2008 vol. 68, 81-91 DOI: 10.2478/v10032-008-0007-2 ______

EFFFECT OF CROP PLANT SPECIES ON THE EFFICACY OF PHEROMONE TRAPS FOR MONITORING OF THE TURNIP ( SEGETUM [SCHIFF.]) (LEP., )

Jakub GARNIS, Zbigniew T. DBROWSKI Department of Applied Entomology, University of Life Sciences – SGGW Nowoursynowska 156, 02-776 Warsaw, Poland Received: August 31, 2007, Accepted: November 29, 2007

Summary Common cutworm (Turnip moth) (Agrotis segetum), a serious polypha- gous pest of many agricultural and horticultural crops, attacks a wide range of plant species in their various growth stages. The larvae are nocturnal in habits, spending the day hiding in the litter or in the soil and their presence is often only notice by farmers when the damage already occurred. Therefore develop- ment of an effective monitoring of the adults migration into a crop may help in controlling the pest. The pheromone traps are presently considered as the most effective monitoring system of A. segetum moth. Optimization of pheromone traps location will reduce cost of purchasing traps and labour and at the same time assuring collection of reliable information on A. segetum migration. The “on – farm research” with active participation of farmer in planning and execu- tion of the project was carried out in the two growing seasons: 2005 and 2006 on 10 crop fields and natural vegetation of various ecological infrastructures of a selected representative farm in Piaski village, near Warsaw. A Delta type traps were used for monitoring. The relations between the dynamics of trapping month and density of traps per chosen area and characteristics of agrocenosis (type of crop and uncultivated land, drainage ditches, river embankment, etc.) were established. The collected data may be used in improving the present methods of short- and longterm forecasting of A. segetum population dynamics and optimize the pest chemical control. key words: common cutworm, Turnip moth, Agrotis segetum, pheromone traps, monitoring, forecasting

INTRODUCTION

Common cutworm (turnip moth), a serious polyphagous pest of many ag- ricultural and horticultural crops attacks a wide range of plant species in their

Corresponding author: e-mail: [email protected] , [email protected] © Copyright by RIVC 82 VEGETABLE CROPS RESEARCH BULLETIN 68 ______various growth stages (Lipa 1977). The larvae are nocturnal in habits, spending the day hiding in the litter or in the soil and their presence is after only noticed by farmers when the damage already occurred. The economic importance of cutworms of the turnip moth (Agrotis segetum [Schiff.]) attacking field vegeta- bles and root crops has increased during last years in Poland (Szwejda 2001, Mrówczyski et al. 2006). The high damages were noted not only for its tradi- tional host plants as field vegetables, beets and potatoes but also on winter oil rapes and cereals (Walczak et al. 2004). High infestation was for the first time observed on crops in September and abundance of numerous young cutworm instars, indicating presence of the 3rd generation. The favourable weather condi- tions during the last years caused rapid development of A. segetum, reaching up to 200 cutworms·m-² in south-western and central regions of Poland (Mrów- czyski et al. 2003). Proper monitoring techniques based on sex pheromone traps especially en- sures control more effective through improving the timing of pesticide treat- ment (Malavolta et al. 2005). In spite of official recommendations released by the Research Institute of Vegetable Crops on chemical control of cutworms, the Polish vegetable growers are facing problems in choosing proper period of pes- ticide treatment. The application of pheromone traps for monitoring the flight activity of turnip moth is not yet commonly accepted by farmers in Poland. There are also needs to develop standardized monitoring procedure including visual inspections establishing the pest pressure on a given crop and forecasting models. Our studies were initiated by the demand from vegetable growers suffering from high vegetable losses caused by common cutworms on their major vegeta- ble crops. On-farm experiments were established with farmers’ participation on two farms specialized in field vegetable production: Piaski village, approx. 22 km south of Warsaw and Siekierki district of Warsaw outskirts. Participatory approach with farmers’ active involvement was used in planning, execution and evaluation of results of both field experiments. Because of only one year dura- tion of observations on the Siekierki farm, in this paper we are presenting re- search data collected on the Piaski farm.

MATERIALS AND METHODS

The “on - farm” research was carried out on the selected specialized farm growing field vegetables in Piaski village, in the vicinity of Warsaw, in the 2005 and 2006 growing season. The chosen farm was a representative for farming in the Piaski community and its ecological infrastructure was rich in woodland patches, shrub hedges and diversified herbaceous plants on field verges (Table 1). The farm 30 ha area was composed of ten individual fields under regular rotation (Fig. 1). J. GARNIS, Z.T. DBROWSKI – EFFECT OF CROP PLANT SPECIES ... 83 ______

Table 1. Composition of plant species in neighbourhood of the chosen vegetable farm in the Piaski village

Type of ecological structures Plant species Irrigation canal & river embankment Achillea millefolium, intybus, Echium vulgare, Leontodon hispidus, Matricaria chamomilla, Pimpinella major, Silene alba, Tanacetum vulgare, Trifolium pratense, Verbascum densiflorum Vegetation strips between cultivated Alnus incana, Cornus alba, Crataegus mono- fields gyna, Ulmus minor, Prunus padus, Rosa canina, Rubus caesius, Salix alba

The Delta type traps distributed by the P.P.H. “Medchem” company car- rying the synthetic pheromone of MTA Novenyvedelmi Kutatointezete Hun- garian producer for capturing turnip male were used in the experiment. Twenty seven sticky traps were located on the farm: twenty one on the fields and six on surrounded natural vegetation areas (Fig. 1). Natural vegetation sur- rounding the selected farm may have effect on Agrotis population as a place of cutworm development (barren and uncultivated land), food sources for adult moth (flowering plants on hedges and herbaceous strips) and hiding places for adult moth during day period (tree trunks). The terminology of various “ecological infrastructures” embracing all these elements of agrocenosis was adopted after Boller et al. (2004).

Fig. 1. Location of pheromone traps on ten fields and on their surrounding natural vegetation in the 2005 and 2006 growing seasons on the selected farm, Piaski village 84 VEGETABLE CROPS RESEARCH BULLETIN 68 ______

Geographic coordinates of traps were determined by the GPS Geko 201 (GARMIN) in 2005 allowing placing traps in the same point in the 2006 grow- ing season. Traps were positioned on 70 cm long wooden poles in the studied fields and hanged on tree branches at 1.70 cm hight. Traps were regularly checked for number of trapped A. segetum males aftenoon in weekly intervals between June and October; dead were removed from sticky bottoms. When the bottoms got dirty they were immediately replaced by new ones. The pheromone dispensers were changed in four week intervals. Average numbers of captured insects in traps located on individual fields and surrounded natural vegetation were used for: (a) drawing a general popula- tion migration of A. segetum males into farm; (b) statistical analysis of the ef- fect of timing of catches measured by weekly catches of males during the growing season; and (c) effect of ten crops and two natural vegetation areas on the efficacy of trappings. Statraphic® Plus for Windows 4.1 (copyright© 1994- 1999 by Statistical Graphics Corp., USA) was used for statistical analyses of collected data. The numbers of weekly trappings were transformed to their natu- ral logarithms to meet requirements necessary for the Kruskal-Wallis and mul- tiple range tests.

RESULTS

General characteristic of A. segetum males migration The total number of trapped turnip moth males was higher in the 2006 than during the 2005 growing season. The maximal catches were noted in the second week of June, suggesting mass migration of the first generation of moths. Lower flying activities of males were observed in July, with higher starting at the beginning of August and maximal at the third week of August. In both growing seasons the males were trapped until third week of September. The August migration of males indicated the appearance of the second generation of A. segetum adults. Two picks of numbers of trapped males of overwintering generation in June and July was later expressed in larval development and emergence of adults of the second generation. Higher A. segetum flight activities were ob- served in two periods at the end of August and during September in the both seasons.

Effect of a season on the efficacy of trappings of A. segetum males Statistical analysis of average number of trapped A. segetum males in con- secutive periods of the 2005 and 2006 growing season shown significant differ- ences (Fig. 2). The significant lower number of male catches took place be- tween the 18th-25th July and on the 21st September in the both growing seasons. The Kruskal-Wallis test did not confirm the significant effect of location of traps on individual fields in the both growing seasons (p=0.2680, K-W=13.385 at the 95% level of confidence). J. GARNIS, Z.T. DBROWSKI – EFFECT OF CROP PLANT SPECIES ... 85 ______

Fig. 2. Average number of A. segetum males captured by pheromone traps in consecu- tive weeks in the 2005 and 2006 season, Piaski village. Within each term, means followed by the same letter are not significantly different at P=0.05

Changing of crop species on individual fields affected the attractiveness of pheromone traps for A. segetum males. The highest differences equal to 50 males/trap were recorded for the 1, 7 and 10 c fields. Field 1 and 7 were under celeriac production in one of the season, explaining the high catches. crop, which showed lower attractiveness was grown on the 10 c field in the 2006 and more attractive carrot in the 2005 season, which was expressed in the large differences in the male catches in the both studied seasons.

Effect of crop species and natural vegetation on the efficacy of pheromone traps Twelve different groups of trap locations and eleven ones in the 2005 and 2006 season, respectively were compared for their effects on intensity of the A. segetum male catches. The highest number of captured males was observed on traps located on celeriac fields, average 107.7 and 123.0 insects/trap in the 2005 86 VEGETABLE CROPS RESEARCH BULLETIN 68 ______and 2006 season, respectively (Fig. 3). The numbers of trapped males recorded for parsley, sunflower and leek were similar and varied between 88.0-91.0 in- sects/trap. Much lower numbers were recorded for traps located in wheat (50.2), pumpkin (39.0) and white head cabbage and red cabbage (30.0 males/trap).

Fig. 3. Average number of A. segetum males attracted to pheromone traps located on various crop species in 2005 and 2006, Piaski village.

It should be explained that the white head cabbage and red cabbage crops were grown for late autumn harvesting and therefore the traps were placed only on the 13th July 2005, a month later than on other fields. Much smaller differences in trapping were recorded for traps placed out- side the cultivated land. Traps located on border trees of apple orchard attracted an average of 83 males/trap in the 2005 season (Fig. 4). Traps positioned on natural vegetation strip adjacent to the irrigation canal and river embankment attracted an average of 70.0 and 68.5 males/trap, respectively. Only av. 50 and insects/trap were caught in traps located on barren land adherent to the farm in the 2005 season (Fig. 4 ). J. GARNIS, Z.T. DBROWSKI – EFFECT OF CROP PLANT SPECIES ... 87 ______

Fig. 4. Average number of A. segetum males captures by pheromone traps located on various ecological infrastructures around the experimental farm in the 2005 and 2006 growing season.

During the 2006 growing season the traps placed on the celeriac field again captured the highest number of A. segetum males, av. 123 insects/trap (Fig. 3). Similar number of caught insects, approx. 98 males/trap were recorded for traps located in the red head cabbage and Chinese cabbage and parsley. Much lower number were captured in ten traps placed on sunflower (av. 68.5) and wheat (av. 64.2 males/trap) in the 2006 season (Fig. 3). Analysis of catches on various ecological infrastructures in the 2006 sea- son showed that traps located on the natural vegetation strip adhering to irriga- tion canal (av. 91.5) and hung on apple trees (av. 90 males/trap) attracted a much higher number of A. segetum males than located on the barren land (av. 62.0) and on the top of river embankment (av. 44.5) adjacent to the farm. Com- paring intensity of captured males in pheromone trap located on various eco- logical infrastructures revealed that much lower number of males was recorded for traps placed on the river embankment in 2006 (Fig. 4). 88 VEGETABLE CROPS RESEARCH BULLETIN 68 ______

Detailed analysis of male catches by traps located on various fields and surrounded ecological infrastructures confirmed the occurrence of two broods of A. segetum population in the studied region. The most distinct variations in males migration was demonstrated by catches in traps located on celeriac, parsley and sunflower fields, independently from the field location. Unfortu- nately, the farmer cultivated leak, pumpkin and Chinese cabbage only during one season, therefore the relevant data could not be used to draw full meaning conclusions. Pheromone traps located on border line trees of the apple orchard also at- tracted high number of A. segetum males during the whole 2005 and 2006 growing season. Traps placed on natural vegetation areas in the neighbourhood of the vegetable fields better indicated the A. segetum males migration than by traps located on river embankment.

DISCUSSION

There is presently common opinion that forecasting attacks is a cen- tral part of Integrated Pest Management (IPM) and Integrated Production (IP) strongly linked to the principles of proper timing of chemical control based on a pest monitoring, using economic injury level and selective pesticides to opti- mizing control actions economically as well environmentally (Malavolta et al. 2005). Our data showing much higher catches of A. segetum males in August than May and June 2005 and 2006 season in central Poland confirmed the results obtained by light traps for the Pozna and Wicawice region of western and northern part of Poland (Walczak et al. (2004). The authors noted up to two weeks of interval in maximal catches, indicating mass flight period of A. segetum females and males in three locations, separated by approx. 100 km distance. Observed fluctuations in the number of captured moths in a given location were referred to variations in climatic conditions, mainly temperatures at sunset and indirectly by changes in the air relative humidity. Our field obser- vations indicated that there is an additional factor influencing the efficacy of trappings: location of a trap on a field with specific crop species. The role of proper forecasting of cutworm attacks based on the sex phero- mone traps was developed and implemented in Denmark and Sweden (Esbjerg et al. 1986). As cited by Esbjerg (2003) there has not been any case of impor- tant damage (> 2% non marketable carrots, red beets, leeks or onion) at farms formally linked to and following the advice of the forecasting system in Den- mark since 1978. The Danish forecasting system has evolved during last thirty years. Light traps were first used for forecasting of A. segetum moth migrations. First ex- periments with prototype sex traps with virgin females in 1977-1978 showed that light traps could be replaced and became the source of biological informa- tion ever since in Denmark (Esbjerg et al. 1980). Before 1986 forecasting of cutworm attack was based on the average catch per night, modulated by soil J. GARNIS, Z.T. DBROWSKI – EFFECT OF CROP PLANT SPECIES ... 89 ______type precipitation and temperature so that high soil moisture during the roughly estimated period of L1 and L2 would cause a high mortality and subsequently a low risk. A more precise Day Degree-based calculation of development times of eggs and the first three larval instars was introduced in 1994 in Denmark and Sweden (Esbjerg 2003). The implementation of using pheromone traps for monitoring A.segetum is not yet as commonly used by the Polish vegetable growing farmers as phero- mones of pome fruit pests by orchard owners in Poland (Dbrowski & Majew- ski 2006). Recommended application of light traps was restricted only to re- search institutions responsible for forecasting of agricultural and horticultural pests. Availability of synthetic pheromones for A. segetum on market presently makes the forecasting more simple than previously using laborious and de- manding entomological knowledge on species identification of insects bulk cached by light traps. Unfortunately as shown by other authors there is not di- rect correlation between the intensity of captured males of A. segetum and later crop infestation by cutworms (e.g. Esbjerg 2003). Developed forecasting system based on pheromone catches of males and including Day Degree-based calcula- tion of development times of eggs and the first three larval instars should be evaluated for Polish climatic and social conditions. There is an urgent need to validate the system to improve crop protection programme again Agrotis spp. cutworms in various regions of Poland, taking under consideration local cli- matic conditions. As shown by Walczak et al. (2004) there were two week in- tervals in A. segetum moth flights between locations hundred kilometers away. We believe that our field experiments carried out with the farmers active participation on two farms in Piaski and Siekierki area confirmed high efficacy of available A. segetum synthetic pheromones and that their application will be disseminated to other vegetable growers in central Poland.

CONCLUSIONS

1. Available commercial synthetic pheromone evoked high response of males of A. segetum population in the Warsaw region. 2. Application of pheromone traps confirmed occurrence of two flight picks in June and July, later reflected in the appearance of two broods of the second generation in August and September of the pest in the both studied seasons. The delayed migration of A. segetum adults may be one of the reason of un- satisfactory chemical control of cutworms by farmers. 3. There was a significant effect of a crop species on the efficacy of A. segetum catches by pheromone traps. Positioning of a trap on celeriac culti- vated field attracted the highest number of A. segetum males and showed clear dynamic of population migrations. 4. The wider use of pheromone traps and carrying out regular field observa- tions for monitoring should improved decision making and eliminate re- gional differences in undertaking chemical treatments of cutworms. 90 VEGETABLE CROPS RESEARCH BULLETIN 68 ______

Acknowledgement We thank Mr. Grzegorz Kowalik of Piaski village for making his farm available for our field experiments and his assistance during the project execution .

REFERENCES

Boller E.F., Häni F., Pehling H-M. 2004. Ecological Infrastructures. Ideabook on Func- tional Biodiversity at the Farm Level. Swiss Centre for Agricultural Extension and Rural Development (LBL), Eschikon, Switzerland, pp. 211. Dbrowski Z.T., Majewski M. 2006. Farmers’ knowledge, attitude and practices in integrated apple production in central Poland. Folia Hortic. 18(1): 111-125. Esbjerg P. 2003. Cutworm (Agrotis segetum) forecasting. Two decades of scientific and practical development in Denmark. IOBC WPRS Bulletin 26(3): 239-244. Esbjerg P., Philipsen H., Zethner O. 1980. Monitoring of flight periods of Agrotis segetum using sex traps baited with virgin females. Danish J. Plant Soil Sci. 84: 387-397. Esbjerg P., Nielsen J. K., Philipsen H., Zethner O., Øgaard L. 1986. Soil moisture as a mortality factor for cutworms, Agrotis segetum Schiff. (Lep., Noctuidae). J. Appl. Ent. 102: 277-278. Lipa J.J. 1977.[Mass appearance of cutworms (Agrotinae) in Europe in 1975-1976 and the researchers on their pathogens in Poland]. Materiay 17. Sesji Nauk. Inst. Ochr. Rolin: 305-319. [in Polish with English summary] Malavolta C., Boller E.F., Wijnands F.G. 2005. Guidelines for integrated production of field grown vegetables. Technical guidelines III. IOBC WPRS Bulletin 28(5): 1- 24. Mrówczyski M., Wachowiak H., Boron M. 2003. Rolnice grony szkodnik jesieni 2003 r. Ochrona Rolin 47: 24-26. [in Polish] Mrówczyski M., Wachowiak H., Pruszyski G. 2006. [New endangerment of agricul- tural crops by soil pests]. Prog. Plant Protection/Post. Ochr. Rolin 46(1): 300- 304. [in Polish with English summary] Szwejda J. 2001. Aktualna ocena zagroenia polowych upraw warzywnych przez szkodniki. pp. 5-16. In: Szkodniki, choroby i chwasty w warzywach polowych (M. Pluciska ed.). Instytut Warzywnictwa, Skierniewice, Poland. [in Polish] Walczak F., Jakubowska M., Banaszak H. 2004. [Cutworms (Noctuinae) – major im- portant pests of cultivated plants in Poland]. Prog. Plant Protection/Post.Ochr. Rolin 44 (1): 486-495. [in Polish with English summary]

WPYW GATUNKU ROLINY UPRAWNEJ NA EFEKTYWNO PUAPEK FEROMONOWYCH W MONITORINGU ROLNICY ZBOÓWKI (AGROTIS SEGETUM [SCHIFF.]) (LEP., NOCTUIDAE)

Streszczenie Rolnica zboówka jest wanym szkodnikiem wieloernym, uszkadzajcym wiele upraw rolniczych i ogrodniczych, atakujc szeroki zakres gatunków rolin w rónym stadium ich rozwoju. Larwy rolnic prowadz nocny tryb ycia, ukrywajc si w cióce lub ziemi w cigu dnia, a ich obecno producenci z reguy spostrzegaj, gdy wystpi uszkodzenia rolin. Dlatego te opracowanie efektywnego monitoringu migracji doro- sych owadów na uprawy powinno udoskonali program ochrony rolin przed tym szkodnikiem. Obecnie wykorzystanie puapek lepnych, zawierajcych dyspensery J. GARNIS, Z.T. DBROWSKI – EFFECT OF CROP PLANT SPECIES ... 91 ______z syntetycznym feromonem seksualnym, jest uznawane jako najefektywniejszy system monitoringu motyli A. segetum. Optymalizacja rozmieszczenia puapek powinna zmniejszy koszty zwizane z zakupem puapek, pracochonno prowadzenia obserwacji, przy jednoczesnym zapew- nieniu wiarygodnoci informacji o dynamice nalatywania szkodnika na uprawy. Bada- nia prowadzono wedug metodyki “on-farm research”, z aktywnym udziaem waci- ciela gospodarstwa w planowaniu, zbieraniu danych i interpretowaniu uzyskanych wy- ników, na 10 polach i w otoczeniu gospodarstwa, w sezonie wegetacyjnym 2005 i 2006. Wybrane gospodarstwo w Piaskach jest reprezentatywne dla gospodarstw wa- rzywniczych regionu podwarszawskiego. Stosowano puapki typu Delta, rozprowadza- ne przez firm Medchem. Okrelono zalenoci pomidzy dynamik odowów a poo- eniem puapek na polach z rónymi gatunkami warzyw i upraw rolniczych, jak i na uytkach ródpolnych w otoczeniu gospodarstwa (wa melioracyjny, wa nadrzeczny, obrzee sadu jaboniowego, roliny zielne na miedzach). Uzyskane wyniki pozwol na dopracowanie obecnie stosowanych metod monitoringu, krótko- i dugoterminowego prognozowania wystpowania rolnicy zboówki oraz optymalizacji chemicznego zwal- czania tego szkodnika.