Assessing European Egg Parasitoids as a Mean of Controlling the Invasive South American Tomato Pinworm Tuta absoluta

Abstract

The South American tomato pinworm (Tuta absoluta) has recently invaded Europe and is rapidly spreading in the Afro-Eurasian continent where it is becoming a major pest on tomato crops. Laboratory tests were undertaken to evaluate the potential of 29 European strains of Trichogramma parasitoids to control T. absoluta. In addition to the host itself, the host plant (tomato) was used during the laboratory tests in order to increase the chance of selecting the best parasitoid strains. Trichogramma females were placed with T. absoluta eggs on a tomato leaflet in tubes. We compared the parasitism of T. absoluta by the various Trichogramma species tested to the Trichogramma species currently commercially available for the pest control in Europe, i.e. Trichogramma achaeae. Thereafter, the more promising strains were tested on a larger scale, in mesocosm (i.e. cages in greenhouses) and in greenhouse compartments to evaluate efficiency of laboratory selected strains under cropping conditions. The most efficient strain from the laboratory screening trials did not perform as efficiently under the greenhouse conditions. We discuss differences in parasitism levels among species and strains and among the different scales tested in the experiments, as well as implications of these results for further screening for biocontrol agents.

Assessment of Two <i>Trichogramma</i> Species with <i>Bacillus thuringiensis</i> var. krustaki for the Control of the Tomato Leafminer <i>Tuta absoluta</i> Meyrick (Lepidoptera: Gelechiidae) in Iran

“…Results showed that both T. richogramma species accepted T. absoluta eggs as host and the species of T. embryophagum exhibited promising (31.18%) parasitism when treated in combination with Bt vs. 23.05% of parasitism without Bt. Our result were in line with results obtained by Chailleux et al [23] that investigated twenty-nine Trichogramma speciesstrains on T. absoluta eggs under laboratory conditions and recorded the highest rate of egg parasitism (35.4%) for T. achaeae. Furthermore, we found a significant increase in the number of parasitized eggs when the tomato plants were simultaneously treated with Bt.…”

Oviposition deterrent activity of basil plants and their essentials oils against Tuta absoluta (Lepidoptera: Gelechiidae)

“…Moreover, these insecticides also negatively impact the natural enemy populations of T. absoluta (Arnó and Gabarra 2011;Biondi et al 2013;Abbes et al 2015) owing to multiple potential side effects as described by Desneux et al (2007) in a review. The effectiveness of biological control using entomopathogenic organisms (González-Cabrera et al 2011;Ben Khedher et al 2015) beneficial insects (Ferracini et al 2012;Chailleux et al 2012;Chailleux et al 2013;Öztemiz 2013;Salehi et al 2016) present valuable alternative methods to synthetic pesticides. For example, the use of certain Miridae as Macrolophus pygmaeus Rambur or Dicyphus maroccanus Wagner appears to be a reliable biological alternative for the control of T. absoluta (Urbaneja et al 2013;Abbas et al 2014;Jaworski et al 2015).…”

The New Invasive Pest <i>Tuta absoluta</i> (Meyrick) (lepidoptera: Gelechiidae) in India and its Natural Enemies along with Evaluation of Trichogrammatids for its Biological Control

“…Adults emerged from parasitized T. absoluta eggs (4.8%, 97.5% and 90.0% adult emergence respectively), however, they appeared to be weak, smaller and with reduced longevity. Chailleux et al 16 also observed that adult trichogrammatids emerging from Tuta eggs possessed inferior biological traits like wing deformations, lower parasitism rates and reduced longevity. Some reports indicate that field releases of trichogrammatids were not consistently effective, which could have been because of the weak adults emerging from the parasitized T. absoluta eggs.…”

“…However, information is scarce on the per cent Trichogramma adult emergence from parasitized Tuta eggs, and the parasitizing efficiency of the emerged adults. Laboratory, cage and greenhouse studies indicate that strainal variations exist in trichogrammatids with respect to their parasitizing efficiency on T. absoluta eggs [16][17][18][19] . In order to develop a Tuta adapted strain of Trichogramma, trichogrammatids which emerged from Tuta eggs were further allowed to parasitise rice moth (Corcyra cephalonica Stainton) eggs.…”

“…Greenhouse studies indicated that T. achaeae was most efficient in management of Tuta absoluta 16,18,19 . Trichogramma pretiosum was introduced from Colombia into Brazil 20 and was reported to be unsuccessful in managing T. absoluta population 21 .…”