Early Spray Applications to Control Alfalfa Weevil

Spray applications enable a uniform distribution of substances on surfaces in a highly efficient manner, and thus can be found at workplaces as well as in consumer environments. A systematic literature review on modelling exposure by spraying activities has been conducted and status and further needs have been discussed with experts at a symposium. This review summarizes the current knowledge about models and their level of conservatism and accuracy. We found that extraction of relevant information on model performance for spraying from published studies and interpretation of model accuracy proved to be challenging, as the studies often accounted for only a small part of potential spray applications. To achieve a better quality of exposure estimates in the future, more systematic evaluation of models is beneficial, taking into account a representative variety of spray equipment and application patterns. Model predictions could be improved by more accurate consideration of variation in spray equipment. Inter-model harmonization with regard to spray input parameters and appropriate grouping of spray exposure situations is recommended. From a user perspective, a platform or database with information on different spraying equipment and techniques and agreed standard parameters for specific spraying scenarios from different regulations may be useful.

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Management of the Egyptian alfalfa weevil, Hypera brunneipennis (Boheman) (Coleoptera: Curculionidae), in the alfalfa, Medicago sativa L., using the entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-019-0171-3 ◽

2019 ◽

Vol 29 (1) ◽

Author(s):

Monir M. M. El Husseini

Keyword(s):

Medicago Sativa ◽

Beauveria Bassiana ◽

Entomopathogenic Fungus ◽

Larval Population ◽

Alfalfa Weevil ◽

Alfalfa Field ◽

Medicago Sativa L ◽

Hypera Brunneipennis ◽

Fungus Beauveria Bassiana ◽

Sweep Net

AbstractLarval and adult populations of the Egyptian alfalfa weevil (EAW) Hypera brunneipennis (Boheman) (Coleoptera: Curculionidae) was monitored after application of the entomopathogenic fungus Beauveria bassiana in the alfalfa field (Medicago sativa L.) in two successive seasons 2014/2015 and 2015/2016. The second and last generation of the weevil on April 10, 2016, was controlled by only one application with the conidiospores of the entomopathogenic fungus B. bassiana (3 × 108 spores/ml). Accordingly, the larval population decreased from 16.07 ± 1.09 in season 2015/2016 to 7.37 ± 0.05 individuals/50 sweep net double strokes in season 2016/2017. Also, the adult weevil’s population decreased from 5.66 ± 0.8 to 2.55 ± 0.6 individuals/50 sweep net double strokes in the two seasons, respectively. 39.66% mortality rate was recorded in the Hypera brunneipennis adults aestivated under loose bark of the surrounding eucalyptus trees, which received the application of B. bassiana in the field. Another application with the fungus, targeting the second generation of the pest adults in alfalfa each season, will undoubtedly lead to a further decrease in the pest population.

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A Technique for Evaluation of Field Control of the Alfalfa Weevil Using a Fixed Population12

Journal of Economic Entomology ◽

10.1093/jee/64.1.327 ◽

1971 ◽

Vol 64 (1) ◽

pp. 327-328

Author(s):

Hilary F. Goonewardene ◽

Robert S. Filmer

Keyword(s):

Alfalfa Weevil ◽

Field Control

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Assessing the role of generalist predators in the biological control of alfalfa weevil (Coleoptera: Curculionidae)

The Canadian Entomologist ◽

10.4039/tce.2017.9 ◽

2017 ◽

Vol 149 (4) ◽

pp. 525-533 ◽

Cited By ~ 1

Author(s):

Tatyana A. Rand

Keyword(s):

United States ◽

Biological Control ◽

Experimental Work ◽

United States Of America ◽

Acyrthosiphon Pisum ◽

The United States ◽

Generalist Predators ◽

Alfalfa Weevil ◽

Exclusion Experiment ◽

Predator Exclusion

AbstractAlfalfa weevil (Coleoptera:Curculionidae) is a major pest of alfalfa throughout the United States of America. Biological control research has disproportionately focussed on introduced parasitoids. Generalist predators may also be important, but experimental work evaluating their impacts is lacking. I combined a cross-site survey with a predator exclusion experiment to identify key predators, and test for impacts on weevil survival and plant defoliation levels in Montana and North Dakota, United States of America. Spiders (Araneae) dominated the complex, followed by Nabidae (Hemiptera) and Coccinellidae (Coleoptera). None of the dominant predators showed aggregative responses to weevil (Hypera postica (Gyllenhal); Coleoptera: Curculionidae) or pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) densities across 10 sites surveyed. However, weevil densities were positively correlated with both coccinellid and nabid densities across transects at the experimental site. Thus, predator groups traditionally associated with aphids can show strong aggregative numerical responses to alfalfa weevil larvae at smaller scales. Predator exclusion revealed no significant predator effects on larval survival or alfalfa damage. However, final densities of pea aphids were significantly higher in exclusion treatments relative to controls. The results suggest that even under conditions where predators exert significant pressure on aphids, they may still have minimal impacts on weevils. Additional experimental work is necessary to determine the broader potential of generalist predators as alfalfa weevil control agents.

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A natural epizootic of a coccidian in a population of the Egyptian alfalfa weevil, Hypera brunneipennis, and the alfalfa weevil, H. postica

Journal of Invertebrate Pathology ◽

10.1016/0022-2011(75)90245-1 ◽

1975 ◽

Vol 26 (3) ◽

pp. 413-414 ◽

Cited By ~ 1

Author(s):

C.M. Merritt ◽

G.M. Thomas ◽

J. Christensen

Keyword(s):

Alfalfa Weevil ◽

Hypera Brunneipennis

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