In-Flight Transport of Algae and Protozoa by Selected Odonata

Abstract

This study was designed to show what dissemules may be carried by selected Odonata, show where the dissemules may be carried on selected Odonata, relate the frequency of occurrence of microorganisms on the insects to patterns of behavior of the selected Odonata. Thirty-three dragonflies belonging to 6 species, and 53 damselflies belonging to 5 species were collected aseptically and washed with sterile soil water extract. Washings of dissected body parts of 10 specimens of Libellula auripennis (Hagen) were placed in separate labeled vials of soil water extract, while fore- and midgut, and hind-gut from each L. auripennis were treated in a similar manner. Washings were cultured in a growth chamber, and cultures were examined at 2-week intervals for 6 weeks. Data showing frequency of occurrence for each alga and protozoan is given according to per cent from a total of 50 positive cultures and from 11 insect species collected. Chlorococcum sp. and Chlorella sp. showed the highest per cent occurrence in cultures and from collected insects. Results from washings of external body parts of 10 specimens of L. auripennis indicated that contact between legs and damp soil may effect pickup of algae and Protozoa. Culturing of the gut contents of L. auripennis indicated that viable algae and Protozoa may be carried internally by this species. This report concludes that the sampled Odonata are significant in pickup and deposition of algae and Protozoa.