ECONEX ORTHOTOMICUS EROSUS 60 DAYS

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ECONEX CATALOGUE OF PRODUCTS AND SERVICES FOR FOREST PESTS

Aggregation pheromone diffuser for the attraction of both sexes of the species Orthotomicus erosus, with a duration of 60 days in normal field conditions.

The diffuser is blister-pack shaped, with a polyolefin layer permeable to the active ingredients, and it is packaged in an aluminium sachet with labelled specifications. Once taken out of the sachet, the diffuser do not need any activation operation. Simply place it directly in the trap. DO NOT OPEN, CUT OR PERFORATE THE BLISTER. The appropriate emission rate is achieved by diffusion through the polyolefin layer.

The Orthotomicus erosus (Wollaston, 1857) belongs to a genus made up of 24 species of Palearctic and Paleotropical distribution that attack many species of trees.  Orthotomicus erosus is a bark beetle that mainly attacks the Pinus species, although it has also been sighted on Cupressus, Picea, Cedrus libani, Abies pinsapo and Pseudotsuga menziesii.  It is distributed in a natural manner through circunmediterranean Europe, central Europe, the British Isles, North Africa, central Asia and China.  O. erosus is considered an invasive exotic species that has introduced itself into South Africa, Chile, Uruguay, Fiji Islands, USA and other islands of the Pacific.

In general, it is considered a secondary species that attacks very weak trees, but it can also attack live trees in states more or less at the beginning of deterioration or extremely stressed out.  The causes of this stress tend to be the extreme lack of water due to drought or fires.  Also, blue stain fungi can vectorise, like Ophiostoma o Leptographium (Kirisitis, 2004) or other pathogens, such as Fusarium calmorum (Romón et al, 2007) or Sphaeropsis sapinea (Zwolinski, 1995).

BIOLOGY

This species can produce more than three generations a year depending on the temperature.  It is a polygamous species, meaning that its biological potential is enormous in the Mediterranean areas where the temperature is high in summer.

The male excavates the entry point and the nuptial chamber, emitting aggregative pheromones which attract many females, normally three. The pregnant females excavate the maternal gallery leaving the nuptial chamber and following the longitudinal axis of the tree.  The males remove the sawdust from the maternal galleries.

When the larvae are born, they begin to feed on the phloem creating sinuous galleries very close to each other at the beginning.  As the larvae continue to grow the galleries increase their diameter and separate from one another.

The larval galleries are full of compacted sawdust and excrement, product of the food supply, while the maternal galleries remain clean.  When the larva reaches its maturity, it excavates a pupa chamber where it transforms into an imago.  It emerges on the outside through a hole that it has perforated in the bark after a period of maturity on the inside of the pupal chamber.

The duration of the larval period is variable.  Normally, a week passes from the eggs laying to the eggs hatching if the temperature is between 15 and 25⁰C.  The larval period lasts about 20 days and the pupa one week.  So normally, the cycle is completed in about 35 days.  Exceptionally, it can be completed in 15 days if the conditions are favourable.

The new imagoes come out ready to start the cycle again.  When the temperatures start to lower, between the months of September and November, the adults group together in the winter galleries, where they get through the coldest months.

These winter galleries have a different shape that are more irregular.  Grouping can cause the bark to lift up and detach itself.  Its activity begins again when the temperature rises, beginning a biological cycle again.

DETECTION AND MONITORING

In forests 1 CROSSTRAP^® MINI trap per 20 ha should be installed, the traps should be separated at least 1000 m from each other.  In surfaces less than 20 ha at least 1 trap should be installed per forest stand.

The traps should be installed in areas with good visibility, such as edges of the forest, forest paths or fire-breaks.  Especially windy areas should be avoided, as it makes it difficult for the insects to fly and could damage the traps.

A detection trap should cover the environmental changes of the target forest area.  In general, the traps should be installed and operative between May and October.

For monitoring it is recommended to choose wet captures, given that it will allow the precise identification of the captures. For this purpose, the collection cups can be filled with 10 ml of diluted propylene glycol at 10% or 20%, or anti-freeze for the car could be used. 

This liquid is used for killing the captured insects as well as preserving them, as long as, it does not get too diluted by the rain, in which case it should be replaced.  As a minimum, it is recommended that captured insects be collected fortnightly.

EXHAUSTIVE MONITORING

To intensify monitoring, the traps should be placed at a distance of between 100 and 500 metres apart, following forest trails, fire-breaks or the edges of the forest.

The amount of traps can rotate between 0,3 and 3 CROSSTRAP^® MINI traps per ha.  They can also be installed inside the forest, provided that the forest is not too dense. For exhaustive monitoring dry (live) captures are recommended, using the collection cup with a stainless steel mesh and a slippery film.

MATERIAL NECESARIO

A CROSSTRAP^® MINI trap and an ECONEX ORTHOTOMICUS EROSUS 60 DAYS pheromone diffuser which will be hung on the trap using one of the holes made for this purpose in one of the PVC sheets.

DAMAGES AND ELEMENTS OF DIAGNOSIS

The larval galleries made by the larvae when they feed cut the circulation of water and nutrients in the tree.  As a general rule, Orthotomicus erosus attacks very weak, but still living stems. On occasions, and in areas where the forest is much debilitated, primary insect behaviour has been detected.  That is to say, that they are capable of colonising apparently healthy trees.

The affected pines initially turn yellow on the upper part of the crown, until finally reaching the lower branches of the tree.  The dark sawdust is very obvious having been evacuated from the galleries in mass attacks. Orthotomicus erosus is a transmitter of blue stain fungus, apart from the direct damage to the tree, it causes losses to the wood.

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.