title: Influence of Temperature on Intra- and Interspecific Resource Utilization within a Community of Lepidopteran Maize Stemborers.
abstract: Competition or facilitation characterises intra- and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15°C, 20°C, 25°C and 30°C) in an incubator. The experiments involved single- and multi-species infestation treatments. Survival and relative growth rates of each species were assessed. Both intra- and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops).
authors: International Centre of Insect Physiology and Ecology, Nairobi, Kenya.|Unit of Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
authors: Eric Siaw
authors: ES
authors: Ntiri
authors: International Centre of Insect Physiology and Ecology, Nairobi, Kenya.|UMR IRD 247 Laboratoire Evolution, Génomes, Comportement et Ecologie, Diversité, Ecologie et Evolution des Insectes Tropicaux, CNRS, Gif-sur-Yvette, France and Université de Paris-Sud, Orsay, France.
authors: Paul-Andre
authors: PA
authors: Calatayud
authors: Unit of Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
authors: Johnnie
authors: J
authors: Van Den Berg
authors: Postfach 508, Chur, Switzerland.
authors: Fritz
authors: F
authors: Schulthess
authors: International Centre of Insect Physiology and Ecology, Nairobi, Kenya.|UMR IRD 247 Laboratoire Evolution, Génomes, Comportement et Ecologie, Diversité, Ecologie et Evolution des Insectes Tropicaux, CNRS, Gif-sur-Yvette, France and Université de Paris-Sud, Orsay, France.
authors: Bruno Pierre
authors: BP
authors: Le Ru
mesh_terms: D017954:Africa South of the Sahara; D000818:Animals; D057231:Climate Change; D018556:Crops, Agricultural / Q000469:parasitology; D017753:Ecosystem; D006790:Host-Parasite Interactions; D007814:Larva / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology; D007915:Lepidoptera / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology*; D000067936:Natural Resources; D018547:Plant Stems / Q000469:parasitology; D013045:Species Specificity; D013696:Temperature; D003313:Zea mays / Q000469:parasitology*