## 5 Cuticular Hydrocarbons
### CHs in Tehrritid Species and Their Described Roles  
Earlier comparative studies on adults of _A. ludens_, _A. suspensa_, _C. capitata_, _C. rosa_, _Z. cucurbita_ and _B. dorsalis_ failed to identify substantial sex-specific differences in CH profiles [414; 420]. It seems that the only difference detected is the much higher amount of \(n\)-alkanes in males compared to females in both _B. dorsalis_ and _Z. cucurbita_[420]. However, further research reported sex- and age-dependent differences in CH production for a laboratory population of _A. fraterculus_ (Brazilian-1 morphotype). Sexually mature males have specific unsaturated hydrocarbons (7-monoenes) on their cutictics that lack in females [90; 289]. In follow-up studies, sexual dimorphism has been evaluated in the Brazilian-1 (Argentina), Brazilian-3, Andean, Peruvian and Mexican morphotypes of the _A. fraterculus_ species complex [92; 93]. The Brazilian-1 morphotype expresses the highest sexual dimorphism (29.46%), followed by the Mexican (15.42%) and Peruvian (13.79%) ones [93]. Males and females from the five abovementioned morphotypes diverge in alkene and alkadiene content. In _A. ludens_, the age-dependent CHs production in males originated from a standard mass-reared colony, a genetic-sexing strain, a hybrid strain and a wild population has been recently described [415]. Wild males of _A. ludens_ differ from the mass-reared strains in the amount of nonacosane, while genetic sexing strain expressed higher values of 2-methylhexacosane. It has been suggested that the observed differences in CHs profiles may be due to environmental pressures [415], but additional research efforts are still needed to clarify these issue. Further research also focused on the CH composition of males and females of the African fruit fly cryptic species FAR complex, demonstrating that sex-specific differences in the CH composition do exist [214; 274]. The CH sex-specificity was proved by multivariate statistical analyses of the GC\(\times\)GC-MS data of 59 CHs identified in the epicuticular extracts of _C. capitata_, _C. fascicutris_, and _C. rosa_. In contrast, the cuticular profiles of _C. anonae_ display no sex-specificity [274]. In species of the _B. dorsalis_ complex, abundant complex mixtures of sex-specific oxygenated lipids (i.e., three fatty acids and 22 fatty acid esters) with so far unknown biological function were identified in epicuticle extracts from females [421]. Such sex \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Genus** & **Species** & **Developmental Stage** & **References** \\ \hline _Anstrepleu_ & _A. ludens_ & larvae and adults & [414; 415] \\ _A. suspensa_ & larvae and adults & [41; 414; 416; 417; 418] \\ _A. fraterculus_ & larvae and adults & [90; 93; 289; 416; 417; 419] \\ _A. acris_ & larvae & [416; 417] \\ _A. obliqua_ & larvae and adults & [417] \\ _A. serpentintia_ & larvae & [417] \\ _A. ipckii_ & larvae & [417] \\ _A. striata_ & larvae & [417] \\ \hline _Bactrocera_ & _B. dorsalis_ & larvae and adults & [414; 420; 421] \\ _B. carumelidae_ & adults & [421] \\ _B. oleae_ & adults & [422] \\ _B. tryori_ & adults & [423] \\ _B. zonata_ & adults & [422] \\ \hline _Zengodacus_ & _Z. cucurbine_ & larvae and adults & [205; 414] \\ \hline _Ceratitis_ & _C. capitata_ & larvae and adults & [274; 289; 414; 418] \\  & _C. fasciurensis_ & & [274; 289] \\  & _C. anonae_ & & [274; 289] \\  & _C. rosa_ & larvae and adults & [92; 274; 289; 414] \\ _Rugoletis_ & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 4: List of tebriritid species for which CHs have been characterised. specificity may be driven by sexual selection if the chemical composition of the cuticle is used as a pheromone signal in mate choice. Although early studies suggested that _B. dorsalis_ males are able to recognise females at short distance and that physical contact may play key roles in courtship and _copula_[424], only limited functional information are currently available.