Faglig grunnlag for handlingsplan for strandmaurløve ... - NINA

NINA Rapport 889
Abstract
Endrestøl, A. 2012. A scientific basis for a management action plan for the antlion Myrmeleon
bore – NINA Report 889. 84 pp.
The antlion Myrmeleon bore (Tjeder, 1941) belongs to the order Neuroptera (net-winged insects).
We have 57 species from this order in Norway. Antlions belong to the family Myrmeleontidae,
consisting of only two species in Norway; Myrmeleon formicarius and Myrmeleon bore. M. bore
was separated from M. formicarius and scientifically described as a new species by Tjeder in
1941.
The adult individuals of antlions are relatively large, flying insects that are somewhat similar to
dragonflies. The difference is e.g. that the antlions have long, club-shaped antenna and that the
wings are positioned in a “roof” shape when the animal is at rest. The adult antlions are active
at dusk and at night and are therefore not very easy to spot. The larvae, however, have a very
characteristic way of life. The larvae of the antlion live in the bottom of conical pits which they
have constructed in loose sand. They are typical sit-and-wait predators. The larvae of the antlion
have powerful jaws that they use to catch and digest their prey. The habitat of M. bore is confined
to hot, coastal sandy beaches, habitats that both have limited distribution in Norway, and which
are threatened.
M. bore has a very limited distribution in Norway along the southeast coast from Telemark County
to Østfold County. Today we know of 20 certain localities of M. bore in Norway, one in Telemark
County (Sandbakken, Jomfruland), three in Vestfold County (Sandø, Lilleskagen and Ula) and
16 in Østfold County (Søndre Sandøy, Kirkøy, Asmaløy, Åven, Nordre Nesetbukta, Rauer, Store
Sletter og Eldøya).
Beach habitats, where M. bore exists, are dependent on some form of disturbance. This may
be due to natural factors like weather and wind, but it can also be due to grazing and mowing,
or other human activity. The threats against M. bore are associated with these disturbances
either becoming too intense, which prevent the antlion from pit-making and hunting, or too light,
resulting in areas becoming overgrown such that the antlion will no longer find open sandy
areas for pit-making. M. bore is therefore naturally rare with limited distribution in Norway and its
populations are threatened. The species is therefore red listed as endangered (EN) in Norway.
To ensure robust populations of M. bore at each locality, local distribution and actual threats must
be identified. If the use is too intense, it will be appropriate to channel and manage the public
outside the main antlion-areas. If the main threats are associated with overgrowth, other measures
such as light grazing, exposure of sand and removal of vegetation should be considered.
An action plan with a duration of five years, 2012-2016, is suggested.
The main objective of the action plan should be to ensure a long-term existence of M. bore
in Norway.The County Governor in Østfold would be responsible for implementing this action
plan. The first phase of the plan would be mapping of local distribution and threats at each
known locality, and preparation of local management plans. The next phase includes a survey of
potential sites, as well as monitoring effects of the management implemented on each site. The
final phase includes evaluation and further recommendations.
Anders Endrestøl, NINA, Gaustadalléen 21, 0349 Oslo, Norway, anders.endrestol@nina.no
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