title: Effects of size, sex and teneral resources on the resistance to hydric stress in the tephritid fruit fly Anastrepha ludens.
abstract: Water availability is recognized as one of the most important factors in the distribution and activity of terrestrial organisms. In the case of insects, hydric stress imposes a major challenge for survival because of the small surface-area-to-volume ratio they exhibit. In general, stress resistance is expected to co-vary positively with size; however, this pattern can become obscured in insects that exhibit sexual size dimorphism, as sexes differ in size and/or shape and have dissimilar resource allocations. In the present study, we use an allometric-based approach to (i) assess the desiccation and starvation stress resistance of teneral Anastrepha ludens flies, (ii) disentangle the relationships between resistance, size and sex and (iii) examine the adult fly body differences in water and lipid contents before and after exposure to stress. After controlling for sexual size dimorphism, an allometric increase of resistance with overall size was observed for all stress-based treatments. The scaling exponents that define the proportion of increase resistance varied with size traits and with type and degree of hydric stress. In this allometric relationship, and also in the relationships between mass and wing length and between size and teneral resources, the sexes maintained similar scaling exponents but differed in the intercepts. Males were more resistant to stress than females; this competitive advantage is probably linked to greater amounts of teneral lipids and more water use during stress.
authors.affiliation: INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico. Electronic address: marco.tejeda@programamoscamed.mx.
authors.forename: M T
authors.initials: MT
authors.lastname: Tejeda
authors.affiliation: Departamento de Biología, Ecología y Comportamiento, Desarrollo de métodos, Programa Moscafrut acuerdo SAGARPA-IICA, Camino a cacahoatales S/N, CP 30860 Metapa de Domínguez, Chiapas, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Arredondo
authors.affiliation: INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico.
authors.forename: D
authors.initials: D
authors.lastname: Pérez-Staples
authors.affiliation: Laboratorio de Genética y Toxicología Ambiental & Drosophila Stock Center México, Facultad de Ciencias, UNAM, Universidad 3000 Circuito Exterior S/N, C.P. 04510 Ciudad Universitaria, Distrito Federal, Mexico.
authors.forename: P
authors.initials: P
authors.lastname: Ramos-Morales
authors.affiliation: El Colegio de la Frontera Sur, Carretera Antiguo Aeropuerto Km 2.5, CP 30700 Tapachula, Chiapas, Mexico.
authors.forename: P
authors.initials: P
authors.lastname: Liedo
authors.affiliation: INBIOTECA, Universidad Veracruzana, Av. Culturas Veracruzanas No. 101, Col. E. Zapata, CP 91090 Xalapa, Veracruz, Mexico.
authors.forename: F
authors.initials: F
authors.lastname: Díaz-Fleischer
mesh_terms: D000818:Animals; D049628:Body Size / Q000502:physiology; D003681:Dehydration / Q000503:physiopathology; D005260:Female; D008297:Male; D012727:Sex Characteristics; D033621:Tephritidae / Q000502:physiology*
keywords: Allometry; Body size; Desiccation; Sexual size dimorphism; Starvation; Tephritidae