Sustainable pest management implies less pesticide use and replacement by safe control alternatives. This requires decision support for rational pest management. However, in practice, successful decision making is dependent upon the availability of integrated, high-quality information. Computer-aided forecasting and related decision support systems make pest control more sustainable by avoiding unwanted consequences of pesticide applications. Here, I review integrated pest management for web-based decision support systems. The major points are the following: (1) Principles of integrated pest management are compatible with sustainable agriculture. (2) Pest models serve as basis of decision making because they offer means to predict the exact time of pest phenological development and initiate management actions. Most models are climate driven. (3) New hardware technology has permitted the registration of automatically recorded climatic data. This data can be combined with pest models through logical operations and forecasting algorithms to develop a software of pest management. (4) Dynamic web interfaces can serve as decision support systems providing the user with real-time pest warnings and recommendations for management actions. (5) Ontology web programing and semantic knowledge representations provide a way to classify and describe agrodata to facilitate information sharing and data exploitation over distributed systems. (6) Most available pest management data is published on static web pages and, thus, cannot be classified as decision support systems. Some web-based decision support systems provide user-interactive content and real-time pest forecasts and management support.

/pdf/modular-structure-of-web-based-decision-support-systems-for-253t957qpc.pdf

Modular structure of web-based decision support systems for integrated pest management. A review

Plastic adjustments of physiological tolerance to a particular stressor can result in fitness benefits for resistance that might manifest not only in that same environment but also be advantageous when faced with alternative environmental stressors, a phenomenon termed 'cross-tolerance'. The nature and magnitude of cross-tolerance responses can provide important insights into the underlying genetic architecture, potential constraints on or versatility of an organism's stress responses. In this study, we tested for cross-tolerance to a suite of abiotic factors that likely contribute to setting insect population dynamics and geographic range limits: heat, cold, desiccation and starvation resistance in adult Ceratitis rosa following acclimation to all these isolated individual conditions prior to stress assays. Traits of stress resistance scored included critical thermal (activity) limits, chill coma recovery time (CCRT), heat knockdown time (HKDT), desiccation and starvation resistance. In agreement with other studies, we found that acclimation to one stress typically increased resistance for that same stress experienced later in life. A more novel outcome, however, is that here we also found substantial evidence for cross-tolerance. For example, we found an improvement in heat tolerance (critical thermal maxima, CTmax ) following starvation or desiccation hardening and improved desiccation resistance following cold acclimation, indicating pronounced cross-tolerance to these environmental stressors for the traits examined. We also found that two different traits of the same stress resistance differed in their responsiveness to the same stress conditions (e.g. HKDT was less cross-resistant than CTmax ). The results of this study have two major implications that are of broader importance: (i) that these traits likely co-evolved to cope with diverse or simultaneous stressors, and (ii) that a set of common underlying physiological mechanisms might exist between apparently divergent stress responses in this species. This species may prove to be a valuable model for future work on the evolutionary and mechanistic basis of cross-tolerance.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/jeb.13201

Plasticity and cross‐tolerance to heterogeneous environments: divergent stress responses co‐evolved in an African fruit fly

For effective foraging, many insect pollinators rely on the ability to learn and recall floral odours, behaviours that are associated with a complex suite of cellular processes. Here, we investigated how acute exposure to a high-dose of diesel exhaust (containing 19.8 and 17.5 ppm of NO and NO2, respectively) affected associative learning behaviour of honey bees (Apis mellifera) and expression of a ubiquitous heat shock protein, HSP70, in their central nervous system (CNS). To determine whether exposure to diesel exhaust would alter their tolerance to a subsequent abiotic stress, we further subjected individuals to heat stress. Diesel exhaust exposure decreased honey bees’ ability to learn and recall a conditioned odour stimulus. Whilst there was no significant difference in CNS HSP70 expression between honey bees exposed to either diesel exhaust or clean air across the entire duration of the experiment (3.5 h), there was a significant effect of time and a significant interaction between exposure treatment and time. This interaction was investigated using correlation analyses, which demonstrated that only in the diesel exhaust exposed honey bees was there a significant positive correlation between HSP70 expression and time. Furthermore, there was a 44% reduction in honey bee individuals that were able to recall the odour 72 h after diesel exposure compared with clean air control individuals. Moreover, diesel exhaust affected A. mellifera in a way that reduced their ability to survive a second subsequent stressor. Such negative effects of air pollution on learning, recall, and stress tolerance has potential to reduce foraging efficiency and pollination success of individual honey bees.

/pdf/acute-exposure-to-diesel-exhaust-induces-central-nervous-24i5owru8v.pdf

Acute exposure to diesel exhaust induces central nervous system stress and altered learning and memory in honey bees

Recently, recognition of negative environmental impacts associated with overuse of pesticides in the agricultural regions of Bangladesh has made it clear that unsustainable pest-control strategies must change. Integrated Pest Management (IPM) was developed for use as a tool in the production of healthy, sustainably grown food. A strategic approach to crop-pest control, IPM aims to minimize pest populations by combining environmentally friendly pest-control methods and economically viable farming practices. This study examined the impact of IPM on insect damage to crop-yield parameters in a rice agro-ecosystem. IPM methods tested were: 1) collection of egg masses; 2) sweeping (using a funnel shaped net to capture insects); 3) perching (installing a branch or pole which serves as a resting place for predatory birds); and 4) Economic Threshold Level (ETL) based insecticide application (The ETL is the point at which the value of the crop destroyed exceeds the cost of controlling the pest). We also examined the effects of prophylactic insecticide application and current management practices on rice yield. Rice-yield indicators included number of healthy tillers, number of hills, central leaf drying (Dead Heart), and grain-less panicles (White Head). For two consecutive years, the lowest percentages of Dead Heart (1.23 and 1.55) and White Head (2.06) were found in the IPM-treated plots. Further, the IPM-treated plots had higher yields (7.3-7.5 ton/ha) compared with the non-IPM treatments (6.28-7.02 ton/ha). The location of the plots appeared to be non-significant for all measured yield components. The effect of treatment on the percentage of Dead Heart, White Head, number of hills, and yield was statistically significant (p ≤ 0.05). We concluded that IPM is an effective strategy for obtaining high rice yields in sustainable rice agro-ecosystems.

/pdf/effects-of-integrated-pest-management-on-pest-damage-and-4unvqvy4om.pdf

Effects of Integrated Pest Management on Pest Damage and Yield Components in a Rice Agro-Ecosystem in the Barisal Region of Bangladesh

Physical quality of maize grain harvested and stored by smallholder farmers in the Northern highlands of Tanzania: Effects of harvesting and pre-storage handling practices in two marginally contrasting agro-locations

Insects are powerful and rapid adaptive organisms with high fecundity rate and short life cycle. Due to human interruption in agro-ecosystem and global climatic variations are disturbing the insect ecosystem. Erosion of natural habitats, urbanization, pollution and use of chemicals in agroecosystem manifold the intensity of environmental variations. Both a-biotic (temperature, humidity, light) and biotic (host, vegetative biodiversity, crowding and diets) stresses significantly influence theinsects and their population dynamics. In response to these factors insect may prolong their metamorphic stages, survival and rate of multiplication. Insect’s immune responses as melanization,lysozyme level and phenoloxidase (PO) modify the physiology and morphological behavior against rndifferent factors like diets, gases and chemicals.

https://www.entomoljournal.com/vol2Issue2/pdf/32old.1.pdf

M. Sohail

Papers

Environmental effects on insects and their population dynamics