Using the zoophytophagous plant bug, Nesidiocoris tenuis, for the control of Tuta absoluta in tomato: Its direct effects on the plants and their yield and its control efficacy
Plant Protectionאורגני; הגה"צ; ירקות
תאריך עדכון 14/3/2012
Using the zoophytophagous plant bug, Nesidiocoris tenuis, for the control of Tuta absoluta in tomato: Its direct effects on the plants and their yield and its control efficacy
Danit Parker, Ela Yosel, Shimon Pivonia, Rachel Levite – Central and Northern Arava Research and Development
Arnon Allush and Shimon Shtainberg – Bio-Bee.
E-mail address for correspondence: shimonp@arava.co.il
Abstract
Tuta absoluta is a new pest in Israel that causes a great deal of damage to different crops, especially tomato. In the U.S., T. absoluta is considered a quarantine pest. This species is a member of the Order Lepidoptera and the Family Gelechiidae. After the larvae of this species emerge, they burrow through leaves to fruit and stems, forming characteristic tunnels and trenches. Sometimes the larvae will penetrate the stems and tips of the canopy, strangling these tips and causing them to wither. The adult of the species is about 10 mm long. The control measures and materials available for use against this insect are not sufficient, especially those that can be used in organic agricultural systems, for which the number of permitted products is extremely limited. In response to the recent spread of this species throughout the Mediterranean basin, intensive studies have been conducted in many areas with the goal of developing ways to cope with this problem. One area of this research is the development of an integrated management system involving the local natural predator Nesidiocris tenius, which is particularly suited to tomato. N. tenius is a member of the Order Hemiptera and the Family Miridae. The adults of this omnivorous species can feed on animals or plants. N. tenius feeds on eggs and first-stage larvae of the T. absoluta moth and, therefore, holds potential for use as a biological control agent against this species. When this insect subsists on a plant diet, it sucks the sap from leaves, stems and young fruit, creating bands of dead tissue that can lead to the desiccation and eventual shedding of leaves and fruit.
In an experiment conducted at the Yair Experimental Station during the 2010/11 season, we examined the efficacy of N. tenuis against the moth T. absoluta, evaluated the level and character of the damage N. tenuis caused to tomatoes in the greenhouse and compared the biological-control efficacy of this insect with the amount of damage it caused to the tomato crop. The experiment was conducted using tomato line 1402 (Hazera). At the beginning of the season, T. absoluta was not present in the tunnels we were using for the experiment and we focused on evaluating the level of direct damage caused to the tomato plants by N. tenius. We evaluated three treatments with different levels of N. tenius: unregulated, regulated and a N. tenius -free control. When T. absoluta appeared in the tunnels, we examined the effects of the treatments listed above on the level of damage T. absoluta was able to inflict on the tomato plants and their yield.
The regulated N. tenius treatment included chemical intervention each time there were more than five individuals per stem meristem. It was very difficult to control the N. tenius population using the chemicals labeled for use in organic agriculture. We found that the N. tenius caused a lot of leaf damage, but did not negatively affect yield over the winter or through April. Later on, there could have been a certain amount of damage related to the dramatic increase in the N. tenius populations. Next season, we will also examine the effect of N. tenius on the quality of cluster tomatoes in addition to its effects on tomatoes that produce individual fruits (as we examined this year). It is possible that the damage to the main stem caused by N. tenius will negatively affect the crop. After T. absoluta appeared in the tunnels in March, we found less T. absoluta-inflicted damage in the leaves and fruit in the N. tenius treatments than in the control. The lowest level of T. absoluta damage was observed in the regulated N. tenius treatment. This is apparently due to the fact that the product that was used to control N. tenius in this treatment (Tracer; spinosad) also controls T. absoluta. Experiments with N. tenius and the evaluation of its efficacy against T. absoluta in organic crops will continue in the coming season.
שפה English
מחבר Danit Parker, Ela Yosel, Shimon Pivonia, Rachel Levite, Arnon Allush, Shimon Shtainberg
שנה 2011
שייכות yzvieli
תאריך יצירה 14/3/2012
תאריך עדכון 14/3/2012