Abstract. 1. Advances in LED technology combined with solar, storable energy bring light to places remote from electricity grids. Worldwide more than 1.3 billion of people are living off-grid, often in developing regions of high insect biodiversity. In developed countries, dark refuges for wildlife are threatened by ornamental garden lights. Solar powered LEDs (SPLEDs) are cheaply available, dim, and often used to illuminate foot paths, but little is known on their effects on ground living (epigeal) arthropods.2. We used off-the-shelf garden lamps with a single 'white' LED (colour temperature 7250 K) to experimentally investigate effects on attraction and nocturnal activity of ground beetles (Carabidae).3. We found two disparate and species-specific effects of SPLEDs. (i) Some nocturnal, phototactic species were not reducing activity under illumination and were strongly attracted to lamps (>20-fold increase in captures compared to dark controls). Such species aggregate in lit areas and SPLEDs may become ecological traps, while the species is drawn from nearby, unlit assemblages. (ii) Other nocturnal species were reducing mobility and activity under illumination without being attracted to light, which may cause fitness reduction in lit areas.4. Both reactions offer mechanistic explanations on how outdoor illumination can change population densities of specific predatory arthropods, which may have cascading effects on epigeal arthropod assemblages. The technology may thus increase the area of artificial light at night (ALAN) impacting insect biodiversity.5. Measures are needed to mitigate effects, such as adjustment of light colour temperature and automated switch-offs.

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Geographic variation of sexually selected male traits is common in animals. Female choice also varies geographically and several studies found female preference for local males, which is assumed to lead to local adaptation and, therefore, increases fitness. As females are the nondispersing sex in most mammalian taxa, this preference for local males might be explained by the learning of male characteristics. Studies on the preference of females in female-dispersing species are lacking so far. To find out whether such females would also show preferences for local males, we conducted a study on greater sac-winged bats (Saccopteryx bilineata), a species where females disperse and males stay in their natal colony. Male greater sac-winged bats possess a wing pouch that is filled with odoriferous secretion and fanned toward females during courtship display. In a combination of chemical analysis and behavioral preference tests, we analyzed whether the composition of wing sac secretion varies between two geographically distinct populations (300 km), and whether females show a preference for local or distant male scent. Using gas chromatography, we found significant differences in the composition of the wing sac odors between the two geographically distinct populations. In addition, the behavioral preference experiments revealed that females of both populations preferred the scent of geographically distant males over local males. The wing sac odor might thus be used to guarantee optimal outbreeding when dispersing to a new colony. This is—to our knowledge—the first study on odor preference of females of a species with female-biased dispersal.

350 plant extracts were studied regarding to their characteristic repellency to Blattella germanica by means of a preference method. The repellency value reveals strong dispersion variation within plant families and, in some cases, also within genera. The individual developmental stages and sexes of B. germanica reveal differing behavioural patterns concerning test extracts. In the case of the strongly repellent extracts from Citrus sinensis and Allium sativum, there are indications for habituation processes regarding the repelling stimuli during long‐term tests. Zusammenfassung Verhaltensreaktionen von Blattella germanica L. (Orthopt., Blattellidae) auf abweisende Pflanzenextrakte Es wurden Extrakte von 350 Pflanzenarten hinsichtlich ihrer abweisenden Wirkung auf die Deutsche Schabe Blattella germanica untersucht. Der Abweisungswert der Extrakte erwies sich als deutlich nach Pflanzenfamilien und in einigen Fällen auch nach Gattungen verschieden. Die Entwicklungsstadien und Geschlechter von B. germanica zeigten unterschiedliche Verhaltensmuster den getesteten Extrakten gegenüber. Im Fall der stark abweisenden Extrakte von Citrus sinensis und Allium sativum deuteten Hinweise auf eine Gewöhnung der Schabe an Abweisreize im Langzeittest.