Tuta absoluta

Tuta absoluta (Meyrick) is a serious tomato pest that also damages aubergines, potatoes and can use other Solanaceae as host plants.

The geographical distribution of Tuta absoluta spreads throughout South America, Argentina (introduced by Chile in 1964, according to García and Espul, 1982), Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay and Venezuela. Tuta absoluta is not present in Andean regions in altitudes above 1.000 m because the low temperatures are a limiting factor for its survival (Notz, 1992).


MORPHOLOGY

Egg: It is creamy white, sometimes yellow, turning a darker shade when close to hatching. It is cylindrical with an average length of 0.36 mm and width of 0.22 mm.

The eggs are individually laid and rarely, they can be found in groups of 5, preferably on the underside of young or fairly mature leaves (Notz, 1992). The average duration before hatching is 4.5 days at a temperature of 24.6 oC.


Larva:
The prothoracic shield has a dark stripe on its backside. The newly hatched larva is creamy yellow to later turn a greenish colour. Its size varies from 0.9 mm at the beginning to 7.5 mm at the end of its growth period.

Once the larva emerges, it starts walking and finds its penetration point. It then breaks the epidermis and penetrates into the leaf, consuming the mesophyll. The larva can abandon the mine at any given moment and build another one on a nearby leaf. They can spread very quickly to other plants by hanging on silk threads and then being transported by the wind. The average growth period lasts 12.01 days, therefore they need to go through 4 stages.


Pupa:
Newly formed it is green, turning a dark brown colour when the adult is about to emerge. The female pupa is larger than the male pupa, measuring 4.67 mm and 4.27 mm long and 1.37 mm and 1.23 mm wide, respectively. Larvae that are ready to pupate, stop feeding and begin to spin a cocoon.

This can happen in the leaves, inside the mines, on the ground or in the fallen leaves. The average growth period for male pupae is 7.80 days and for female pupae 6.72 days.


Adult:
Both sexes have ashen forewings with shades that vary from blackish to grey. The hindwings are a bright black colour with dark cilia. The head, thorax and palps are ash grey with dark shades. The length of the back wings is from 4.5 to 4.7 mm.

They are nocturnal, remaining hidden amongst the leaves during the day. When they are annoyed, they begin an erratic and short flight. Copulation starts immediately after the adult emergence.

Fertility is high with an average of 241 eggs per female and a fertility rate of almost 100%. The vast majority of eggs are laid during the first 10 days at the beginning of oviposition. Life expectancy for males is 27 days and for females is 24 days.


SYMPTOMS AND DAMAGES

The larvae attack the fruits and the leaves by entering inside them and feeding on the mesophyll. This produces the typical damage of a leaf miner and consequently, they wither. When the attacks are severe, the damaged leaves look burnt, which could be confused with disease.

The damage produced by Tuta absoluta to tomatoes, aubergines and potatoes causes a devastating effect on the economy.


DETECTION AND MONITORING

For the detection and monitoring of Tuta absoluta, the ECONEX WHITE TRIANGULAR without sheets (Code: TA118) is recommended because of its high sensitivity and ease when counting the captured insects.

Traps should be placed on the ground 2 or 3 weeks before planting, using 1 to 2 traps per hectare. The traps can also be placed on a plastic box near the tomato plants, but at a low height.

The trap is activated by placing an ECONEX SHEET FOR TRIANGULAR (Code: TA248) on its base. The sheet is impregnated with a pressure-sensitive adhesive, without solvents, in which the insects are trapped.

The diffuser ECONEX TUTA ABSOLUTA is placed in the centre of the sticky sheet where it remains fixed by the adhesive.

ECONEX WHITE TRIANGULAR without sheets stands out mainly because of its simplicity of use. It will function until the pheromone runs out or the adhesive sheet is saturated.


MASS TRAPPING

The males of Tuta absoluta are captured in order to reduce mating, meaning that the unfertilised females will lay unviable eggs. This greatly reduces the population of the pest.

For mass trapping, the following wet traps are recommended: ECONEX WATER TRAP (Code: TA133) or ECONEX WATER TRAP (ECO) (Code: TA246) because of their effectiveness, large capacity and low maintenance.

To carry out mass trapping, the number of traps per surface area should be increased, depending on location and homogeneity of the plots. A trap controls a surface area between 250 and 500 m2. This means a density of 20 to 40 traps per hectare.


NECESSARY MATERIAL

ECONEX WATER TRAP or ECONEX WATER TRAP (ECO) should be placed with a pheromone diffuser: ECONEX TUTA ABSOLUTA 0.50 MG 60 DAYS (Code: VA220), ECONEX TUTA ABSOLUTA 0.80 MG 60 DAYS (Code: VA275) or ECONEX TUTA ABSOLUTA 1 MG 90 DAYS (Code: VA328).

5.21 € (excl. VAT)

3.73 € (excl. VAT)

ECONEX WATER TRAP is made up of 6 parts which have to be assembled. It measures 17.5 cm high x 35 cm diameter and the tray has a 3.7 litre capacity. In this wet trap, you have to pour water into the tray and we recommend adding a film of oil to the water to increase the captures. The pheromone diffuser is placed in the upper cage.

ECONEX WATER TRAP (ECO) is made up of 2 parts: a tray of 5 cm high x 34 cm diameter with a 3.5 litre capacity and a cage to place the pheromone diffuser. In this wet trap, you have to pour water into the tray and we recommend adding a film of oil to the water to increase the captures. The pheromone diffuser is introduced into the cage which is placed in the centre of the trap.

ECONEX TUTA ABSOLUTA pheromone diffuser:

Active ingredients of the Tuta absoluta pheromone: E3, Z8, Z11 tetradecatrienyl acetate: E3, Z8-tetradecadienyl acetate (90:10).

Duration of the diffuser: Once the trap has been placed, the diffuser lasts 60 or 90 days (depending on the chosen product) in field conditions.

Product storage: The ECONEX TUTA ABSOLUTA pheromone diffusers must be stored in their original packaging and in the refrigerator at 4 ºC or in the freezer at -18 ºC, in which case they will last for 2 and 4 years respectively.

2.93 € (excl. VAT)

3.39 € (excl. VAT)

3.75 € (excl. VAT)


PERIOD OF USE

To obtain good control of the Tuta absoluta it is advisable to combine two methods: detection and monitoring; and mass trapping. 2 to 3 weeks before planting, 1 or 2 traps per hectare should be placed to detect the pest and observe its population levels.

With tolerance thresholds established in each area, the moment to adopt control measures, in this case mass trapping, can later be defined.

The tolerance threshold of Tuta absoluta is very low and depends on the area. In general, it is approximately 3 captures per trap and per week. For mass trapping, traps should be placed throughout the plots.


FACTORS THAT INFLUENCE THE NUMBER OF TRAPS NEEDED

The pest population, the bordering crops, the level of control required, etc….

One important factor is the size of the crop. In small and irregular crops, a greater number of traps are required than in larger and more uniform plots.

Another important factor is the distance between plots that have the same pest. In cases like this, the borders of the plots must be reinforced, so it could be necessary to place up to 40 traps per hectare or even more for mass trapping.


ADVICE

  • Once the commercial harvesting period has finished, during which time the crops are stored in good phytosanitary conditions, the rest of the plantation must be cleared as quickly as possible. This includes any fruit that may have been left on the ground.
  • Place all of the traps throughout the plots again and leave them there for a minimum of 3 weeks after having cleared the remaining crops.
  • Where possible, apply soil solarisation and biosolarisation treatments straight after having cleared the remaining crops. This ensures that any remaining larvae or chrysalis will be eliminated.
  • When planting new crops, ensure the plots are very well cleaned, at least 3 weeks before replanting. Close the greenhouses with netting (6 x 9 threads/cm2) and double doors.
  • Keep the traps in place for two weeks before planting and if captures are detected inside the plot, carry out special monitoring of the new plants. When the amount of captures exceeds 3 – 4 adults per trap and per week, mass trapping should be carried out.
  • If the level of damage is very low in crops, then the damaged leaves can be manually disposed of.
  • In the event that new larvae appear in the crops and the amount of adults captured exceeds 30 – 40 per trap and per week, a treatment should be applied using specific products.

RESULTS

If specialists or farmers use traps and pheromones correctly, as previously described, especially during the early stages when adults of the first generation appear, this monitoring system is very effective. A very low level of damage, mainly on organic land, has been demonstrated.

A level of control of more than 90% is fairly common, especially in large areas of crops. A limiting factor of this system could be when there are small plots distributed all around, surrounded by others that have a high level of infestation of Tuta absoluta.

Despite some important basic rules for an effective control of Tuta absoluta, every farmer or specialist has to find their own system of control to achieve it. They can experiment with this system, even establishing their own tolerance thresholds.


PACKAGING – ECONEX TUTA ABSOLUTA 0.50 MG 60 DAYS

Corrugated cardboard box of 3.000 units (150 packs of 20 units)
Box size: 0.60×0.40×0.35 m (length x width x height)
Box weight: 9.8 kg.
No. of boxes per pallet: 20.
Pallet size: 1.20×0.80×1.90 m (length x width x height).
Pallet weight: 203 kg.


PACKAGING – ECONEX TUTA ABSOLUTA 0.80 MG 60 DAYS

Corrugated cardboard box of 3.000 units (150 packs of 20 units)
Box size: 0.60×0.40×0.35 m (length x width x height)
Box weight: 9.8 kg.
No. of boxes per pallet: 20.
Pallet size: 1.20×0.80×1.90 m (length x width x height).
Pallet weight: 203 kg.


PACKAGING – ECONEX TUTA ABSOLUTA 1 MG 90 DAYS

Corrugated cardboard box of 3.000 units (150 packs of 20 units)
Box size: 0.60×0.40×0.35 m (length x width x height)
Box weight: 9.8 kg.
No. of boxes per pallet: 20.
Pallet size: 1.20×0.80×1.90 m (length x width x height).
Pallet weight: 203 kg.


Recommended information:


ECONEX TUTA ABSOLUTA LEAFLET

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ECONEX WEB RESOURCES

Section of the ECONEX corporate website that allows you access to online information about ECONEX solutions for the biocontrol of other relevant agricultural and forest pests.

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