Classical biological control against insect pests in Europe, North Africa, and the Middle East: What influences its success?

Many factors can affect the success and failure of classical biological control. However, these factors have mainly been studied independently of each other, which leaves their relative importance within the complexity of classical biological control (CBC) programmes unknown. Therefore, we set out to take a more holistic view on the factors that may impact the outcome of CBC of insect pests by insect predators and parasitoids. To this end, we filtered the BIOCAT catalogue to extract entries for the Greater Western Palearctic ecozone and added 15 new explanatory variables. These mainly concerned traits of released biological control agents, target pests, and host plants of the target, but also included the number of introductions for specific agent-target combinations as a management aspect. We then analysed the data regarding three levels of success: agent establishment, impact on the target population, and complete control of the target. Between 1890 and 2010 a total of 780 introductions of insects for biological control were undertaken in the analysed area, constituting 416 agent-target combinations. Overall success of agent establishment was 32%, successful impact of single agents on their target was 18%, and success of complete control was 11%. The number of factors significantly influencing the outcome of CBC decreased with increasing level of success. Remarkably few agent-related factors influenced the success: insect predators as agents decreased the probability of establishment and using oligophagous parasitoids significantly decreased the chances of complete control. Other significant factors were related to traits of target pests or their host plants. For example, sap feeders and target pests attacking reproductive plant parts were more likely to be successfully controlled. The rate of success increased with the number of introductions of CBC agents, in particular against univoltine target pests. These findings suggest that a focus on agent-related traits to increase the chances of successful CBC is not fully justified and should be complemented with the consideration of lower trophic levels and other aspects of CBC, such as abiotic factors and management.

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Yellow Brazilian Pepper-tree Leaf Galler (suggested common name) Calophya latiforceps Burckhardt (Insecta: Hemiptera: Calophyidae: Calophyinae)

EDIS ◽

10.32473/edis-in1186-2017 ◽

2017 ◽

Vol 2017 (6) ◽

Author(s):

James P. Cuda ◽

Patricia Prade ◽

Carey R. Minteer-Killian

Keyword(s):

Biological Control ◽

North America ◽

Natural Enemies ◽

Host Plants ◽

Classical Biological Control ◽

Biological Control Agents ◽

Pepper Tree ◽

Brazilian Pepper ◽

Close Relatives ◽

Tree Leaf

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]

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Using lower trophic level factors to predict outcomes in classical biological control of insect pests

Basic and Applied Ecology ◽

10.1016/j.baae.2005.05.006 ◽

2005 ◽

Vol 6 (6) ◽

pp. 571-584 ◽

Cited By ~ 7

Author(s):

Paul Gross ◽

Bradford A. Hawkins ◽

Howard V. Cornell ◽

Balakrishna Hosmane

Keyword(s):

Biological Control ◽

Trophic Level ◽

Insect Pests ◽

Classical Biological Control ◽

Lower Trophic Level

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Papaya Mealybug, Paracoccus marginatus Williams and Granara de Willink (Insecta: Hemiptera: Pseudococcidae)

EDIS ◽

10.32473/edis-in579-2003 ◽

1969 ◽

Vol 2005 (1) ◽

Author(s):

Alison Walker ◽

Marjorie Hoy ◽

Dale Meyerdirk

Keyword(s):

Biological Control ◽

Management Strategy ◽

Host Plants ◽

Control Program ◽

Classical Biological Control ◽

Cooperative Extension Service ◽

Joint Effort ◽

Department Of Agriculture ◽

University Of Florida ◽

The Us

The papaya mealybug, Paracoccus marginatus Williams and Granara de Willink, is a small hemipteran that attacks several genera of host plants, including economically important tropical fruits and ornamentals. The papaya mealybug was discovered in Manatee and Palm Beach counties in Florida in 1998 and subsequently spread rapidly to several other Florida counties. It potentially poses a multi-million dollar threat to numerous agricultural products in Florida, as well as other states, if not controlled. Biological control was identified as a key component in a management strategy for the papaya mealybug, and a classical biological control program was initiated as a joint effort between the US Department of Agriculture, Puerto Rico Department of Agriculture, and Ministry of Agriculture in the Dominican Republic in 1999. This document is EENY-302, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: August 2003. EENY302/IN579: Papaya Mealybug, Paracoccus marginatus Williams and Granara de Willink (Insecta: Hemiptera: Pseudococcidae) (ufl.edu)

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Successful Invasions and Failed Biocontrol: The Role of Antagonistic Species Interactions

BioScience ◽

10.1093/biosci/biz075 ◽

2019 ◽

Vol 69 (9) ◽

pp. 711-724 ◽

Cited By ~ 10

Author(s):

Ashley N Schulz ◽

Rima D Lucardi ◽

Travis D Marsico

Keyword(s):

Biological Control ◽

Species Interactions ◽

Classical Biological Control ◽

Enemy Release Hypothesis ◽

Trophic Levels ◽

Enemy Release ◽

Nonnative Species ◽

Natural Environments ◽

Top Down

Abstract Understanding the successes and failures of nonnative species remains challenging. In recent decades, researchers have developed the enemy release hypothesis and other antagonist hypotheses, which posit that nonnative species either fail or succeed in a novel range because of the presence or absence of antagonists. The premise of classical biological control of invasive species is that top-down control works. We identify twelve existing hypotheses that address the roles that antagonists from many trophic levels play during plant and insect invasions in natural environments. We outline a unifying framework of antagonist hypotheses to simplify the relatedness among the hypotheses, incorporate the role of top-down and bottom-up influences on nonnative species, and encourage expansion of experimental assessments of antagonist hypotheses to include belowground and fourth trophic level antagonists. A mechanistic understanding of antagonists and their impacts on nonnative species is critical in a changing world.

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Classical biological control of insect pests of trees: facts and figures

Biological Invasions ◽

10.1007/s10530-017-1414-4 ◽

2017 ◽

Vol 19 (11) ◽

pp. 3401-3417 ◽

Cited By ~ 48

Author(s):

Marc Kenis ◽

Brett P. Hurley ◽

Ann E. Hajek ◽

Matthew J. W. Cock

Keyword(s):

Biological Control ◽

Insect Pests ◽

Classical Biological Control

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"Strains" and the classical biological control of insect pests

Canadian Journal of Zoology ◽

10.1139/z95-210 ◽

1995 ◽

Vol 73 (10) ◽

pp. 1777-1790 ◽

Cited By ~ 40

Author(s):

A. R. Clarke ◽

G. H. Walter

Keyword(s):

Biological Control ◽

Success Rate ◽

Cryptic Species ◽

Insect Pests ◽

Classical Biological Control ◽

Control Technique ◽

Genetic Theory ◽

Multiple Introductions ◽

Theoretical Support ◽

Applied Biology

The classical biological control technique of introducing two or more populations of the same species of beneficial agent to increase the genetic diversity of that species (and so increase the chances of achieving a successful project) is reviewed. From standard literature sources, all cases of multiple introductions of conspecific populations against insect targets were listed and the effect of subsequent introductions on the outcome of the project was recorded. Of 178 projects identified, involving 417 separate importations, only 11 (6.2%) were successful through a second or later importation of the same morphologically defined species of beneficial agent. Of these, five involved host-related "strains" that are likely to be cryptic species, so the success rate for the introduction of conspecific populations falls to 3.4%. The possibility that some (or even all) of the other six cases also involved cryptic species awaits investigation. Our analysis demonstrates that introducing two or more populations of the same species is less likely to result in enhanced success than if other species of natural enemies are sought for "normal" classical biological control (historical success rate 12–16%). In our discussion we focus on the genetic theory of species which underpins this area of applied biology and find that there is also no theoretical support for the continued introduction of strains.

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Classical Biological Control and Insect Conservation: Are They Compatible?

Environmental Conservation ◽

10.1017/s0376892900029842 ◽

1988 ◽

Vol 15 (4) ◽

pp. 349-354 ◽

Cited By ~ 18

Author(s):

Michael J. Samways

Keyword(s):

Biological Control ◽

Life Histories ◽

Insect Pests ◽

Classical Biological Control ◽

Extreme Caution ◽

Economic Method ◽

Biotic Diversity ◽

Exotic Pests ◽

Taxonomic Groups ◽

Endangered Status

Exotic insect pests worldwide are many. They are accidental biotic contaminants. Classical biological control (CBC) agents can be considered as deliberately introduced biotic contaminants that, when successful, reduce the overall biomass of contamination and often bring considerable self-sustaining economic relief to farming communites.Although the introduction of exotic agents would seem to be contrary to conservation philosophy, there are no quantified instances to date where the introduction of arthropod agents has been shown to have harmed a specific conservation programme or has been categorically damaging to native fauna. There is only limited anecdotal evidence that introduced parasitoids may have damaged certain specific native taxa. CBC in some cases actually assists conservation by reducing the level of exotic pests in nature reserves.As CBC is an important socio-economic method of pest control, especially for tropical farmers, and as the taxonomic groups and life-histories of its targets are so different from those insects of endangered status, the two approaches are not in conflict. But as CBC is virtually irretrievable, it must continue to be carried out carefully and selectively only by truly responsible CBC agencies using appropriate quarantine facilities.Tourists and general travellers pose a greater threat to native faunas than do the activities of such CBC agencies. It is well known that vertebrate agents and certain invertebrates, especially snails, can be devastating to certain native biotas. Additionally, and in view of the impending world-wide biotic diversity crisis, even traditional agents such as insect pathogens, insect parasitoids, and insect and mite predators, should be viewed with extreme caution—especially when oligophagous, and unquestionably when polyphagous.

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Understanding the Causes and Genetic Effects of Thelytoky in the Aphelinidae: A Key to Improving Biological Control

10.32747/1992.7561058.bard ◽

1992 ◽

Author(s):

Richard Roush ◽

David Rosen

Keyword(s):

Electron Microscopy ◽

Biological Control ◽

Insect Pests ◽

Strong Association ◽

Classical Biological Control ◽

Scale Insect ◽

Female Offspring ◽

Follicle Cells ◽

Biological Control Agents ◽

Micro Organisms

Helytoky is a type of parthenogenesis whereby females produce only female offspring without the involvement of males, even where males are occasionally produced. In the last few years, strong circumstantial evidence has implied that thelytoky can be caused by micro-organisms called Wolbachia in at least some species of wasps. The thelytoky can be "cured" by treatment with antibiotics. Further Wolbachia-like organisms can be found in microscopic examinations and genetically identified through their DNA. The aphelinid wasps, and especially species in the genus Aphytis, are among the most important of all classical biological control agents. Aphytis species are critical in the biological control of scale insect pests in commercial orchards and ornamental plantings. About 30% of Aphytis species are thelytikous, of which we were able to study three in detail. In all three, thelytoky was curable by treatment with antibiotics and Wolbachia were identified morphologically and through their DNA. In contrast, Wolbachia were not detectable in biparental species of Aphytis. Studies of Wolbachia gene sequences obtained from Aphytis showed that they were most closely related to those from a very distantly related wasp, Muscidifurax uniraptor, strongly implying that the Wolbachia can be horizontally transferred. As revealed by electron microscopy, the Wolbachia show a strong association with the nurse and follicle cells of the female wasps.

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