Tecia solanivora has caused important damages to potato crops in the North of Tenerife and recently in potato crops of Gran Canaria and La Palma. Its importance is based as much on the damage it causes to potatoes in fields, as well as the damage later produced in warehouses, where the conditions are ideal for its fast reproduction.It is native to Guatemala, where it was described for the first time. Since then, it has spread throughout Central America (Costa Rica, Panama, Honduras, Nicaragua, El Salvador) and later to South America. Venezuela, Colombia and Ecuador are the only countries to have suffered from potato crop damage. In The Canary Islands it was detected in 1999, specifically in Tenerife and later in Gran Canaria and La Palma in 2002.
It only grows over Solanum tuberosum potatoes. As with all moths, they are nocturnal and begin their cycle by laying their eggs above the potatoes or near them. They lay between 200 to 500 eggs. The fertility of the eggs reaches 95% and the incubation period can last between 5 and 15 days, depending on the temperature.
Once hatching has taken place, the larva, which measures 1.5 mm and is a creamy white colour, enters inside the potato where it grows. It is responsible for the damage of the potato, characterised by loss of weight and quality. At the end of the larval phase, that lasts between 15 and 29 days, the larva abandons the potato measuring 16 mm and a greenish colour to later turn a pinkish colour.
Once outside the potato, the larva stops feeding on it and creates a cocoon of silk together with bits of different materials. Inside it, stays the chrysalis (pupa). This phase can occur in the ground, sacks, fissures and cracks on the floors and walls. It can also pupate inside the potato. At the beginning, the chrysalis (pupa) is light brown but when the adult emerges, it turns a darker colour. This phase lasts between 10 and 20 days.
According to the previous table, the moth can finish its biological cycle between 42 and 95 days, depending on the temperature.
Important facts of its biology:
– In high temperatures, there are more generations but a higher percentage of mortality.
– The minimum temperature for its growth is from 7 to 9 oC.
– Temperatures below 10 oC and rain are a limiting factor for its growth.
SOURCE: Consejería de Agricultura, Ganadería, Pesca y Alimentación de la Comunidad Autónoma de Canarias.
DETECTION AND MONITORING
1 to 2 traps per hectare should be placed at the same height as the crops or on an ECONEX TRAPS SUPPORT (Code: TA051).
The traps should be placed as soon as the Tecia solanivora populations increase during the crop cycle. This usually happens during the process of tuberisation, so it is recommended to place the traps when the flowers bloom until harvest time.
The traps should be placed approximately 30 to 60 cm high from the ground and the maximum height will be determined by the growth of the plants (if the traps are placed lower than usual, once the crops have grown, it will be difficult to find them).
The traps should be placed in the field paying attention to the plot’s borders, where the populations increase much faster. In addition, if the traps are placed inside the plots it makes access to them very difficult due to the high density of the potato crops.
POTATO CROPS IN FIELDS:
For mass trapping, the amount of traps per surface area must be increased, depending on the location or homogeneity of the plots. One trap controls a surface area between 500 and 1.000 m2. This means a density of 10 to 20 traps per hectare.
STORED POTATOS IN WAREHOUSES:
For an effective use of the traps, it is necessary to have knowledge of the biology of the insect.
The traps should be placed where there is more possibility of finding the Guatemalan potato moth, as well as in specific phases of the food production process where a fast detection of the insects’ presence is important. In warehouses with a smaller quantity of stored produce, it is also convenient to place traps. In places where the activity is important, the traps should be monitored weekly to observe the amount of captured insects. In other areas, every 15 days.
In warehouses, the density of traps is a minimum of 3 traps and a maximum of 9 traps per 1000 square metres. Enclosures near to the infected area should have traps as well as the corridors that are connected to this area. If the corridors come from the infected area, they should have 2 traps (one in front of the other).
A trap ECONEX POLILLERO (Code: TA001), EOSTRAP® (Code: TA042) or ECONEX WHITE TRIANGULAR without sheets (Code: TA118) and an ECONEX TECIA SOLANIVORA 2 MG 60 DAYS attractant diffuser (Code: VA182).
For mass trapping, the ECONEX POLILLERO and the EOSTRAP® are more ap-propriate than the ECONEX TRIANGULAR. In the ECONEX POLILLERO and the EOSTRAP®, it is recommendable to place any substance capable of killing or re-taining the captured insects inside the trap, such as olive oil.
The ECONEX WHITE TRIANGULAR without sheets trap is activated by placing an ECONEX SHEET FOR TRIANGULAR (Code: TA248) on its base and the ECONEX TECIA SOLANIVORA 2 MG 60 DAYS diffuser on the centre of the sheet. The sticky sheet of ECONEX SHEET FOR TRIANGULAR is impregnated with a pressure-sensitive adhesive, without solvents, in which the insects are trapped. The trap is provided with a special wire hanger.
The ECONEX WHITE TRIANGULAR without sheets trap stands out especially because of its simplicity of use. It will work until the pheromone runs out or the adhesive sheet is saturated. It is less recommendable in areas with lots of dust.
PERIOD OF USE
To obtain good control of the Tecia solanivora, it is advisable to combine the two methods: detection and monitoring; and mass trapping.
1 or 2 traps per hectare should be placed to detect the pest and observe its population levels, 60 days before harvesting.
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 for Tecia solanivora is very low and depends on the area. In general, it is approximately 21 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 crops. 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 20 traps per hectare or even more for mass trapping.
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 95% is very common, especially in large areas of crops. A limiting factor of this system could be when there are small plots distributed all around and the neighbours have a high level of infestation of this pest.
Despite important basic rules for an effective control of Tecia solanivora, 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.
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.
TECIA SOLANIVORA 2 MG 60 DAYS 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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