Esterase polymorphism in the corn earworm, Heliothis zea (Boddie): A survey of temporal and spatial allelic variation in natural populations

1975 ◽  
Vol 13 (11-12) ◽  
pp. 885-898 ◽  
Author(s):  
Douglas K. Sell ◽  
Gregory S. Whitt ◽  
W. H. Luckmann
Keyword(s):  
Allelic Variation ◽  
Heliothis Zea ◽  
Natural Populations ◽  
Corn Earworm ◽  
Esterase Polymorphism ◽  
Temporal And Spatial

Observations on the Emergence of Adults from Natural Populations of Corn Earworm, Heliothis zea (Boddie) (Lepidoptera: Noctuidae)1

1988 ◽  
Vol 17 (2) ◽  
pp. 254-258 ◽  
Author(s):  
P. D. Lingren ◽  
W. B. Warner ◽  
J. R. Raulston ◽  
M. Kehat ◽  
T. J. Henneberry ◽  
...  
Keyword(s):  
Heliothis Zea ◽  
Natural Populations ◽  
Corn Earworm ◽  
Lepidoptera Noctuidae

ENZYME POLYMORPHISM IN THE CORN EARWORM, HELIOTHIS ZEA (LEPIDOPTERA: NOCTUIDAE). HEMOLYMPH ESTERASE POLYMORPHISM

1974 ◽  
Vol 106 (7) ◽  
pp. 701-709 ◽  
Author(s):  
Douglas K. Sell ◽  
Gregory S. Whitt ◽  
Robert L. Metcalf ◽  
Lu-ping Kan Lee
Keyword(s):  
Host Plant ◽  
High Frequency ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Heliothis Zea ◽  
Enzyme Polymorphism ◽  
Corn Earworm ◽  
Environmental Pressures ◽  
Esterase Polymorphism ◽  
Lepidoptera Noctuidae

AbstractEsterases present in the hemolymph of last instar Heliothis zea (Boddie) were separated by polyacrylamide gel electrophoresis. Four systems, all polymorphic, were observed. One system, Est-II, appeared especially suited for the study of some of the important population processes of this species; these include host–plant relations, migration, and the effects of environmental pressures such as pesticides on the species.Est-II was classified as a carboxylesterase, being sensitive only to organophosphate inhibitors. Dichlorvos at 10−5M completely inhibited Est-II activity.Populations collected from corn from Tifton, Ga., and in two locations in Illinois, at approximately the same time were very similar genetically when compared on the basis of Est-II allele frequencies. A population collected from leguminous hosts in Tifton, Ga., at the same time as the above three populations was different genetically.Est-IIc, an allele normally rare or absent in the populations studied, was present at a high frequency in one Urbana population collection. Est-IIc may be useful in studying the long-range dispersal of H. zea.

scholarly journals Nucleotide sequences of highly repeated DNAs; compilation and comments

1982 ◽  
Vol 39 (1) ◽  
pp. 1-30 ◽  
Author(s):  
George L. Gabor Miklos ◽  
Amanda Clare Gill
Keyword(s):  
Satellite Dna ◽  
Germ Line ◽  
Sequence Data ◽  
Allelic Variation ◽  
Neutral Theory ◽  
Natural Populations ◽  
Evolutionary Significance ◽  
Nucleotide Sequence Data ◽  
A Genome ◽  
Repeated Dnas

SummaryThe nucleotide sequence data from highly repeated DNAs of inverte-brates and mammals are summarized and briefly discussed. Very similar conclusions can be drawn from the two data bases. Sequence complexities can vary from 2 bp to at least 359 bp in invertebrates and from 3 bp to at least 2350 bp in mammals. The larger sequences may or may not exhibit a substructure. Significant sequence variation occurs for any given repeated array within a species, but the sources of this heterogeneity have not been systematically partitioned. The types of alterations in a basic repeating unit can involve base changes as well as deletions or additions which can vary from 1 bp to at least 98 bp in length. These changes indicate that sequence per se is unlikely to be under significant biological constraints and may sensibly be examined by analogy to Kimura's neutral theory for allelic variation. It is not possible with the present evidence to discriminate between the roles of neutral and selective mechanisms in the evolution of highly repeated DNA.Tandemly repeated arrays are constantly subjected to cycles of amplification and deletion by mechanisms for which the available data stem largely from ribosomal genes. It is a matter of conjecture whether the solutions to the mechanistic puzzles involved in amplification or rapid redeployment of satellite sequences throughout a genome will necessarily give any insight into biological functions.The lack of significant somatic effects when the satellite DNA content of a genome is significantly perturbed indicates that the hunt for specific functions at the cellular level is unlikely to prove profitable.The presence or in some cases the amount of satellite DNA on a chromosome, however, can have significant effects in the germ line. There the data show that localized condensed chromatin, rich in satellite DNA, can have the effect of rendering adjacent euchromatic regions rec−, or of altering levels of recombination on different chromosomes. No data stemming from natural populations however are yet available to tell us if these effects are of adaptive or evolutionary significance.

scholarly journals The molecular through ecological genetics of abnormal abdomen. IV. Components of genetic variation in a natural population of Drosophila mercatorum.

Genetics ◽  
1992 ◽  
Vol 130 (2) ◽  
pp. 355-366
Author(s):  
H Hollocher ◽  
A R Templeton ◽  
R DeSalle ◽  
J S Johnston
Keyword(s):  
Genetic Variation ◽  
Natural Population ◽  
Allelic Variation ◽  
Natural Populations ◽  
Developmental Time ◽  
Ecological Genetics ◽  
Adult Longevity ◽  
Genetic Determinants ◽  
Drosophila Mercatorum ◽  
Y Chromosomes

Abstract Natural populations of Drosophila mercatorum are polymorphic for a phenotypic syndrome known as abnormal abdomen (aa). This syndrome is characterized by a slow-down in egg-to-adult developmental time, retention of juvenile abdominal cuticle in the adult, increased early female fecundity, and decreased adult longevity. Previous studies revealed that the expression of this syndrome in females is controlled by two closely linked X chromosomal elements: the occurrence of an R1 insert in a third or more of the X-linked 28S ribosomal genes (rDNA), and the failure of replicative selection favoring uninserted 28S genes in larval polytene tissues. The expression of this syndrome in males in a laboratory stock was associated with the deletion of the rDNA normally found on the Y chromosome. In this paper we quantify the levels of genetic variation for these three components in a natural population of Drosophila mercatorum found near Kamuela, Hawaii. Extensive variation is found in the natural population for both of the X-linked components. Moreover, there is a significant association between variation in the proportion of R1 inserted 28S genes with allelic variation at the underreplication (ur) locus such that both of the necessary components for aa expression in females tend to cosegregate in the natural population. Accordingly, these two closely linked X chromosomal elements are behaving as a supergene in the natural population. Because of this association, we do not believe the R1 insert to be actively transposing to an appreciable extent. The Y chromosomes extracted from nature are also polymorphic, with 16% of the Ys lacking the Y-specific rDNA marker. The absence of this marker is significantly associated with the expression of aa in males. Hence, all three of the major genetic determinants of the abnormal abdomen syndrome are polymorphic in this natural population.

SEASONAL ABUNDANCE AND OVIPOSITION RESPONSE OF THE CORN EARWORM, HELIOTHIS ZEA (LEPIDOPTERA: NOCTUIDAE), ON OKRA IN VIRGINIA

1983 ◽  
Vol 115 (11) ◽  
pp. 1539-1541 ◽  
Author(s):  
M. A. Latheef ◽  
J. H. Ortiz
Keyword(s):  
United States ◽  
Insect Pests ◽  
Heliothis Zea ◽  
Limited Resource ◽  
The United States ◽  
Corn Earworm ◽  
Seasonal Abundance ◽  
Vegetable Production ◽  
Fresh Market ◽  
Important Pest

Okra, Abelmoschus esculentus (L.) Moench, is a member of the Malvaceae. It is an important crop in the southern United States where vegetable production becomes precarious during the summer owing to extreme conditions of temperature and drought. Okra is grown in most southern home gardens and is consumed as a main dish vegetable or used in soups and gumbos.Because of its popularity and environmental adaptability, okra may have the potential for attracting fresh market premium prices for limited resource farm operations. However, little has been published on insect pests of okra in the United States. In an investigation at Petersburg, Virginia, during 1979 and 1980, we found that the corn earworm, Heliothis zea (Boddie), was an important pest of okra.

scholarly journals Enzyme variability in the Drosophila willistoni Group. V. Genic variation in natural populations of Drosophila equinoxialis

1972 ◽  
Vol 20 (1) ◽  
pp. 19-42 ◽  
Author(s):  
Francisco J. Ayala ◽  
Jeffrey R. Powell ◽  
Martin L. Tracey
Keyword(s):  
Genetic Variation ◽  
Allelic Variation ◽  
Natural Populations ◽  
Starch Gel Electrophoresis ◽  
Gene Frequencies ◽  
Group V ◽  
Neutral Genetic Variation ◽  
Starch Gel ◽  
Genic Variation ◽  
Standard Techniques

SUMMARYWe have studied genetic variation at 27 loci in 42 samples from natural populations of a neotropical species, Drosophila equinoxialis, using standard techniques of starch-gel electrophoresis to detect allelic variation in genes coding for enzymes. There is considerarle genetic variability in D. equinoxialis. We have found allelic variation in each of the 27 loci, although not in every population. On the average, 71% of the loci are polymorphic – that is, the most common allele has a frequency no greater than 0·95 – in a given population. An individual is heterozygous on the average at 21·8% of its loci.The amount of genetic variation fluctuates widely from locus to locus. At the Mdh-2 locus arout 1% of the individuals are heterozygotes; at the other extreme more than 56% of the individuals are heterozygous at the Est-3. At any given locus the configuration of allelic frequencies is strikingly similar from locality to locality. At each and every locus the same allele is generally the most common throughout the distribution of the species. Yet differences in gene frequencies occur between localities. The pattern of genetic variation is incompatible with the hypothesis that the variation is adaptively neutral. Genetic variation in D. equinoxialis is maintained by balancing natural selection.The amount and pattern of genetic variation is similar in D. equinoxialis and its sibling species, D. willistoni. Yet the two species are genetically very different. Different sets of alleles occur at nearly 40% of the loci.

COMPARATIVE PERFORMANCE OF STANDARD AND MODIFIED PHEROMONE-BAITED WING TRAPS FOR CAPTURING HELIOTHIS ZEA (BODDIE)1 (LEPIDOPTERA: NOCTUIDAE)

1989 ◽  
Vol 24 (4) ◽  
pp. 482-488
Author(s):  
H. R. Gross ◽  
J. E. Carpenter
Keyword(s):  
Heliothis Zea ◽  
Corn Earworm ◽  
Cotton Bollworm ◽  
Hardware Cloth ◽  
Comparative Performance ◽  
Equivalent Distance ◽  
Lepidoptera Noctuidae

The wing trap, although economical and commercially available, has never been seriously considered as a standard for monitoring populations of the corn earworm (CEW)/cotton bollworm, Heliothis zea (Boddie), mainly because it is considered inefficient relative to other available traps. Attempts were made to enhance the performance of the Pherocon 1C (P-1C) wing trap by modifying its structure and by varying the placement of the pheromone within the trap. P-1C traps receiving 40–50 g of supplemental adhesive captured 5.1-fold more CEW males than did the P-1C standard. The introduction of horizontal barriers of either Lexan or hardware cloth across the center of the P-1C trap or the placement of Lexan strips to close side trap openings had no effect on the number of CEW males captured. Traps with the pheromone located 1.0–1.5 cm from the top center of the trap captured more males than did traps with the pheromone placed an equivalent distance from the bottom of the trap. Centering the pheromone approximately 2.5 cm back from the end opening of the trap also increased the number of CEW males captured over that of traps in which the pheromone was placed at the top center of the trap. Data suggest that parameters influencing the efficiency of P-1C traps for capturing male CEW are poorly understood.

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