W. G. Carson

Economics of reducing insecticide use on celery through low-input pest management strategies

A low pesticide input management system for celery, Apium graveolens, was developed and implemented. The overall effectiveness of this system was compared with a conventional pesticide application program and an untreated control, over 4 years in field station trials, and then implemented in a commercial trial. The low-input program relied on biological control agents and rotations of selective, environmentally-safe biorational insecticides (Bacillus thuringiensis, spinosad, tebufenozide) applied only when pests exceeded threshold levels. The conventional program included prophylactic applications of broad spectrum synthetic pesticides. Yield losses from key insect pests were documented and economic analyses comparing the monetary returns accruing from the use of the different programs were generated. Insect damage was lower for conventional program in only one of the 4 years. The integrated pest management (IPM) program utilized significantly fewer applications of insecticides, but there were no significant differences in the total number of marketable cartons. These lower insecticide costs resulted in greater net profits for the IPM program. A commercial trial, which included a low input program for managing the fungal pathogen Septoria apiicola, was conducted in collaboration with a celery producer in Ventura county, California and provided similar results to the field station trials. The combined IPM program used over 25% fewer pesticides than the grower’s program, and pest management costs were over

Toxicity of linear furanocoumarins toSpodoptera exigua: Evidence for antagonistic interactions

250 ha ˇ1 lower for the IPM program than for the grower standard program. Although the IPM program used fewer pesticide applications, there were no significant differences in yield or net profits among treatments. # 1999 Elsevier Science B.V. All rights reserved.

Effect of Insecticides on Tomato Insects, 2014

The linear furanocoumarins psoralen, bergapten, and xanthotoxin were tested for toxicity to the beet armywormSpodoptera exigua (Hübner) under short ultraviolet (UVB) radiation. Increased dietary concentrations of each furanocoumarin significantly decreased insect larval weight, extended generation time, and induced higher mortality. Xanthotoxin was the most toxic, followed by psoralen and bergapten. Combining psoralen with bergapten, xanthotoxin, or both resulted in significantly antagonistic effects on insect mortality. The combination of bergapten and xanthotoxin, however, produced additive effects. The implications of these observations forS. exigua resistance in the wild plant accession ofApium prostratum and the enigma the findings represent for plant-insect relationships are discussed.

Acylsugars of Wild Tomato Lycopersicon pennellii Alters Settling and Reduces Oviposition of Bemisia argentifolii (Homoptera: Aleyrodidae)

“Bobcat” fresh market tomato seedlings were transplanted in a sandy loam type soil on 10 June 2014 at the University of California’s South Coast Research and Extension Center. Experimental plots were 3 rows wide (5-ft centers) by 40 ft long and separated by a 3-ft buffer. The tomato transplants were drip irrigated (water pH 7.2–7.5). Treatments were replicated four times in an RCB block design. Foliar applications …