scholarly journals Insect parasitoids : a Canadian perspective on their use for biological control of forest insect pests

2005 ◽  
Vol 74 (1) ◽  
pp. 51-67 ◽  
Author(s):  
S.M. Smith

An overview of biological control programs against forest insect pests is presented with emphasis on Canadian case histories. The work is examined in the context of conservation, introduction, and augmentation (environmental manipulation and inoculative and inundative release) of insect natural enemies, specifically parasitoids. Historically, studies have concentrated on introductions of exotic parasitoids for control of introduced pests where a number of successes have been recorded. More recent work has entailed inoculative and inundative releases of parasitoids against native pests in an attempt to establish new host-parasitoid relationships to reduce pest populations. These have had limited success and are still being explored by Canadian researchers. Current strategies for using natural enemies are inundative release of native species against native pests and conservation of native parasitoids through selective insecticide timing and forest manipulation. Future directions in biological control programs will include these approaches with increased emphasis on biotechnology and the genetic selection or manipulation of 'desired strains' for release. Continued ecological studies will be essential to ensure a more complete understanding of the interaction between these 'selected parasitoids' and the forest/tree parameters which will influence their success (tri-trophic interactions). These parameters, such as tree vigour (pest resistance), spatial distribution and diversity, will also be targeted for selection to improve the effect of insect natural enemies in the forest environment.

1991 ◽  
Vol 67 (5) ◽  
pp. 500-505 ◽  
Author(s):  
V. G. Nealis

Forest insect pest management differs from pest management in other renewable-resource industries because of the relative complexity and stability of the forest environment. An important component of this complexity is the rich fauna of natural enemies attacking most forest insect pests. Understanding the relationship between forest insect pests and their natural enemies would permit better insight into the dynamics of pest populations.The active release of natural enemies in inoculative or inundative release strategies is a direct application of biological control to pest management. The conservation of resident natural enemies is an indirect biological control method with great potential. Knowledge of the ecology of natural enemies can be used to modify other forest practices such as reforestation and insecticide use to conserve or enhance the action of natural enemies.


2019 ◽  
Vol 112 (4) ◽  
pp. 1581-1586
Author(s):  
Huifang Guo ◽  
Yufeng Qu

Abstract Compared with the numerous natural enemies against insect pests that have been identified, the commercialization of natural biological control resources remains very limited. To increase the use of natural enemies for biological control, determining how to improve the low efficacy, slow speed, and high cost of natural enemies is very important. Mediterranean species of The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodoidea), increasingly threatens many crops in China, and control primarily depends on chemical insecticides. Here, the effect of ethanol extracts from two plants, Agrimonia pilosa (Ledeb) (Rosales: Rosaceae) and Melia azedarach (Linn) (Meliaceae: Melia), on predominant natural enemies of B. tabaci was investigated using a leaf dipping or spraying method. The results showed that the ethanol extract of A. pilosa significantly improved the infectivity of the fungus Isaria javanica (Friedrichs & Bally) (Ascomycota: Hypocreales), and the mortality of whiteflies caused by the combination of fungus (105 spores/mL) with the extract of A. pilosa (2 mg/mL dried powder of A. pilosa containing 0.0942 mg/mL total polyphenols) was 81.6%, which was significantly higher than that caused by the fungus only. However, the ethanol extract of M. azedarach had no effect on fungus infectivity. Additionally, insecticide tolerance of the predator Pardosa pseudoannulata was also significantly improved by the extract of A. pilosa. The longevity of the parasitoid Encarsia formosa was not affected by the extracts. These findings indicate that the extract of A. pilosa played a dual role that included improving pathogenic fungi infectivity and insecticidal tolerance of a predator and thus could be a synergist in the biological control of B. tabaci.


Author(s):  
Xing-eng Wang

Abstract Drosophila suzukii (Matsumura) is native to East Asia but has widely established in the Americas and Europe, where it is a devastating pest of soft-skinned fruits. It has a wide host range and these non-crop habitats harbor the fly which then repeatedly reinvades crop fields. Biological control in non-crop habitats could be the cornerstone for sustainable management at the landscape level. Toward this goal, researchers have developed or investigated biological control tactics. We review over 100 studies, conducted in the Americas, Asia and Europe on natural enemies of D. suzukii. Two previous reviews provided an overview of potential natural enemies and detailed accounts on foreign explorations. Here, we provide an up-to-date list of known or evaluated parasitoids, predators and entomopathogens (pathogenic fungi, bacteria, nematodes, and viruses) and summarize research progress to date. We emphasize a systematic approach toward the development of biological control strategies that can stand alone or be combined with more conventional control tools. Finally, we propose a framework for the integrated use of biological control tools, from classical biological control with host-specific Asian parasitoids, to augmentative and conservation biological control with indigenous natural enemies, to the use of entomopathogens. This review provides a roadmap to foster the use of biological control tools in more sustainable D. suzukii control programs.


2018 ◽  
Vol 10 (7) ◽  
pp. 167 ◽  
Author(s):  
Angélica Massarolli ◽  
Ana Regina Lucena Hoffmann ◽  
Bruna Magda Favetti ◽  
Alessandra Regina Butnariu

Studies on natural enemies are important to find new species and to develop management strategies to preserve them to help control pests in biological control programs. For the state of Mato Grosso, Brazil, which comprises the Amazon, Cerrado, and Pantanal biomes, few studies have been conducted on the diversity of these parasitoids, possible endemic and/or new species, as well as their potential as natural enemies. Thus, the present study was aimed at describing the diversity of parasitoids of the families Ichneumonidae (Hymenoptera) and Tachinidae (Diptera) associated with pest lepidopterans in soybean crops. Weekly sampling of pest lepidopterans was carried out during four soybean seasons (2009/2010, 2010/2011, 2011/2012 and 2012/2013). Parasitoid larvae were observed in the main lepidopteran pest species of soybean during the four soybean seasons. Three genera of the Ichneumonidae family, belonging to the genera Microcharops Roman, Ophionellus Westwood, and Podogaster Brullé. Six genera of the Tachinidae family occur in the state of Mato Grosso in soybean fields. The following genera were recorded: Archytas spp. Jaennicke, Phorocera spp. Robineau-Desvoidy, Gymnocarcelia spp. Townsend, Lespesia spp. Robineau-Desvoidy, Eucelatoria spp. Townsend, Chetogena spp. Rondani. These parasitoids were found parasitizing caterpillars of the Noctuidae (Lepidoptera), in species that had not yet been reported as hosts for the Neotropical region. Further studies are needed on the beneficial entomofauna and their preservation in agricultural environments.


1988 ◽  
Vol 3 (2-3) ◽  
pp. 102-109 ◽  
Author(s):  
Joop C. van Lenteren

AbstractThe number of species of insect pests, estimated to be maximally 10,000 worldwide, forms only a small part of the millions of species of plant-eating insects. Chemical pest control is becoming increasingly difficult and objectionable in terms of environmental contamination so that other methods of pest control need to be developed. One of the best alternatives is biological control. Natural and inoculative biological control has already proven successful against a variety of pests over large areas. One is inclined to forget, however, how successful a biological control program has been as soon as the pest problem has been solved. Other types of biological control involving the regular introduction or augmentation of natural enemies are better known, although these have been applied on a much smaller scale; a survey of the present-day application of these latter types of biological control is presented here. Phases in the implementation of biological control are illustrated and needed future developments in research are discussed. The main limitation on the development of biological control is not the research, since natural enemies are easier found and with a much lower investment than new chemical pesticides, but rather the attitudes held by growers and disinterest on the part of industry, policy-makers, and politicians. The first priority for those concerned with the development and application of safer pest control should, therefore, be to change the perceptions that these other groups have of biological control.


Parasitology ◽  
1982 ◽  
Vol 84 (4) ◽  
pp. 241-268 ◽  
Author(s):  
J. K. Waage ◽  
M. P. Hassell

SUMMARYThis review begins with a description of the parasitoid life-style and the ecological and evolutionary factors which generate the remarkable diversity of insect parasitoids. We then describe the various ways that parasitoids have been used in the biological control of insect pests, and survey their success to date. The use of parasitoids remains largely an art, aided by past experience of success and failure. A more fundamental approach, involving basic research and theory, has not as yet contributed significantly to practical biological control. We explore the potential for such a science of parasitoid use and review basic research on parasitoid ecology and evolution which is of particular relevance to biological control. Mathematical models are used to identify and examine those parasitoid and host attributes which lead to successful biological control. Factors such as parasitoid foraging behaviour, fecundity, larval survival and sex ratio are shown to be important in influencing the depression of host populations and/or the stability of host–parasitoid interactions after depression. Multiple release is discussed and a model for inundative release of parasitoids is explored.


2012 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Gislayne Trindade Vilas-Bôas ◽  
Rita C. Alvarez ◽  
Clelton A. Dos Santos ◽  
Laurival A. Vilas-Boas

As proteínas Cry produzidas pela bactéria entomopatogênica Bacillus thuringiensis Berliner são bem conhecidas devido a alta citotoxicidade que exibem a uma variedade de insetos-alvo. O modo de ação destas proteínas é específico e torna os produtos à base de B. thuringiensis os mais amplamente utilizados em programas de controle biológico de pragas na agricultura e de importantes vetores de doenças humanas. Contudo, embora as proteínas Cry sejam os fatores de virulência inseto-específico mais conhecidos, linhagens de B. thuringiensis apresentam também uma ampla gama de fatores de virulência, os quais permitem à bactéria atingir a hemolinfa e colonizar eficientemente o inseto hospedeiro. Dentre estes fatores, destacam-se as proteínas Vip, Cyt, enterotoxinas, hemolisinas, fosfolipases, proteases, enzimas de degradação, além das recentemente descritas parasporinas. Essa revisão aborda a ação desses fatores de virulência, bem como a caracterização e o controle da expressão de seus genes. Adicionalmente, são discutidos aspectos relacionados ao nicho ecológico da bactéria com ênfase nas características envolvidas com a biossegurança da utilização dos produtos à base de B. thuringiensis para o controle biológico de insetos-alvo. Virulence Factors of Bacillus thuringiensis Berliner: Something Beyond of Cry Proteins? Abstract. The Cry proteins produced by the entomopathogenic bacterium Bacillus thuringiensis Berliner are widely known due to its high toxicity against a variety of insects. The mode of action of these proteins is specific and becomes B. thuringiensis-based products the most used in biological control programs of insect pests in agriculture and of important human disease vectors. However, while the Cry proteins are the best-known insect-specific virulence factor, strains of B. thuringiensis show also a wide range of other virulence factors, which allow the bacteria to achieve the hemolymph and colonize efficiently the insect host. Among these factors, we highlight the Vip proteins, Cyt, enterotoxins, hemolysins, phospholipases, proteases and enzymes of degradation, in addition to the recently described parasporin. This review explores the action of these virulence factors, as well as, the characterization and control of expression of their genes. Additionally, we discuss aspects related to the ecological niche of the bacteria with emphasis on the characteristics involved in the biosafety of the use of B. thuringiensis-based products for biological control of target insects.


2018 ◽  
Author(s):  
P. Amouroux ◽  
D. Crochard ◽  
M.C.G. Correa ◽  
G. Groussier ◽  
P. Kreiter ◽  
...  

AbstractScale insects (Hemiptera: Coccoidea) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18°S) to Frutillar (41°S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 40 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. In Chalcidoidea, 22 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile.


2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Ana Paula Magalhães Borges Battel ◽  
◽  
Rafael de Andrade Moral ◽  
Camila Alves Rodrigues ◽  
Márcio da Silva Araújo ◽  
...  

ABSTRACT: This study investigated the influence of cage sizes on the survival and reproductive potential of Chrysoperla externa (Hagen). Size of breeding cages significantly affected the reproductive potential of C. externa . Our results indicated that in cages smaller (7.5cm of diameter) than those usually recommended for the rearing of this insect (10cm diameter), females showed higher rates of oviposition. Reduction of space for rearing natural enemies in the laboratory is very important for developing biological control programs.


Author(s):  
Danny Haelewaters ◽  
Thomas Hiller ◽  
Emily A. Kemp ◽  
Paul S. van Wielink ◽  
David I. Shapiro-Ilan ◽  
...  

ABSTRACTHarmonia axyridis is an invasive alien ladybird in North America and Europe. Studies show that multiple natural enemies are using Ha. axyridis as a new host. However, thus far, no research has been undertaken to study the effects of simultaneous infections of multiple natural enemies on Ha. axyridis. We hypothesized that high thallus densities of the ectoparasitic fungus Hesperomyces virescens on a ladybird weaken the host’s defenses, thereby making it more susceptible to infection by other natural enemies. We examined mortality of the North American-native Olla v-nigrum and Ha. axyridis co-infected with He. virescens and an entomopathogenic fungus—either Beauveria bassiana or Metarhizium anisopliae. Laboratory assays revealed that He. virescens-infected O. v-nigrum individuals are more susceptible to entomopathogenic fungi, but Ha. axyridis does not suffer the same effects. This is in line with the enemy release hypothesis, which predicts that invasive alien species in new geographic areas experience reduced regulatory effects from natural enemies compared to native species. Considering our results, we can ask how He. virescens affects survival when confronted by other pathogens that previously had little impact on Ha. axyridis.


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