Dead bodies still tell tales: An alternative noninvasive and nondestructive protocol to extract cuticular hydrocarbons from museum specimens

Abstract

Natural history museums represent valuable spaces for science outreach and as repositories of biodiversity data. The collections maintained in these institutions are often used as data sources for studies across various disciplines, such as ecology, phylogenetics, and population genetics. Another field that can also benefit from these resources is chemical ecology. Using insects stored in museums offers an alternative avenue for addressing new questions about the dynamics of their cuticular hydrocarbons (CHCs) with respect to different factors such as their interspecific variability, temporal stability and in chemotaxonomy. CHCs play a dual role in insects, serving as mechanical protection against desiccation and pathogens and mediators of communication processes. However, conventional extraction procedures can compromise the specimens given their invasive nature (e.g., hexane immersion approach). Here (1) we propose an alternative, noninvasive and non-destructive method to study CHCs in pinned insects from museum collections and (2) we examine the efficacy of this alternative compared to a more conventional approach for determining CHC profiles. We used two model organisms to address our goals, the Apis mellifera Linnaeus, 1758 and the Tetragonisca angustula (Klug, 1807). We were able to detect CHCs in pinned specimens from both species though there was a qualitative reduction in pinned specimens when compared to fresh ones. The observed variability may reflect confounding differences associated with sampling locality. Our results suggest that this alternative protocol can be applied to assess the CHC composition of museum specimens without causing destruction and represent an effective method to be used in studies integrating taxonomy and chemical ecology.