On Farm Trials of Alternative Controls for Striped Cucumber Beetles on Summer Squash 2001
Project Leader: Brian Caldwell, Farm Educator, Northeast Organic Farming Association, New York Chapter
Cooperator: Mandeville Farm, Spencer, NY
West Haven Farm, Ithaca, NY
Type of Grant: Pheromones; biorationals; microbials; conventional pesticides
Project Location: Throughout the northeast
Abstract: Alternate methods for striped cucumber beetle (SCB) control were trialed on zucchini summer squash at two commercial vegetable farms, one of which was managed organically. On the organic farm, Rotenone 5%WP, row cover, and Surround (a new kaolin clay-based product) were compared to an untreated control. On the conventionally managed farm, two treatments included the use of Invite, a cucurbitacin-based feeding stimulant. This stimulant was used with a reduced rate of Sevin 4F (carbaryl) and, in a separate treatment, a reduced rate of Rotenone 5%WP. The other treatments were Sevin 4F (regular rate), Surround, and an untreated control.
SCB pressure was very different at the two farms. On the conventional farm, SCB was first observed on May 25, while on the organic farm, SCB didn't show up until June 28. Pressure continued to be heavy on the conventional farm, but quickly fell on the organic farm.
On the conventional farm, the Sevin-sprayed plots had the most SCB beetles killed, the largest plants at first flowering, and highest yields. About 80% as many beetles were killed in the Sevin plus Invite (S+I) treatment, while only a few dead beetles were found on the Surround-sprayed plants and none in the control plots. The Surround, control, and S+I treatments were very similar in terms of plant size and yield. In the Rotenone plus Invite treatment, 5-20% as many SCB beetles were killed compared to Sevin, but plants were smallest and yields were significantly less than the other treatments.
On the organic farm, SCB played an insignificant role in plant growth and yield, though it has been a problem there in past years. A surprising result was that yields were retarded and reduced under the row cover treatment compared to the control. The reasons for this are unclear.