Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters











Database
Language
Publication year range
1.
Bull Entomol Res ; 93(6): 561-7, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14704103

ABSTRACT

The genus Diabrotica includes a large number of pest species, including some of the most important crop pests of the Americas. The parasitoid Centistes gasseni Shaw is the first braconid to be described parasitizing Diabrotica in South America, and high natural infestations are reported. Field and experimental observations on the host range, distribution and biology of this parasitoid are described. Centistes gasseniwas collected in southern Brazil, eastern Paraguay and northeastern Argentina, in a region comprising humid lowlands and highlands, and cool temperate to warm subtropical climates, with regular rainfall in excess of 1300 mm. Three Diabroticaspecies, D. limitata (Sahlberg), D. speciosa (Germar) and D. viridula (Fabricius) were found to host the parasitoid, with mean percent parasitism of 5.4, 2.0 and 1.0%, respectively. Diabrotica speciosa and D. viridula are the two most important pest Diabroticaspecies in South America. Laboratory experiments with field-collected beetles and parasitoid cocoons indicated that C. gasseni overwinters in adult host beetles, remaining dormant in its live host below developmental temperatures. A potential distribution of C. gasseni in North America is proposed based on its known climatic range and the distribution of the main pest species of adult overwintering North American Diabrotica.


Subject(s)
Coleoptera/parasitology , Hymenoptera/physiology , Animals , Climate , Demography , Female , Host-Parasite Interactions , Hymenoptera/growth & development , Male , North America , South America
2.
Biochem Genet ; 34(7-8): 253-68, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8894048

ABSTRACT

Restriction endonuclease analyses of mitochondrial DNA (mtDNA) were used to examine genetic variability and population structure in Leptinotarsa decemlineata (Say). A group of three enzymes, EcoRI, HpaI, and PstI, was used to reveal polymorphism both within and among some of the 10 populations tested, yielding 16 haplotypes in combination. The frequencies of these 16 haplotypes differed significantly across geographic regions, indicating some partitioning of mtDNA haplotypes. Estimates of mtDNA sequence divergence (delta) between haplotypes ranged from 0.016 to 0.135%, suggesting local differentiation of mtDNA in some populations. Analysis of these data suggests that Texas was colonized by more than one mtDNA lineage, most likely originating in Mexico. We hypothesize that a larger founder size for the initial introductions or high levels of variability in the parent population at the edge of the CPB expanding range led to the initial partitioning of haplotypes observed in samples from Texas.


Subject(s)
Coleoptera/genetics , DNA, Mitochondrial/genetics , Genetic Variation , Animals , Coleoptera/classification , DNA Restriction Enzymes , Haplotypes , Species Specificity , United States
SELECTION OF CITATIONS
SEARCH DETAIL