This dissertation is done as a preparatory step for the action plan of environmental protection shall issue to preserve the Phytoecia nigricornis in the country when it is red-listed and classified as vulnerable (VU). My task was to investigate the prevalence of the Phytoecia nigricornis in Halland County. They wanted to see if it existed in Halland (Ehnström, 1999). If it did not exist they wanted to know how to improve its habitat.
the Phytoecia nigricornis is difficult to inventory because when it is larvae it lives in the roots and lower parts of the trunk of the Solidago Virgaurea plant and the adult beetles only keeps to Solidago Virgaurea by mating and egg laying and larval caterpillars when they hatch (Bily, 1989; Molander, 1999). Often it is overlooked or missed, and one question was whether it existed in the whole country or only in those parts where it was previously found in, Skåne, Blekinge and Östergötland (Ehnström, 1999).
One problem for the Phytoecia nigricornis is that their habitats is declining. Because the gravel and sand is an ending resource which means that today more and more go on to find materials that will replace the gravel and sand. Gravel and sand pits are closed and then gets overgrown which means that the Solidago Virgaurea is outcompeted by other stronger plants.
In early May, the beginning of the plan of the thesis and inventory were made. Premises suitable for the inventory was investigated and eventually was 16 of them elected. 9 of these facilities would, in the County Administrative Board's previous inventories have Solidago Virgaurea. Once the premises had been selected an inventory protocol were formed (Appendix 5) where information of the premises would be noted such as the weather and so on. The first inventory were outcarried on June 13th. The premises that contained Solidago Virgaurea were inventoried twice each and the other only once. The last inventory was conducted on July 6th. The inventories were carried out during this period because it is during this time Phytoecia nigricornis lay their eggs on Solidago Virgaurea and that's when you can find them in one place at the same time. None of the inventories was carried out when it rained or blew over small breezes because under these conditions Phytoecia nigricornis is hiding. After the inventories were compiled information was collected and then the report was written. No Phytoecia nigricornis were found during the inventories.