Dispersal in Host–Parasitoid Interactions: Crop Colonization by Pests and Specialist Enemies

Interactions of insect pests and their natural enemies increasingly are being considered from a metapopulation perspective, with focus on movements of individuals among habitat patches (e.g., individual crop fields). Biological control may be undercut in short-lived crops as natural enemies lag behind the pests in colonizing newly created habitat. This hypothesis was tested by assessing parasitism of cereal leaf beetle (Oulema melanopus) and alfalfa weevil (Hypera postica) larvae at varying distances along transects into newly planted fields of small grains and alfalfa in northern Utah. The rate of parasitism of cereal leaf beetles and alfalfa weevils by their host-specific parasitoids (Tetrastichus julis (Eulophidae) and Bathyplectes curculionis (Ichneumonidae), respectively) was determined for earliest maturing first generation host larvae. Rates of parasitism did not vary significantly with increasing distance into a newly planted field (up to 250–700 m in individual experiments) from the nearest source field from which pest and parasitoid adults may have immigrated. These results indicate strong, rapid dispersal of the parasitoids in pursuing their prey into new habitat. Thus, across the fragmented agricultural landscape of northern Utah, neither the cereal leaf beetle nor the alfalfa weevil initially gained substantial spatial refuge from parasitism by more strongly dispersing than their natural enemies into newly created habitat. Additional studies, including those of colonization of newly planted crops by generalist pests and natural enemies, are called for in assessing these results with a broader perspective.

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Parasitoids of cereal leaf beetle, Oulema gallaeciana (Heyden, 1879)

Plant Protection Science ◽

10.17221/1260-pps ◽

2008 ◽

Vol 44 (No. 3) ◽

pp. 108-113 ◽

Cited By ~ 4

Author(s):

M. Jeloková ◽

J. Gallo

Keyword(s):

Biological Control ◽

Natural Enemies ◽

Leaf Beetle ◽

Leaf Beetles ◽

Cereal Leaf Beetle ◽

To Receive

Cereal leaf beetles are serious animal pests of crops in many areas of western and eastern Slovakia. Research was carried out in these areas in order to receive knowledge on occurrence of natural enemies of Oulema gallaeciana. We were detecting particular species of parasitoids parasitising Oulema gallaeciana and their spreading in particular area. The results showed that dominant parasitoid was Necremnus leucarthros. Other parasitoids with bigger proportion on parasitisation were Pteromalus vibulenus and Diplazon spp. with parasitisation up to 30%. In respect of significant parasitisation of Oulema gallaeciana by parasitoid Necremnus leucarthros, it would be appropriate to use this species for biological control of cereal leaf beetle.

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Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance in Soybean Fields Protected and Unprotected by Shelterbelts

Journal of Entomological Science ◽

10.18474/0749-8004-35.4.385 ◽

2000 ◽

Vol 35 (4) ◽

pp. 385-390 ◽

Cited By ~ 3

Author(s):

S. D. Danielson ◽

J. R. Brandle ◽

L. Hodges ◽

P. Srinivas

Keyword(s):

Insect Pests ◽

Agricultural Research ◽

Insect Pest ◽

Leaf Beetle ◽

Leaf Beetles ◽

Bean Leaf Beetle ◽

Two Generations ◽

Agricultural Research And Development ◽

Soybean Plants ◽

The University

The bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is a major insect pest of soybean in Nebraska and throughout much of the Midwest. This insect overwinters in the adult stage in litter in wooded areas such as shelterbelts. Historically, crop producers have been unsure of the merits of shelterbelts, especially if nearby crops are more likely to be infested by insect pests as a result. In this study, bean leaf beetle adults were sampled during the season by visually counting the number of beetles found on soybean plants early in the season and by sweep net sampling once plants were at the V4 stage (approximately 0.33 m tall). Sampling was done in 1997 and 1998 at the University of Nebraska Agricultural Research and Development Center in Saunders Co. in east-central Nebraska. Beetle counts were compared between shelterbelt-protected and -unprotected fields. In general, bean leaf beetles were more numerous in 1997 than in 1998, with abundance peaks occurring in late-July and early-September in both years. There were significant differences in bean leaf beetle counts from protected and unprotected fields on only three of the 11 and four of the 13 sampling dates in 1997 and 1998, respectively. On the sampling dates when significant differences were found, two of three in 1997 and three of four in 1998 had higher bean leaf beetle abundance in the protected soybean fields. The results of this study indicate a tendency for more bean leaf beetles in shelterbelt-protected soybean fields when differences are found, but beetle numbers were not significantly different between protected and unprotected fields on the majority of sample dates in the two years of this study. This study also reconfirms the presence of two generations of the bean leaf beetle in Nebraska.

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Anatomical features of leaves of three cultivars of winter wheat (Triticum aestivum L.) and settling the plants by cereal leaf beetles, Oulema spp. (Coleoptera, Chrysomelidae)

Acta Agrobotanica ◽

10.5586/aa.1994.012 ◽

2013 ◽

Vol 47 (2) ◽

pp. 53-62 ◽

Cited By ~ 1

Author(s):

Elżbieta Weryszko-Chmielewska ◽

Grzegorz Soczyński

Keyword(s):

Winter Wheat ◽

Cell Walls ◽

Triticum Aestivum L ◽

Leaf Beetle ◽

Leaf Beetles ◽

Anatomical Features ◽

Cereal Leaf Beetle ◽

Adaxial Epidermis ◽

Winter Wheat Cultivars ◽

Made In

Investigations of flag leaves anatomy of three winter wheat cultivars: Almari, Gama and Weneda were carried out as it was state that there are great differences in the intensity of cereal leaf beetle feeding on the leaves. In order to determine the features conditioning the differentiated resistance of these cultivars following parameters were measured: the thickness of leaf blade, the length of trichomes and their density in the adaxial epidermis, the number of silicon cells in 1 mm2 epidermis and the thickness of the external cell walls of epidermis. The observations of cross section of the leaves were made in a light microscope and that of surface of the adaxial epidermis in a scanning electron microscope. In this study it was shown that Gama cv. distinguishes of the shortest trichomes with poor density, the lowest number of the silicon cells in 1 mm2 and epidermis cells with the thinest walls. This features indicate a poor resistance of Gama cv. against feeding of the pests and give reasons for the presence a much higher number of the cereal leaf beetle larvae (about 100%) than at the extant two cultivars. Dependence between the thickness of leaf blades and the number of larvae of the infesting pests has not been stated.

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Genetic Architecture of Cereal Leaf Beetle Resistance in Wheat

Plants ◽

10.3390/plants9091117 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1117

Author(s):

Tobias Würschum ◽

Willmar L. Leiser ◽

Simon M. Langer ◽

Matthew R. Tucker ◽

Thomas Miedaner

Keyword(s):

Genetic Architecture ◽

Insect Pests ◽

Flag Leaf ◽

Heading Date ◽

Leaf Beetle ◽

Genotypic Variance ◽

Cereal Leaf Beetle ◽

Winter Wheat Cultivars ◽

Trait Locus ◽

Prediction Approach

Wheat production can be severely damaged by endemic and invasive insect pests. Here, we investigated resistance to cereal leaf beetle in a panel of 876 winter wheat cultivars, and dissected the genetic architecture underlying this insect resistance by association mapping. We observed an effect of heading date on cereal leaf beetle infestation, with earlier heading cultivars being more heavily infested. Flag leaf glaucousness was also found to be correlated with resistance. In line with the strong effect of heading time, we identified Ppd-D1 as a major quantitative trait locus (QTL), explaining 35% of the genotypic variance of cereal leaf beetle resistance. The other identified putative QTL explained much less of the genotypic variance, suggesting a genetic architecture with many small-effect QTL, which was corroborated by a genomic prediction approach. Collectively, our results add to our understanding of the genetic control underlying insect resistances in small-grain cereals.

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Linear woody landscape elements may help to mitigate leaf surface loss caused by the cereal leaf beetle

Landscape Ecology ◽

10.1007/s10980-020-01097-3 ◽

2020 ◽

Vol 35 (10) ◽

pp. 2225-2238

Author(s):

Károly Lajos ◽

Orsolya Császár ◽

Miklós Sárospataki ◽

Ferenc Samu ◽

Ferenc Tóth

Keyword(s):

Biological Control ◽

Natural Enemies ◽

Natural Enemy ◽

Leaf Surface ◽

Leaf Beetle ◽

Agricultural Landscapes ◽

Natural Habitats ◽

Landscape Elements ◽

Surface Loss ◽

Cereal Leaf Beetle

Abstract Context Woody semi-natural habitats serve as permanent habitats and hibernation sites for natural enemies and, through spillover processes, they play an important role in the biological control of insect pests. However, this service is also dependent on the amount and configuration of the dominating woody habitat types: linear landscape elements (hedgerows, shelterbelts), and more evenly extended plantations. Relating natural enemy action to the landscape context can help to identify the effect of woody habitats on biological control effectiveness. Objectives In the Central European agricultural landscapes such as in the Hungarian lowlands, where our study took place, woody linear elements are characterised by high, while woody areal elements, mostly plantations, by low biological and structural diversity. In this study, we aimed to determine which composition and configuration of woody linear and areal habitats in the landscape may enhance the effect of natural enemy action on plant damage caused by the cereal leaf beetle (CLB, Oulema melanopus). Methods Herbivory suppression by natural enemies was assessed from the leaf damage difference between caged and open treatments. These exclusion experiments were carried out in 34 wheat fields on plants with controlled CLB infections. The results were related to landscape structure, quantified by different landscape metrics of both woody linear and areal habitats inside buffers between 150 and 500 m radii, surrounding the wheat fields. Results The exclusion of natural enemies increased the leaf surface loss caused by CLBs in all fields. Shelterbelts and hedgerows in 150–200 m vicinity of the wheat fields had a strong suppressing effect on CLB damage, while the presence of plantations at 250 m and further rather impeded natural enemy action. Conclusions Our results indicate that shelterbelts and hedgerows may provide a strong spillover of natural enemies, thus contribute to an enhanced biological control of CLBs.

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The effect of growing mixtures of spring barley cultivars on pest occurrence and yields

Polish Journal of Entomology ◽

10.2478/pjen-2014-0023 ◽

2014 ◽

Vol 83 (4) ◽

pp. 295-311

Author(s):

Anna Tratwal ◽

Kamila Roik ◽

Jan Bocianowski

Keyword(s):

Spring Barley ◽

Rhopalosiphum Padi ◽

Leaf Beetle ◽

Meteorological Conditions ◽

Sitobion Avenae ◽

Leaf Beetles ◽

Grain Yields ◽

Barley Cultivars ◽

Cereal Leaf Beetle ◽

Growing Seasons

ABSTRACT . Experiments were conducted in the 2010 and 2011 growing seasons at two locations differing in their edaphic and meteorological conditions to assess the effects of mixtures of spring barley cultivars on the occurrence of harmful pests and yields. The most significant pests in the experiment on spring barley in pure sowings and mixtures were cereal leaf beetles (Oulema spp.), with bird cherry-oat aphids (Rhopalosiphum padi) and grain aphids (Sitobion avenae) being somewhat fewer in number. With some mixtures, numbers of cereal leaf beetle larvae, bird cherryoat aphids and grain aphids in comparison with pure stands were reduced. Grain yields from mixtures increased in comparison with those from pure sowings up to 6.48 dt·ha-1 in 2010 and up to 3.99 dt ha-1 in 2011.

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