α between –1.63 and 6.92, and β from 1.49 to 3.25. These values indicate that the population is aggregated due to habitat heterogeneity, and younger instars may demonstrate a propensity to congregate with one another. A relationship between water temperature and mean number of larvae sampled at each transect point was observed in Pond One in 1989, suggesting that larvae aggregate where water temperatures are higher.

Ninety-nine and 476 clones of Myzus persicae (Sulzer) were sampled on tobacco at Kyoto (Shimogamo) (1996–2000) and at 23 other localities (1998–1999) in Japan, respectively. The clones were classified into colour-esterase forms, distinguished by combinations of body colour and electrophoretically detectable esterases, to verify the changes in genotypic composition during the past two decades. Fifteen and 31 colour-esterase forms were found at Kyoto (Shimogamo) and at 23 other localities, respectively. Fourteen (representing c. 95% of the total clones sampled) and 24 (c. 44%) colour-esterase forms, respectively, were different from those found on tobacco during 1978–1985. The frequency of the green form and the very highly insecticide-resistant form increased. More than half of the colour-esterase forms found in the present survey were newly detected. The factors associated with these changes are discussed.

Records of daily catches of males of Spodoptera littoralis (Boisd.) at pheromone traps in or near the Nile Delta, Egypt, during 1979 and 1980 were used to investigate both the seasonal variation in catch and the possibility that migration, associated with particular weather systems, may significantly affect moth numbers in a particular area. Although more moths were caught in 1979 than in 1980, in both years there was a similar seasonal variation in catch, with low numbers in January and February followed by an increase to a maximum in June or August. There was no systematic seasonal change in the area of highest catch that would suggest seasonal migrations. On some nights, large increases in catch were associated with weather disturbances, notably windshift lines, suggesting that flying moths are sometimes redistributed by wind systems. Catches at two traps far from the main source area suggest that moths may have flown at least 50 km downwind from sources in the Nile Delta. The pattern of nightly catches at most traps indicated that build-up of local populations is the most important factor affecting the population dynamics of the pest but that some, mainly local, redistribution by wind systems takes place.

A laboratory evaluation of growth, food consumption and food utilisation by larvae of Spodoptera littoralis (Boisd.) was made from the beginning of the fifth instar to the prepupal stage on cabbage, cotton, kenaf and Congo jute (Urena lobata). Growth, measured by daily larval fresh weight, was highest on cabbage and similar on kenaf, Urena and cotton. Development was fastest on cabbage and slowest on cotton and Urena. Larvae underwent an extra moult on the latter two food-plants. Weight gain was highest on cabbage, followed by cotton, Urena and kenaf, in that order. Total food consumption was highest on cotton and lowest on kenaf and Urena. Cabbage was most efficiently digested, followed by kenaf, cotton and Urena, in that order. Digestive efficiency on all four plants declined with larval age. The efficiency of conversion of ingested food to body material was highest on cabbage and lowest on cotton and kenaf. Digested portions of Urena were most efficiently converted to body substance while digested portions of cabbage and kenaf were most inefficiently converted to body material. It is concluded that S. littoralis is better adapted to cabbage than any of the other three plants and that increasing cultivation of cabbage in Ghana is likely to enhance the pest status of the insect.

The optimum size range of particles of two carbamates and two organophosphorus compounds in deposits on plywood and plaster for contact toxicity to blood-fed females of Anopheles stephensi List, was 5–30 µm. The effect of particle size on the contact toxicity of these compounds of high intrinsic toxicity was not great and in this respect resembled that found previously for dieldrin and γBHC. In the few tests done, the concentration of active ingredient in wettable powder formulations was not an important factor in determining the contact toxicity of deposits of such toxic materials.

Feeding by adults of Neochetina eichhorniae Warner on water hyacinth, Eichhornia crassipes, significantly increased the hardness of the lamina of the youngest leaf and the petioles of the youngest three leaves, while the moisture content of the petioles and laminae was significantly reduced. However, variations in leaf hardness did not significantly affect feeding by the weevils, and leaf age was considered to have a greater effect. The results help explain field observations of the relative abundances of N. eichhorniae and the pyralid Sameodes albiguttalis (Warren), which also attacks water hyacinth.

Pretreatment of first instar larvae of 28 resistant strains of Lucilia cuprina(Wiedemann) with the inhibitor of microsomal oxidases, piperonyl butoxide, resulted in a biphasic response to the phosphorothioate insecticide diazinon. Analysis of the data revealed a complex response in which both synergist-dependent and independent effects occurred. The responses varied markedly from strain to strain. A laboratory susceptible strain and field strains with resistance factors of less than 20-fold exhibited, in the presence of piperonyl butoxide, an increased LC50 with respect to diazinon whereas those strains with > 20-fold resistance were synergized by the compound. We conclude tentatively that microsomal mixed-function oxidases play a contributory role in the development of resistance and that the variation in synergist effect from strain to strain may be attributed, at least in part, to the two-fold effect of these enzymes on phosphorothioate insecticides such as diazinon.

A trade-off is a relationship between two life history characteristics principally reproduction and adult longevity that are fundamental in predicting the optimal life history in any given environment. Mating is indispensable for sexual reproduction, but also can impose risks to females. Nevertheless, in the majority of insects, females allow multiple mating. Dichelops furcatus (Hemiptera: Pentatomidae) is a pest of wheat and corn in Argentina and southern Brazil, but little is known about its reproduction (i.e., the characteristics of the process that results in offspring). We analyzed reproductive attributes of D. furcatus, and the effect of single mating vs. multiple matings, evaluating the trade-off between fecundity and adult female longevity. We found that mating is not required for D. furcatus to oviposit, and multiple copulations were costly in terms of reduced longevity. Although multicopulated females lived a shorter period, only the pre- and post-reproductive periods were shortened. Fecundity was not affected but fertility was incremented in multicopulated females. Females copulated only once oviposited most of the eggs in the first half of the reproductive period, while eggs oviposited in the second half were all inviable (did not hatch). Studying demographic attributes of phytophagous insects provides relevant information to better understand the population dynamics of pests.

Agriculture is one of the major farming activities, representing 32% of the gross domestic product of Madagascar and 74.3% of the population is involved in this activity. Fruit flies of the Tephritidae family are considered as the most destructive pests for agriculture in the country, nevertheless, few data exist on host plants and distribution of those pests. In the present study, we address those questions by conducting a large survey between November 2016 and July 2018 across the six agroecological regions of Madagascar. Fruit and vegetable were sampled from 198 plant species (wild and cultivated) and represented 37,965 fruits from all regions of Madagascar. The infestation index ranged from 0.06 to 538.46 pupae/kg, the infestation percentage was up to 54.84% in some samples, 63 plant species were considered as host of Tephritidae. Twelve fruit fly species were identified, seven of which were previously described as endemic, five species could be considered as widespread (altitudinal gradients between 1 and 1634 m asl) and major pests in Madagascar: Ceratitis malgassa (23 plant species from 12 families), Neoceratitis cyanescens (16 plant species from one family), Bactrocera dorsalis (18 plant species from 12 families), Dacus demmerezi (ten plant species from one family), Dacus vertebratus (six species from one family). Those results are of importance for implementation of control measures.

Environmental temperature is an important driver of the population dynamics of tsetse (Glossina spp) because the fly's immature stages are particularly vulnerable to temperatures (T) outside the range T = 16–32°C. Laboratory experiments carried out 50 years ago provide extensive measures of temperature-dependent rates of development, fat consumption and mortality in tsetse pupae. We improve on the models originally fitted to these data, providing better parameter estimates for use in population modelling. A composite function accurately models rates of pupal development for T = 8–32°C. Pupal duration can be estimated by summing the temperature-dependent daily percentage of development completed. Fat consumption is modelled as a logistic function of temperature; the total fat consumed during pupal development takes a minimum for T ≈ 25°C. Pupae experiencing constant temperatures <16°C exhaust their fat reserves before they complete development. At high temperatures, direct effects kill the pupae before fat stores are exhausted. The relationship between pupal mortality and temperature is well described by the sum of two exponential functions. Summing daily mortality rates over the whole pupal period does not reliably predict overall mortality. Mortality is more strongly correlated with the mean temperature experienced over pupal life or, for T ≤ 30°C, the fat consumption during this period. The new results will be particularly useful in the construction of various models for tsetse population dynamics, and will have particular relevance for agent-based models where the lives of individual tsetse are simulated using a daily time step.

In a study of the incidence of funnel ants (Aphaenogaster spp.) on the Atherton and Evelyn Tablelands of northern Queensland in 1959–61, 422 farms were surveyed, totalling over 98,000 acres of pasture, of which 10.8 per cent. proved to be infested with A. pythia Forel. The ants damage the introduced pasture grasses (Paspalum dilatatum and Pennisetum clandestinum) by removing soil from around their roots to from loose mounds, which smother the closely-grazedsward. Inferior species of grass and deep-rooted weeds are thus encouraged and affected areas become useless for dairying.

The natural habitat of A. pythia is wet sclerophyll forest which occurs in narrow belts fringing the rain forest and in pockets within it; the rain forest does not harbour the ant, but following its clearance and its replacement by pastures, A. pythia has spread out and colonised the latter. In areas of lower annual rainfall (under 50 in.) occupied dry sclerophyll forest and Eucalyptus woodland, A. pythia is replaced by A. longiceps F. Smith. Improved pastures have not been established here, but in the relatively restricted areas of infestation by this species, the large funnel-shaped orifices of its mounds create a hazard to stock.

Australoglypta latrobei gen. et sp.n., an ichneumonid parasitic on the larvae of the tortricid Epiphyas postvittana (Wlk.) in Australia, is described and compared with related genera. The mating and oviposition behaviour of the ichneumonid is noted, and its abundance over 13 generations of E. postvittana between 1972 and 1976 was investigated. A delayed inverse (density-dependent) relationship was found to exist between host and parasite. Possible beneficial effects of this parasite are discussed.

The diurnal flight activity of Simulium griseicolle Becker was determined at Shambat, Khartoum, by means of a suction trap and a vehicle-mounted trap; and the biting activity by means of a chicken-baited trap. Only incidental observations of mammal-biting activity were made. The three trapping methods indicated two peaks of activity, one in the morning and the other late in the afternoon. Fly activity was lowest in the early afternoon when temperature and light intensity were highest, wind speed was moderate and relative humidity was least. Females outnumbered males in all the catches, except in the early morning when more males were sometimes recorded.

The North American and European maize pest Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) was used to assess whether conditions of the natal field, subsequent laboratory rearing, or genetic population origin affect phenotypic traits of fitness, activity, or morphometrics. Standardized laboratory bioassays with large sample sizes revealed that none of the 16 tested traits, except crawling behaviours, appeared consistently stable across all seven tested colonies. Environmental conditions in the natal field of the F0 generation affected trait averages of the subsequently reared F1 generation in laboratory in ca. 47% of cases, and trait variability in 67% of cases. This was apparent for fitness and morphometrics, but less obvious for activity traits. Early generation laboratory rearing affected trait averages in ca. 56% of cases: morphometrics changed; fecundity and egg survival increased from F1 to F2. Trait variability increased or decreased in 38% of cases. Laboratory rearing for over more than 190 generations affected the trait averages in 60% of cases, reflected by decreases in flight activity and increases in body size, weight, and fecundity to some extent. It had little effect on trait variability, especially so for morphometric variability. The genetic population origin affected average levels of 55% and variability of 63% of phenotypic traits. A comparison among D. v. virgifera studies might be difficult if they use different populations or laboratory colonies. It is advised to consider possible effects of original field conditions, laboratory rearing, and population genetics when planning comparative studies targeting fitness, activity, or morphometric questions regarding Diabrotica species.

Nowadays, the sterile insect technique is broadly used as a pest control measure. Therefore, the present study was conducted to investigate the alteration occurred in testes and DNA pattern as an effect of inherited sterility. Full grown pupae of the wax moth, Galleria mellonella were irradiated with 80 and 160 Gy of γ irradiation. The size of the testes was decreased by increasing of γ irradiation dose. Also, the size of the testes was decreased in F1 males comparing with the size of the testes of both the parents and the untreated control. The effects of γ rays on the DNA patterns of adult male parents and F1 males showed alterations among the controls, the treated parents and F1 individuals. Exposure to radiation caused very frequently the appearance of some extra bands and the deficiency of others in the arbitrary random amplified polymorphic DNA-polymerase chain reaction amplification patterns of the irradiated insects.