Neolasioptera g-circaezans-stem-swelling

Neolasioptera erigerontis

Dasineura parthenocissi

Unknown t-virginiana-leaf-fold

Unknown v-angustifolium-leaf-edge-fold

Larvae and adults of the host midge on Galium circaezans (Rubiaceae) were preserved and identified as a possible new species of Neolasioptera. The previously undocumented gall (Figure 2 [see paper for photo]) is a fusiform, sometimes curved stem swelling, 6–9 mm long, typically containing 2–5 larvae (M.W. Palmer, in litt.). Pupation takes place within the gall. The reared adult midges emerged in early spring from galls collected in October. 

[The platygastrid parasitoid Metanopedias eupatorii was reared from this gall]

Neolasioptera erigerontis Felt

No adult midges emerged from the Conyza canadensis (Asteraceae) galls, which were rough, brown swellings to one side of the stem [no photo appears in the paper]. Based on Gagné (1989), the gall inducer was likely Neolasioptera erigerontis Felt, which pupates within the gall. M.W. Palmer’s rearing notes record orange and white larvae exiting the stems, however. This suggests that inquilines were present, and leaves some doubt as to which larvae served as the host for the platygastrids [Metanopedias eupatorii, a parasitoid reared from this gall].

Dasineura parthenocissi

[The platygastrid parasitoids Platygaster munita and Trichacis virginiana were reared from galls induced by Dasineura parthenocissi on Parthenocissus quinquefolia.]

From the 69 midge larvae that emerged from the galls and burrowed between the collection date and 30 June 2016, 14 adults of Dasineura parthenocissi emerged from 26 April to 1 May 2017, in addition to the seven of Trichacis virginiensis that had emerged two weeks earlier.

[A photo of this gall is included in the paper]

Lasiopteridi on Tephrosia virginiana. The host midge causes leaflets of Tephrosia virginiana (Fabaceae) to fold in half longitudinally, and the white larva feeds within a slight swelling along the midrib (Figure 6 [see paper for image of the gall]). This gall has not been documented previously and no adults have been reared, but similar galls on other genera of Fabaceae are caused by various Dasineura spp. (Gagné 1989). Although both larvae from the 2016 collection of these galls produced adults of Platygaster tephrosiae, CSE preserved four larvae from the same gall type in July 2014. These were identified by R.J. Gagné as an undetermined Lasiopteridi.

?Putoniella sp. on Vaccinium angustifolium

The host midge causes a downward marginal fold in leaves of Vaccinium angustifolium (Ericaceae), in which the orange larva feeds (Figure 8 [see paper for photo]). This gall is previously undocumented and adults have not been reared, but two larvae that died before they could be transferred to soil were preserved. Among known cecidomyiid larvae, these appeared closest to those of Putoniella, but adults will be needed to confirm this placement. CSE has found similar galls on V. corymbosum L., but they seem to be uncommon on both hosts.

Host records of five species of Platygastrinae (Hymenoptera, Platygastroidea: Platygastridae) from the United States, with the description of two new species of Platygaster