Prediction of insect pest distribution as influenced by elevation: Combining field observations and temperature-dependent development models for the coffee stink bug, Antestiopsis thunbergii (Gmelin)

Abstract

The antestia bug, Antestiopsis thunbergii (Gmelin 1790) is a major pest of Arabica coffee in Africa. The bug prefers coffee at the highest elevations, contrary to other major pests. The objectives of this study were to describe the relationship between A. thunbergii populations and elevation, to elucidate this relationship using our knowledge of the pest thermal biology and to predict the pest distribution under climate warming. Antestiopsis thunbergii population density was assessed in 24 coffee farms located along a transect delimited across an elevation gradient in the range 1000–1700 m asl, on Mt. Kilimanjaro, Tanzania. Density was assessed for three different climatic seasons, the cool dry season in June 2014 and 2015, the short rainy season in October 2014 and the warm dry season in January 2015. The pest distribution was predicted over the same transect using three risk indices: the establishment risk index (ERI), the generation index (GI) and the activity index (AI). These indices were computed using simulated life table parameters obtained from temperature-dependent development models and temperature data from 1) field records using data loggers deployed over the transect and 2) predictions for year 2055 extracted from AFRICLIM database. The observed population density was the highest during the cool dry season and increased significantly with increasing elevation. For current temperature, the ERI increased with an increase in elevation and was therefore distributed similarly to observed populations, contrary to the other indices. This result suggests that immature stage susceptibility to extreme temperatures was a key factor of population distribution as impacted by elevation. In the future, distribution of the risk indices globally indicated a decrease of the risk at low elevation and an increase of the risk at the highest elevations. Based on these results, we concluded with recommendations to mitigate the risk of A. thunbergii infestation.

Temperature‐dependent development models describing the effects of temperature on the development of Spodoptera eridania

“…Numerous studies have demonstrated the influence that temperature exerts on the development and survival of insects 7,14,39 . Yet, because the response of insects to temperature is species‐specific, studies about the effect of temperature on insect biology are still relevant, particularly for agricultural and forest pests due to their application in pest management and prediction of species distributions under current and projected climate conditions using mechanistic or hybrid models 8,40–42 . In this context, knowledge of the thermal thresholds of insect pests may help in understanding the risks of a given species spreading to regions outside its native range.…”

Climate Change Effects on Trophic Interactions of Bark Beetles in Inner Alpine Scots Pine Forests

“…Generally, the density of these insects and their herbivory, particularly on tree host species, are thought to decrease at higher elevations because of temperature constraints on herbivore development and reproduction [67][68][69]. However, in several studies, the opposite pattern or an intermediate optimum elevation for density and herbivory have been reported [70][71][72]. These discrepancies in phloeophagous as well as phyllophagous species emphasize the decisive role of host plant susceptibility as affected by e.g., water supply [54] and potentially of natural enemies [14] for herbivores in general.…”

Temperature-dependent development and survival of immature stages of the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae)

“…Although insects do not develop at a constant temperature in nature, development models obtained from laboratory studies provide useful information on their thermal biology, such as thermal thresholds. As such, they help understand and predict the pest distribution and population dynamics in plantations according to temperature (Tonnang et al, 2013;Azrag et al, 2018). To the best of our knowledge, the only study that adopted a similar approach for H. hampei is that of Jaramillo et al (2009).…”

“…As poikilotherm animals, insects depend primarily on the temperature of their environment to develop (Régnière et al ., 2012). Pest distribution and population dynamics, therefore, can be largely predicted by running temperature-dependent models of development (Tonnang et al ., 2013; Azrag et al ., 2018). These tools also provide standard life history traits such as temperature thresholds and thermal constant that characterize the relationships between insect development and temperature (Wagner et al ., 1991; Nielsen et al ., 2008; Azrag et al ., 2017).…”