The Tomicus genus is composed of seven species of Coleoptera from the subfamily Scolytinae (Curculionidae). They cause damage to species of the Pinus, Abies, Larix and Picea genus. They are distributed throughout most of the Palearctic region since their first appearance in North America in the 1990s.The Tomicus piniperda species attacks P. pinaster, P. sylvestris and especially P. nigra.

MORPHOLOGY AND BIOLOGY

Tomicus piniperda can measure between 4 and 5 mm long. It has a black head and thorax and the elytrons are dark brown. Oviposition takes place in the maternal galleries, in incisions under the bark on both sides of the gallery. The eggs are white and round. The number of eggs that the females lay can vary between 20 and 50. The larvae are apodous, curved and whitish. They have brown cephalic capsules. The pupae always grow at the end of the larval galleries.

T. piniperda is a monogamous species, in which the female creates the first colony by boring a hole that leads to a chamber under the bark. It is slightly wider and is known as the nuptial chamber. The female creates the gallery whilst the male removes the sawdust, as well as preventing the resin secreted by the pine tree from blocking the gallery. The female lays the eggs in niches inside the maternal gallery.

As a rule, T. piniperda lays the eggs during the first weeks of March up to August.  Therefore, the T. piniperda period of attack on tree trunks is much shorter than the T. destruens period. After the young emerge, from July to December, they fly to the crown of the trees to feed just like T. destruens.

With the arrival of the cold weather, the adults take refuge in the roughness of the thick bark. They remain there throughout winter until the beginning of their flight period in March.

SYMPTOMS AND DAMAGES

The Tomicus genus produces two types of damage: galleries under the bark of the tree trunks and thick branches; and galleries in the twigs or crowns. The attack in the crowns is irrelevant, given that the trees they attack have enough strength to regenerate their losses. However, the attacks in the tree trunk are always deadly. Through the maternal galleries and most of the larval galleries fungus is introduced, which deteriorates the phloem of the gallery perimeter. Furthermore, whilst the larvae are feeding, a mechanical destruction is produced in the phloematic canals.

They go for trees or sections of trunk, with bark that is neither too thin nor too thick. They do not tend to attack reforested trees. The trees that have been attacked are easily identified because of the volcanoes of yellow resin that surround the entrance holes. On occasion, trees with rejected attacks can be found alive, but with volcanoes of resin.

They prefer to reproduce in trees that are in the initial stages of decline, mainly due to lack of water, competition with other trees and mechanical or fire damage.

In the absence of occasional damages, such as fires or drought, the trees that are at most risk of attack are found in thin, poor soil with scarcely any rain and too many trees per ha. Frequent attacks on very old trees (more than 80 years) have also been detected, possibly linked to the trees aging. Another risk factor is  the forest work involved in clearing and extracting trees. In some cases, attacks have been registered in healthy trees.

Special attention must be paid to the periods of intense and prolonged drought, as they influence Tomicus sp. attacks.

Abandoned wood from forest work is the perfect material for Tomicus destruens to reproduce and once the population density has reached high levels, it could become a real threat for other trees and forests. Regarding the pest situation, at first the dead trees appear to be alone or in a small circular areas. The pest populations grow rapidly and the outbreaks change into continuous stains, more spread out every time.

Visual diagnosis is based on the presence of volcanoes of yellow resin in the tree trunks and thick branches. Normally, this symptom is detected after the crown suddenly turns yellow. By removing the bark, the presence of the species is confirmed. This discolouration is produced in advanced stages of infestation, when the parent and part of the offspring generation have already abandoned the host.

This makes controlling it more difficult, as the treatments for cutting down and debarking a tree are partly effective, by working solely on the part of the offspring population and practically nothing on the parental population. In very weak or cut down trees no volcanoes of resin form, so diagnosis can only be carried out by debarking the trees and identifying the galleries.

SCALE OF DAMAGE

There are two types of damage, with different management methods.

EXTENSIVE DAMAGE, in forests. The following grades of damage have been suggested:

Grade 0: Stand with some dead trees. It is possible to find rejected attacks.
Grade 1: Stand with dispersed dead trees.
Grade 2: Stand with dead trees and some small dispersed circular areas.
Grade 3: Stand with clear evidence of large or many small circular areas tending towards mass mortality.
Grade 4: Mass mortality.

LOCALISED DAMAGE in public areas, such as parks and gardens.

Grade 0: Some dead trees and rejected attacks in other trees.
Grade 1: Death of less than half of the trees.

DETECTION AND MONITORING

In forests 1 CROSSTRAP® MINI should be placed every 20 ha, separated at least 1000 m from each other. In surfaces less than 20 ha, at least one trap should be placed per stand or forest. The traps should be placed in areas with good visibility, such as forest borders, forest trails or fire-breaks. Windy areas should be avoided, as the wind complicates the insects’ flight and could damage the traps. A detection trap system should cover the environmental variability of the monitored forest.

As a rule, traps should be placed and active between mid-September and mid-April. These periods of time could be shorter in years with the beginning of autumn and spring being very warm.


For monitoring, wet captures are recommended
as they allow for the precise identification of the captures. For this purpose, fill the collection cups with 10 ml of diluted propylene glycol (10 to 20%), or with antifreeze for the car. This liquid is used for killing the captured insects as well as preserving them. It must not be dissolved too much with the rainwater, in which case it should be replaced. It is recommended to collect the captured insects at least every 15 days.

EXHAUSTIVE MONITORING

In forests

For exhaustive monitoring, the traps should be placed between 100 and 500 metres apart from each other in forest trails, fire-breaks or forest borders.

This means a density of 0.3 to 3 CROSSTRAP® MINI per ha. They can also be placed inside the forest, as long as it is not too dense. Dry captures are recommended for exhaustive monitoring using the slippery collection cup with a stainless steel mesh on the base. The collection cup stops the bark beetles from escaping because they cannot climb out due to the slippery product, although it allows the entrance and exit of the predator Thanasimus formicarius, which devours the captured insects. In this way, the impact of the trap system on useful fauna is minimal.


In parks, gardens and residential areas

The management of Tomicus in parks and gardens presents some peculiarities that differentiate it from management in forest environments. The biggest risk of attack in ornamental trees is caused by mechanical damage. Work involving excavation around the trees, more or less severe, destroys the roots and often causes a weakening that facilitates the attacks by Tomicus. In general, ornamental trees are not very vulnerable to attacks by Tomicus, provided that they maintain the same conditions that they grew in. Sometimes, placing or removing irrigation systems in garden areas can provoke attacks from these insects.

The control of Tomicus in these situations must be very effective, as it is about reducing the mortality rate of the trees to zero. Therefore, efforts should be made to intensify trapping to the maximum. This means a density of 3 CROSSTRAP® MINI per ha, that should be controlled each week.

NECESSARY MATERIAL

CROSSTRAPs® MINI and diffusers of kairomones ECONEX TOMICUS PINIPERDA 60 DAYS (Code: VA188)  should hang on the trap using one of the lateral holes on the vanes of the trap.

ECONEX TOMICUS PINIPERDA 60 DAYS contains two diffusers of kairomonal attractant for males and females of Tomicus piniperda + 2 hangers in the form of a clip to hang the diffusers on the trap.

Diffuser A contains 25 ml of a-Pinene with 98% purity. The release rate is 0.3 gr. per day at 20 oC.

Diffuser B contains 100 ml of ethanol with 96% purity. The release rate is 2 gr. per day at 20 oC.

The diffusers are in a blister pack and individually packaged in an aluminium sachet with label specifications. They last 60 days in field conditions. Once removed from the packaging, the diffusers need no activation or opening, just placed correctly in the trap.

17,82 € (excl. VAT)

CROSSTRAP® MINI is a state-of-the-art forest trap. This trap has been created through an R + D project (University of Murcia – ECONEX) aimed at developing traps and attractants for forest insects.

The trap consists of a 33 cm diameter polypropylene lid with a central carabiner attached to a steel spring. Two reinforced PVC vanes are held in place by four steel springs in the lid’s upper section. They are used as elements of dynamic suspension, serving as shock absorbers against the force of the wind exerted on the trap, avoiding its breakage in the forest. The vanes are also fixed to the lower part of a 30 cm diameter polypropylene funnel. The collection cup is fixed to the lower part of the funnel by screws.

The vanes, funnel and collection cup are treated with a slippery product that increases the amount of captures considerably, also preventing the insects from escaping.

CROSSTRAP® MINI can last up to 7 years due to its structure and highly resistant components. The unfolded trap measures 33 cm diameter x 100 cm high. Once folded, it is 33 cm diameter x 40 cm high, making its transport easier.

48,27 € (excl. VAT) 48,27 € (excl. VAT)

The trap can be used with two types of collection cup: CROSSTRAP® WET COLLECTION CUP for wet captures (with liquid), and CROSSTRAP® DRY COLLECTION CUP for live captures (without liquid).

CROSSTRAP® WET COLLECTION CUP (Code: TA156) has an approximate capacity of 2 litres and a drain in the upper section to prevent it from filling with rainwater.  It measures 12.5 cm diameter x 19 cm high and has a slippery product to prevent the captured insects from escaping.

CROSSTRAP® DRY COLLECTION CUP (Code: TA157) has the same capacity and measurements as the CROSSTRAP WET COLLECTION CUP® but it has a base made of stainless steel mesh that drains away the rainwater 100% and eases air circulation.

3,48 € (excl. VAT) 5,08 € (ecxl. VAT

FACTORS THAT INFLUENCE THE NUMBER OF TRAPS NEEDED

In forest environments the number of traps are determined by the area that needs to be covered, forest trails, fire-breaks and accessible borders. For exhaustive monitoring, a density of between 0.1 and 0.3 CROSSTRAP® MINI per ha is recommended, separated between 100 and 500 lineal metres. Therefore, it is recommended to use a GPS system during installation.

In parks, private gardens, play areas, public gardens or small forest areas (<5 ha), the density of traps increases greatly, even using up to 3 CROSSTRAP® MINI per ha.

In these areas, the death of just one tree is shocking enough to intensify trapping and to capture the greatest number of insects possible.

STORING THE DIFFUSERS

The product should not be stored for long periods of time. It must be stored in its original packaging and in the refrigerator at 4 oC; or in the freezer at -18 oC, in which case it will last between 90 and 150 days respectively.

PACKAGING

ECONEX TOMICUS PINIPERDA 60 DAYS

Corrugated cardboard box of 100 units (20 packs of 5 units).
Box size: 0.60×0.40×0.35 m (length x width x height).
Box weight: 23.5 kg.
No. of boxes per pallet: 20.
Pallet size: 1.20×0.80×1.90 m (length x width x height).
Pallet weight: 477 kg.

Recommended information:

ECONEX CATALOGUE OF PRODUCTS AND SERVICES FOR FOREST PESTS

Catalogue in PDF format with 94 pages. It is an essential reference book about the biological behaviours of the main forest insect populations. It also includes ECONEX solutions to solve the problems caused by these insects through the use of traps and specific attractants.

You can download the catalogue by clicking on the image.

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.

To access ECONEX WEB RESOURCES click on the image.