Viticultural Information

Indianmeal moth larvae

Driedfruit beetle, Carpophilus hemipterus (L.) (Coleptera: Nitidulidae), is a sap beetle that attacks ripe and overripe vegetation, particularly fruits, throughout the world. In California, it breeds in stone fruits, figs, dates, melons, and citrus, as well as in grapes, and migrates from crop to crop as the fruits become attractive. It is especially attracted to grapes with bunch rot, and its population increases through the season.

When harvested grapes are drying on trays, those that are damaged attract sap beetles and more damage occurs. High-moisture content of fruit favors their development, and periods of high humidity at harvest generally are conducive to greater damage of berries.

Indianmeal moth, Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae), is found worldwide and seriously affects raisins, dried fruits, nuts, grains, and cereal products. Although it is not as widespread a field pest as raisin moth, many consider this moth the world's number one storage pest. Moths lay eggs on field raisins, in sweatboxes, and in storage, and young, first-instar larvae can enter crevices as small as 0.13 mm (1/200 inch), thus infesting commodities in containers thought to be insect-proof.

Raisin moth, Cadra figulilella (Gregson) (Lepidoptera: Pyralidae), while known to feed on ripening grapes, chiefly affects stored raisins, especially those in farm storage before they are delivered to the packinghouses.

Young larvae hatched on raisins in storage feed chiefly on the ridge crests of the raisins, but they may also bore into the flesh. They do not completely consume the raisin but move about, leaving masses of excreta and webbing. During its development one larva can damage about 20 Thompson Seedless or 9 Muscat raisins.