Bollettino del Laboratorio di Entomologia Agraria (2000) 56, 33-41

Fulvio Baldanza and Massimo Giorgini (2000)
Karyotype and NOR localization differences between Encarsia formosa Gahan and Encarsia luteola Howard (Hymenoptera: Aphelinidae)
Bollettino del Laboratorio di Entomologia Agraria 56, 33-41
Abstract: Basic karyotaxonomic survey started on closely related parasitoid species Encarsia formosa Gahan and Encarsia luteola Howard (Hymenoptera: Aphelinidae), revealed the presence of chromosomal differences both in their morphometric traits such as relative length and Centromeric Index and in active nucleolus organizer regions (NORs) localization. The two karyotypes show the same diploid number (2n=10), but different formulae. E. formosa (2n=6m+2sm+2st) reveals a more asymmetric set with a large first metacentric pair and couple 2 beeing submetacentric. E. luteola (2n=8m+2st) shows no submetacentric couple and the first metacentric pair is only slightly larger than the second one. Besides, the nucleolus organizer region located in pericentromeric position on the couple 2 in E. formosa, shifts on the small arm of the last subtelocentric chromosome pair in E. luteola. These differences reveal the occurrence of some rearrangements between the genomes of the two species, such as inversions and translocations. The observed karyotype differences provide suitable cytotaxonomic markers useful for the distinction of the two species which in some cases cannot be easily separated by classical morphological characters alone.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Massimo Giorgini, Fulvio Baldanza

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
identification/taxonomy

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Trialeurodes vaporariorum		Italy
Encarsia formosa (parasitoid)	Trialeurodes vaporariorum		Italy
Encarsia luteola (parasitoid)			Italy