EUROPEAN JOURNAL OF ENTOMOLOGY

Eur. J. Entomol. 90 (4): 403-414, 1993

Long-distance flights in Coccinellidae (Coleoptera)

HODEK I., IPERTI G., HODKOVA M.

N/A

In the period of reproductive activity and foraging for prey coccinellids undertake trivial (appetitive) flights. The irregular long-distance flights of ''swarms'' of ladybirds originate in hypermobility of starving beetles of the new generation. Two types of regular long-distance flights are related to dormancy: diapausing coccinellids migrate to dormancy sites by directional flight and after dormancy they disperse gradually to breeding sites. There is abundant evidence that most long-distance migrants are hypsotactically attracted to prominent landmarks, at least in the closing part of their migratory flight. None of the methods used to quantify the tendency to migratory flight (duration of tethered flight, incidence of take-offs, wing-spreading response) gave a completely satisfactory result; the first-mentioned technique is the most promising.

When migrating to dormancy sites coccinellids usually have immature ovaries (primary or regressed), and thus conform to Johnson's ''oogenesis - flight syndrome''. In contrast, during the dispersal flight their ovaries are partly matured. Although there is a general consent about the importance of juvenile hormone for the flight, it is still not clear how the regulation of flight is coordinated with the well established stimulatory role of JH in reproduction. There are indications that an intermediate titre of JH might stimulate both the flight and the early phases of ovarial maturation.

Keywords: Trivial flight, foraging, migration, dispersal, diapause, dormancy sites, Richardson's index, air turbulence, Coccinella septempunctata, Coleomegilla maculata, Harmonia axyridis, Hippodamia convergens, Semiadalia undecimnotata

Accepted: September 25, 1993; Published: December 30, 1993  Show citation