Trials of foliar sprays to Colorado potato beetle were conducted at the Michigan State University Montcalm Potato Research Farm, Entrican, MI. Potatoes were planted on 13 May 1988. Plots were 3 rows wide (34 inch row spacing) by 40 ft long and treatments were arranged in a randomized complete block design with 4 replications/treatment. Adjacent plots were separated by two untreated rows. Treatments were applied on 17 and 23 Jun, and 1 Jul with a tractor-mounted boom sprayer at 30 gal/acre, 40 psi, with a cluster of 3 nozzles over each row. The middle nozzle directed spray down over the top of the plant, and the other nozzles directed the spray at the sides of the plant. Insects were counted from randomly-selected plants (1/plot prior to treatment, 2/plot for post-spray samples) on 14 Jun (pretreatment count), 21 and 23 Jun, and 7 Jul. Damage ratings both on a per plot and a per plant (2 plants/plot) basis were made on 7 Jul. The center row of each plot was harvested and potatoes sorted by size and weighed on 5 Oct.

Trials were conducted in a severely infested field of celery near Hudsonville MI (Ottawa Co.). Adult populations were in excess of 500 per 50 sweeps and flies were present on nearly every new leaf. Defoliation exceeded 80% (only new growth was free of mines). Plots were 3 rows by 25 ft, arranged linearly along the eastern border of the field, 3 replications per treatment, arranged in a randomized complete block design. Treatments were applied to the center row of each plot on 10 Sep and 17 Sep ’85 with a CO2 hand sprayer with a single nozzle over the row at 50 gpa and 30 psi. New leaflets without visible mines (10 per plot) were randomly sampled immediately after treatment, as soon as the spray had dried. The leaflets were placed in plastic bags, returned to the laboratory and kept at room temperature. Larvae and pupae were counted 9 and 13 days after collection and were retained in screen-covered vials for assessment of adult emergence. Older leaflets were also randomly collected immediately after treatment (10 per plot) and returned to the laboratory for evaluation. Larvae and pupae were counted 6 days after collection and retained in vials. Numbers of emerged adults were recorded 20 days after collection. 8 days after the 2nd application, 3 plants were randomly selected from each plot. For each plant, the terminal leaflet from each of the newest 3 stalks was collected, number of visible mines recorded and larval and adult emergence measured, as before. The oldest of these 3 stalks was generally the same age as stalks sampled as “new growth without mines” at the beginning of the study. Several had already had their terminal leaflets removed during the earlier sampling. All pupae were retained for several weeks to allow time for emergence of parasitoids.

Beans were planted 7 July in 5 ft rows at the M.S.U. Horticultural Experimental Station in Sodus, Mich. (Berrien Co.). Plots were arranged in a randomized complete block design with four replications (= blocks) per treatment. Each plot was three rows wide (15 ft) and 15 ft long. Treatments were applied on 11, 18, 25, 31 Aug. and 6 Sept., with a tractor-mounted boom sprayer at 30 gal/acre. Efficacy was determined by examining two leaves from the center of each plot for both leafhoppers and aphids. A 5 ft section from the center row of each plot was harvested and bean weight and percentage of insect-damaged beans were recorded.

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Onions were direct seeded at approximately 15/row ft on 20 Apr at Keilen Farms, Inc., Lansing, MI. Plots were 2 rows wide (6 inch double rows), 30 inch spacing between double rows, 25 ft long, arranged in a randomized complete block design with 4 replications. One double row was left unsprayed between each plot. Treatments were applied with a hand-held COa sprayer, 2 nozzle boom (1 nozzle/row), at 40 psi and 30 gpa. On 1 Jun, malathion (1.25 lb (AI)/acre) was applied by air. Treatments were applied 9, 17, and 25 Aug. On 20 Jul a pre-spray sampling of 10 samples (20 plants/sample) was conducted, leaf bases of the pulled plants were rinsed with 70% ethanol. The rinsate (with thrips) was collected in a cup and returned to the lab. Samples were filtered through a Buchner funnel onto filter paper, and the number of thrips counted under the binocular microscope (120 x). On 3 Aug a second pre-spray sampling of 16 samples (20 plants/sample) was done. On 14, 23 and 31 Aug, 20 plants/plot were randomly selected. Numbers of thrips collected from each plot for all of the post-spray samples were summed to estimate season long impact.