All posts by Andrew Gutierrez

Bioeconomic analysis of olive in the Mediterranean Basin

The Mediterranean Basin is a climate change and biodiversity hot spot, and climate change threatens its agroecosystems including olive, an ancient drought-tolerant crop of considerable ecological and socio-economic importance. Climate change will impact the interactions of olive and the obligate olive fruit fly (Bactrocera oleae) and affect the economics of olive culture across the Basin. … Continue reading Bioeconomic analysis of olive in the Mediterranean Basin →

Transgenic cotton in China under ecosystem disruption

Economic analysis of chemical pesticide use has shown that the interactions between plants, pests, damage control technology and state of the ecosystem are important variables to be considered. Hence, a bio-economic model was developed for the assessment of Bt variety and pesticide-based control strategies of the cotton–bollworm in China. The model simulates plant growth, the … Continue reading Transgenic cotton in China under ecosystem disruption →

Bt cotton

Transgenic cotton expressing the genes for the production of protoxin of the bacterium Bacillus thuringiensis (Bt) is used to control lepidopterous pests. Among the most successful applications is for control pink bollworm (Pectinophora gossypiella Saunders (i.e. PBW)) in irrigated cotton of the southwestern United States. A major threat to this technology is the development of … Continue reading Bt cotton →

Colony development and dynamics of neotropical Bombus atratus

The bumblebees, a group of bees with more than 250 species worldwide, are one of the three groups of bees which show a well-developed social behavior. They are present in most of the bio geographical regions of the world, but the Ethiopian, Australian, and Oceanic. The group is especially diverse in the Paleartic and Oriental regions, and is well represented in the new world, especially in the Western Neartic and Western Neotropical regions. The group was recently organized in 15 subgenera, three of them with species in the neotropics.

New World Screwworm Analysis

The new world screwworm (Cochliomyia hominivorax (Coquerel)) was eradicated in North America, Libya and other locations using the sterile insect technique (SIT).  A physiologically-based demographic model (PBDM) was developed and used to characterize its range of year-round persistence and to examine the role of weather in its eradication. Published data on developmental times, fecundity and … Continue reading New World Screwworm Analysis →

Mediterranean Fruit Fly Analysis

The polyphagous tropical Mediterranean fruit fly (Ceratitis capitata Weid. (medfly)) was detected in California in 1975, and a large-scale detection/eradication campaign was begun in the absence of sound knowledge of the fly’s potential invasiveness and geographic distribution. Persistent measurable populations of the fly have not been found in California, but a scientific explanation for this … Continue reading Mediterranean Fruit Fly Analysis →

Grape Agro-ecosystem Analysis-Glassy winged sharpshooter

The invasiveness of the polyphagous glassy-winged sharpshooter (Homalodisca vitripennis (Germar), GWSS) using the PBDM approach. GWSS is indigenous to the southeastern United States and northeastern Mexico, and extended its range into California USA in 1989. GWSS is a vector of the pathogenic bacterium, Xylella fastidiosa (Wells et al. 1987), which causes Pierce’s disease (PD) in … Continue reading Grape Agro-ecosystem Analysis-Glassy winged sharpshooter →

Alfalfa Agro-ecosystem Analysis

The control of insect pests and other taxa may be a result of many factors that are difficult to separate and quantify. Introduced parasitoids, host plant resistance, pathogens and native predators led to the successful control of the spotted alfalfa aphid (SAA; Therioaphis maculata Monell) in California and elsewhere, although the relative contribution of each … Continue reading Alfalfa Agro-ecosystem Analysis →

Climate Change Effects on Olive Fly

Climate change is expected to alter the geographic distribution and abundance of many species. Here we examine the potential effects of climate warming on olive (Olea europaea) and olive fly (Bactrocera oleae) across the ecological zones of Arizona–California (AZ–CA) and Italy. A weather-driven physiologically-based demographicmodel was developed from the extensive literature and used to simulate … Continue reading Climate Change Effects on Olive Fly →

East African Agro-pastoral Systems with Multiple Disease Constraints

The effectiveness of international research and development efforts in Africa has been questioned on scientific, administrative and social grounds, and for the lack of conceptual models to place observed eco-social change in interpretive dimensions. To illustrate how the latter problem may be addressed, we examine the ongoing suppression of trypanosomiasis disease affecting cattle in an … Continue reading East African Agro-pastoral Systems with Multiple Disease Constraints →

Tsetse Fly Trypanosomiasis System

A key constraint for development of many East African agro-pastoral communities is African animal trypanosomiasis or nagana caused by Trypanosoma spp. and vectored by species of tsetse flies (Glossina spp.). Suppression of trypanosomiasis through trapping of tsetse fly populations was conducted from 1995 to 2005 at and near Luke, Southwest Ethiopia. Odor baited mass trapping … Continue reading Tsetse Fly Trypanosomiasis System →

Rice /Fish System in South East Asia

A modular, object oriented, multitrophic model of the mass dynamics of a tropical rice/fish pond is reported. The model includes the interactions of bacteria, blue_/green algae, small and large phytoplankton in the first trophic level; heterotrophic nanoflagellates (HNF), ciliates rotifers and cladocerans in the second; phytoplankton grazing fish (Nile tilapia, Oreochromis niloticus L.) in the … Continue reading Rice /Fish System in South East Asia →