J. KISS¹, C.R. EDWARDS², L. VASAS³, F. MOLNAR³, Ä. SZASZ⁴, E. PETRO⁴, T. TUSKA¹, E. SZABO¹, Z. SZABO⁵, G. PRINCZINGER⁶, G. RIPKA^4
1 Department of Plant Protection, Gödöllö University, Gödöllö, Hungary
² Department of Entomology, Purdue University, W. Lafayette, IN 47907-1158, USA
³ Plant Health and Soil Conservation Station of Bekes County, Bekescsaba, Hungary
⁴ Plant Heafth and Soll Conservation Station of Budapest, Hungary
⁵ State Stud-Estate Corporation, Mezöhegyes, Hungary
⁶ Ministry of Agriculture and Regional Development, Hungary

The spread and population buildup of the Western corn rootworm (WCR) in Hungary requires that multiple management strategies be developed for the control of this corn pest. The concept of SLAM® - based areavvide pest management of WCR is being developed in the USA (CHANDLER, 1998) and has been adapted in Hungary as part of UN FAO TCP 6712 Project.
The aim of areawide pest management is to:

• keep the WCR population below economic threshold levels in defined areas over multiple years;
• manage WCR in a more economically and environmentally safe way than through the use of (soil) insecticides.

Larval damage by WCR to corn is prevented in areawide pest management programs by controlling adults, thus significantly reducing egg laying. SLAM® is a semiochemical insecticide-bait containing a WCR feeding arrestant/stimulant, (cucurbitacins), a low rate of carbaryl insecticide as the toxicant, and inert ingredients.

The adaptation of areavvide pest management of WCR in Hungary included the follovving:

• selection of suitable area (farms, fields, etc.) for the management program;
• adaptation of application techniques (aircraft and/or ground application equipment, application parameters, spray adjustments, droplet deposition, etc.);
• field scouting of WCR for decision making on treatment and timing of application;
• post treatment scouting and evaluation to determine outcomes.

WCR infested areas in Southern Hungary were selected as testing sites (Szeged region for application trials and ground application studies), and Mezöhegyes State Stud Estate Corporation Farm for full implementation of areavvide pest management.

This presentation focuses on the results for 1998-1999 and the feasibility for application of the areawide pest management concept in Hungary. Technical air and ground application details have already been reported on by PETRO et al. (1998a, b) and EDWARDS et al. (1999) and further papers are in preparation on this subject.

The Mezöhegyes State Stud Estate Corporation Farm encompasses an area of 9500 ha of which 3500 ha are in corn (seed, silage, and sweet corn). The remaining 6000 ha are made up of wheat, oats, sunflower, peas, alfalfa, sugar beet, and various vegetables. The crops grown on this farm represent the typical cultivated plants found on arable land in Hungary.

1998 management program:

• scouting with Csalomone and Multigard traps
• 1888 ha seed corn treated on 13-15 August;
• 0,42 g/ha SLAM® + 0,1 v / v%-l. WINDBRAKE® drift retardant in 9,7 l / ha spray volume.

1999 management program:

• scouting with Csalomon® and Multigard® traps
• 550 ha seed corn and silage corn treated on 01-04 August
• 0,45 g/ha SLAM® + 0,5 v/v-/. MIST-CONTROL® drift retardant in 9,6 l / ha spray volume

Some results, conclusions and recommendations:
Preparation of a preliminary risk assessment is required for each field in an areawide pest management program. This is accomplished by estimating the overwintering population in the field concerned (pre-crop, pest management applications in pre-crop) and by considering planned insecticide applications (soil application, control of other pests, etc.) while taking into account WCR immigration from the surrounding fields.

The WCR infestation within an area can dramatically change from one year to the next and this was the case at the study site. The highest number of WCR adults was 24,0 and 0,4 adults/trap/day in Csalomon® and in Multigard® traps, respectively, in a 5-day period in one field in 1998. These values increased to 47,4 and 8,1 adults / trap / day in one field over a sampling period of one week in 1999. The trap catch values for Multigard traps were above the economic threshold (6 adults / day / trap) as estimated for Indiana (USA) comfields.

Silage corn fields, especially after corn, are of great importance for managing WCR populations over a wide area. Under Hungarian conditions soil insecticide and foliar insecticide applications are not used in silage corn thus WCR populations easily build up in these fields under favorable conditions.

Timing of adult control is crucial to the success of an areawide pest management program for WCR. Field scouting should start by mid July since WCR populations may reach or exceed threshold levels by the last decade of July. For proper timing of control, WCR females need to be examined to see if gravity exists. The female beetles can easily be checked in traps like the Multigard trap. At low WCR population levels (far below estimated economic threshold levels), use of Csalomon pheromone traps is advised for WCR detection purposes since adult numbers in Multigard traps are relatively low.

Application of SLAM, as well as other control products, should only be made after determining if other crops within the area to be sprayed are blossoming (such as sunflower and alfalfa) so that bee poisonings can be avoided.

SLAM®-based areavvide management of WCR resulted in efficacy rates of over 90% (5 days after treatment) with a slow decrease after 10 and 15 days in 1998 and 1999. The concept of areawide management has proven to be an effective way to manage WCR and should be considered a viable control strategy in Europe.