Nine new species of Dasineura (Diptera: Cecidomyiidae) from flowers of Australian Acacia (Mimosaceae)

Abstract

Abstract. Thirteen species of Australian acacias are invasive plants in agricultural and native vegetation areas of South Africa. Biological control programmes for Australian acacias in South Africa have been implemented and are aimed at suppressing reproductive vigour and, in some cases, vegetative growth of these weeds. Gall‐forming midges are under consideration as potential biological control agents for invasive acacias in South Africa. Entomological surveys in southern Australia found a diverse cecidomyiid fauna associated with the buds, flowers and fruits of Acacia species. Nine new Dasineura species are described and two species, D. acaciaelongifoliae (Skuse) and D. dielsi Rübsaamen, are redescribed. The newly described taxa are D. fistulosasp.n., D. furcatasp.n., D. glaucasp.n., D. glomeratasp.n., D. oldfieldiisp.n., D. oshanesiisp.n., D. piliferasp.n., D. rubiformissp.n. and D. sulcatasp.n. All eleven species induce galls on ovaries and prevent the formation of fruit. Two general types of gall are caused. Type A comprises woody, tubular galls with larvae living inside ovaries (D. acaciaelongifoliae, D. dielsi, D. fistulosa, D. furcata, D. glauca, D. glomerata, D. oldfieldii). Type B includes soft‐tissued, globose galls that belong to four subtypes: inflated, baglike, hairy galls with larvae living between ovaries (D. pilifera); pyriform, pubescent swellings with larvae living inside ovaries (D. rubiformis); globose, hairy, swellings with larvae living superficially on ovaries in ovoid chambers (D. oshanesii); and inconspicuous, glabrous swellings with larvae living superficially on ovaries in shallow groovelike chambers (D. sulcata). The gall types are associated with a particular pupation pattern. In type A galls, larvae pupate within larval chambers in galls, whereas in type B galls pupation takes place between ovaries in galls or in the soil beneath the host tree. Gall midges responsible for the same general gall type are morphologically related and differ from species causing the other gall type. Phylogenetic analysis of a 410 bp fragment of the mitochondrial cytochrome b gene supports the division of the gall midge species into two groups except for D. sulcata, which appears as a subgroup of the group causing type A galls. The interspecific divergence values in group A species were between 0.5 and 3.9% with intraspecific divergence estimates of 0–0.2%. Gall midges causing type B galls had interspecific divergence values of 4.6–7.3% and intraspecific divergence values of 0–3.7%. Closely related biology and morphology together with low cytochrome b divergence estimates suggest a more recent speciation in group A when compared with species of group B. Dasineura rubiformis and D. dielsi are proposed as potential biological control agents for Acacia mearnsii De Wild. and Acacia cyclops A. Cunn. ex G. Don, respectively, in South Africa due to their narrow host range and ability to form high population densities that reduce seed formation. Both species produce galls with low biomass, which makes them comp...

Biodiversity of Australasian Insects

“…The Chrysomelinae (leaf beetles) demonstrate a radiation associated with eucalypts of some 750 species, but are virtually lacking on Proteaceae (C. A. M. Reid, personal communication). Notable Australian plant-associated radiations include several independent originations of gall-inducing Coccoidea (scale insects) Gullan 2004, Gullan et al 2005); the phlaeothripid Acacia thrips (Crespi et al 2004); the ecologically significant, lerp-forming spondyliaspine Psylloidea (Hollis 2004; the cecidomyiid gall midges (Kolesik et al 2005) and near-endemic Fergusoninidae (Diptera) (Scheffer et al 2004, Taylor 2004); gall-inducing Chalcidoidea (Hymenoptera) (La Salle 2004); and the several thousand (perhaps 5000) species of oecophorine moths (Oecophoridae), whose larvae consume mainly fallen myrtaceous leaves (Common 1994). Other disproportionately represented insect groups include the Phasmatodea, cicadas, and pselaphine Staphylinidae.…”

Description ofEucalyptodiplosis chionochloaesp. nov., a cecidomyiid feeding on inflorescences ofChionochloa(Poaceae) in New Zealand

“…The species is formally described and named here, and placed in Eucalyptodiplosis, a genus previously containing two species feeding on leaf and branch buds of Eucalyptus trees in Australia. Canada balsam mounts of larvae, pupa and adults were prepared according to the technique outlined in Kolesik et al (2005). Length measurements were made with a microscope imaging system.…”

Dasineura banksiae: a new species of gall midge (Diptera: Cecidomyiidae) feeding on Banksia coccinea (Proteaceae) in Australia

“…Dasineura acaciaelongifoliae (Skuse) Kolesik, D. pilifera Kolesik, D. rubiformis Kolesik and D. sulcata Kolesik cause flower galls on various Acacia spp. (Mimosaceae) (Skuse 1890;Rübsaamen 1916;Kolesik et al 2005). Dasineura wahlenbergiae Kolesik galls shoot tips of Wahlenbergia stricta (Campanulaceae) (Kolesik 1998).…”