Ampeloglypter sesostris

Ampeloglypter sesostris (Leconte)

The grape cane gallmaker, Ampeloglypter sesostris (Leconte), is a native weevil that infests new shoots of wild and cultivated grapes (Vitisspp.). Females oviposit on the tender portions of new shoots, producing a reddish gall that can expand the shoot to twice its normal diameter. These galls can be quite numerous in eastern vineyards, and their effects are unknown. We studied the spatial distribution of grape cane gallmaker and its impact on berry size, sugar content, and nutrient and mineral uptake. We observed spatial trends in grape cane gallmaker distribution in vineyards adjacent to woodland margins, with the trend emanating from the woodline. In vineyards without woodland margins, there was little spatial dependency in grape cane gallmaker distribution in individual years. However, grape cane gallmaker density on a single vine was spatially cross-correlated between 2 yr. The presence of galls did not significantly affect berry quality, or the uptake of nutrients and minerals, and we conclude that grape cane gallmaker does not negatively impact berry quality or mature vine vigor.

THE GRAPE CANE gallmaker, Ampeloglypter sesostris (Leconte), is a native weevil that infests new shoots of wild and commercially grown grapes (Vitis spp.) (Webster 1900, Brooks 1909). Adult grape cane gallmaker emerge in spring from the litter in which they overwinter and mate. Females proceed to oviposit on the tender portions of new grape shoots by excavating a deep puncture just distal to a node. In Concord variety grapes, this puncture nearly always occurs on a node distal to the last cluster-bearing node (Brooks 1909). A female deposits a single egg, '0.64 mm long, in the puncture, and using her mouthparts, scrapes a longitudinal groove above the ovipositional puncture and packs some of the removed plant material over the egg (Brooks 1909). Proceeding distally along the groove, the female excavates a series of punctures 1Ð2.5 cm long. After the completion of each puncture, a clear liquid droplet is deposited in the hole by means of a mock oviposition. 

The newly eclosed larva burrows directly to the pith of the shoot, where it completes larval and pupal development over a period of 6-8 wk. Damaged shoots respond by forming a reddish gall around the series of punctures, which can expand the shoot to twice its normal diameter (Brooks 1909). Galls retain an opening to permit adult emergence, and adults generally exit the grape shoot by burrowing out through the ovipositional furrow (Webster 1900). These galls can be quite numerous in eastern vineyards, and Brooks (1909) reported up to nine galls on one cane.

Grape Cane Gallmaker (Coleoptera: Curculionidae) and its impact on cultivated grapes