Mimicry, Commensalism, Detritophagous, Predators, Migration and All These in Volucella Zonaria (Poda 1761) Species
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Sustainable use, protection of animal world and forest 170 management in the context of climate change MIMICRY, COMMENSALISM, DETRITOPHAGOUS, PREDATORS, MIGRATION AND ALL THESE IN VOLUCELLA ZONARIA (PODA 1761) SPECIES Asea M. Timus Institute of Zoology, Academy of Sciences of Moldova, Chişinau, e-mal: [email protected] The species Volucella zonaria (Poda 1761), syn. Conops zonaria Poda 1761 (Diptera, Syrphidae) were observed on campus The State Agrarian University of Moldova (SAUM) in Chisinau, on the stems of linden trees in 25.VI.2016. Over 30 flies standing under the shadiest and the thicker branches (Fig. 1). This syrphid flies have not a popular name in Romanian, therefore was named hornet bite because the life of flower flies V. zonaria (Poda 1761) and the hornet Vespa crabro L. 1758 occurs in absolute commensalism. In indigenous literature about the genus Volucella it exposes on information on species V. bombylans, and nothing about the zonaria, therefore any information on this species we consider relevant and useful. Hornet mimic hoverfly compared to oth- er species of Sirphidae family has gigantic dimensions: up to 20-22 mm, while through the length and body colour– black with yellow – perfectly mimics V. crabro L. 1758. The egg is yellow and about 1 mm. The larva is legless and headless, light brown col- oured, with rudimentary mouthparts that have aspect „horns”. The pupae is obtect with 35-40 mm in length, and in brownish glossy colored. Mimetism. The V. zonaria (Poda 1761)species is resembling with wasps in that: large body size; the dominant yellow colour of abdomen and wit three transverse black stripes; the shape of the head and the thorax viewed from the dorsal part; forewings rest state are kept stretched along the body. It is distinguished by short arista anten- nas, very large eyes, in wide and yellow part between the eyes, and the hind wings are modified into halteres. imago under looking wasp flies = the second pair of wings = the linden branch mimetism halteres Figure 1. The species of Volucella zonaria (Poda 1761) – hornet bite (foto Asea M. Timuş). IX-th International Conference of Zoologists, 12-13 October 2016 171 The Hornet mimic hoverfly winter in the pupal stagein soiland the adult fly in early spring, feeding with pollen and nectare specially of Buddleja davidii, Cirsium spp., Card- uus spp., and other plants (Fig. 2). The female lay eggs in nests of wild bees, bumblebees and wasps, but prefers in those of V. crabro L. 1758. For to get into the wasps nest and lay the eggs, and at maturity it can leave the nest without being discovered by the host- victim, evolutionary the fly has been adjusted by the two options. The first option is the morphological changes that are similar to the wasps hosts phenomenon called mimicry; the second one are glands that produce odorous substances or gives off a calming hor- mone and wasps become gentle and indifferent to what is happening in their nest. The larva feeds on decaying organic material from the nest wasps: dead wasps and other putrefying materials (species with a so lifestyle is named detritivores or detrito- phages), they also eat larvae and pupae sick or with abnormal development, such a way of life being called predation. It is mentioned that hornet mimic hoverfly migrate from hot areas to cold ones, in- cluding being registered increasingly in the urban parks, especially in private gardens with ornamental vegetation, the same can be said about V. crabro L. 1758 (information from literature and own observations) (Fig. 2). Months and decades IV V VI VII VIII IX X III III III III III III III II II II II II II II I I I I I I I (0) (0) + + + + + + + + flowering plants (pollen and nectar) Hibernation o o o o wasp nest I I I I I I I I detritophagous and predators (0) (0) (0) 0 0 0 0 0 0 0 soil around nests Legend: 0 – pupae; (0) – hibernating pupae; + – imago; o – egg; I – larvae. Figure 2. Phenologicaltable of the V. zonaria Poda 1761 species (orig.) In the result of our investigation of V. zonaria Poda 1761 species can be concluded the following: in 2016 the fly was registered on plants of the genus Tilia from SAUM campus. The hornet mimic hoverfly develops one generation per year, overwinters in the pupal stage in soil in wasps nest. The fly adults feed with pollen and nectar; the larvae consume decaying organic matter, they are also predators. The mimicry was developed to access to the nests hosts and victims (food). The V. zonaria Poda 1761 can be considered as an indicator of environmental change in Moldova cities..