ECONEX TOMICUS PINIPERDA 60 DAYS

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ECONEX CATALOGUE OF PRODUCTS AND SERVICES FOR FOREST PESTS

Kairomone diffusers for the attraction of both sexes of the species Tomicus piniperda, with a duration of 60 days in normal field conditions.

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

The Tomicus genus is composed of seven species of Coleoptera from the subfamily Scolytinae (Curculionidae) that cause damage in species of the Pinus, Abies, Larix and Picea genus. They are mainly distributed in the Palearctic region, having been introduced into North America in the 1990s.

The Tomicus piniperda species are widely distributed in pine forests. It attacks P. pinaster, P. sylvestris and has been found on P. nigra.

MORPHOLOGY AND BIOLOGY

T. piniperda can measure between 4 mm and 5 mm long, the elytrons are dark chestnut brown with a black head and thorax.

Egg laying takes place in the maternal galleries, below the bark in some fissures on both sides. The eggs are white and round, the number of eggs laid by each female oscillates between 20 and 50. The larvae are apodous, whitish, curved and with a brown cephalic capsule. The pupae always live at the end of the larval galleries.

It is a monogamous species in which the female creates the first colonisation by making a hole that will lead to a subcortical chamber, which is a little bit wider.  It is known as the nuptial chamber.  The gallery is made by the female while the male is in charge of throwing out the sawdust, as well as, preventing the resin that the pine tree secretes from blocking the gallery.  The female places the eggs in tiered cells in the maternal gallery.

Generally, T. piniperda lays its eggs in the first weeks of March up to August.  Therefore, the T. piniperda period of attack on tree trunks is much shorter than T. destruens.  After the juveniles emerge, from July to December, they fly to the crown of the trees to feed themselves the same as T. destruens. 

With the arrival of the cold weather, the adults take refuge in the bends of the thick bark, to get through the winter until the beginning of their flight period in March.

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. Detection sampling should cover the environmental variability of the forest, the object of monitoring.

In general, traps should be installed and working between the beginning of March and the end of September.

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 propilenglicol 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

In forests

To intensify monitoring, the traps should be placed at a distance of 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.

This collection cup prevents the beetles from escaping, as they cannot climb up due to the slippery film. But, it allows the entrance and exit of the predator Thanasimus formicarius, which eats the captured insects. In this way, it minimizes the impact of trapping non-target species.

In parks, gardens and residential areas

The management of Tomicus piniperda in parks and gardens presents some peculiarities that differentiate it from management in forests.  The biggest risk of attack on ornamental trees is the one induced by mechanical damages.

Work involving excavation around the trees destroy the roots, often causing a weakening that facilitates the attack by Tomicus piniperda. In general, the ornamental trees are not very susceptible to attacks by Tomicus piniperda, provided that they maintain the conditions in which they grew up in.  Sometimes putting or taking away irrigation in garden areas can provoke attacks by these insects.

Controlling Tomicus piniperda in these circumstances should be very effective, given that it is about reducing the mortality rate of trees to zero.  Therefore, efforts should be made to intensify trapping to the maximum, so that a density of 3 CROSSTRAP^® MINI traps per hectare can be used.  They should be controlled weekly.

NECESSARY MATERIAL

CROSSTRAP^® MINI traps and ECONEX TOMICUS PINIPERDA kairomone diffusers which will be hung on the trap using the holes made for this purpose in one of the PVC sheets.

SYMPTOMS AND DAMAGES

The Tomicus genus produces two types of damage: subcortical galleries in trunks and thick branches and galleries in the small branches on the crowns of the trees.  The attack on the crowns of the trees is irrelevant given that the trees that they attack have enough strength to regenerate the losses.  However, attacks on the tree trunk are always mortal, given that through the maternal galleries and especially the larval chambers the fungi gets in and produces the degradation of the phloem around the gallery.  Also, during larvae feeding, a mechanical destruction of the phloematic canals is produced. 

They select trees or sections of tree trunk with bark that is not too thin nor too thick.  They do not tend to attack the reforestated trees. The attacked trees are easy to identify because of the volcanoes of yellow resin that surround the entrance holes.  Sometimes, trees with rejected attacks can be found alive, but with volcanoes of resin.

They prefer to reproduce in trees with initial stages of deterioration, mainly due to lack of water, competition with other trees, damage by fire or mechanically damaged.  They behave like a primary species, capable of killing very weakened trees and they do not tend to damage previously attacked trees by other bark beetles (except in very rare cases in Pinus pinaster is attacked by Ips sexdentatus).

In the absence of episodic damages, such as fires or droughts, the trees at most risk of attack are the ones situated in poor, not very deep soil, little rain and too many trees per hectare.  Also, frequent attacks on very old trees have been detected (>; 80 years), which is possibly linked to ageing.  Another risk factor is forest work, such as thinning out the forest and extraction, given that in certain conditions, attacks have been registered in healthy trees.

Special attention must be paid to the periods of intense and prolonged drought, given that they are predisposed to attacks by Tomicus not only to individual trees, but also to large masses of forest.  Between 1994 and 1996 almost 40,000 ha of pine forest in the Region of Murcia (Spain) were affected, after a prolonged drought.

Wood abandoned in the forests from forestry work is the perfect material for reproduction and once its populations reach the highest levels, they can become a real threat for other trees and forests. 

When infested, at the beginning the dead trees appear isolated or in small stands. The insect population increases rapidly and the focus changes into continuous stains, becoming more extensive every time.

The visual diagnosis is based on the presence of volcanoes of yellow resin on the trunks and thick branches.  Normally this symptom is detected after the crowns of the trees suddenly turn yellow.  After debarking the tree the presence of the specie is confirmed. This discolouration is produced in the advanced stages of infestation, when the parents and part of the offspring generation have already abandoned the host.

This contributes to making it more difficult to control, given that treatments such as tree felling and debarking the tree are only partly effective, by acting solely on part of the offspring population and practically nothing on the parent generation.  In very weak or felled trees the volcanoes of resin are not formed, so diagnosis will only be carried out by debarking and gallery identification.

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 90 and 150 days respectively.