Side effects of selected insecticides on the Tuta absoluta (Lepidoptera: Gelechiidae) predators Macrolophus pygmaeus and Nesidiocoris tenuis (Hemiptera: Miridae)

2011 ◽  
Vol 84 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Judit Arnó ◽  
Rosa Gabarra
Author(s):  
G. Kinyanjui ◽  
F. M. Khamis ◽  
F. L. O. Ombura ◽  
E. U. Kenya ◽  
S. Ekesi ◽  
...  

Abstract Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± 0.45, respectively. Trap captures in terms of moth/trap/day were linearly and positively related to leaf infestations in open fields (R2 = 0.81) and greenhouses (R2 = 0.61). Highest fruits’ infestation and damage were 60.00 and 59.61%, respectively, while the highest number of mines per fruit was 7.50 ± 0.50. Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus (Rambur) were identified as predators of T. absoluta larvae. Nine species of larval parasitoids were recovered from infested foliage, with a combined parasitism of 7.26 ± 0.65%. Hockeria species was the most dominant (31.25%) and accounted for 12.88 ± 1.47% parasitism. Two species of larval parasitoids, Hockeria and Necremnus were obtained from sentinel plants with an average parasitism of 1.13 ± 0.25. The overall abundance and parasitism rates of recovered natural enemies were low to effectively control the field populations of T. absoluta. These findings form the basis of researching and developing effective and sustainable management strategies for the pest.


2011 ◽  
Vol 136 (6) ◽  
pp. 401-409 ◽  
Author(s):  
L. Zappalà ◽  
G. Siscaro ◽  
A. Biondi ◽  
O. Mollá ◽  
J. González-Cabrera ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257925
Author(s):  
Kouassi Arthur J. Konan ◽  
Lucie S. Monticelli ◽  
San-Whouly M. Ouali-N’goran ◽  
Ricardo Ramirez-Romero ◽  
Thibaud Martin ◽  
...  

Tuta absoluta is one of the most damaging pests of tomato crops worldwide. Damage due to larvae may cause up to 100% loss of tomato production. Use of natural enemies to control the pest, notably predatory mirids such as Nesidiocoris tenuis and Macrolophus pygmaeus, is increasingly being promoted. However, considering the potential damage caused to tomatoes by these omnivorous predators in the absence of T. absoluta, an alternative solution could be required to reduce tomato damage and improve the predators’ performance. The use of companion plants can be an innovative solution to cope with these issues. The present study aimed to determine the influence of companion plants and alternative preys on the predators’ performance in controlling T. absoluta and protecting tomato plants. We evaluated the effect of predators (alone or combined) and a companion plant (sesame (Sesamum indicum)) on T. absoluta egg predation and crop damage caused by N. tenuis. The influence of an alternative prey (Ephestia kuehniella eggs) on the spatial distribution of predators was also evaluated by caging them in the prey presence or absence, either on tomato or sesame plants or on both. We found that the presence of sesame did not reduce the efficacy of N. tenuis or M. pygmaeus in consuming T. absoluta eggs; hatched egg proportion decreased when N. tenuis, M. pygmaeus, or both predators were present. More specifically, this proportion was more strongly reduced when both predators were combined. Sesame presence also reduced necrotic rings caused by N. tenuis on tomato plants. Nesidiocoris tenuis preferred sesame over tomato plants (except when food was provided only on the tomato plant) and the upper part of the plants, whereas M. pygmaeus preferred tomato to sesame plants (except when food was provided only on the sesame plant) and had no preference for a plant part. Combination of predators N. tenuis and M. pygmaeus allows for better coverage of cultivated plants in terms of occupation of different plant parts and better regulation of T. absoluta populations. Sesamum indicum is a potential companion plant that can be used to significantly reduce N. tenuis damage to tomatoes.


BioControl ◽  
2011 ◽  
Vol 56 (6) ◽  
pp. 883-891 ◽  
Author(s):  
Oscar Mollá ◽  
Joel González-Cabrera ◽  
Alberto Urbaneja

2019 ◽  
Vol 109 (05) ◽  
pp. 617-625
Author(s):  
M.A. Mirhosseini ◽  
Y. Fathipour ◽  
M. Soufbaf ◽  
G.V.P. Reddy

AbstractTomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive tomato pests worldwide. We tested quantity and quality of tomato fruits after simultaneous use of two biological control agents, the predatory mirid bug Nesidiocoris tenuis (Reuter) and the egg parasitoid Trichogramma brassicae Bezdenko against TLM. We varied the timing of predator releases (before or after pest establishment) and the number of parasitoids released (ten or 30 females per week per m2). The highest number of fruits per cage, percentage of undamaged fruits, total yield weight, and undamaged yield weight were all obtained with predator-in-first treatments, with or without parasitoid releases. Furthermore, measures of fruit quality were also highest in predator-in-first treatments, including, highest percentage of water, greatest proportional fresh weight of carbohydrates, most lycopene, most β-carotene, most flavonoids, and highest total chlorophyll. Thus, our findings support a predator-in-first augmentation approach for management of TLM.


2006 ◽  
Vol 37 (4) ◽  
pp. 385-404 ◽  
Author(s):  
Juan Antonio Sanchez ◽  
Jose Luis Cenis ◽  
Gerasimos Cassis ◽  
Jose Isidro Martinez-Cascales

AbstractMacrolophus contains a small group of Palaearctic species with very simple and similar external morphology. The classification of these species has been based on variable characters such as body measurements, the height of the black band-shaped macula behind the eyes and the colour of the first antennal segment. Macrolophus melanotoma (Costa 1853), Macrolophus pygmaeus (Rambur 1839) and Macrolophus costalis Fieber 1858, are the most reputed predators of the genus. The classification history of M. melanotoma and M. pygmaeus shows a great number of misconceptions that have left the identity of the two species in confusion. Despite the economic importance of these two species, they have not received comprehensive taxonomical treatment until now. In this work, the morphological and sequence variation of a cytochrome b fragment (320 bp) were analysed to determine the identity of M. melanotoma and M. pygmaeus. Macrolophus costalis, Dicyphus cerastii Wagner 1951b, Dicyphus tamaninii Wagner 1951b, Cyrtopeltis geniculata Fieber 1861 and Nesidiocoris tenuis (Reuter 1895) were used as outgroup taxons in the phylogenetic analyses. Several evolutionary models were explored under a maximum likelihood framework. Macrolophus melanotoma and M. pygmaeus were classified as two distinct species based on monophyly, molecular and morphological data. Nodes at the species level were supported by high bootstrap values. M. pygmaeus and M. costalis are sister species, M. melanotoma basal to them. The shape of the black macula behind the eye may be used as a diagnostic character to differentiate M. melanotoma from M. pygmaeus with some degree of confidence.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 274
Author(s):  
Nomi Sarmah ◽  
Athanasios Kaldis ◽  
Clauvis Nji Tizi Taning ◽  
Dionysios Perdikis ◽  
Guy Smagghe ◽  
...  

RNAi-mediated insect pest management has recently shown promising results against the most serious pest of tomato, the tomato leafminer, Tuta absoluta. This study aimed to investigate whether dsRNA (dsTa-αCOP) designed to target the T. absoluta-αCOP gene could cause adverse effects to its biocontrol agent, the mirid predator, Nesidiocoris tenuis. Oral exposure of N. tenuis to dsRNA (dsNt-αCOP) designed to target N. tenuis-αCOP resulted in a 61%, 67% and 55% reduction in its transcript level in comparison to the sucrose, dsGFP and dsTa-αCOP treatments, respectively. In addition, significantly higher mortality of 57% was recorded in dsNt-αCOP-treated N. tenuis when compared to the sucrose (7%), dsGFP (10%) and dsTa-αCOP (10%) treatments. Moreover, the predation rate of ~33–39 Ephestia kuehniella eggs per N. tenuis adult dramatically reduced to almost half in the surviving dsNt-αCOP-treated N. tenuis. This worst-case exposure scenario confirmed for the first time that the RNAi machinery is functional in this species and that the risk of exposure through the oral route is possible. In contrast, dsTa-αCOP did not cause any sub-lethal effects to N. tenuis upon oral exposure. Oral exposure of T. absoluta to dsTa-αCOP resulted in 50% mortality. In the context of a biosafety risk assessment of RNAi-mediated insect management, investigating the effects on non-target organisms is essential in order to include this method as part of an integrated pest management strategy. Based on our laboratory assays, RNAi-mediated control is compatible with the biological control of T. absoluta by its natural enemy N. tenuis, adding the RNAi approach in the armoire of integrated pest management of T. absoluta.


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