scholarly journals The pest kill rate of thirteen natural enemies as aggregate evaluation criterion of their biological control potential of Tuta absoluta

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joop C. van Lenteren ◽  
Alberto Lanzoni ◽  
Lia Hemerik ◽  
Vanda H. P. Bueno ◽  
Johanna G. Bajonero Cuervo ◽  
...  

AbstractEcologists study how populations are regulated, while scientists studying biological pest control apply population regulation processes to reduce numbers of harmful organisms: an organism (a natural enemy) is used to reduce the population density of another organism (a pest). Finding an effective biological control agent among the tens to hundreds of natural enemies of a pest is a daunting task. Evaluation criteria help in a first selection to remove clearly ineffective or risky species from the list of candidates. Next, we propose to use an aggregate evaluation criterion, the pest kill rate, to compare the pest population reduction capacity of species not eliminated during the first selection. The pest kill rate is the average daily lifetime killing of the pest by the natural enemy under consideration. Pest kill rates of six species of predators and seven species of parasitoids of Tuta absoluta were calculated and compared. Several natural enemies had pest kill rates that were too low to be able to theoretically reduce the pest population below crop damaging densities. Other species showed a high pest reduction capacity and their potential for practical application can now be tested under commercial crop production conditions.

2019 ◽  
Vol 109 (6) ◽  
pp. 812-820 ◽  
Author(s):  
J.C. van Lenteren ◽  
V.H.P. Bueno ◽  
G. Burgio ◽  
A. Lanzoni ◽  
F.C. Montes ◽  
...  

AbstractTuta absoluta (Meyrick), a key pest of tomato, is quickly spreading over the world and biological control is considered as one of the control options. Worldwide more than 160 species of natural enemies are associated with this pest, and an important challenge is to quickly find an effective biocontrol agent from this pool of candidate species. Evaluation criteria for control agents are presented, with the advantages they offer for separating potentially useful natural enemies from less promising ones. Next, an aggregate parameter for ranking agents is proposed: the pest kill rate km. We explain why the predator's intrinsic rate of increase cannot be used for comparing the control potential of predators or parasitoids, while km can be used to compare both types of natural enemies. As an example, kill rates for males, females and both sexes combined of three Neotropical mirid species (Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stål)) were determined, taking all life-history data (developmental times, survival rates, total nymphal and adult predation, sex ratios and adult lifespan) into account. Based on the value for the intrinsic rate of increase (rm) for T. absoluta and for the kill rate km of the predators, we predict that all three predators are potentially able to control the pest, because their km values are all higher than the rm of the pest. Using only km values, we conclude that E. varians is the best candidate for control of T. absoluta on tomato, with C. infumatus ranking second and M. basicornis last.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1004
Author(s):  
Pascal Osa Aigbedion-Atalor ◽  
Martin P. Hill ◽  
Pascal Mahukpe Ayelo ◽  
Shepard Ndlela ◽  
Myron P. Zalucki ◽  
...  

The koinobiont solitary larval endoparasitoid Dolichogenidea gelechiidivoris (Marsh) (Syn.: Apanteles gelechiidivoris) (Hymenoptera: Braconidae) and the predatory bug Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) are important natural enemies of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a serious pest of tomato. Although N. tenuis preferentially feeds on T.absoluta eggs, it is also recorded as a predator of first and second instar larval stages. Dolichogenidea gelechiidivoris preferentially seeks these early larval stages of T. absoluta for oviposition. The occurrence of intraguild predation between N. tenuis and D. gelechiidivoris and the consequences on the oviposition performance of D. gelechiidivoris were investigated in the laboratory. Regardless of the manner of introduction (i.e., the sequence of combinations with D. gelechiidivoris) or density (i.e., number of N. tenuis combined with D. gelechiidivoris), the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris or the parasitoid’s progeny. Combination assays revealed that the efficacy of the combined use of N. tenuis and D. gelechiidivoris in controlling T. absoluta populations was significantly higher than that of either natural enemy alone. Our results highlight the potential of combining mirid predators and koinobiont larval endoparasitoids to control T. absoluta. The findings further contribute to data supporting the release of D. gelechiidivoris in tomato agroecosystems for the control of T. absoluta in Africa, where N. tenuis is widespread and abundant.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Xiao-wei Li ◽  
Xin-xin Lu ◽  
Zhi-jun Zhang ◽  
Jun Huang ◽  
Jin-ming Zhang ◽  
...  

Intercropping of aromatic plants provides an environmentally benign route to reducing pest damage in agroecosystems. However, the effect of intercropping on natural enemies, another element which may be vital to the success of an integrated pest management approach, varies in different intercropping systems. Rosemary, Rosmarinus officinalis L. (Lamiaceae), has been reported to be repellent to many insect species. In this study, the impact of sweet pepper/rosemary intercropping on pest population suppression was evaluated under greenhouse conditions and the effect of rosemary intercropping on natural enemy population dynamics was investigated. The results showed that intercropping rosemary with sweet pepper significantly reduced the population densities of three major pest species on sweet pepper, Frankliniella intonsa, Myzus persicae, and Bemisia tabaci, but did not affect the population densities of their natural enemies, the predatory bug, Orius sauteri, or parasitoid, Encarsia formosa. Significant pest population suppression with no adverse effect on released natural enemy populations in the sweet pepper/rosemary intercropping system suggests this could be an approach for integrated pest management of greenhouse-cultivated sweet pepper. Our results highlight the potential of the integration of alternative pest control strategies to optimize sustainable pest control.


2021 ◽  
Author(s):  
Steven E Naranjo ◽  
James R Hagler ◽  
John A Byers

Abstract Conservation biological control is a fundamental tactic in integrated pest management (IPM). Greater biological control services can be achieved by enhancing agroecosystems to be more favorable to the presence, survival, and growth of natural enemy populations. One approach that has been tested in numerous agricultural systems is the deployment of synthetic chemicals that mimic those produced by the plant when under attack by pests. These signals may attract arthropod natural enemies to crop habitats and thus potentially improve biological control activity locally. A 2-yr field study was conducted in the cotton agroecosystem to evaluate the potential of synthetic methyl salicylate (MeSA) to attract native arthropod natural enemies and to enhance biological control services on two key pests. Slow-release packets of MeSA were deployed in replicated cotton plots season long. The abundance of multiple taxa of natural enemies and two major pests were monitored weekly by several sampling methods. The deployment of MeSA failed to increase natural enemy abundance and pest densities did not decline. Predator to prey ratios, used as a proxy to estimate biological control function, also largely failed to increase with MeSA deployment. One exception was a season-long increase in the ratio of Orius tristicolor (White) (Hemiptera: Anthocoridae) to Bemisia argentifolii Bellows and Perring (= Bemisia tabaci MEAM1) (Hemiptera: Aleyrodidae) adults within the context of biological control informed action thresholds. Overall results suggest that MeSA would not likely enhance conservation biological control by the natural enemy community typical of U.S. western cotton production systems.


Author(s):  
Greissi Tente Giraldi ◽  
Julio César Guerreiro ◽  
Cawana Parrow Augusto ◽  
Thainara Ferreira Alves Pessoa ◽  
Luiz Gustavo Dos Santos ◽  
...  

Whitefly complex is one of the most severe pests affecting different crops of significant agricultural interest. It causes critical damage to plants, and hence considerably affect crop productivity and the related commercials. This insect has been managed using insecticides; however, there have been reports of resistance of this insecticide to various active ingredients, making it difficult to reduce this pest’s population. Hence, other ways of handling this insect population have been investigated, including through biological control. Several past studies have reported the existence of natural enemies of the whitefly, including coccinellids such as those belonging to the genus Delphastus have gained much attention. These coccinellids are predators and hence perform the important role of controlling pest population. Moreover, the whitefly is a staple food in certain diets.


1956 ◽  
Vol 47 (4) ◽  
pp. 685-702 ◽  
Author(s):  
F. J. Simmonds

The biology and general ecology ofMelittomma insulareFairm. in the Seychelles is briefly described and the difficulties in the biological control of this pest are stressed.As much information as possible was obtained concerning the species of the little-known family Lymexylonidae, particularly with regard to their biology, which in most cases has not been investigated. Several species might warrant further investigation with a view to providing natural enemies for use againstM. insulare, but in general what is known of their biology does not afford much hope that an effective parasite or predator will be found.The biology ofAtractocerus brasiliensisLep. & Serv. was investigated in detail in Trinidad but no natural enemy was found.The only possibility is thatRhizophagus dispar(Payk.), recorded as attackingHylecoetus dermestoides(L.) in England, might also attack the eggs ofM. insulare.


2009 ◽  
Vol 100 (3) ◽  
pp. 367-371 ◽  
Author(s):  
O.L. Kvedaras ◽  
M. An ◽  
Y.S. Choi ◽  
G.M. Gurr

AbstractSilicon (Si) is known to have a role in constitutive plant defence against arthropod pests, and recent work has illustrated involvement in induced plant defences. The present tri-trophic study tested the hypothesis that Si increases natural enemy attraction to pest-infested plants and improves biological control. Cucumber plants treated with potassium silicate (Si+) and untreated control plants (Si−) were maintained in separately vented glasshouse compartments. Y-tube olfactometer studies showed that adult Dicranolaius bellulus were significantly more attracted to Si+ plants upon which Helicoverpa armigera larvae had fed compared with Si−, pest-infested plants. Predators were not significantly more attracted to Si+ plants when comparing uninfested cucumbers. In a field experiment, we placed H. armigera-infested and uninfested Si+ and Si− cucumber plants in a lucerne stand. Removal rates of H. armigera egg baits showed predation was greater for Si+ infested plants than for other treatments. Results suggest that Si applied to plants with a subsequent pest infestation increases the plants' attractiveness to natural enemies; an effect that was reflected in elevated biological control in the field.


2007 ◽  
Vol 97 (3) ◽  
pp. 309-315 ◽  
Author(s):  
D.J. Skirvin ◽  
L. Kravar-Garde ◽  
K. Reynolds ◽  
J. Jones ◽  
A. Mead ◽  
...  

AbstractTwo experiments were done to examine the predation of thrips, and the movement of Orius laevigatus Fieber and Neoseiulus cucumeris (Oudemans) in the presence and absence of two supplemental food sources, pollen and the fungus Trichoderma viride. The presence of pollen led to a 55% reduction in predation of the thrips by N. cucumeris and a 40% reduction in thrips predation by O. laevigatus, in experiments using single predators. The presence of fungus had no significant effect on thrips predation by either of the natural enemy species. Movement of the natural enemies was examined in a multiple predator experiment, and this showed that O. laevigatus was more likely to remain on the plant in the presence of thrips and when supplemental food, either pollen or fungus, was present. For N. cucumeris, there was no association between the presence of thrips and the mite, with the majority of the mites being found on the leaves where pollen was present. Although the single and multiple predator experiments were done at different times, the indications are that the predation rates of the N. cucumeris do not differ greatly between the two experiments, suggesting that there may be a potential interference effect between the mites, which is not present for O. laevigatus. The significance of these results for the use of supplemental food sources in biological control is discussed.


2021 ◽  
Author(s):  
Jie Zhang ◽  
Shijun You ◽  
Dongsheng Niu ◽  
Karla Giovana Gavilanez Guaman ◽  
Ao Wang ◽  
...  

ABSTRACTBackgroundConservation biological control provides an environment-friendly approach to improve the efficacy of natural enemies. Although numerous studies have demonstrated the potential of semi-natural habitats in promoting biological control in organic or unsprayed agroecosystems, few studies were conducted in conventional agricultural fields. In this study, we investigated the effects of landscape composition on the major pests of cruciferous vegetables and on the assemblages of their natural enemies in southeastern China.ResultsHabitat diversity, particularly increasing grassland proportion in the landscape, had a positive impact in controlling both small-sized pests (aphids, leaf miners, thrips and flea beetles) and Plutella xylostella. This increasing proportion also promoted greater abundance and diversity of canopy-dwelling predators, more forests supported a higher diversity of airborne enemies (parasitoids and canopy-dwelling predators) as well as a higher abundance of ground-dwelling predators. A general increase in habitat diversity was beneficial to parasitoids and ground-dwelling predators. Additionally, the proportion of forest, grassland, and non-cruciferous vegetable area, as well as habitat diversity, affected the compositions of natural enemy communities. Moreover, inconsistent effects of non-cruciferous and grassland habitats were found between sampling regions for small-sized pests and canopy-dwelling predators. Moreover, the scale at which pests and natural enemies’ abundance and richness responded most to landscape composition varied with their feeding range and dispersal ability.ConclusionOur study provides evidence that increasing the amount of semi-natural habitats and habitat diversity can result in lower pest and higher natural enemy abundance in conventional cruciferous agroecosystems. Regional conditions and spatial scales also should be considered in designing the agricultural landscape mosaic.


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