Effect of Colored Sticky Cards on Non-target Insects

Zhen CHEN,Yihang GE,Xia LIU,Rongping KUANG1,*

1.School of Life Science,Yunnan University,Kunming 650091,China;

2.Pesticide Eco-Alternatives Center,Kunming 650224,China;

3.Forestry School,Southwest Forestry University,Kunming 650224,China

Effect of Colored Sticky Cards on Non-target Insects

Zhen CHEN1,2,Yihang GE3,Xia LIU3,Rongping KUANG1,3*

1.School of Life Science,Yunnan University,Kunming 650091,China;

2.Pesticide Eco-Alternatives Center,Kunming 650224,China;

3.Forestry School,Southwest Forestry University,Kunming 650224,China

Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China.Yellow,blue,green,and red sticky cards were used to trap insects in the field.The total number of insects species caught was 54,with 3,862 individuals recorded.Over half of the specimens caught were non-target insects,including phytophagous insects,particularly dipteran species(including many mosquitoes) (50.3%),followed by target pests(37.0%),and beneficial insects(12.7%).Statistical analysis revealed a significant difference in attraction to target pests,non-target pests,and beneficial insects among treatment groups.The results showed that higher numbers of target pests(Myzus persicae Sulzer,Empoasca flavescens Fabricius,Nysius ericaecshinly Schilling)were caught on yellow sticky card traps compared with blue,green,or red sticky card traps,indicating that yellow was the best trap color for target pests,with green and blue being progressively less attractive.For non-target insects,including phytophagous insects,flies,and mosquitoes, higher numbers of were caught on blue sticky card traps compared with yellow, green,or red sticky card traps.Our study indicated that blue was the most attractive color for flies,especially for the housefly,Musca domestica Linnaeus.Our study also showed that most beneficial insects exhibited preferences to particular trap color characteristics:yellow was the most attractive color for parasitic wasps and lady beetles;blue was the most attractive color for hoverflies and honeybees.In contrast, green and red had no significant attraction to beneficial insects.

Colored sticky cards;Color trap;Non-target insects;Beneficial insects; Natural enemies;Conservation

While chemical pesticides have been widely used for controlling pest insects and diseases,the increasing use of pesticides poses serious threats to human health and the environment[1].In order to reduce chemical pesticide use, many countries have made efforts to promote ecologically friendly pest control methods and technology. Physical pest control,such as the use of light traps and colored sticky traps, is one such method that has been widely applied to crops both to monitor and control pests in response to food safety problems around the world,es pecially in China[2].In Yunnan province,located in southwest China,for an example,the area using trap lights ecologically friendly.

Materials and Methods

Study region

Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in 2012 in an organic maize field in the village of Heinigou,Songming county,Yunnan province,China. Heinigou is a mountainous area populated by the Miao ethnic minority.The local farmers grow mainly maize,barley,tobacco,potato,yacon(Smallanthus sanchifalius),and Chinese cabbage.The village comprises 163 hectares,of which farmland covers 40.9%,and forest covers 16.2%.

Trap design

The experiment was conducted from 25 May to 15 June 2012 in an organic field(area≈600 m2)of maize located in the center of the village. Yellow,blue,green and red sticky cards(ZHONG KUN LV KONG;size: 20×30 cm)were used to trap insects in the field.Each treatment(one color) was replicated four times,giving 20 colored sticky cards in the field at any one time.Traps were placed randomly along a maize row separated by4 m. Rows in which replicates of traps were 3 m apart,and the plants(≈20-30 cm high during the experimental period)were spaced 35-40 cm apart within each row.The sticky cards were mounted vertically on wood stakes, with the bottom trap edges≈3 cm above the plant tops.The sticky cards were placed in every other row for a total of 3 rows(replicates).Upon retrieval the sticky cards were covered with transparent plastic wrap and new cards were placed in the field for theand colored sticky cards to monitor and control pests reached about 87 000 hectares in 2010[3].Although these are generally regarded as ecologically friendly pest control methods, insects vary in their phototactic responses[4-5],and many studies have found that non-target insects including natural enemies and other beneficial insects are also killed during pest trap ping[6-22].Despite this growing understanding,not enough attention has been paid to the negative effects of this technology.The large number of colored sticky traps and their wide use could negatively affect insect diversity. This study attempts to deal with the technology’s potential to harm nontarget insects to better ensure that it iscourse of the experiment.In all treatments,insects were counted in the laboratory with the aid of a stereomicroscope.

Statistical analysis

The number of target pests,nontarget insects,and natural enemies caught were analyzed using one-way analysis of variance(ANOVA).An LSD test(significance level was P= 0.05)was performed to analyze differences between experimental groups.

Results

The total number of insects species caught was 54,with 3,862 individuals recorded including Hemiptera,Diptera,Coleoptera,Lepidoptera, Isoptera,Hymenoptera,Odonata,and Neuroptera.Among the insects caught,target pests were Myzus persicae Sulzer,Empoasca flavescens Fabricius,and Nysius ericaecshinly Schilling,with 1 428 individuals.Nontarget insects included 38 species with 1 942 individuals,and beneficial insects included 13 species with 492 individuals.Over half of the specimens caught were non-target insects,including phytophagous insects,especially flies,including mosquitoes(50.3%),followed by target pests(37.0%),and beneficial insects (12.7%)(Table 1).

Higher numbers of target pests were caught on yellow sticky card traps compared with blue,green or red sticky card traps(Fig.1)(F=6.908, df=3,P=0.013).Yellow sticky cards caught 675 target pest individuals, compared with 94 caught on blue,450 caught on green and 209 caught on red sticky cards,indicating that yellow was the best trap color for target pests, followed by green,while blue was the least attractive.However,the effect of yellow sticky cards on beneficial insects was also the largest compared with blue,green or red sticky card traps(F=7.439,df=3,P=0.011).Yellow sticky cards caught 235 beneficial insects compared with 163 caught on blue,65 caught on green,and 29 caught on red sticky cards.For nontarget insects,higher numbers were caught on blue sticky card traps compared with yellow,green,or red sticky card traps(F=7.528,df=3,P=0.01). Blue sticky cards caught 1 075 non-target individuals compared with 355 caught on yellow,348 caught on green,and 195 caught on red sticky cards.

For target pests,yellow was the most effective color for M.persicae and N.ericaecshinly,while green was the most attractive color for E.flavescens.Among non-targets insects,blue was the most attractive color for flies spp.compared with yellow, green,or red sticky card traps.

The effects of the four differentcolored sticky cards on the main beneficial insects,including lady beetles, hoverflies,parasitic wasps,and honeybees are shown in Fig.2.Higher numbers of lady beetles were caught on yellow sticky card traps compared with blue,green,or red sticky card traps(F=3.109,df=3,P=0.089).Yellow sticky cards caught 71 lady beetles compared with 6 caught on blue,29 on green and 3 on red sticky cards,indicating that yellow was the most attractive color for lady beetles,especially for Harmonia axyridis Pallas,followed by green,with red being the least attractive.

Table 1 The number of individuals and species(in parentheses)of insects caught by four different colored sticky cards,in Heinigou,China, in maize from 25 May to 15 June 2012

Meanwhile,higher numbers of hoverflies were caught on blue sticky card traps compared with yellow, green,or red sticky card traps(F= 13.661,df=3,P=0.002).Blue sticky cards caught 90 hoverflies compared with 0 caught on yellow,1 on green, and 4 on red sticky cards,indicating that blue was the most attractive color for hoverflies.

For parasitic wasps,on the other hand,higher numbers were caught on yellow sticky card traps compared with blue,green,or red sticky card traps (F=3.549,df=3,P=0.067).Yellow sticky cards caught 148 parasitic wasps compared with 1 on blue,32 on green,and 15 on red sticky cards,indicating that yellow was the most attractive color for parasitic wasps,followed by green,with blue being the least attractive.

Higher numbers of honeybees were caught on blue sticky card traps compared with yellow,green,or red sticky card traps(F=3.954,df=3,P= 0.054).Blue sticky cards caught 66 honeybees compared with 12 on yellow,2 on green,and 4 on red sticky cards,indicating that blue was the most attractive color for honeybees, followed by yellow,with green being the least attractive.

Discussion

We found significant differences in the attraction of the treatment groups to target pests,non-target pests,and beneficial insects.Higher numbers of target pests were caught on yellow sticky card traps compared with blue,green,or red sticky card traps,indicating that yellow was the best trap color for target pests,followed by green,red,and blue.Yet on a species level,while yellow was the most effective color for attracting M.persicae and N.ericaecshinly, green was the most attractive color for E.flavescens.Similarly,Cesar et al.[21]reported that green was the most attractive color to blunt-nosed leafhoppers,followed by red and yellow,while yellow was most attractive to sharpnosed leafhoppers,followed by green and red,findings which are consistent with our studies.

Mccann and Arnett[23]reported that the spectral sensitivity of Diptera was characterized by two approximately equal sensitivity peaks at 350 nm(UV light)and 480 nm(blue light). It is also known that the photoreceptors in the compound eyes of the housefly,Musca domestica Linnaeus, are sensitive to ultraviolet(340-365 nm)and blue-green(450-550 nm) light[24-26].Our finding that blue was the most attractive color for fly spp.,especially for the housefly,is consistent with these studies of spectral sensitivity of Diptera and the photoreceptors of the housefly.

Our study showed that most beneficial insects also exhibited preferences to particular trap color characteristics:yellow was the most effective color for parasitic wasps and lady beetles;blue was the most attractive color for hoverflies and honeybees.In contrast,green and red have no significant attraction to beneficial insects.

Many studies have shown that yellow sticky traps are the most effective color for trapping parasitic wasps[7,17,19,21,27-30].Dowell and Cherry[7]and Maredia et al.[31]both reported that yellow sticky traps caught significantly more lady beetles in their field tests. Meanwhile,Chen et al.[14]found that the number of the hoverfly,Allograpta oblique Say,caught on blue sticky card traps ranged from 2.4 to 18.7 per trap per week compared with 0-2.1 on yellow and 0 on white sticky card traps. Hoback et al.[32]and Cesar et al.[21]also reported that hoverflies were attracted to blue traps.These results support the present finding that yellow is an effective color for trapping the ladybirds and parasitic wasps and that blue is an effective color for trapping hoverflies.

Hou et al.[33]reported that the daily maximum number of the aphid M.persicae preyed upon by one adult ladybird Coccinella septempunctata L.was theoretically 332 aphids.Zhao et al.[34]reported that the average number of M.persicae parasitized by one female parasitic wasp Aphidius gifuensis Ashmead was theoretically 128.Ourstudy found the ratio of ladybirds,parasitic wasps,and aphids trapped by yellow sticky cards to be 1∶2.1∶4.4,and the ratio of trapped ladybirds,parasitic wasps and aphids by the four colored sticky cards combined to be 1∶1.8∶5.4. Therefore,we propose that the negative effect of colored sticky cards,especially yellow sticky cards,on ladybirds and parasitic wasps was considerably more than on the aphid itself from a biological control point of view.

Our study found that honeybees were highly attracted to blue compared with yellow,green,or red.In a similar study,Cesar et al.[21]reported that honey bees were highly attracted to white compared with yellow,green,or red.Roubos and Liburd[18]reported that multicolored traps were significantly more attractive to honeybees compared with green,yellow,green top, and yellow top.Adams et al.[35]report catching more stinging Hymenoptera in yellow and white traps and suggest using all green traps to reduce nontarget captures.In consideration of the importance of conserving beneficial insects,we suggest that blue,yellow, white and multicolor sticky cards not be used to control crop pests during the height of the honeybee population.

In conclusion,the results of this experiment have shown that yellow and blue traps are highly effective at trapping non-target insects,especially in yellow traps for parasitic wasps and lady beetles and blue traps for hoverflies and honeybees.In contrast,the effect of green and red traps on beneficial insects can be neglected.The widespread use of yellow and blue sticky traps could negatively affect beneficial insects such as parasitic wasps,lady beetles,hoverflies,and honeybees,making trap use less environmentally friendly.However,the full extent of the negative effect of yellow and blue sticky cards on beneficial insects and other non-target insects is yet to be determined and requires further study.

Acknowledgment

We are grateful to Ms.S.L.Zhang and X.M.Long from Heinigou village for help collecting colored sticky cards in field experiments,and to professor R.David Clements of Trinity Western University for statistical advice.

[1]KUANG R P,XIANG R J,TU W L,et al. Pesticide development in China:a comprehensive Report[M].Beijing: China Environmental Science Press, 2005.

[2]JING X F,LEI C L.Advances in research on phototaxis of insects and the mechanism[J].Entomological Knowledge,2004,41:198-203.

[3]Yunnan Plant Protection Station.Plant protection progress report in Yunnan Province[R].Kunming:YPPS,2010.

[4]K?HN A.Phototropism us und phototaxis der tiere.Bethes Handb.Norm[J]. Pathology Physiology,1929,12:17-33.

[5]MENZEL R,GREGGERS U.Natural phototaxis and its relationship to colour vision in Honeybees[J].Journal of Comparative Physiology A,1985,157: 311-321.

[6]HONEK A.Annual variation in the complex of aphid predators:investigation by light trap[J].Acta Entomologica Bohemoslovaciae,1977,74:345-348.

[7]DOWELL R V,Cherry R H.Survey traps for parasitoids,and coccinellid predators of the citrus blackfly,Aleurocanthus woglumi[J].Entomological Experimental Application,1981,29:356-361.

[8]PETER N.Beneficial insects caught by yellow traps used in mass-trapping of the olive fly,Dacus oleae[J].Entomological Experimental Application,1982, 32:286-296.

[9]HONEK A.KOCOUREK F.The flight of aphid predators to a light trap possible interpretations,In:Ecology of Aphidophaga[M],Ed.by Hodek,I.Pragua: Academia and Dordrecht:Dr.W.Junk, 1986.

[10]UDAYAGIRI,SUJAYA,MASON,et al. Coleomegilla metadata,Coccinella septempunctata(Coleoptera:Coccinellidae),Chrysoperla carnea(Neuroptera:Chrysopidae),and Macrocentrus grandii(Hymenoptera:Braconidae)trapped on colored sticky traps in corn habitats[J].Environmental Entomology,1997,26:983-988.

[11]HENDA N,WAYNE C B,SEMI N.Beneficial insect attraction to light traps with different wavelengths[J].Biological Control,1999,16:185-188.

[12]OCKROYM L,TURLINGS T C J,EDWARDS P J.et al.Response of natural populations of predators and parasitoids to artificially induced volatile emissions in maize plants(Zea mays L.)[J].Agricultural Forest Entomology, 2001,3(3):201-209.

[13]PARAJULEE M N.SLOSSER J E.Potential of yellow sticky traps for lady beetle survey in Cotton[J].Journal of Economic Entomology,2003,96:239-245.

[14]CHEN T Y,CHI C C,FITZGERALD G. et al.2004.Trap evaluations for thrips (Thysanoptera:Thripidae)and hoverflies(Diptera:Syrphidae)[J].Environmental Entomology,2004,33:1416-1420.

[15]ZHANG G X,ZHENG G,ZHANG X J. et al.Discussion of using frequency trembler grid lamps from angle of protecting biodiversity[J].Entomological Knowledge,2004,41:532-535.

[16]HOELMER K A,SIMMONS A M.Yellow sticky trap catches of parasitoids of Bemisia tabaci(Hemiptera:Aleyrodidae)in vegetable crops and their relationship to in-field populations[J].Environmental Entomology,2008,37: 391-399.

[17]JACQUELYN L B,JOHN A B,CESAR R S.Evaluation of color traps for monitoring Lygus spp.:design,placement, height,time of Day,and non-target Effects[J].Crop Protection,2008,27: 171-181.

[18]ROUBOS C R,LIBURD O E.Effect of trap color on captures of grape root borer(Lepidoptera:Sesiidae)males and non-target insects[J].Journal of Agricultural and Urban Entomology, 2008,25:99-109.

[19]WALLIS D R,SHAW P W.Evaluation of coloured sticky traps for monitoring beneficial insects in apple orchards[J]. New Zealand Plant Protection,2008, 61:328-332.

[20]ZHU M H,CHEN W L,GU D.et al.The natural enemies of leaf miners effected by the process of killing leaf miners with yellow sticky traps[J].Journal Southwest China Normal University (Natural Science Edition),2008,33: 48-51.

[21]CESAR R R S,JOHN A B,DANIEL S. Effect of trap color and height on captures of blunt-nosed and sharp-nosed leafhoppers(Hemiptera:Cicadellidae) and non-target arthropods in Cranberry Bogs[J].Crop Protection,2012,40: 132-144.

[22]HEN Z,KUANG R P,ZHOU J X.et al. Phototactic behaviour in Aphidius gifuensis(Hymenoptera:Braconidae)[J]. Biocontrol Science and Technology. 2012,22:271-279.

[23]MCCANN G D,ARNETT D W.Spectral and polarization sensitivity of the Dipteran visual system[J].The Journal of general physiology,1972,59:534-558.

[24]MAZOKHIN-PORSHNIAKOV G A.Colorometric study of the properties of colour vision of insects as exemplified by the house fly[J].Biofizika,1960,5: 295-303.

[25]GOLDSMITH T H,FERNANDEZ H R. The sensitivity of housefly photoreceptors in the mid-ultraviolet and the limitsof the visible spectrum[J].Journal of Experimental Biology,1968,49:669-677.

[26]BELLINGHAM J,ANDERSON M.Variations and sexual differences in the spectral sensitivity of the compound eye of the housefly Musca domestica (L.)and the lesser housefly Fannia canicularis(L.)[C].Proceedings of the First International Conference on Urban Pests,1993,1:480.

[27]KRYSAN L,JAMES,HORTON et al. Seasonality of catch of pear psylla Cacopsylla pyricola(Homoptera: Psyllidae)on yellow traps[J].Environmental Entomology,1991,20:626-634.

[28]ROMEIS J,SHANOWER T G,ZEBITZ C P W.Response of trichogramma egg parasitoids to colored sticky traps [J].BioControl,1998,43:17-27.

[29]THOMSON L J,NEVILLE P J,HOFFMANN A A.Effective trapping methods for assessing invertebrates in Vineyards[J].Australian Journal of Experimental Agriculture,2004,44: 947-953.

[30]PRISCHMANN D A,JAMES D G, STORM C P.et al.Identity,abundance,and phenology of Anagrus spp. (Hymenoptera:Mymaridae)and leafhoppers(Homoptera:Cicadellidae) associated with grape,blackberry,and wild rose in Washington State[J].Annals of The Entomological Society of America,2007,100:41-52.

[31]MAREDIA K M,GAGE S H,LANDIS D A.et al.Visual response of Coccinella septempunctata(L.),Hippodamia parenthesis(Say),(Coleoptera:Coccinellidae),and Chrysoperla carnea (Stephens),(Neuroptera:Chrysopidae)to colors[J].Biological Control, 1992,2:253–256.

[32]HOBACK W W,SVATOS T M, SPOMER S M.et al.Trap color and placement affects estimates of insect family-level abundance and diversity in a Nebraska Salt Marsh[J].Entomological Experimental Application,1999, 91:393-402.

[33]HOU M L,WAN F H.Predation of Myzus persicae by adults of Coccinella septempunctata[J].Entomological Knowledge,2004,41:347-350.

[34]ZHAO W Y,DING C P,DONG D Z,et al.The bionomics of Aphidius gifuensis Ashmead and its utilization for the control of tobacco aphid Myzus persicae Sulzer.Zoological Research,1980, 1:405-415.

[35]ADAMS R G,MURRAY K D,LOS L M. Effectiveness and selectivity of sex pheromone lures and traps for monitoring fall armyworm(Lepidoptera: Noctuidae)adults in Connecticut sweet corn.Journal of Economic Entomology,1989,82:285-290.

Responsible editor:Xiaoxue WANG

Responsible proofreader:Xiaoyan WU

Supported by the Misereor Foundation(grant ref:335-031-1028 Z).

*Corresponding author.E-mail:rongping.kuang@gmail.com Received:March 3,2015 Accepted:April 14,2015