The seasonal occurrence of Odonata in the Liwonde Nationale Park, Malaŵi

The Liwonde National Park in Malaŵi was sampled for Odonata species on 32 occasions from October 1975 to June 1977. The principal aims were to record the seasonal distribution and imaginal habitats of the Park’s odonate fauna, since little information of this nature has been published for specific areas in Africa and none was available for Malaŵi. Since the Liwonde National Park has a continental tropical climate with pronounced dry and wet seasons, and a range of habitat types including large and small rivers, swamps, waterholes, grassland, savanna woodland and rocky hills, the seasonal distributions and habitat preferences of Odonata were varied. Sixtyone species of 9 families (33 libellulids, 14 coenagrionids and 14 species distributed amongst the Lestidae, Protoneuridae, Calopterygidae, Chlorocyphidae, Gomphidae, Aeshnidae and Corduliidae) were recorded. The seasonality of the species was summarized using the following categories: 1. Species flying throughout the year (e.g. Ischnura senegalensis). 2. Species occurring through the year but with a dry season break (e.g. Pantala flavescens). 3. Species flying for a single period extending into the dry and wet seasons (e.g. Orthetrum chrysostigma). 4a. Species flying only in the wet season — long flight period (e.g. Phaon iridipennis); 4b. — Short flight period (e.g. Elattoneura glauca). 5. Species with very restricted period — dry season only (e.g. Paragomphus elpidius). 6. Species with long but irregular flight periods (e.g. Ceriagrion kordofanicum). 7. Species with 2 or 3 short, widely separated flight periods (e.g. Platycypha caligata). Of the total of 61 species, 36 were associated with the Shiré River (which connects Lake Malaŵi with the Zambezi River). These “Shiré River” species could be divided into those also found in few other habitats (10 stenovalent species, e.g. Pseudagrion acaciae) and those occurring frequently in a large range of habitats (26 euryvalent species, e.g. Ceriagrion glabrum). Twenty-five species occurred in habitats other than the Shiré River itself. Most of these were rarities in the Park, but a few (e.g. Pseudagrion kersteni) were common or moderately common. Irregular periods of flooding of the low-lying parts of the Park by closure of the barrage across the Shiré River at Liwonde probably had deleterious effects on many breeding Odonata populations. Six species were new records for Malaŵi.