ECONEX TECIA SOLANIVORA 2 MG 60 DAYS

Sexual pheromone diffuser of the species Tecia solanivora to attract males, with a duration of 60 days in normal field conditions.

Diffuser of natural rubber in capsule-shape. It is packaged individually in an aluminium sachet with labelled instructions. Once taken out of the sachet, the diffuser does not need any activation operation. Simply place it directly in the trap

The Tecia solanivora has caused considerable damage to potato crops in the north of Tenerife (Spain) and has recently been introduced in the potato-growing areas of Gran Canaria and La Palma (Spain). Not only can it cause damage to tubers in the field but also to potatoes stored in warehouses, which have ideal conditions for their numbers to multiply.

Originally from Guatemala where it was first noted, it has colonized all of Central America (Costa Rica, Panama, Honduras, Nicaragua, El Salvador) and South America, affecting countries such as Venezuela, Colombia and Ecuador.  It was detected in the Canary Islands in Tenerife in 1999 and in Gran Canaria and La Palma in 2002.

BIOLOGY

It grows exlusively on Solanum tuberosum potato tubers.  It has nocturnal habits like all moths. The new life cycle begins with the eggs being laid on or near the tubers in numbers from 200 to 500. 95% of eggs are fertilized and the incubation period lasts between 5 and 15 days depending on the temperature.

Once the eggs have hatched, the larva is 1.5 mm long and creamy white. It punctures the tuber to develop inside it and is responsible for the damage which is characterized by loss in tuber weight and quality. The larval period lasts 15-29 days, at the end of which the larva leaves the tuber. It now measures 16 mm and has first a greenish and later a pinkish hue.

Once it has left the tuber it stops feeding and forms a cocoon made of silk and other materials, inside of which it pupates. This pupa stage can occur on the ground or in bags, fissures and cracks in floors and walls. The larvae can also pupate inside the tuber. The chrysalis (pupa) is initially light brown but darkens just before the adult emerges.  Pupation lasts approx. 10-20 days.

It can be seen from the table above that the moth can complete its life cycle in 42 to 95 days depending on the temperature.

Some points to note about their development include:

-  A greater number of generations at higher temperatures, but also a higher mortality rate.

 - The minimum temperature for development is 7-9 C.

 - Temperatures below 10^OC and the presence of rain limit their development.

SOURCE: Council of Agriculture, Livestock, Fisheries and Food of the Autonomous Community of the Canary Islands (Spain).

NECESSARY MATERIAL

An ECONEX POLILLERO, EOSTRAP®, ECONEX TRIANGULAR without sheets, ECONEX DISPOSABLE WHITE TRIANGULAR or ECONEX DISPOSABLE WHITE TRIANGULAR MINI, and a pheromone diffuser ECONEX TECIA SOLANIVORA 2 MG 60 DAYS.

The trap ECONEX WHITE TRIANGULAR without sheets is activated by placing an ECONEX SHEET FOR TRIANGULAR (Code: TA248) at the base of it. The sheet is impregnated with a pressure sensitive adhesive, solvent free, in which insects are trapped.  The trap ECONEX DISPOSABLE WHITE TRIANGULAR is coated on its inner face with a layer of contact adhesive, solvent free, for the retention of the insects.

Both traps stand out above all for their simplicity of use, and will be operative until pheromone depletion or saturation of the sheet or adhesive surface. The pheromone diffuser is placed inside the trap on the sheet or adhesive surface.

DETECTION AND MONITORING

1 to 2 traps should be set per hectare at crop level and can be placed on an ECONEX TRAP SUPPORT if required.

The traps should be set as soon as the Tecia solanivora populations increase during the growing season which usually occurs during the tuberisation period. It is advisable to set traps from flowering to harvest time.

The traps should be set at a height of approx. 30-60 cm. from the ground. The maximum height at which traps can be suspended from depends on foliage growth, (if they are placed too low, they will be difficult to locate once the crop starts to grow).

The traps should be set in the field taking into account crop boundaries as this is where the pest population can increase more rapidly. If the traps are set in the centre of the field it will become difficult to find the traps due to the potato crop foliage.

MASS TRAPPING

A) IN FIELDS WITH POTATO CROPS

Mostly the males of this species are captured, in order to reduce the mating, so that non-copulated females will have unviable eggs. This reduces the pest population.

To carry out mass trapping the number of traps per area should be increased depending on the location and homogeneity of the crops. One trap can control an area of between 500 and 1,000 m². This entails a trap density of 10 to 20 traps per hectare.

B) IN WAREHOUSES WITH STORED POTATOES

The pest's biology should be understood in order to use the traps effectively.

The traps should be set where the Guatemalan potato moth is likely to be. Traps should also be set at key places in the food production process where the rapid detection of insects is vital. In warehouses with smaller amounts of produce, traps should also be set.  Where insect activity is high traps should be inspected weekly in order to observe the number of insects caught and every 2 weeks for other areas.

The trap density can range from a minimum of 3 to a maximum of 9 traps per 1,000m² of storage space.  The areas adjoining an infected area should also have traps, in addition to any connecting corridors. If a corridor leads directly to an infected area, then 2 traps should be set.

PERIOD OF USE

To achieve good control of the Tecia solanivora, it is advisable to combine the two methods: detection and monitoring and mass trapping.

1 or 2 traps should be set per hectare in spring for pest detection and monitoring of population levels. Traps should be set 60 days before harvesting.

Through established thresholds of tolerance in each area, the control measures are later defined, in this case mass trapping.

The threshold of tolerance for Tecia solanivora is very low and varies according to the area. Generally it is around 21 captures per trap and per week. Moment in which we recommend to set traps all over the crop for mass trapping.

FACTORS THAT INFLUENCE THE NUMBER OF TRAPS REQUIRED

Pest population, adjoining crops, level of control required, etc.

An important factor is crop size. In small and irregular sized crops a greater number of traps will be needed. Another important factor is the distance between crops with the same pest. In such cases the crop boundaries should be reinforced, so a trap density of about 20 traps per hectare may be needed.  More traps may be needed in the case of mass trappings.

RESULTS

If technicians or farmers use the traps and pheromones as described here and when the first generation of adults emerges, then the effectiveness of this control system is very good, with a very low level of damage. When large crop areas are covered, more than 95% of the pest is often controlled.

A factor limiting this system is where there are small farms surrounded by other plots with a high level of infestation of this pest.  Apart from some important basic rules in controlling Tecia solanivora effectively, each farmer/technician should find his/her own system of achieving this and he/she may experiment with this system, even establishing his/her own tolerance thresholds.

STORAGE OF THE DIFFUSERS

The diffusers must be kept in their original container and in a refrigerator at 4^oC, or in the freezer at -18^oC, in which case they will remain valid for 2 and 4 years respectively.