Taxonomy and phylogeny of sawfly genus Empria (Hymenoptera, Tenthredinidae)
Date
2012-08-21
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Abstract
Elurikkust on teaduslikult kirjeldatud üle 250 aasta, kuid suurem osa (hinnanguliselt 80–90%) sellest on teadusele ikka veel tundmata. Suurema osa palja silmaga nähtavast kirjeldatud ja kirjeldamata elurikkusest moodustavad putukad. Neid on teada ligi miljon liiki, kuid avastamata võib olla lausa kümme korda rohkem. Üks liigirikkamaid putukaseltse on kiletiivalised (nt. herilased, mesilased ja sipelgad), kuhu kuulub ka doktoritöös uuritud põhja poolkeral levinud 60 liigiline perekond Empria. Tegemist on lehevaablastega, kes vastsestaadiumis on kõik taimtoidulised ja meenutavad liblikaröövikuid. Täiskasvanud empriad on väiksed (4–9 mm) mustad putukad. Iseloomulikuks tunnuseks on tagakehal paiknevad valged laigud, mille põhjal on perekonda teistest lehevaablastest kerge eristada. Liikide määramine on paraku aga võimalik pea ainult mikroskoobi abiga ja seejuures tuleb tavaliselt isastel genitaalkapslist eraldada peenisvalvid ja emastel munetid. Aga kui see on tehtud, siis on liikide määramine üldjuhul lihtne igaühele, kuna tavaliselt erinevad eri liikidel peenisvalvid ja munetid väga selgesti. Võib öelda, et on lihtsalt vaja galeriid kõikide liikide peenisvalvidest ja munetitest ning seejärel üles leida otsitav. Doktoritöö raames koostati ida poolkera empria liikide (50) jaoks määramistabel koos fotodega peenisvalvidest ja munetitest (lääne poolkera liikide kohta oli vastav info juba olemas). Nende seas on 13 uut liiki teadusele, millest 9 ootab veel nimetamist. Lisaks kasutati 46 liigi (nii ida kui lääne poolkeralt) DNA andmeid põlvnemissuhete väljaselgitamiseks. Edasiste uurimuste ülesandeks oleks kirjeldada seni teadusele tundmatud liigid ja välja selgitada kõikide liikide toidutaimed (rohkem kui pooltel teadmata). Lähemat uurimist vääriks empria ka liigitekke aspektist, kuna perekonnas paistab olevat enam-vähem pidev skaala nii rohkem kui vähem eristunud liikidest ja mõnede liigirühmade või -paaride puhul polegi liigipiirid päris selged. Aga miks meil üldse neid empria liike vaja tunda? Otsest majanduslikku tähtsust neil pole (Põhja-Ameerikas võivad paar liiki siiski olla maasika kahjurid). Teaduse seisukohalt on aga tegemist ühe pusletükiga teadmiste üldises mosaiikpildis, mille kokkupanemine aitab meil üha paremini mõista ümbritsevat maailma.
Although scientists have been describing biodiversity for more than 250 years, most of the species (probably 80–90%) remain unknown. Insects form the largest proportion of known and unknown macroscopic biodiversity. Nearly million insect species have been described, but the number of undescribed species could be ten times greater. Among the insects, order Hymenoptera (e.g. ants, bees, and wasps) is one of the largest, which also includes the sawfly genus Empria (60 species). Sawflies are plant feeding and caterpillar-like in the immature stage. Adults of Empria are small (4–9 mm) black insects. Characteristic of the genus are pale paired patches on abdominal terga, which makes it easy to distinguish from other sawflies. Species identification, however, is possible only using a microscope and usually penis valves need to be dissected from genital capsules of males and ovipositors from females. If this is done, the species identification is generally quite easy for anyone with a microscope, because the differences between penis valves and ovipositors of different species are usually obvious. It could be said that you simply need a gallery of penis valves and ovipositors to determine a species. The doctoral thesis includes a key to adults of Empria from eastern hemisphere (50 species) with photos of penis valves and ovipositors (corresponding information was already available for species of western hemisphere). There are 13 species new to science, 9 of which are still without a name. In addition, DNA sequence data from 46 species (including both hemispheres) was used to reconstruct the phylogeny of the genus. Future studies should describe the remaining unknown species and elucidate the host plants of all the species (unknown in more than half of the species). Closer look at Empria could also contribute to speciation studies, as there appear to be more or less continuous variation from highly distinct species to species pairs or groups with fuzzy species boundaries. Why is it necessary to know Empria species at all? The genus is not economically particularly important (couple of species in North America can be pests of strawberry), but from a scientific point of view the knowledge about it can be considered as a piece of a puzzle, assembling of which continuously improves our ability to make sense of the world.
Although scientists have been describing biodiversity for more than 250 years, most of the species (probably 80–90%) remain unknown. Insects form the largest proportion of known and unknown macroscopic biodiversity. Nearly million insect species have been described, but the number of undescribed species could be ten times greater. Among the insects, order Hymenoptera (e.g. ants, bees, and wasps) is one of the largest, which also includes the sawfly genus Empria (60 species). Sawflies are plant feeding and caterpillar-like in the immature stage. Adults of Empria are small (4–9 mm) black insects. Characteristic of the genus are pale paired patches on abdominal terga, which makes it easy to distinguish from other sawflies. Species identification, however, is possible only using a microscope and usually penis valves need to be dissected from genital capsules of males and ovipositors from females. If this is done, the species identification is generally quite easy for anyone with a microscope, because the differences between penis valves and ovipositors of different species are usually obvious. It could be said that you simply need a gallery of penis valves and ovipositors to determine a species. The doctoral thesis includes a key to adults of Empria from eastern hemisphere (50 species) with photos of penis valves and ovipositors (corresponding information was already available for species of western hemisphere). There are 13 species new to science, 9 of which are still without a name. In addition, DNA sequence data from 46 species (including both hemispheres) was used to reconstruct the phylogeny of the genus. Future studies should describe the remaining unknown species and elucidate the host plants of all the species (unknown in more than half of the species). Closer look at Empria could also contribute to speciation studies, as there appear to be more or less continuous variation from highly distinct species to species pairs or groups with fuzzy species boundaries. Why is it necessary to know Empria species at all? The genus is not economically particularly important (couple of species in North America can be pests of strawberry), but from a scientific point of view the knowledge about it can be considered as a piece of a puzzle, assembling of which continuously improves our ability to make sense of the world.
Description
Väitekirja elektrooniline versioon ei sisalda publikatsioone.
Keywords
lehevaablased, taksonoomia, fülogenees, liigikirjeldused, määramine, Tenthredinidiae, taxonomy, phylogeny, species descriptions, determination