scholarly journals Southern Corn Rootworm (Coleoptera: Chrysomelidae) Adult Emergence and Population Growth Assessment After Selection With Vacuolar ATPase-A double-stranded RNA Over Multiple Generations

2019 ◽  
Vol 112 (3) ◽  
pp. 1354-1364
Author(s):  
Adriano E Pereira ◽  
Brigitte Tenhumberg ◽  
Lance J Meinke ◽  
Blair D Siegfried
1997 ◽  
Vol 24 (2) ◽  
pp. 128-134 ◽  
Author(s):  
D. A. Herbert ◽  
W. J. Petka ◽  
R. L. Brandenburg

Abstract The southern corn rootworm, Diabrotica undecimpunctata howardi Barber, is a primary pest of peanut, Arachis hypogaea L., in Virginia and North Carolina and an occasional pest in South Carolina, Georgia, Alabama, and Texas. Currently, no alternatives involving integrated pest management exist for this pest, and control is based solely on preventive application of soil insecticides. Recent reductions in federal price support for peanut grown in the U.S. have provided incentives for growers to look for ways to reduce production costs. A risk index was developed that integrates factors that influence rootworm abundance and peanut pod damage to estimate levels of risk in individual peanut fields, and thus allows for more prescriptive and economical rootworm management. This index was evaluated using 44 field case studies in Virginia and North Carolina commercial peanut fields over the period 1989 to 1996. In each field case, predicted risk was compared to actual percent pod damage. Results showed that in 29 of 44 cases, the index accurately predicted general levels of risk to pod damage, and insecticide treatment decisions based on the index would have been correct in 32 of 44 cases. This report contains the individual index components, the justification for each, the indexing process, example index scenarios, and results of the process used in field case study evaluation.


2008 ◽  
pp. 3519-3522
Author(s):  
John B. Heppner ◽  
David B. Richman ◽  
Steven E. Naranjo ◽  
Dale Habeck ◽  
Christopher Asaro ◽  
...  

EDIS ◽  
2013 ◽  
Vol 2013 (9) ◽  
Author(s):  
Harsimran Kaur Gill ◽  
Gaurav Goyal ◽  
Jennifer Gillett-Kaufman

Spotted cucumber beetle is a major agricultural pest of North America. Another name for the spotted cucumber beetle is “southern corn rootworm”. Many Diabrotica species cause damage to field crops, especially corn, making these beetles a major agricultural concern. Because of the subterranean nature of their larvae, these insects are hard and expensive to control. This 6-page fact sheet was written by Harsimran Kaur Gill, Gaurav Goyal, and Jennifer Gillett-Kaufman, and published by the UF Department of Entomology and Nematology, September 2013. http://edis.ifas.ufl.edu/in1008


1998 ◽  
Vol 88 (12) ◽  
pp. 1248-1254 ◽  
Author(s):  
William E. Snyder ◽  
David W. Tonkyn ◽  
Daniel A. Kluepfel

The southern corn rootworm, Diabrotica undecimpunctata subsp. howardi, a common and mobile insect pest, was shown to transmit the rhizobacte-rium Pseudomonas chlororaphis strain L11 between corn plants. Strain L11 has been genetically modified to contain the lacZY genes from Escherichia coli. It can reach high densities on roots and invade the roots and move into the foliage. D. undecimpunctata subsp. howardi became infested with L11 as larvae while feeding on roots of seed-inoculated corn and retained the bacteria through pupation, molting to the adult stage, and emergence from the soil. Bacterial densities on or in the insects increased 100-fold after they fed again as adults on L11-infested foliage. Adults retained the bacteria for at least 2 weeks after last exposure and could transmit L11 to new plants. The likelihood of transmission decreased with time since last exposure to L11, but increased with time spent on the new plants. This research demonstrates that rhizobacteria can escape the rhizosphere by moving in or onto foliage, where they can then be acquired and transmitted by insects. This transmission route may be common among naturally occurring rhizobacteria and facilitate the dispersal of both beneficial and harmful soilborne microorganisms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Man P. Huynh ◽  
Chad Nielson ◽  
B. Wade French ◽  
Dalton C. Ludwick ◽  
Ryan W. Geisert ◽  
...  

AbstractThe northern corn rootworm, Diabrotica barberi Smith & Lawrence, has a univoltine life cycle that typically produces one generation a year. When rearing the northern corn rootworm in the laboratory, in order to break diapause, it is necessary to expose eggs to a five month cold period before raising the temperature. By selective breeding of the small fraction of eggs that hatched without cold within 19–32 days post oviposition, we were able to develop a non-diapausing colony of the northern corn rootworm within five generations of selection. Through selection, the percentages of adult emergence from egg hatch without exposure to cold treatment significantly increased from 0.52% ± 0.07 at generation zero to 29.0% ± 2.47 at generation eight. During this process, we developed an improved method for laboratory rearing of both the newly developed non-diapausing strain as well as the diapausing strain. The development of the non-diapausing colony along with the improvements to the rearing system will allow researchers to produce up to six generations of the northern corn rootworm per year, which would facilitate research and advance our knowledge of this pest at an accelerated rate.


Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 748 ◽  
Author(s):  
Jacques Régnière ◽  
Barry Cooke ◽  
Ariane Béchard ◽  
Alain Dupont ◽  
Pierre Therrien

Management of spruce budworm, Choristoneura fumiferana (Clem.), outbreak spread requires understanding the demographic processes occurring in low, but rising populations. For the first time, detailed observations were made in the early stages of outbreak development. We sampled populations over a three-year period in both treated and untreated populations in the Lower St-Lawrence region of Quebec, Canada, and measured the density-dependence of survival and population growth rates, and the impact of natural enemies and insecticides. Insecticides tested were Bacillus thuringiensis (Berliner 1915) and tebufenozide. We recorded strong density-dependence of survival between early larval stages and adult emergence, explained largely by the variation of natural enemy impacts and overcrowding. We also observed inverse density-dependence of apparent fecundity: net immigration into lower-density populations and net emigration from the higher, linked to a threshold of ~25% defoliation. Because of high migration rates, none of the 2013 treatments reduced egg populations at the end of summer. However lower migration activity in 2014 allowed population growth to be reduced in treated plots. This evidence lends support to the conclusion that, for a budworm population to increase to outbreak density, it must be elevated via external perturbations, such as immigration, above a threshold density of ~4 larvae per branch tip (L4). Once a population has increased beyond this threshold, it can continue growing and itself become a source of further spread by moth migration. These findings imply that populations can be brought down by insecticide applications to a density where mortality from natural enemies can keep the reduced population in check, barring subsequent immigration. While we recognize that other factors may occasionally cause a population to exceed the Allee threshold and reach outbreak level, the preponderance of immigration implies that if all potential sources of significant numbers of moths are reduced on a regional scale by insecticide applications, a widespread outbreak can be prevented, stopped or slowed down by reducing the supply of migrating moths.


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