LIFE-HISTORY AND DESCRIPTION OF DASINEURA-GLEDITCHIAE (DIPTERA, CECIDOMYIIDAE) IN CALIFORNIA

The biology of Dasineura gleditchiae (Osten Sacken) (Diptera: Cecidomy iidae) was studied in California on honeylocust trees, Gleditsia triac anthos L. First appearance of the gall midge, documented by the captur e of adults in emergence traps placed under G. triacanthos, was in mid -February 1996. Opaque-white, ovoid eggs with a mean (+/- 1 SE) length of 0.36 +/- 0.006 mm were oviposited in clusters along the rachis or margins of expanding leaves. Three instars were identified; mean (+/- 1 SE) head capsule widths (mm) were 0.02 +/- 0.001, 0.03 +/- 0.001, an d 0.05 +/- 0.001 for the first, second, and third instars, respectivel y. A single first instar was found capable of initiating gall formatio n. Three forms of leaf galls were observed: 1) a partial fold, 2) a co mplete fold, and 3) a roll gall. Gall forms were found to be related t o the number of larvae inhibiting galls. The mean (+/- 1 SE) number of larvae per gall form was 1.88 +/- 0.119, 3.18 +/- 0.160, and 6.88 +/- 0.792, for partial, complete, and roll galls, respectively. The paras itoid and predator guild that emerged from galls containing D. gleditc hiae included Ceraphron sp. (Ceraphronidae), Lyrcus sp. and Mesopolobu s spp. (Pteromalidae), Brasema sp. (Eupelmidae), Aprostocetus sp. (Eul ophidae) and Orius tristicolor (White) (Anthocoridae).