Arthropod fauna recorded in flowers of apomictic Taraxacum section Ruderalia

Abstract

Abstract. Flowers of dicotyledonous plants host communities of arthropod species. We studied the community associated with dandelion (Taraxacum section Ruderalia), a complex of apomictic micro-species abundant in central Europe. Identifi cation of microspecies in the fi eld was impracticable. These plants produce an abundance of fl owers that host arthropod communities that are not yet fully documented. We investigated species occurrence, its diurnal and seasonal variation and some of the factors that determine the abundance of the dominant species. Insect and spiders were collected from 2010 to 2012 at a locality in Prague. Whole capitula were harvested at weekly intervals and resident arthropods were identifi ed. Diurnal variation in insect presence and the effect of pollen and microclimate on some of the species were also examined. The insect community (> 200 species) consisted mainly of species of Hymenoptera (86 spp.), Coleoptera (56 spp.), Diptera (46 spp.) and Heteroptera (23 spp.). The most abundant were Thysanoptera (2 spp.). Pollen eaters/collectors and nectar feeders dominated over predators and occasional visitors. From April to mid-August, the insect community was dominated by Coleoptera, and later by Diptera and Hymenoptera. Except for Meligethes spp. and species breeding in the capitula, the insects occupied fl owers during the daytime when the fl owers were open (10-12 h in spring and only 2-4 h in late summer). The presence of Meligethes spp. in particular fl owers was associated with the presence of pollen; the occurrence of Byturus ochraceus with pollen and fl ower temperature. Although pollination is not necessary, dandelion plants produce both nectar and pollen. The community of arthropods that visit dandelion fl owers is rich despite their being ephemeral. The composition of local faunas of fl ower visitors, presence of fl oral rewards and fl ower microclimate are important factors determining the composition of the fl ower community.

A comparison of wild bee communities in sown flower strips and semi‐natural habitats: A pollination network approach

“…Plants offering high amount of nectar may be favoured not only by bees but also by butterflies and some groups of long‐tongued Diptera (Labandeira, 2000). On the other hand, other groups of flower visiting insects such as Coleoptera and many groups of Diptera or parasitic Hymenoptera visit flowers mainly for pollen (Labandeira, 2000), so different flowering species such as yellow Asteraceae and Apiaceae may be more important food source for these groups of pollinators (Hegland & Boeke, 2006; Honěk et al, 2016; Klecka, Hadrava, Biella, & Akter, 2018). Although different groups of pollinators may vary in their floral and habitat requirement, we suggest that the exclusive focus of our study on aculeate Hymenoptera is justified for several reasons: (i) sown flower strips were designed mainly to support bees; (ii) in comparison with many other groups of pollinators, bees usually have a relatively narrow diet and may thus be sensitive to inappropriate selection of sown plants; (iii) unlike other groups of pollinators, the whole life‐cycle of bees is dependent on plant–pollinator interactions, because not only adults but also larvae are fully reliant on food from flowers; and (iv) aculeate Hymenoptera is a diverse group with a number of species of conservation relevance with specialised requirements of floral resources, climatic and habitat conditions, and high degree of philopatry because of their nesting strategy, so they can serve as proper bioindicators at small spatial scales (Talašová et al, 2018; Tscharntke et al, 1998).…”

Are plants in sown flower strips suitable for communities of wild bees? Pollination network approach in conservation biology

“…Plants offering high amount of nectar may be favoured not only by bees, but also by butterflies and some groups of long-tongued Diptera (Labandeira 2000). On the other hand, other groups of flower visiting insects such as Coleoptera and many groups of Diptera or parasitic Hymenoptera visit flowers mainly for pollen (Labandeira 2000), so different flowering species such as yellow Asteraceae and Apiaceae may be more important food source for these groups of pollinators (Hegland & Boeke 2006, Honěk et al 2016, Klečka et al 2018b). Although different groups of pollinators may vary in their floral and habitat requirement, we suggest that the exclusive focus of our study on aculeate Hymenoptera is justified for several reasons: i) sown flower strips were designed mainly to support bees; ii) in comparison with many other groups of pollinators, bees usually have a relativelly narrow diet and may thus be relatively sensitive to inappropriate selection of sown plants; iii) in bees, not only adults, but also larvae are reliant on food from flowers, so the pollination network should also reflect the food web of bee larvae; and iv) aculeate Hymenoptera is a diverse group with a number of species of conservation relevance with specialised requirements of floral resources, climatic and habitat conditions, and high degree of philopatry because of their nesting strategy, so they can serve as proper bioindicators at small spatial scales (Tscharntke et al 1998, Talašová et al 2018).…”

Flower scent of Ceropegia stenantha: electrophysiological activity and synthesis of novel components

“…Flowers of C. stenantha do not offer such rewards but may attract food-seeking Scatopsidae to its trap flowers by emitting reward-indicating aromatic components commonly found in rewarding flowers. Scatopsidae are known to visit such flowers to feed on pollen and/or nectar (Apiaceae: Haenni 1997 ; Asteraceae: Haenni 1990 ; Honěk et al 2016 ; Dipsacaceae: Haenni 1984 ; Rubiaceae: García-Robledo and Mora 2007 ) and probably use chemical cues to find them. Food deception through signals that indicate a reward/rewarding species is a well-studied strategy with different facets, e.g., Batesian mimicry and generalized food deception (see Johnson and Schiestl 2016 ).…”