Larval Diet Affects Male Pheromone Blend in a Laboratory Strain of the Medfly, Ceratitis capitata (Diptera: Tephritidae)

Abstract

The Mediterranean fruit fly (medfly) Ceratitis capitata is a polyphagous pest of fruits and crops with a worldwide distribution. Its ability to use different larval hosts may have multiple effects, including impacts on adult reproductive biology. The male sex pheromone, which plays a key role in attracting both other males to lekking arenas and females for mating, is a mixture of chemical compounds including esters, acids, alkanes and terpenes known to differ between laboratory strains and wild-type populations. The relationship between larval diet and adult pheromone composition remains unexplored. Here, we investigated the effect of larval diet, including laboratory media and fresh fruits, on the composition of the male pheromone mixture. Using Headspace Solid Phase Microextraction we collected the pheromone emitted by males reared as larvae on different substrates and found both qualitative and quantitative differences. A number of alkanes appeared to be typical of the pheromone of males reared on wheat bran-based larval medium, and these may be cuticular hydrocarbons involved in chemical communication. We also detected differences in pheromone composition related to adult male age, suggesting that variations in hormonal levels and/or adult diet could also play a role in determining the chemical profile emitted. Our findings highlight the plasticity of dietary responses of C. capitata, which may be important in determining the interactions of this pest with the environment and with conspecifics. These results also have applied relevance to increase the mating competitiveness of mass-reared C. capitata used in Sterile Insect Technique programs.

Sampling technique biases in the analysis of fruit fly volatiles: a case study of Queensland fruit fly

“…Kumaran et al 43 also tentatively identified only 3 amides as components of rectal glands including, N- (3-methylbutyl)acetamide, N-hexylpropanamide and N-propylbutyramide, two of which are different from those reported by Bellas and Fletcher 37 and the present study. Of these, N-(3-methylbutyl)acetamide) and N-hexylpropanamide, as well as 2-hydroxypropanamide and two propanoic acid derivatives, 2-methyl propanoic acid and 2-methylundecyl propenoate, were also reported in the volatiles released by male B. tryoni by Kumaran et al 43 Although pheromone composition may be affected qualitatively and quantitatively by larval diets 49 , the additional compounds found in the present study have most likely been overlooked previously. The ethyl and propyl esters are highly volatile and may have been lost through volatilization during extraction or trapping 50 .…”

Structural and biochemical evaluation of Ceratitiscapitata odorant‐binding protein 22 affinity for odorants involved in intersex communication

“…Sexually mature males produce a complex pheromone blend that plays a synergistic role: it attracts other males in leks, increasing pheromone concentrations that, in turn, attract females for mating (Prokopy and Hendrichs, 1979;Arita and Kaneshiro, 1989). The pheromone is a mixture of several compounds (Jang et al, 1989;Gonçalves et al, 2006;Alfaro et al, 2011;Merli et al, 2018), amongst which (E,E)-α-farnesene is one of the most abundant. Here, we provide evidence that the protein encoded by the CcapObp22 gene is an OBP involved in recognition of various medfly male pheromone components.…”

“…In C. capitata, pheromone intersex communication is mostly mediated by male emissions, with female volatile emissions being present only in trace amounts (Jang et al, 1989;Siciliano, He, et al, 2014). The pheromone is a mixture of several compounds (Jang et al, 1989;Gonçalves et al, 2006;Alfaro et al, 2011;Merli et al, 2018), amongst which (E,E)-α-farnesene is one of the most abundant. The pheromone is a mixture of several compounds (Jang et al, 1989;Gonçalves et al, 2006;Alfaro et al, 2011;Merli et al, 2018), amongst which (E,E)-α-farnesene is one of the most abundant.…”

Contribution of maternal effects to dietary selection in Mediterranean fruit flies

“…; Merli et al. ). The availability of key nutrients during early life determines characteristics such as developmental speed and survival (Nijhout ) and this has knock‐on impacts on adult traits such as body size (Nijhout ).…”

“…A large body of experimental work has documented the proximate responses of individuals to diet (House 1962;Coudron et al 2006;Boggs 2009). This has been important in defining the specific ratios of dietary components such as proteins and carbohydrates that maximize the expression of different life-history traits (Tu and Tatar 2003;Boggs and Freeman 2005;Zajitschek et al 2009;Joy et al 2010;Merli et al 2018). The availability of key nutrients during early life determines characteristics such as developmental speed and survival (Nijhout 2003a) and this has knock-on impacts on adult traits such as body size (Nijhout 2003b).…”