New data on hoverfly fauna (Diptera: Syrphidae) of Bosnia and Herzegovina

Hoverflies (Syrphidae) are a large Dipteran family, distributed almost worldwide. They play very important ecological roles such as plant pollination, nutrient recycling and predation of plant pests. The members of the genus Epistrophe Walker, 1852 are medium-sized hoverflies of which about 75 species have been described in the World, and 12 of them occur in Europe. During a survey, conducted from 16th June to 4th July 2021 at Blidinje Nature Park (Bosnia and Herzegovina), a new species, of the fauna of Bosnia and Herzegovina, was recorded – Epistrophe diaphana (Zetterstedt, 1843) and new records for species Epistrophe leiophthalma (Schiner & Egger, 1853) were observed. Specimens were collected from inflorescences of Common Hogweed (Heracleum sphondylium L.). Information about the records, species habitats, distribution and status in the country and the region is presented and discussed in this research work.

Population- and Species-Based Variation of Webworm–Parasitoid Interactions in Hogweeds (Heracelum spp.) in the Netherlands

In three Dutch populations of the native small hogweed (Heracleum sphondylium L. [Apiales: Apiaceae]), and one of the invasive giant hogweed (H. mantegazzianum Sommeier & Levier [Apiales: Apiaceae]), interactions between a specialist herbivore, the parsnip webworm (Depressaria radiella), and its associated parasitoids were compared during a single growing season. We found host plant species-related differences in the abundance of moth pupae, the specialist polyembryonic endoparasitoid, Copidosoma sosares, the specialist pupal parasitoid, Barichneumon heracliana, and a potential hyperparasitoid of C. sosares, Tyndaricus scaurus Walker (Hymenoptera: Encyrtidae). Adult D. radiella body mass was similar across the three small hogweed populations, but moths and their pupal parasitoid B. heracliana were smaller when developing on giant than on small hogweeds where the two plants grew in the same locality (Heteren). Mixed-sex and all-male broods of C. sosares were generally bigger than all-female broods. Furthermore, adult female C. sosares were larger than males and adult female mass differed among the three small hogweed populations. The frequency of pupal parasitism and hyperparasitism also varied in the different H. sphondylium populations. These results show that short-term (intra-seasonal) effects of plant population on multitrophic insects are variable among different species in a tightly linked food chain.

Trace Element Uptake by Herbaceous Plants from the Soils at a Multiple Trace Element-Contaminated Site

The uptake of trace elements by wild herbaceous plants in a multiple trace element-contaminated site was investigated. The bioaccumulation factor (BF) of trace elements was markedly variable among the different plant species. On average, the BF for various trace elements was in the following decreasing order: Zn > Cu > Mn > Ni > As > Pb > Cr. The translocation factor among the investigated plant species was also considerably variable and showed the following decreasing order: Mn > Zn > Ni > Cu > Cr > As > Pb. Several hyperaccumulating plants were identified: Artemisia vulgaris for As, Mn and Zn, Phalaris arundinacea for Mn and Ni, Heracleum sphondylium for Cr and Zn, and Bistorta officinalis for Mn and Zn. The marked accumulation of trace elements in the plant tissue suggests that the site may not be suitable for urban agricultural production. The plant tissue-borne trace elements could affect microbial activities and consequently interfere with the ecosystem functioning in the affected areas.

Pollination biology of Heracleum sphondylium L. (Apiaceae): the advantages of being white and compact

Two questions were addressed in the present study: (1) What are the main pollinators of the two subspecies of <em>H. sphondylium</em>?, and (2) Do the studied plants share the pollinators' set or are they attractive for different groups of insects? The survey showed that among 40 insect taxa visiting both subspecies of <em>H. sphondylium</em> approx. only 53% carried significant pollen loads. However, the Pollinator Importance Coefficient (IC) calculated for each insect group, and based on observation of insects' abundance, within-umbel activity and pollen load revealed that only two taxa in case of <em>H. s</em>. ssp. <em>sibiricum</em> (<em>Thricops nigrifrons</em>, <em>Eriozona syrphoides</em>) and four in case of <em>H. s</em>. ssp. <em>sphondylium</em> (<em>T. nigrifrons</em>,<em>E. syrphoides</em>, <em>Meliscaeva cinctella</em> and <em>Arge ustulata</em>) were truly important pollinators. Although both subspecies were visited by similar insects, <em>H. s.</em> ssp. <em>sphondylium</em>, with its characteristic compact and white umbels, was visited more frequently by <em>Diptera</em> and <em>Hymenoptera</em>, while yellow-greenish loose umbels of <em>H. s</em>. ssp. <em>sibiricum</em> were preferred by <em>Coleoptera</em>. This paper indicates that the concept of faithful pollinators may also apply to a broader spectrum of <em>Apiaceae</em>, usually considered primitive in terms of pollination strategies, and suggests possible ways of differentiation in two closely related taxa.