|Hausmann, A; Dötterl, S: Nectar plants and larval food-plants of the genus Glossotrophia (Geometridae, Sterrhinae): studies on pollen grains attached to museum specimens. , Nota Lepidopterologica, 26, 127-136 (2004)|
|Key words: Geometridae, Sterrhinae, Glossotrophia, pollen load, museum specimens, nectar sources, host plants, Caryophyllaceae|
544 specimens of the Geometrid moth genus Glossotrophia, belonging to nine species, were examined under the stereomicroscope searching for attached pollen grains. Pollen was found on 105 specimens (8 species). In addition we identified pollen grains of further 39 specimens under the scanning electron microscope. Pollen grains attached to the tip of the abdomina of nine females strongly indicate egg deposition at or in those flowers (mainly Caryophyllaceae). Pollen grains attached to the proboscis or neighbouring structures, most frequently found in the subgenus Glossotrophia, and here preferably in females, are suggestive of nectar plant use. The subgenus Glossotrophia turned out to be almost exclusively specialised on Caryophyllaceae nectar plants (mainly Silene, Dianthus), whereas the other subgenera utilize a wider spectrum of nectar sources. This finding does well correspond to the known spectra of larval host-plants. A strong positive correlation was found between length of proboscis, preference for Caryophyllaceae, and frequency of pollen grain attachment. Collectively, these results demonstrate that the analysis of pollen loads in museum specimens (though sometimes being very old) may provide valuable data on host use patterns through time and space.