Gianni Gilioli

Prospective analysis of the invasive potential of the European grapevine moth Lobesia botrana (Den. & Schiff.) in California

1 The polyphagous European grapevine moth Lobesia botrana (Den. & Schiff.) is the principal native pest of grape berries in the Palearctic region. It was found in Napa County, California, in 2009, and it has subsequently been recorded in an additional nine counties, despite an ongoing eradication programme. The present study aimed to assess prospectively its potential geographical distribution and relative abundance in California and the continental U.S.A. A subsidiary goal was to provide explanation for timing control measures. 2 Data from the European literature were used to formulate and parameterize a holistic physiologically‐based demographic model for L. botrana. This model was linked to an extant mechanistic model of grapevine phenology, growth and development that provides the bottom‐up effects of fruiting phenology, age and abundance on L. botrana dynamics. Fruit age affects larval developmental rates, and has carryover effects on pupal development and adult fecundity. Also included in the model were the effects of temperature on developmental, survival and fecundity rates. 3 Observed daily weather data were used to simulate the potential distribution of the moth in California, and the continental U.S.A. The relative total number of pupae per vine per year was used as the metric of favourability at all locations. The simulation data were mapped using grass gis (http://grass.osgeo.org/). 4 The model predicts L. botrana can spread statewide with the highest populations expected in the hotter regions of southern California and the lower half of the Central Valley. In the U.S.A., areas of highest favourability include south Texas, and much of the southeast U.S.A. 5 The effects of a warmer climate on pest abundance were explored by increasing observed mean temperatures 2° and 3 °C. L. botrana abundance is expected to increase in northern California and in the agriculturally rich Central Valley but to decrease in the hot deserts of southern California where summer temperatures would approach its upper thermal limit. 6 Analysis of the timing of mating disruption pheromone for control of L. botrana suggests the greatest benefit would accrue by targeting adults emerging from winter diapause pupae and the flight of first summer adults.

A lumped parameter model for acarine predator-prey population interactions

Abstract We hereby describe a modelling strategy, based on the implementation of composite models for the numerical simulation of the predator–prey local dynamics. We define a lumped parameter model for the dynamics of the system, where the abundance of the populations are given in terms of their biomass. The model is characterised by bio-ecological parameters (maximum specific rates and conversion factors) and by two functions: the specific growth rate of the prey in absence of predator, and the specific rate of predation, called trophic function. We consider prey growth rates which take into account either undercrowding and overcrowding effects, or only overcrowding effects. We also consider trophic functions depending either on the prey abundance, or on the ratio of the abundance of prey and predator. The responses of the model to different prey growth rates and trophic functions are investigated. Procedures are given for estimating the lumped parameters by means of demographic models of a single species population with stage structure, and formulated in terms of individual life history data. The methodology is applied to a case study of biological control of an acarine population system. Numerical experiments have been performed to illustrate the behaviours of the model with different prey growth and trophic functions. Results of numerical simulations are compared to the dynamics obtained in field experiments.

Adaptive Ecosocial System Sustainability Enhancement in Sub-Saharan Africa

A conceptual framework is developed and used for improving the livelihood of Sub-Saharan communities faced with multiple stresses resulting from adverse environments, vector-transmitted diseases, and limited food. Ecosocial systems are the units for management. The accumulation of ecological, economic, and social capital is the objective of management, the reduction of maintenance costs is the key strategy, and technologies must satisfy ecological, economic, and social criteria. Interacting social system components are communities, facilitators, scientists, and political as well as administrative organizations. An adaptive approach to management allows flexibility in human and financial resource allocation and results in changes in knowledge and efficacy of management operations. The implementation strategy at two sites in Ethiopia relies on a two-stage procedure. In Stage 1, human and cattle health management set the conditions for development. In Stage 2, the ecosocial system is kept on a trajectory to enhanced ecological, economic, and social capital. In each stage, the assignment of responsibilities leads to four implementation phases. In Stage 1, successful precision targeting of tsetse and drug-based Trypanosoma spp. control increased the economic and social capital at the Luke site in southwestern Ethiopia but threatened the ecological capital because of overstocking and land degradation. In Stage 2, a women’s group living in the outskirts of Addis Ababa (Ethiopia) transformed barren land into a horticultural enterprise to enhance ecosystem service provision, including production of horticultural goods, and increase soil fertility expressed by nutrients and water availability. This article reviews concepts on human livelihood improvement in Sub-Saharan Africa and identifies principles that became important during project execution.

Sensitivity of Anopheles gambiae population dynamics to meteo-hydrological variability: a mechanistic approach

BackgroundMechanistic models play an important role in many biological disciplines, and they can effectively contribute to evaluate the spatial-temporal evolution of mosquito populations, in the light of the increasing knowledge of the crucial driving role on vector dynamics played by meteo-climatic features as well as other physical-biological characteristics of the landscape.MethodsIn malaria eco-epidemiology landscape components (atmosphere, water bodies, land use) interact with the epidemiological system (interacting populations of vector, human, and parasite). In the background of the eco-epidemiological approach, a mosquito population model is here proposed to evaluate the sensitivity of An. gambiae s.s. population to some peculiar thermal-pluviometric scenarios. The scenarios are obtained perturbing meteorological time series data referred to four Kenyan sites (Nairobi, Nyabondo, Kibwesi, and Malindi) representing four different eco-epidemiological settings.ResultsSimulations highlight a strong dependence of mosquito population abundance on temperature variation with well-defined site-specific patterns. The upper extreme of thermal perturbation interval (+ 3°C) gives rise to an increase in adult population abundance at Nairobi (+111%) and Nyabondo (+61%), and a decrease at Kibwezi (-2%) and Malindi (-36%). At the lower extreme perturbation (-3°C) is observed a reduction in both immature and adult mosquito population in three sites (Nairobi -74%, Nyabondo -66%, Kibwezi -39%), and an increase in Malindi (+11%). A coherent non-linear pattern of population variation emerges. The maximum rate of variation is +30% population abundance for +1°C of temperature change, but also almost null and negative values are obtained. Mosquitoes are less sensitive to rainfall and both adults and immature populations display a positive quasi-linear response pattern to rainfall variation.ConclusionsThe non-linear temperature-dependent response is in agreement with the non-linear patterns of temperature-response of the basic bio-demographic processes. This non-linearity makes the hypothesized biological amplification of temperature effects valid only for a limited range of temperatures. As a consequence, no simple extrapolations can be done linking temperature rise with increase in mosquito distribution and abundance, and projections of An. gambiae s.s. populations should be produced only in the light of the local meteo-climatic features as well as other physical and biological characteristics of the landscape.

Occupancy of the territory by Lymantria dispar (L.) (Lepidoptera Erebidae) egg masses as a predictive index of damage

(*) Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy (**) Istituto per lo Studio degli Ecosistemi, Consiglio Nazionale delle Ricerche, Traversa la Crucca 3, 07100 Sassari, Italy (***) Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy (°) Corresponding author: Roberto Mannu, e-mail: roberto.mannu@ise.cnr.it

Implementation of a socio-ecological system navigation approach to human development in Sub-Saharan African communities

This paper presents a framework for the development of socio-ecological systems towards enhanced sustainability. Emphasis is given to the dynamic properties of complex, adaptive social-ecological systems, their structure and to the fundamental role of agriculture. The tangible components that meet the needs of specific projects executed in Kenya and Ethiopia encompass project objectives, innovation, facilitation, continuous recording and analyses of monitoring data, that allow adaptive management and system navigation. Two case studies deal with system navigation through the mitigation of key constraints; they aim to improve human health thanks to anopheline malaria vectors control in Nyabondo (Kenya), and to improve cattle health through tsetse control and antitrypanosomal drug administration to cattle in Luke (Ethiopia). The second case deals with a socio-ecological navigation system to enhance sustainability, establishing a periurban diversified enterprise in Addis Ababa (Ethiopia) and developing a rural sustainable social-ecological system in Luke (Ethiopia). The project procedures are briefly described here and their outcomes are analysed in relation to the stated objectives. The methodology for human and cattle disease vector control were easier to implement than the navigation of social-ecological systems towards sustainability enhancement. The achievements considerably differed between key constraints removal and sustainability enhancement projects. Some recommendations are made to rationalise human and cattle health improvement efforts and to smoothen the road towards enhanced sustainability: i) technology system implementation should be carried out through an innovation system; ii) transparent monitoring information should be continuously acquired and evaluated for assessing the state of the system in relation to stated objectives for (a) improving the insight into the systems behaviour and (b) rationalizing decision support; iii) the different views of all stakeholders should be reconciled in a pragmatic approach to social-ecological system management. Significance for public health Recently, there is a growing interest in studying the link between human, animal and environmental health. The connection between these different dimensions is particularly important for developing countries in which people face the challenge of escaping vicious cycle of high diseases prevalence, food insecurity driven by absolute poverty and population growth, and natural capital as a poverty trap. The design and implementation of such efforts, aiming at human health improvement and poverty alleviation, should be framed into adaptive social-ecological system management perspectives. In this paper, we present few case studies dealing with human health improvement through anopheline malaria vectors control in Kenya, cattle health improvement through tsetse vectored nagana control, antitrypanosomal drug administration to cattle in Ethiopia and with the development of rural sustainable communities in Ethiopia. Some recommendations are given to rationalise human and cattle health improvement efforts and to smoothen the road towards enhanced sustainability.

The effects of triflumuron against the western flower thrips (Frankliniella occidentalis (Pergande)) on pepper: an evaluation based on the analysis of population dynamics

Abstract:  The population response of western flower thrips, Frankliniella occidentalis (Pergande) to triflumuron, growth regulator of the benzoyl‐phenyl‐urea group which performs a chitin‐inhibiting action, was the subject of an experimental field test. The characteristics of the active ingredient (knock‐down effect, temporal persistence and overall effect of the substance) were assessed in comparison with the responses of two synthetic insecticides (methiocarb, chlorpyrifos‐methyl) and in relation to the different treatment strategies (number and dates of treatments). The results of the experimental tests were analysed using a specially developed innovative method, which allows to evaluate precisely and in quantitative terms the response of the system (modification in the population dynamics of thrips) to the treatment carried out. The observations performed highlight that, at the considered doses, triflumuron is characterized by a weak knock‐down effect but by good temporal persistence which makes it a product endowed with a distinct larvicidal activity. Furthermore, its action is better overall than that of chlorpyrifos‐methyl and is comparable with that of methiocarb.