scholarly journals The effect of within-crop habitat manipulations on the conservation biological control of aphids in field-grown lettuce

2011 ◽  
Vol 101 (6) ◽  
pp. 623-631 ◽  
Author(s):  
D.J. Skirvin ◽  
L. Kravar-Garde ◽  
K. Reynolds ◽  
C. Wright ◽  
A. Mead
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Floral Resources ◽  
Cereal Crops ◽  
Field Crops ◽  
Natural Regulation ◽  
Wildflower Strips ◽  
Natural Pest Regulation ◽  
The Impact ◽  
Regulation Changes

AbstractWithin-crop habitat manipulations have the potential to increase the biological control of pests in horticultural field crops. Wildflower strips have been shown to increase the abundance of natural enemies, but there is little evidence to date of an impact on pest populations. The aim of this study was to determine whether within-crop wildflower strips can increase the natural regulation of pests in horticultural field crops. Aphid numbers in plots of lettuce grown adjacent to wildflower strips were compared with those in plots grown in the absence of wildflowers. The presence of wildflower strips led to a decrease in aphid numbers on adjacent lettuce plants during June and July, but had less impact in August and September. The decrease in aphid numbers was greatest close to the wildflower strips and, the decrease in aphid numbers declined with increasing distance from the wildflower strips, with little effect at a distance of ten metres. The main natural enemies found in the crop were those that dispersed aerially, which is consistent with data from previous studies on cereal crops. Analysis and interpretation of natural enemy numbers was difficult due to low recovery of natural enemies, and the numbers appeared to follow changes in aphid abundance rather than being directly linked to the presence of wildflower strips. Cutting the wildflower strips, to remove floral resources, had no impact on the reduction in aphid numbers achieved during June and July, but decreased the effect of the wildflower strips during August and September. The results suggest that wildflower strips can lead to increased natural regulation of pest aphids in outdoor lettuce crops, but more research is required to determine how this is mediated by natural enemies and how the impact of wildflower strips on natural pest regulation changes during the growing season.

The potential for managing indigenous natural enemies of aphids on field crops

1988 ◽  
Vol 318 (1189) ◽  
pp. 183-201 ◽  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Plant Resistance ◽  
Absolute Number ◽  
The Other ◽  
Acceptable Level ◽  
Field Crops ◽  
The Absolute ◽  
Indigenous Natural Enemies ◽  
Relative Selectivity

The co-evolution of aphids and their indigenous natural enemies means that, on field crops, biological control to a grower-acceptable level will occur only sporadically in the absence of manipulative interventions. Such interventions should focus on raising the natural enemy:aphid ratio. This ratio is far more important than the absolute number of natural enemies present. The main interventions for improving the ratio are habitat modifications, advancing in time the activity of natural enemies on the crop, reducing aphid multiplication through genetically based or induced partial plant resistance, and ingenious use of pesticide to build in relative selectivity of kill. The interactions between biological control and some of the other interventions offer exciting opportunities for managing natural enemies.

scholarly journals Whiteflies Provide Honeydew to Camponotus ants Without Receiving Reciprocal Favor

Sociobiology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 755
Author(s):  
Raí Martins De Jesus ◽  
Ramon Paes Junior ◽  
Gleicy Do Carmo ◽  
Danilo Mota ◽  
Lessando Moreira Gontijo ◽  
...  
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Laboratory Study ◽  
Natural Enemies ◽  
Predator Cues ◽  
Sooty Mold ◽  
Field Laboratory ◽  
Important Pest ◽  
The Impact

The notion that tending ants provide protection to honeydew-producing hemipterans is widely accepted. Nevertheless, there have been debates about whether or not this protection can always disrupt the biological control of hemipterans. Although various hemipteran species interact with tending ants, most studies have focused on the mutualism between ants and aphids.  Woolly whitefly Aleurothrixus floccosus (Maskell) is an important pest of citrus whose nymphs are frequently tended by ants such as Camponotus. However, it is unknown whether or not ants in this genus can disrupt biological control of woolly whitefly by protecting this pest’s nymphs from natural enemies. We investigated the impact of Camponotus ants on the biological control of woolly whitefly in the field by excluding or allowing the access of ants to whitefly nymph colonies in different tangerine trees. Furthermore, in a laboratory study we also assessed the behavior of Camponotus ants in response to woolly whitefly’s common predator cues (visual and scent).  In summary, this field-laboratory study suggests that there is no mutualism between tending Camponotus ants and the whitefly A. floccosus; rather it indicates commensalism as an alternative interaction. Interactions as this may provide more benefits for the host plant, whereby Camponotus ants can reduce sooty mold by removing honeydew from the leaves and favor pest biological control by leaving the whiteflies unprotected.

scholarly journals Using flower strips to promote green lacewings to control cabbage insect pests

2021 ◽  
Author(s):  
Rafael Alcalá Herrera ◽  
Belén Cotes ◽  
Nuria Agustí ◽  
Marco Tasin ◽  
Mario Porcel
Keyword(s):  
Natural Enemies ◽  
Habitat Management ◽  
Insect Pests ◽  
Floral Resources ◽  
Choice Test ◽  
Beneficial Arthropods ◽  
Borago Officinalis ◽  
Green Lacewings ◽  
Cabbage Pests ◽  
The Impact

AbstractHabitat management improves biological control by increasing the abundance and fitness of natural enemies through the provision of floral resources along field edges or between crops. Among the natural enemies reliant on flower resources, green lacewings often stand out due to their abundance, predation capacity and polyphagy. We evaluated the impact of tailored flower strips on the enhancement of natural enemies, especially green lacewings, in three organic cabbage (Brassica oleracea) farms in Southern Sweden. Insects were sampled from the flower strips, and cabbage pests and predators were visually recorded in the crop. In a laboratory assay, the pollen feeding preferences of Chrysoperla carnea (Stephens, 1836) were evaluated in a dual-choice test. The pollen consumed by the Chrysopidae was extracted from laboratory and field specimens, then quantified and identified. Flower strips were found to attract predators and parasitoids, whose abundance increased as flowers bloomed. Cabbage plants next to the flower strips showed lower pest infestation as compared to cabbage plant control, although no significant differences were observed in the number of predators. Chrysopidae used flower strips as feeding, reproduction and shelter sites and mainly consumed pollen from Phacelia tanacetifolia Benth. Under laboratory conditions, C. carnea showed a preference for P. tanacetifolia and Coriandrum sativum L. pollen over Borago officinalis L. and Fagopyrum esculentum Moench. We show that tailored flower strips could be an efficient tool for enhancing beneficial arthropods and should be considered in integrated pest management for cabbage crops.

scholarly journals Natural Pest Regulation and Its Compatibility with Other Crop Protection Practices in Smallholder Bean Farming Systems

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 805
Author(s):  
Baltazar J. Ndakidemi ◽  
Ernest R. Mbega ◽  
Patrick A. Ndakidemi ◽  
Philip C. Stevenson ◽  
Steven R. Belmain ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Insect Pests ◽  
Crop Protection ◽  
Sub Saharan Africa ◽  
Aphis Fabae ◽  
Sources Of Resistance ◽  
Resistant Varieties ◽  
Natural Pest Regulation ◽  
Cultural Tools

Common bean (Phaseolus vulgaris) production and storage are limited by numerous constraints. Insect pests are often the most destructive. However, resource-constrained smallholders in sub-Saharan Africa (SSA) often do little to manage pests. Where farmers do use a control strategy, it typically relies on chemical pesticides, which have adverse effects on the wildlife, crop pollinators, natural enemies, mammals, and the development of resistance by pests. Nature-based solutions —in particular, using biological control agents with sustainable approaches that include biopesticides, resistant varieties, and cultural tools—are alternatives to chemical control. However, significant barriers to their adoption in SSA include a lack of field data and knowledge on the natural enemies of pests, safety, efficacy, the spectrum of activities, the availability and costs of biopesticides, the lack of sources of resistance for different cultivars, and spatial and temporal inconsistencies for cultural methods. Here, we critically review the control options for bean pests, particularly the black bean aphid (Aphis fabae) and pod borers (Maruca vitrata). We identified natural pest regulation as the option with the greatest potential for this farming system. We recommend that farmers adapt to using biological control due to its compatibility with other sustainable approaches, such as cultural tools, resistant varieties, and biopesticides for effective management, especially in SSA.

scholarly journals Current status of classical biological control of Cirsium arvense in New Zealand

2010 ◽  
Vol 63 ◽  
pp. 273-273
Author(s):  
M.G. Cripps ◽  
G.W. Bourd?t ◽  
S.V. Fowler ◽  
G.R. Edwards
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Natural Enemies ◽  
Classical Biological Control ◽  
Growth Characteristics ◽  
Cirsium Arvense ◽  
Current Status ◽  
Perennial Herb ◽  
Rust Pathogen ◽  
The Impact

Cirsium arvense (L) Scop (Californian Canada or creeping thistle) is an exotic perennial herb that successfully established in New Zealand (NZ) approximately 130 years ago and is now considered one of the worst invasive weeds in NZ arable and pastoral systems Two insects Cassida rubiginosa and Ceratapion onopordi were recently released for classical biological control Studies carried out from 2006 to 2009 in both the native (Europe) and introduced (NZ) ranges of the plant aimed to quantify C arvense growth characteristics and assess incidence of the specialised rust pathogen Puccinia punctiformis in regions with and without the supposed pathogen vector C onopordi In permanent field plots natural enemies were excluded with insecticides and fungicides and compared with controls The impact of C rubiginosa was also assessed under different pasture competition scenarios The survey data indicate that C arvense expresses similar growth characteristics in both ranges and that incidence of the rust pathogen is similar in both ranges regardless of the presence of C onopordi The data suggest that the overall suite of natural enemies is capable of exerting some regulating influence on the plant in its native range but that the released biocontrol agents will not likely have a significant impact on this weed in NZ

AN ANALYSIS OF THE NATURAL BIOLOGICAL CONTROL OF TRICHOPLUSIA NI (LEPIDOPTERA: NOCTUIDAE) ON COTTON IN CALIFORNIA

1974 ◽  
Vol 106 (10) ◽  
pp. 1067-1073 ◽  
Author(s):  
L. E. Ehler ◽  
R. van den Bosch
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Trichoplusia Ni ◽  
Nuclear Polyhedrosis Virus ◽  
Perennial Crop ◽  
Theoretical Support ◽  
Early Instar ◽  
Nuclear Polyhedrosis ◽  
The Impact ◽  
Lepidoptera Noctuidae

AbstractThe impact of natural enemies on Trichoplusia ni (Hübner) is reviewed. Disappearance of eggs and small larvae (presumably due to predation) is consistently the major intrageneration mortality. Parasitoids and a nuclear polyhedrosis virus effect mortality of larvae surviving early-instar predation. From the analysis, it is argued that natural enemies capable of effective colonization of the habitat and rapid exploitation of the prey population (i.e., r-strategists) are suitable agents for biological control of pests of annual or short-cycle crops. Polyembryony, polyphagy, and polyhedrosis represent attributes which enable the particular natural enemy to implement the rapid-host-exploitation strategy. This interpretation gives added theoretical support for importation of exotic natural enemies of pests of non-perennial crop plants.

scholarly journals How Effective Is Conservation Biological Control in Regulating Insect Pest Populations in Organic Crop Production Systems?

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 744
Author(s):  
Raymond A. Cloyd
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Crop Production ◽  
Scientific Literature ◽  
Production Systems ◽  
Insect Pest ◽  
Conservation Biological Control ◽  
Flowering Plants ◽  
Floral Resources ◽  
Organic Crop Production

Organic crop production systems are designed to enhance or preserve the presence of natural enemies, including parasitoids and predators, by means of conservation biological control, which involves providing environments and habitats that sustain natural enemy assemblages. Conservation biological control can be accomplished by providing flowering plants (floral resources) that will attract and retain natural enemies. Natural enemies, in turn, will regulate existing insect pest populations to levels that minimize plant damage. However, evidence is not consistent, based on the scientific literature, that providing natural enemies with flowering plants will result in an abundance of natural enemies sufficient to regulate insect pest populations below economically damaging levels. The reason that conservation biological control has not been found to sufficiently regulate insect pest populations in organic crop production systems across the scientific literature is associated with complex interactions related to intraguild predation, the emission of plant volatiles, weed diversity, and climate and ecosystem resources across locations where studies have been conducted.

scholarly journals Impact of the number of Spodoptera frugiperda egg layers on parasitism by Trichogramma atopovirilia

2005 ◽  
Vol 62 (2) ◽  
pp. 190-193 ◽  
Author(s):  
Eduardo Barbosa Beserra ◽  
José Roberto Postali Parra
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Egg Parasitoids ◽  
Egg Masses ◽  
Control Programs ◽  
The Impact ◽  
Lepidoptera Noctuidae

Egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) can be found in several crops attacking Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) eggs. It is therefore necessary to demonstrate the capacity of these natural enemies in suppressing populations of the pest to allow them to be used in biological control programs against that species. This work had the objective of evaluating the impact of egg layer distribution in S. frugiperda egg masses on the parasitism capacity of Trichogramma atopovirilia Oatman & Platner, 1983. Masses containing one, two, and three layers were used as treatments, and 1.6 parasitoid per egg of the pest were released. Parasitism percentage differences were observed among the three types of masses under study, on average 66.24 ± 8.56%, 45.20 ± 6.20%, and 40.10± 3.46% for egg masses with one, two, and three layers, respectively, demonstrating the potential of use of the parasitoid for the control of fall armyworm.

scholarly journals The behaviour of hoverfly larvae (Diptera, Syrphidae) lessens the effects of floral subsidy in agricultural landscapes

2016 ◽  
Author(s):  
Elsa A. Laubertie ◽  
Steve D. Wratten ◽  
Alexandra Magro ◽  
Jean Louis RGM Hemptinne
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Laboratory Experiments ◽  
Landscape Management ◽  
Agricultural Landscapes ◽  
Floral Resources ◽  
Insect Behaviour ◽  
Resource Concentration ◽  
Conspecific Density ◽  
Set Up

Modern agricultural landscapes favour crop pests: herbivores benefit from resource concentration and/or the absence of natural enemies in large areas of intensively farmed fields interspersed by small fragments of natural or non-crop habitats. Conservation biological control (CBC) aims at increasing the functional diversity of agricultural landscapes to make them more hospitable to natural enemies, and less to herbivores. Although natural enemies readily respond to this management, very few studies assess if they succeed in effectively protecting crops. We set up a field experiment to study if an ecological infrastructure varying in size and consisting of the provision of floral resources at the centre of lettuce plots would influence the number of eggs laid by hoverflies, and ultimately the control of lettuce aphids. We found that the hoverfly females lay more eggs in the plots with the larger flower resource compared to the control. However, this response had no impact on the abundance of aphids on the lettuces. We designed two laboratory experiments to understand this absence of response. We found mutual interference between hoverfly larvae, and suggest it may undermine the biological control of aphids. This mismatch between landscape management and the response of hoverflies indicates CBC should take into account insect behaviour, particularly their response to conspecific density, additionally to landscape ecology.

The impact of planting buckwheat strips along lowbush blueberry fields on beneficial insects

2020 ◽  
Author(s):  
Robyn McCallum ◽  
Nancy L. McLean ◽  
G. Christopher Cutler
Keyword(s):  
Species Richness ◽  
Natural Enemies ◽  
Habitat Management ◽  
Floral Resources ◽  
Field Margins ◽  
Beneficial Insects ◽  
Lowbush Blueberry ◽  
Bee Community ◽  
Fagopyrum Esculentum Moench ◽  
The Impact

Pollination and pest control are important in many agroecosystems. Beneficial insects that provide these services (e.g. bees and natural enemies) often require floral resources beyond crop bloom. Planting floral resources along crop field margins may be a useful tactic to support communities of beneficial insects in agroecosystems. We examined the effect of planting buckwheat (Fagopyrum esculentum Moench) along lowbush blueberry (Vaccinium angustifolium Aiton) field margins on beneficial insect abundance and species richness. We found that bee abundance was higher in buckwheat transects than control transects in 2014 and 2015, but not 2016, and that bee species richness was higher in buckwheat transects than in control transects in 2015 only. High variability occurred across years. All bee genera recorded during blueberry bloom were also collected in buckwheat transects, suggesting buckwheat is a useful resource for bee community involved in blueberry pollination. The effect of buckwheat on natural enemies was variable and inconsistent. We conclude buckwheat influenced bee and natural enemy communities during certain years, but field edges in the lowbush blueberry fields studied may already adequately support beneficial insects. Thus, not all habitat management efforts with augmentative floral plantings may consistently boost communities of beneficial insects.

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