Growth temperature effect on mandibles' ontogeny and sexual dimorphism in the ambrosia beetle Xyleborus affinis (Curculionidae: Scolytinae). (March 2021)

• Record Type: Journal Article
• Authors: Ospina-Garcés, Sandra M.; Ibarra-Juarez, Luis A.; Escobar, Federico; Lira-Noriega, Andrés
• Is Part Of: Arthropod structure & development. Volume 61(2021)
• Publication Date: 2021-03
• Subjects: Climate change -- Geometric morphometrics -- Insect development -- Xyleborini; Arthropoda -- Morphology -- Periodicals; Arthropoda -- Anatomy -- Periodicals; Arthropoda -- Cytology -- Periodicals; Arthropods -- growth & development -- Periodicals; 595
• DOI: 10.1016/j.asd.2021.101029
• Languages: English
• ISSNs: 1467-8039

Abstract

Abstract: Ambrosia beetles from the genus Xyleborus are important vectors of fungal pathogens in forest and agricultural systems, yet the influence of temperature on their morphological development has been poorly studied. Because host colonization and ambrosial fungi cultivation is mostly restricted to females, it is possible to speculate on strong sexual dimorphism expression in secondary sexual characters and ecological segregation between sexes. Here, we determined the effect of different growing temperatures (17, 23, 26 and 29 °C) on mandible ontogeny of larvae and adult individuals of X. affinis, and sexual dimorphism in adults, in shape and size variation using geometric morphometrics. Mandible shape change showed significant differences in magnitude and direction through larval ontogeny among temperature treatments. Sexual shape and size dimorphism were found in adult mandibles, and the degree of sexual dimorphism was dependent on growth temperature, with a significant effect of the interaction between temperature and sex on mandible shape and size variation. Higher morphological differences were observed at the base of mandibles among temperature treatments in adults and a gradual narrowing trend with temperature increments. These findings could have consequences on feeding performance and fungus cultivation inside colonies, potentially influencing their ability to establish populations in new geographical areas. Highlights: Rates of shape change in mandible ontogeny of Xyleborus affinis larvae are affected by different growing temperatures. Morphological differences in X. affinis larvae related to growing temperatures may have functional implications for feeding. Adults of X. affinis show lower sexual dimorphism in mandible shape and size at the highest temperatures (29 °C).