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Fall armyworm (FAW)

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), has now become a pest of global concern. Originally known to be endemic to the Western Hemisphere, its first detection in Africa was followed by spectacular outbreaks and spread to almost all sub-Saharan countries. The rapid incursion of S. frugiperda on maize (Zea mays L.; Poaceae) fields in Africa highlighted a crucial need for a comprehensive assessment of integrated pest management strategies in most smallholder farms. However, these strategies cannot successfully function without efficient monitoring and surveillance efforts. These trapping studies were designed to provide an indication as to whether pheromone trap-lure combinations and simple changes in landscape and agricultural practices might mitigate fall armyworm infestations. Our data show that the commercially available Unitrap was the most effective design for fall armyworm captures among the traps tested. The inexpensive home-made 2 L jar trap was capable of consistently collecting fall armyworm during the first season of relatively moderate fall armyworm density. However, the number of fall armyworm captured by home-made trap were several fold lower than by the Unitrap under all conditions, and almost no fall armyworm was captured during the second season by home-made 2 L jar when fall armyworm density was low. Substantial differences were observed among the pheromone blends with respect to numbers of fall armyworm and non-targets captured. The 4-component blend attracted the most fall armyworm under all conditions. The 2-component blend was the most selective, with no non-target species found during the second season experiments.

The present study is the first modeling effort at a global scale to predict habitat suitability of fall armyworm (FAW), Spodoptera frugiperda and its key parasitoids, namely Chelonus insularis, Cotesia marginiventris,Eiphosoma laphygmae,Telenomus remus and Trichogramma pretiosum, to be considered for biological control. An adjusted procedure of a machine-learning algorithm, the maximum entropy (Maxent), was applied for the modeling experiments. Model predictions showed particularly high establishment potential of the five hymenopteran parasitoids in areas that are heavily affected by FAW (like the coastal belt of West Africa from Côte d’Ivoire (Ivory Coast) to Nigeria, the Congo basin to Eastern Africa, Eastern, Southern and Southeastern Asia and some portions of Eastern Australia) and those of potential invasion risks (western &amp, southern Europe). These habitats can be priority sites for scaling FAW biocontrol efforts. In the context of global warming and the event of accidental FAW introduction, warmer parts of Europe are at high risk. The effect of winter on the survival and life cycle of the pest in Europe and other temperate regions of the world are discussed in this paper. Overall, the models provide pioneering information to guide decision making for biological-based medium and long-term management of FAW across the globe.

Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) and southern armyworm (SAW) Spodoptera eridania (Stoll) have become major threats to crops in Africa since 2016. African governments adopted emergency actions around chemical insecticides, with limited efforts to assess the richness or roles of indigenous natural enemies. Field surveys and laboratory studies were conducted to identify and assess the performance of parasitoids associated with spodopterans in Cameroon. FAW was the most abundant spodopteran pest. Telenomus remus (Nixon), Trichogramma chilonis (Ishi), Charops sp. (Szépligeti), Coccygidium luteum (Cameron), Cotesia icipe (Fernandez &amp, Fiaboe), and Cotesia sesamiae (Cameron) are the first records in the country on spodopterans. Telenomus remus, T. chilonis, C. icipe, and Charops sp. were obtained from both FAW and SAW, C. luteum and C. sesamiae from FAW. The distribution of spodopterans, their endoparasitoids, and parasitism rates varied with host, season and location. In the laboratory, T. remus showed significantly higher parasitism on FAW than SAW, and significant differences in the development parameters between the two host eggs, with shorter development time on FAW. It induced significant non-reproductive mortality on FAW but not on SAW. Developmental parameters showed that C. icipe has a shorter development time compared to other larval parasitoids. Implications for conservative and augmentative biocontrol are discussed.

Lambda-cyhalothrin (&lambda, cyhalothrin) is the most commonly used pyrethroid insecticide for vegetable farming in Benin. This insecticide is misused and overused by farmers, and hence may pose health hazards to consumers. We monitored &lambda, cyhalothrin residues in lettuce and cabbage from farms at the market gates in Cotonou and Parakou using high performance liquid chromatography (HPLC) analysis techniques. These residues were also monitored on samples directly from farms (on-farm sampling) for 14 days post-treatment. Potential factors such as photolysis and hydrolysis involved in &lambda, cyhalothrin degradation were also screened. Results revealed that the level of &lambda, cyhalothrin residue concentrations in lettuce from Houeyiho decreased from 4.2 mg/kg on Day 1 to about 0.2 mg/kg on Day 7. On Day 9, analyzed lettuces were all &lambda, cyhalothrin free. In contrast, even 14 days after treatment of cabbage from Bawera (Parakou), we still recorded the presence of &lambda, cyhalothrin residues in analyzed samples. For samples from market gates, &lambda, cyhalothrin residues were found in lettuce from two markets out of the nine surveyed in Cotonou. Interestingly, none of these contaminated samples had residues above the maximum residue limit for lettuce (MRL = 0.5 mg/kg). Similarly, in Parakou, samples from all five surveyed vegetable markets were contaminated with &lambda, cyhalothrin residues at concentrations below the MRL for cabbage (MRL = 0.2 mg/kg). We conclude that &lambda, cyhalothrin residues in lettuce and cabbage from farms and markets in Parakou and Cotonou are within the MRL, and hence are relatively safe for consumption.

Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae) has constituted a well-studied parasitoid insect model, but very little is known about the host-instar suitability of aphid for the wasp so far. One of the hosts of L. testaceipes is Aphis gossypii Glover (Hemiptera: Aphididae). The latter is a serious aphid pest to vegetable production in Benin. Therefore, the objectives of our study were to: (1) examine the oviposition behavior of L. testaceipes on A. gossypii; (2) investigate the host-instar suitability of A. gossypii for L. testaceipes; and (3) compare the life table parameters of A. gossypii with aphids parasitized by L. testaceipes and unparasitized aphids (control). The study was conducted in a laboratory at 26 ± 1 °C in petri dishes and revealed that the parasitoid utilized up to seven stabbing stings to handle and oviposit, particularly in older A. gossypii. In aphids parasitized at the third instar, the net reproductive rate R o as well as the intrinsic rate of natural increase r m was significantly lower (2.119 ± 0.272 and 0.110 ± 0.018) compared to the control (15.529 ± 1.287 and 0.272 ± 0.008), respectively (p

Introduction . Small-scale banana producers in Tanzania are facing constraints caused by the destructive activities of the banana weevil (Cosmopolites sordidus Germar). Many currently used methods of addressing the problem are ineffective or too expensive for local farmers to implement. Materials and methods . A combination of two integrated pest management (IPM) tools (regular trapping in combination with field sanitation) was tested at two farmer-managed sites (Bujela and Kyimo) and one researcher-managed site (SUA-Morogoro). Treated areas were surrounded by untreated control areas where no trapping and limited sanitation was done. Changes in population densities were estimated by the mark-recapture procedure and the Lincoln index. Results and discussion . After eight months, weevil populations in the cleaned and trapped areas had been reduced by 33% (Bujela), 33% (Kyimo) and 74% (SUA). The change in population sizes in the control areas differed greatly, possibly due to discrepancies in field management between farmers’ and researchers’ practice. Trap types, areas and sites affected the number of weevils captured. Disc-on-stump (DOS) traps captured more weevils than corm disc (CD) and pseudostem (PS) traps. Weevils responded more strongly to traps in the clean area at SUA compared with the other two sites, probably because the more rigid sanitation practices at SUA meant that volatiles from the traps were less likely to be masked by volatiles from surrounding residues. Conclusion . Regular trapping with field sanitation can greatly reduce populations of banana weevils, but strict adherence to method execution is required in order to gain favourable results.

International audience; The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people.

The banana weevil Cosmopolites sordidus Germar (Coleoptera: Curculionidae) is a major pest in banana (Musa spp.) growing areas. The weevil is known to be relatively sedentary and closely associated with its host plant but little is known about the species' ability to migrate between banana fields and in nonhost habitats. 2 Mark-recapture experiments were conducted to assess the weevils' migration potential, possible differences between the sexes, and the relative attractiveness of pseudostem and pheromone baits. 3 One thousand two hundred marked weevils were released in the nonhost habitat at five distances (5, 10, 20, 40 and 70 m) from fresh pseudostem, and from pitfall traps baited with 45 mg of sordidin. 4 Two hundred males and 200 females were marked and released at five distances (5, 10, 20, 40 and 70 m) from the pheromone traps. 5 Distance and distance/bait interactions had a significant effect on recaptured weevils (binary logistic regression). The two baits were almost equally attractive to weevils in the range 0-10 m, whereas the pheromone was more attractive in the range 10-100 m. 6 Distance, bait and distance/bait interactions had a significant effect on the time elapsed from release to recapture (regression with life data) but the pattern observed was not consistent. 7 There was no significant difference between males and females with respect to distance or time elapsed from release to recapture. 8 The results obtained in the present study show that the migration potential of the banana weevil is greater than previously reported. This should be taken into account when new banana fields are established with clean planting material.

1 Based on climate data from a network of agrometeorological stations in Norway, the effects of current and future climate regimes on the spatial and temporal distribution of the Codling moth (Cydia pomonella) and the establishment potential of the Colorado potato beetle (Leptinotarsa decemlineata) were investigated. 2 The study was accomplished using climex, a dynamic climate matching- and climate response estimation model, which predicts potential distribution of an organism based on its known geographical distribution. 3 Validation of the climex model predictions for C. pomonella against field data on spatial distribution of the species in Norway resulted in a refined set of climate response parameters for C. pomonella. Temporal occurrence of C. pomonella seems to be affected by climate (temperature) and insecticide treatment against the Apple fruit moth (Argyresthia conjugella) in the previous season. 4 Climate change scenarios (0.1 °C increase per degree in latitude in daily maximum and minimum temperatures) indicated an extension of the potential geographical range for C. pomonella, and 23 new locations were found favourable for its long-term survival. The abundance and pest status of C. pomonella could increase dramatically in those locations where the species is already established. 5 Leptinotarsa decemlineata would only temporarily find suitable climate conditions in Norway and hence only be able to establish interim populations in a few regions under current climate conditions. Climate change scenarios for L. decemlineata indicated that the species would be able to establish as far north as 64°N, mainly in the inland of eastern Norway. 6 In general, the methods applied support the process of decreasing the uncertainty both in our knowledge about the pests themselves and about the environment, which are crucial elements in predicting whether a species is able to establish in a new area.

The influence of temperature on oviposition behavior, adult longevity, and fecundity on two Norwegian populations of the codling moth, Cydia pomonella (L.), was investigated within the range of 12.3–25°C. In addition, lower threshold temperatures (T0) and degree-day (DD) requirements for three egg developmental stages are given. The results showed that the Norwegian populations of C. pomonella lay eggs at lower temperatures than reported previously from other countries. Eggs were deposited in ≈40% of the containers at an average temperature of 12.3°C. However, below 15°C

The objectives of the two Norwegian Action programmes for pesticide risk reduction (1990–1994 and 1998–2002) are presented. Norwegian farmers were interviewed about their application of pesticides in different crops. Such information is important and should be updated after a few years to evaluate the current programme. The survey included 16 different crops: potato, strawberry, tomato (in glasshouses), onion, carrot and Chinese cabbage grown in the 1994 growing season; cucumber (in glasshouses), lettuce (in glasshouses and in the fields), cauliflower, cabbage and swedes grown in 1995 and broccoli, cherries and plums grown in 1996. Data on the individual use of different pesticides were obtained. The average number of applications and the total amount (kilograms of active ingredients) per hectare of fungicides, herbicides and insecticides in each crop are given.