Genetic Similarities Among Geographic Isolates of Lysiphlebus testaceipes (Hymenoptera: Aphidiidae) Differing in Cold Temperature Tolerances

Authors

K.A. Shufran, USDAÐARS, Plant Science & Water Conservation Research LaboratoryFollow
A.A. Weathersbee III, USDAÐARS, U.S. Horticultural Research Laboratory
D.B. Jones, Oklahoma State University
N.C. Elliott, USDAÐARS, Plant Science & Water Conservation Research Laboratory

Date of this Version

2-18-2004

Citation

Environ. Entomol. 33(3): 776Ð778 (2004)

Comments

June 2004 SHUFRAN ET AL.: GENETIC SIMILARITIES IN L. testaceipes POPULATIONS

Abstract

Lysiphlebus testaceipes (Cresson) is a solitary endoparasitoid of aphids and is the primary parasitoid attacking cereal aphids in the Great Plains, especially Schizaphis graminum (Rondani). In a previous study, it was found that a Lincoln, NE, isolate of L. testaceipes had a much higher survivorship at cold temperatures than isolates from Stillwater, OK, and Corpus Christi, TX. This suggested that the Nebraska isolate was locally adapted to the northern environment and perhaps genetically divergent from southern populations. We tested for genetic differentiation of the above isolates by sequencing portions of the COI and 16S mtDNA genes. We also examined a Florida isolate reared from Toxoptera citricida (Kirkaldy) and L. fabarum Marshall as an outgroup. The Great Plains isolates (Nebraska, Oklahoma, and Texas) were homogeneous with 0% and 0Ð0.2% sequence divergence in the COI and 16S gene fragments, respectively. The Florida isolate differed from the Great Plains isolates in nucleotide sequence by 1.4% (COI) and 0.5Ð0.7% (16S). Phylogenetic analysis placed the Florida isolate of L. testaceipes basal to the Great Plains isolates with L. fabarum, suggesting a possible species complex within L. testaceipes.