In tribute to the journalists Rafael Serra, José Antonio Montero and Miguel Miralles for his recent Award BBVA Conservation of the Biodiversity in your journal “Quercus”, the dean of the press environment. The article on the bed bug invader (Zelus renardii) published in his notebook 392 is the main source of this article.
Although at the popular level is known internationally as a “Bug killer” that no one panic, because it is a predator very effective, but only of insects and other invertebrates. Zelus renardii is characteristic of the arid regions of southern north America and northern Mexico, and from some years it has been lodged in the Spanish levant, especially in the Valencian Community.
When you say “bug” we refer to insects of the order Hemiptera and suborder heterópteros, and in this case we do not refer to a species very well known, especially decades ago, in the environment of human households: the bug of the beds (Cimex lectularius), the “killer” we are talking about even belongs to the same family.
The first data on the presence of Zelus renardii in our Peninsula date back to 2015, when Luis Vivas discovered the species in a gardened area of Valencia next to the Turia gardens; subsequently, observations have been multiplied in Valencia city and in towns nearby.
The ornamental plants, both the scrub as the aromatic, supported often in the areas designated to the adult bed bug killer and their larvae and placed, they formed for several hundreds of eggs of color, completely white. The broad-leaved plants are preferred to deposit them.
Portrait of a predator
The bug Zelus presents a very streamlined body and is provided of the characteristics wings of the Hemiptera, that have a hard part and other membranous (Hemiélitros). Its general color is orange and red: they are very striking, their antennae and six legs, all of great length.
The most characteristic feature of his predatory behavior is the attitude upright it takes to attack their prey, in a way comparable to that of the well-known praying Mantis. To prevent their victims from escaping, the sticks to their legs by means of a discharge that is sticky warm. Really there is no one who will rejoice in the embrace of such an effective predator.
The ecological importance of the invasion
In principle, the study by Paul Vera, Eduardo Pascual, Rubén Gracia and José Luis Greño , published in the notebook of October of Quercus, tells more of the adventures of our invasive species, that in reference to the invertebrates already exceeds the number of five hundred. The preference to urban ‘s bug on which we are commenting makes it particularly easy to observe, although not so much of control.
The need of such control is not limited to the scientific aspect, that always advisable to avoid these presences undesirable plant and animal species, invasives, but also to the haste to prevent his action may unbalance the ecosystem in which it has been detected.
Because the progress of an insect of these features can be unstoppable if you do not take immediate action, and the consequences of these invasions are unpredictable.
It is true that the bed bug killer consumes aphids and other pests of ornamental plants, in this sense it would be positive for its presence, but otherwise their preferences are oriented towards small beetles that are the best eaters of those, such as the small Crisópidos, beautiful metallic reflections, which by their beauty, listed among the “insects jewel”.
Not only have appeared these bugs in Valencia, but also in different localities of Alicante and Murcia are probably spreading already by all the mediterranean coastal zone.
This is not only a visitor of the plants of gardening, because in the last few months have made observations on the botanical species typical of the mediterranean scrub, such as Lavender, Cistus and Mastic, and also in the wetlands.
The conclusions of the cited authors of the study that it is very possible that the species is already so settled in our waterfront that is impossible to eradicate, and we have to get used to living with it; in these moments it is not possible to exactly determine the ecological consequences of such implementation, but we can venture that will not be good, and that your activity is predatory on beetles could have an impact in the remarkable increase of populations of aphid parasites of the plants, the urban and the Mediterranean Scrub.
The presence in Europe of these invaders, that we dare to qualify by the time of the plague, is not limited to the Spanish mediterranean coast, but also to Greece and Italy. It seems that they have come to stay.
We insist not to confuse these bugs invading with our old enemies, the bugs of the beds, which by the way have become to come back parasitizing our beds, in areas where they had spent decades eradicated.
The biodiversity of ecosystems is viewed very seriously threatened by invasive species, so that it is fair to thank the researchers that work in these aspects as little spectacular for the public at large. To convince the Management that it is necessary to allocate resources to the fight against these enemies will be the next test that must face the scientists.