Arizona Russian Survey and Beneficial Release Report, 1990

Item Type text; Article

Authors Clark, Lee J.; Moore, Leon

Publisher College of Agriculture, University of Arizona (Tucson, AZ)

Journal Forage and Grain: A College of Agriculture Report

Download date 27/09/2021 03:25:45

Link to Item http://hdl.handle.net/10150/201356 Arizona Russian Wheat Aphid Survey and Beneficial Release Report, 1990

Lee J. Clark and Leon Moore

Abstract

During 1990 the emphasis on surveying was placed in the southeastern corner of the state, where damage was found to be most severe in previous years.Estimates of the incidence of and damage caused by the Russian Wheat Aphid (RWA) were made for the entire state.These estimates indicate that small grain producers in the state lost $212,000 due to this in 1990.

Introduction

Russian wheat aphid (RWA) have been a continuing problem in parts of Arizona since their presence was confirmed in 1987. This survey was made to determine its presence throughout the state for our own records as well as to join together with other states to provide an estimate of the RWA damage caused throughout the country. This report was presented at the Fourth Annual Russian Wheat Aphid Conference in Bozeman, Montana.

Materials and Methods

Information in this report on the presence of RWA was summarized from the data found in Russian Wheat Aphid Survey in Southeastern Arizona, 1990, found elsewhere in this same publication and by polling Extension Agricultural Agents and IPM specialists throughout the state.

Information on the beneficial released were summarized from our release records. The release project is a cooperative project between USDA -APHIS -PPQ, the Arizona Department of Agriculture and the University of Arizona Cooperative Extension. Exotic species of parasitic wasps and predatory lady beetles from Europe, Asia and Canada were shipped to Safford from USDA locations in Michigan and Texas. These parasitic and predaceous insects, which were shipped overnight in cooled containers, were released in the chosen sites around dusk of the day they were received.It was important to release them at dusk to keep them from flying from or being blown from the targeted area.In the case of the lady beetle egg release in northern Cochise county, timing of release was not so critical. These eggs were placed during the day that the shipment was received or the next day.

Discussion .

The largest percent infestations occurred in the counties in the high desert ( >3000 feet abovesea level). In addition to these three counties, RWA were also found in Maricopa, Pima and Pinal counties, but at much lower infestation rates. A summary of losses and costs caused by the RWA are found in Table 1. This gives an estimated loss to Arizona grain producers of over $212,000, including crop loss and cost of treatment.

In the central counties of Arizona, infestations were about average to light. Graham county, however, had its worst infestations since RWA came into the county in 1987. RWA are in the Imperial Valley of California and their presence has been expected in Yuma and LaPaz counties on the west edge of the state, butup to this point none have been found.

71 On the exotic beneficial releases, three different species of wasps were released, all were very small probably not exceeding 1/8th inch in length; three species of adult lady beetles were released, one of which was about 1 /4th the size of our common lady beetles; and two species of lady beetle eggs were released, the adults of one, Coccinella septempunctata (the seven spotted lady beetle, C-7) is about twice the size of the common lady beetles. Small predators and parasites have the advantage that they can crawl through the rolled leaves, where the RWA are found, the large C -7 are more voracious and consume larger quantities of the RWA and other . The species and numbers of exotic beneficials released are listed in Table 2.

References

1. Clark, Lee J.1991. Russian Wheat Aphid Survey in Southeastern Arizona, 1990. Forage and Grain, A College of Agriculture Report, The University of Arizona, Tucson, AZ. In this publication.

2. Flanders, R.V., D.J. Nelson, R. Deerberg and CJ. Copeland. 1991. Aphid Biological Control Project, FY 1990 Project Report. USDA -APHIS -PPQ National Biological Control Laboratory, Niles, Michigan.

Table 1. Small grain acreage in RWA infested counties and estimates of infestation, crop losses and treatment costs.

Sm grain Percent Loss Acres Treatment County Acreage Infested' Percent' Value Treated Costs (S)

Cochise 2,500 100% 4.2% S28,040 2250 $20,250 Graham 2,200 88% 5.3% 30,621 418 3,762 Greenlee 1,100 100% 4.5% 13,493 363 3,267 Maricopa 32,800 10% 5.0% 42,640 0 0 Pima 300 20% 5.0% 780 0 0 Pinal 19,800 20% 5.0% 51,480 1980 17,820

Totals 58,700 S 167,054 5011 545,099

1. This indicates the percent of fields that had RWA present, not the percent of tillers infested. 2. This value includes the estimate of the percent of tillers infested times 43.9% loss per infested tiller.

72 Table 2.Exotic beneficial parasiteand predator releasesin 1990.

GREENLEE COUNTY Elevation 3680feet Longitude: 109° 3.2' Latitude: 32° 41.2'

Parasite release Number released by date Species Origin 4/19 425 52 519 Total

Aphidius matricariae USSR -Moldavia 620 2400 550 500 4070 Aphidius picipes Czechoslovakia 1320 2600 2600 950 7470 Diaeretiella rapae Pakistan 650 300 1600 450 3000 Diaeretiella rapae Jordan 655 500 1400 600 3155 Diaeretiella rapae France 950 300 500 500 2250 asychis France 650 1500 500 500 3150 Aphelinus varipes Turkey 550 500 500 500 2050 Aphelinus varipes USSR -Caucasus 525 500 500 500 2025

Totals 5920 8600 8150 4500 27170 These parasites were introduced as exposed aphids of mummified aphids.

Predator release Number released by date Species Origin 4/19 425 52 5/9 Total

Hippodamia variegata Canada 993 526 500 250 2269 Hippodamia variegata France 995 518 500 250 2263 Hippodamia variegata USSR -Kirgiz 820 463 500 250 2033 Hippodamia variegata USSR- Moldavia 1086 486 500 250 2322 Propylea quatuordecimpunctataCanada 449 449 Propylea quatuordecimpunctataUSSR- Mold/Ukraine 502 464 250 250 1466 Propylea quatuordecimpunctataTurkey 1050 415 500 1965 Scymnus frontalis Turkey 1038 580 500 250 2368

Totals 6933 3452 3250 1500 15135 These predators were released as live adults.

COCHISE COUNTY Elevation: 4200 feet Longitude: 109° 58' Latitude: 32° 24.7'

Predator release Number released by date Species Origin 4/19 4125 52 5/9 Total

Coccinella septempunctata USSR -Mold/Ukraine 1327 1076 438 429 3270 Coccinella septempunctata USSR -Kirgiz 1691 931 622 373 3617 Coccinella septempunctata France 854 457 625 249 2185 Hippodamia tredecimpunctata USSR- Mold/Ukraine 3702 1408 1304 848 7262 Hippodamia tredecimpunctata USSR -Kirgiz 1843 1543 1024 1225 5635

Totals 9417 5415 4013 3124 21969 These predators were released as eggs.

Total of all beneficial organisms released in 1990: 64274

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