Asian bedbug: a bactericide to limit its spread

In a rather negative situation, two positive notes emerged in Futurpera: the possible use of bactericides that would work exclusively on eggs preventing the development of H. halys and research on the courtship mechanism between males and females

Barbara Righini by Barbara Righini


The rejection by the Paff Committee of the European Commission of Chlorpyrifos and Chlorpyrifos-Metile was in the air but it is a new tile that falls on the head of Italian fruit growers, the two active ingredients in fact are widely used against the Asian bug which, as it is you know, this year caused millions of euros in damage. We then go to the ban on the two phosphorganics. Already chemical defense, as farmers well know, alone is not decisive, more and more, for the next season, it will therefore be necessary to implement a strategy that involves all the means available in order to literally surround adversity .

It was impossible not to talk about H. halys in Futurpera (28-30 November), since periculture was among the sectors most affected by the bug in 2019. During the World pear forum, which saw the participation of the major experts from H. Halys in Italy, we tried to take stock of the situation and to define strategies for the coming season, hoping to be able to count, from spring, on an ally like T. japonicus. The alien antagonist is already present on Italian territory but, without the successful end of the ongoing bureaucratic procedure, it cannot be launched.

Luca Casoli, director of the Phytosanitary Consortia of Modena and Reggio Emilia, clarified the complexity of an enemy like the Asian bug: “The fundamental element – he said – is that none of the possible solutions is decisive. It takes an integrated strategy and In fact, the species is not only inside the pereti, but it is also outside, this characteristic will have an important role for the multiplication of the antagonists and to achieve a balance. It is our strong point. In the orchard we will have to proceed with a direct and indirect strategy. Each fruit grower has his own experience, and we know that the results are different from context to context. We have a certain number of insecticides to be used at the right times and in the correct location within the orchard, the monitoring that gives years is implemented will give support to make decisions, but the company will have to complete the monitoring, the context of the l single plot. The autochthonous antagonists are then enhanced and the exotic ones eventually introduced. On the one hand, therefore, the control strategy in the orchard with the chemistry and other available means (networks for example), on the other an indirect control with the achievement of an environmental balance outside the orchard “.

Chemistry shows limits for reasons made clear during the conference: H. halys moves from one crop to another, the insecticides available work by contact and have a limited persistence over time, they are also non-specific: “Many low-tech impacts developed over time have found a limitation in the spread of the Asian bug and now we have problems of imbalance for questions of selectivity of the substances “, an annotation reluctantly said still by Casoli and which means that the non-selectivity of the substances and the need to negotiate on several occasions to limit the attacks are jeopardizing a balance that has been achieved over the years. This is to the detriment of “good” insects that helped to defend crops from other adversities.

In a sea of ​​negativity and discouragement, palpable during the conference, two positive notes: Lara Maistrello (Unimore) explained that work is being done (with the Mach Foundation) on the courtship mechanism between males and females of H. halys, so to be exploited in the fight against the insect. To mate, male and female of the Asian bug, communicated through vibrations, signals that have been deciphered by researchers to build traps; Luciana Tavella (Disafa Kingdom) has instead announced that, starting from next season, we can think of using bactericides against the Asian bedbug, in particular experiments have been carried out, also on the field, with good success, on the eggs of the insect.

The bactericides would work exclusively on eggs, preventing the development of H. halys: “The research is by Alberto Alma (Disafa Kingdom) and is giving good results, we also have the first tests in the field. The female – told AgroNotizie Luciana Tavella – lays leaving bacteria on the eggs, these are fundamental for the life of the offspring. We distribute bacteriostatic and bactericidal substances on the vegetation, in this way the bacteria are eliminated and the bedbug cannot develop. The further good news is that these substances, already at disposition, they are not going to interfere with the parasitoids or oophages of which much is being talked about “.


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