Stick glue trap without glue

Bio-Colortrap® green glue stick

7 traps

Official approval is not required!

The glue stick is used to monitor the asparagus fly (Platyparea poeciloptera) and is made of environmentally friendly laminated paper round sticks (40 cm long and 2.5 cm in diameter). The green-coloured traps are coated with insect glue. Years of research by the German Institute for Plant Cultivation and Plant Protection in Mainz and the Biological Regional Institute for Plant Protection in Horticulture in Braunschweig (Germany) have shown that glue sticks are the only effective trap of all studied types.

Mode of action:

Due to the green colour coating, the trap is relatively weather-resistant and has proven to be particularly attractive for both males and females of the asparagus fly. Dark traps enhance the contrast with the usually light soil, making them more visible to the flies. It is also assumed that the vertical outline of the round sticks is crucial for the approach of asparagus flies. The TEMMEN insect glue does not contain any attractants and is used exclusively to catch asparagus flies.

Application:

The use of traps to monitor flight patterns provides, for the first time, the opportunity to accurately match the application of insecticides to the presence of asparagus flies in the field. The need is acute, as currently only a few active substances are available for control. Since the flight of the asparagus fly can extend over a long period (end of April to end of July) and the number of applications is limited, the choice of the ideal spraying time is very important. Monitoring with glue sticks is especially suitable for young plants and high-yield plants with a shortened harvest period. Because asparagus flies only lay their eggs in above-ground plant parts, it is sufficient to place the traps in high-yield plants only after the harvest season has ended in order to assess the need for control in the following year. 

Treat at least the bottom two-thirds of the glue sticks with TEMMEN insect glue. Then place the traps over bamboo sticks which have previously been stuck vertically into the ground. Make sure the glue stick touches the ground. 

At least three to five glue sticks should be placed per field at a minimum distance of 15 metres between two asparagus plants. 

Evaluation of the catches:

Thanks to the conspicuous appearance of the fly, checking the traps is easy. Asparagus flies have a size of 7 to 9 mm and they have a characteristic black and white wing band by which they are easily recognised. The method is therefore not only suitable for the warning service of the plant protection authorities, but also for the growers themselves. Ideally, the sticks should be checked, cleaned and, if necessary, re-glued twice a week. Experience has shown that old glue and dirt can be easily removed with a flexible spatula (e.g. made of slightly thicker cardboard or plastic). If the glue sticks are not checked over a longer period of time, they may become so dirty that they can no longer catch asparagus flies and misrepresent the flight pattern. The glue sticks remain effective for about four weeks.  

Damage threshold:

Effective control of the asparagus fly requires knowledge of its occurrence and flight pattern. Until now, warnings from the plant protection authorities were mostly limited to the first appearance of the flies and were not based on captures in traps. However, since the first appearance of the fly does not coincide with the highest flight activity, this information is of limited use for control purposes. In addition, the flight pattern of the fly can vary greatly between fields within a growing area. It is difficult to define a precise damage threshold above which an asparagus field should be treated against the fly. According to the results of the experiment, values above 5 flies/trap and assessment period (two assessments/week) should be considered as a provisional damage threshold.

Control:

Older plantings that are in production have no above-ground parts during the main flight period of the pest. This means that there is less risk of infestation for these plants. As a preventive measure, it is advisable to cut off the asparagus foliage low to the ground in autumn and destroy it, in order to remove the pupae from the beds. All infested stems - easily recognisable by their crooked growth - should be ruthlessly cut out close to the root crown and burned. During the flight period, from April to July, the beds can be covered with a plant protection net (preferably made of cotton). Chemical treatment should only be carried out on the basis of captures in traps.