Terellia fuscicornis (Diptera: Tephritidae): biological and morphological adaptation on artichoke and milk thistle

Abstract

The biology, morphology, and genetics of Terellia fuscicornis on cultivated artichoke and its new recorded host, Silybum marianum, are examined. Morphometrically, the two host‐associated populations were distinct. Except for egg length, all immature stages of the artichoke‐associated population were larger. Principal component analysis, based on head and wing measurements, showed that the adults from both populations clustered into two groups, with the adults reared from artichoke being larger. The ovipositor was significantly longer and blunter in the artichoke‐associated females, reflecting the larger flower heads exploited. Male terminalia measurements showed significant differences between the two populations. Several differences in courtship behaviour were detected between the two populations. Although the two populations show allochronic isolation, sequencing of two mitochondrial genes, ND1 and COI, and one nuclear gene, 18S, revealed no genetic differences between the two populations.

Keywords:

• Tephritidae
• Terellia fuscicornis
• Silybum marianum
• artichoke
• fruit flies

Acknowledgements

The authors would like to thank Mr Mohammad Al‐Zein for his valuable comments, Miss Houry Zournajian for her technical help, and Mr Emile Moacdieh for his help in flower head dissections.