A regional analysis of weather mediated competition between a parasitoid and a coccinellid predator of oleander scale

Abstract

Análise Regional da Competição Mediada por Fatores Climáticos entre um Parasitóide e um CoccinelídeoPredador da Cochonilha-da-Espirradeira na Califórnia and a coccinellid predator (Rhysobius lophanthae (Blaisd.) (Coleoptera: Coccinellidae), was examined using a general weather-driven, tri-trophic, physiologically based age-mass structured demographic model. The model is of intermediate complexity and was parameterized using extensive laboratory data and fi eld observations from Albany, CA. Temperature-dependent physiological indices were estimated from the laboratory data and used to scale per capita growth, fecundity and survivorship rates from maximal values in a time varying environment. The tri-trophic model was integrated in a GIS (geographic information system) and the species dynamics examined across years and across the ecological zones of California. Field data and simulation results suggested the coccinellid predator was the most important regulating agent of oleander scale in the mild climate of Albany. However, multiple linear regression analysis of simulation data across all ecological zones of California shows that the parasitoid A. chilensis is the most important agent in suppressing oleander scale densities in warmer climates, while the predator R. lophanthae increases scale density an average of 9.7% across all regions.

Towards an improved understanding of the dynamics of vineyard‐infesting Scaphoideus titanus leafhopper populations for better timing of management activities

“…In Vansickle's time‐varying distributed delay model, cohorts pass through a series of cascaded delay substages whose number controls the degree of stochasticity in the developmental process 36, 37. During the past three decades, time‐distributed delay models have found a wide application in pest forecasting systems and in demographic ecosystem studies 38–40. The subsequent section deals with the basic elements only, and the reader is referred to the recent work of Gutierrez,40 Holst and Ruggle,41 Alilla et al ,42 Gutierrez and Baumgärtner,43 Severini44 and Gama et al 45 for additional explanations and applications.…”

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate

“…Direct or indirect climatic influences on the host scale insects or the parasites are important factors in the natural enemy's effectiveness because the dynamics of the same species may vary considerably under different weather regimes (Huffaker et al 1971, Huffaker and Gutierrez 1990, Rochat and Gutierrez 2001. The influence of weather on control by natural enemies has been described for the olive scale (Parlatoria oleae (Colve´e)) (Rochat and Gutierrez 2001), the oleander scale Aspidiotus nerii (Bouche) (Gutierrez and Pizzamiglio 2007), and other scale parasite associations. …”

Climate change effects on poikilotherm tritrophic interactions

“…Similar effects will occur in other biological systems (olive; Gutierrez and Pizzamiglio 2007). Including the interactions between species as altered by their differing responses to weather (and climate change) addresses the criticisms of the 'climate envelope' approach (Davis et al 1998).…”