A further drawback is that the chemicals are hazardous to farm workers and adversely affect biodiversity conservation, particularly natural enemies resulting in outbreaks of new pests and contamination of water and soils, but also pollinators potentially resulting in decreased fruit set. Due to these drawbacks, it has been suggested that farmers should increase resources for field sanitation.Sprays infused with the fungus B. bassiana have been reported as an effective control agent of CBB adults. Using B. bassiana as a stand-alone method of control was questioned by Hollingsworth et al. The infection rates in the field depend on climatic conditions and strain of the pathogen, with mortality rates ranging from 17.7% at a concentration of 106 conidia/ml to 40.6% at a concentration of 109 conidia per plant, though Bustillo reported mortality as high as 75%. Te spores must come in contact with the beetles, and hence are most infective on new adults emerging from host berries or during the initial phases of fruit penetration. Infection by Metarhizium anisopliae has a similar etiology, with reported infection rates ranging between 22.1% and 43.1%.Several studies have reported the use of parasitoids for control of CBB, and their biology were well documented and modeled by Gutierrez et al. and Rodríguez et al.. The bethylids Cephalonomia stephanoderis, C. hyalinipennis and Prorops nasuta enter the CBB gallery to attack the immature stages. In contrast, round pot the eulophid Phymastichus cofea parasitize female CBB adults as they are burrowing into the coffee berry.

Results of Rodríguez et al. show that C. hyalinipennis, interacts negatively with the other betilids and provides poor control of CBB, and this argues against its introduction, and hence was not considered here. The present work explores only the performance of C. stephanoderis, P. nasuta and P. cofea.Bioeconomics is the study of the economics of renewable resource acquisition and allocation applicable to all trophic levels. In human economies, harvesting of renewable resources occur via the economic system. Econometric marginal analysis is best done with extensive field data, but such data may be difficult to collect and is prohibitively expensive . However, simulation data generated by a well parameterized, field validated mechanistic models can provide a highly suitable alternative because the results can be compared to limited field data. Our PBDM system developed to simulate the growth and development of coffee, the dynamics and infestation levels of coffee berry borer and the action of four parasitoids of CBB is based on extensive data and provide a very suitable platform for including the effects of cultural practices such as harvest , cleanup of abscised berries and the time intervals between these activities, and the effects of sprays of insecticide and of bio-pesticides of two fungal pathogens and two nematode parasites. Our simulation results for Colombia explain the average reduction of<15% by parasitoids, entomopathogens, and chemical control. Additionally, antagonistic effects among these control tactics were found. For example, harvesting and cleanup affected the action of CBB parasitoids, P. nasuta and P. cofea increasing CBB infestation levels. Specifcally, positive coefficients for the interactions PnˑH, PcˑH and PcˑCU indicate detrimental effects to parasitoid efficacy of harvesting and cleanup because parasitoid life stages are also removed from the system, resulting in lower future CBB parasitization rates.

The incompatibility between cultural control and parasitoids was also found by Gutiérrez et al. and Aristizábal et al.. Similar antagonistic effects were found for harvests and cleanup with sprays of pathogenic fungi and cultural practices as indicated by the positive sign interactions of BbˑH and BbˑCU. Bustillo reports that sustained efficacy of the pathogen B. bassiana in the field is strongly associated with the production of spores from field infected CBB, but harvest and cleanup remove these inoculum sources. Another significant antagonistic effect identified for Colombia was the interaction of the eulophid parasitoid P. cofea and B. bassiana . In laboratory studies, Castillo et al. found that exposure to B. bassiana caused mortality rates of 100% in P. cofea immature stages and a reduction of 22% in adult longevity which reduces parasitoid efficacy. Chemical control also affects the efficacy of P. cofea as indicated by the positive interaction PcˑC. This occurs because unlike the bethylid parasitoids that enter the berry, P. cofea female are entirely free living and attacks CBB females initiating penetration of coffee berries making them susceptible to insecticides. Despite some detrimental effects on biological control agents, periodic harvest of fruit and clean up were found to be the major control practice reducing CBB infestation levels in both Colombia and Brazil, with the efficacy of the practice decreasing as the time between harvests and cleanup increased from 15 to 60 days. The analysis for Colombia suggests that cleanup is the second most important control strategy for reducing the level of infestations. These simulation result agrees with Johnson et al., who found that ground and tree raisins lef after harvest, could be the main CBB reservoir in the inter-crop season in Hawaii. The results for these cultural practices also agree with field studies of Duque and Cháves who found that>94% of Colombian farmers participating in a survey considered cultural control to be the most important method for reducing CBB populations. Bustillo et al. found that periodic harvesting reduced CBB populations up to 80%, with Benavides et al. and Aristizábal et al. in Colombia and Aristizábal in Hawaii, reporting that periodic harvests at 15 day was the main method for reducing CBB populations, and for generating higher yield and income. Unfortunately, producers have a checkered record of implementation cultural control tactics, as Aristizábal et al. found that only 45% were applying periodic harvest according to the criteria proposed by Bustillo et al.. Gutierrez et al. found for Brazil that harvesting and cleanup had little impact on control because at harvest most berries were infested, the females inside fruits were near the end of their reproductive life, and most adult progeny had emerged. However, as in Colombia, harvesting was the most important factor reducing CBB infestation. In summary, harvesting and cleanup at 15-day intervals is the only control tactic that significantly reduces CBB infestation level in Colombia and Brazil. Aristizabal et al. analyzing the cost of harvesting and cleanups in Hawaii, remarked that while initially the cost appears to be high, in the final analysis, sanitation pays the cost of labor and processing, while reducing the source of the pest.

That study for Hawaii and the study of Benavides et al. for Colombia, shows that harvesting and cleanup can be economically feasible. However, it may not be economic in Londrina, Brazil which is at the southern climatic limits of coffee production, with short dry periods followed by short periods of rain throughout the year, resulting in the production of susceptible berries over a longer period than in Colombia. This fruiting phenology has a strong impact on the dynamics of the system and on CBB control as shown by our PBDM results. Te socio-economic conditions differ in various coffee growing regions, the fuctuation of prices in the international market can vary widely , and infestation levels have an important impact on coffee yield and price. Hence, in economic analyses, control tactics must enter not only as cost, but also as price enhancing attributes. For example, round plastic planter effective CBB control based on sustainable periodic harvesting could be an important element in promoting and positioning select coffees on the international markets as unique, organic, and highest quality. To this end, an in-farm mixture of shade grown, and sun grown coffees using organic cultural practices to control CBB has been proposed as a sustainable option for coffee production on small to medium properties. In conclusion, our model is a realistic virtual crop system that provides a very useful general tool for investigating aspects not readily amenable to field experimentation and has the capacity to integrate more layers such as a socio-economic one. This tool can also be used to examine new technological opportunities prior to their wide adoption. For example, CBB control may be affected by disrupting the symbiotic bacteria in CBB’s microbiome responsible for caffeine breakdown. Another tactic is the development of attractants that are more competitive with the activeness of coffee berries; a tactic that could be especially important because coffee flowering phenology varies widely throughout the world in response to regional climate patterns that influences the phenology and dynamics of CBB infestation and the success of progeny development. Climate change, including climate variability, must be considered as this may change extant regional dynamics of both coffee and CBB, and their interactions. Increased temperature may generate conditions favorable for coffee and CBB allowing range extensions to new areas, and changes in CBB damage levels in its current geographical distribution. Increased dry “El Niño” climatic events in some countries could increase CBB populations, while “La Niña” events with prolonged wet seasons would limit CBB populations. The effects of such phenomena differ across geographical region, and the coffee/coffee berry borer system model provides a framework for analyzing the potential effect of variation in weather, climates and of climate change on coffee yield, and the dynamics of CBB across diverse bio-geographical zones. As an aside, the high pest status of this species in monocultures is a consequence of an evolutionary background, similar to what have been observed in other systems . From the prospective of the ecological theory, the large female bias appears to have had high adaptive value in the African tropical forest where it evolved so that large numbers of the small females with low searching rates could find scattered patches of suitable age berries. This adaptation would appear to occur at the expense of reduction in genetic variability caused by sib-mating and reported pseudo-arrhenotoky. As a final note, our C. arabica PBDM can easily be modified to include other species of coffee , and has transferability enabling its use in a bio-economic analysis on larger, albeit global scale, and in the face of climate change.The polyphagous Asian vinegar fly Drosophila suzukii is a native of Eastern and Southeastern Asia , and emerged as an important invasive insect pest of wild and domesticated berries and stone fruits in the Americas and Europe in the late 2000s . D. suzukii was detected in Hawaii in 1980 and was first found in California in 2008 . Its biology and dispersal were reviewed extensively by Asplen et al. , but unanswered questions remain as to why the pest rapidly expanded its range. Models are commonly used to find explanation for the extant and potential range expansion of invasive species such as D. suzukii. For example, a degree-day model for D. suzukii phenology was developed for the Pacific areas of the USA and Canada , and Damus produced a MaxEnt ecological niche model to predict its range . Demographic models incorporating the effects of temperature were developed by Wiman et al. using data from Tochen et al. to serve as the basis for pest management of the fly. Langille et al. report a well done mechanistic site specific model that relies in part on the preliminary mechanistic physiologically-based demographic model reported by in Asplen et al. by A.P. Gutierrez and L. Ponti . Scientific consensus expressed by the Intergovernmental Panel on Climate Change indicates that ecological niche models, when used to assess climate effects on biological systems, have important shortcomings, among which are a lack of physiological mechanisms and the inability to account for population processes. PBDMs circumvent many of these problems as they are a mechanistic summary of the available information on the weather driven biology of species such as D. suzukii . In this paper, we update the PBDM introduced in Asplen et al. and use it to assess the geographic range and relative abundance of D. suzukii across much of North America , Europe and the Mediterranean Basin. The focus of the analysis is on areas of recent invasion and of predicted high invasiveness. Biology of D. suzukii. Like other Drosophila species, D. suzukii has multiple generations per year , but does not have a true diapause stage, and overwinters as ‘‘reproductively quiescent’’ long-lived melanized winter morph adults . Jakobs et al. found an absence of additional cold tolerance imparted by developmental plasticity, and that adults are chillsusceptible and are killed by exposure to low temperatures. In contrast, Toxopeus et al. and Shearer et al. found that acclimated winter morph adults have enhanced cold tolerance. Furthermore, winter survival of adults is enhanced in natural refuges and around built structures .