Search

The invasive Asian citrus psyllid (Diaphorina citri Kuwayama) is the vector of the bacterial pathogen ('Candidatus Liberibacter asiaticus') that is the putative causal agent of citrus greening disease (Huanglongbing disease) in citrus in many areas of the world. The capacity to predict the potential geographic distribution, phenology and relative abundance of the pest and disease is pivotal to developing sound policy for their management. A weather-driven physiologically based demographic model (PBDM) system was developed to summarize the available data in the literature, and used to assess prospectively the geographic distribution and relative yield of citrus, the relative densities of the psyllid, its parasitoid (Tamarixia radiata Waterston), and the potential severity of citrus greening disease in North America and the Mediterranean Basin. The potential for natural and biological control of citrus psyllid was examined prospectively. [ABSTRACT FROM AUTHOR]

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., 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., 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 ()., 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., 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., 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. [ABSTRACT FROM AUTHOR]

Abstract: This paper is the second of three on the coffee production system consisting of (1) the coffee growth and development, (2) coffee/coffee berry borer (CBB) dynamics, and (3) the role of the CBB parasitoids and complementary strategies for control of CBB. The CBB model is based on a prior model by Gutierrez et al. (1998) with the following modifications: Refinements of the CBB model were made and the model linked to a revised plant model for coffee (Rodríguez et al., 2011). Several mortality factors for CBB and the effect of intraspecific competition were estimated and their importance evaluated. CBB parameters were updated based on recent literature and field observations. The effects of temperature and rainfall on the emergence of CBB adults were added. A nonlinear rate of development function was used to calculate daily degree-days to estimate accurately the effects of temperature extremes on CBB development. New field data from Colombia were used to test coffee fruiting phenology and the effect on CBB attack rates and age-structure population dynamics. CBB preferences for the coffee berry stages were estimated for cv. Colombia. [Copyright &y& Elsevier]

This paper is the first of three on the coffee production system consisting of (1) the coffee plant, (2) coffee berry borer (CBB) and (3) the role of CBB parasitoids. A previous simulation model of the coffee plant was developed using data from Brazil where coffee phenology is characterized by distinct seasonal flowering (). In contrast, flowering in Colombia is continuous with low seasonality. To capture the differences in coffee phenology and growth in the two climatic regions, the model was modified using new data from Colombia. The modifications to the model include: [(1)] The effect of solar radiation on floral buds initiation; [(2)] An age structure population model to track the daily input and development of the floral buds; [(3)] The effect of leaf water potential on breaking dormancy in flower buds, and hence on the timing and intensity of flowering; [(4)] The incorporation of both the vegetative and the reproductive demands to predict the photosynthetic rate. [(5)] The effect of low temperature on photosynthesis and defoliation. Other aspects of the model were re-interpreted and refinements made to generalize its structure for use across coffee varieties and geographic areas. The model, without modification, realistically simulates field data from Brazil and two Colombian locations having different varieties, patterns of rainfall and hence flowering phenology. The model will be used as the base trophic level for incorporating CBB and high tropic levels effects, and for the analysis of management options in the coffee production system. [Copyright &y& Elsevier]