Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter Wheat

1 3

Originalbeitrag

Abstract Orange wheat blossom midge damage can im-part serious loss of quantity and quality of winter wheat. Wheat midges were evaluated in large scale field in winter wheat in bad lausick (leipzig, Saxsony) central germany. the present study aimed at studying the activity of wheat blossom midges WbM, Sitodiplosis mosellana (géhin) and Contarinia tritici (Kirby) using pheromone, sticky traps and two types of water traps. Management of midges with different treatments was studied; Karate (pyrethroid), bis-caya (neonicotinoid) and neemazal t/S (botanical insec-ticide) were sprayed on wheat at heading stage (gS 55). Monitoring was conducted before the treatment and contin-ued for 4 weeks after the treatment. Pheromone traps were used for forecasting midge adult population and determine the control date. Water traps were used to assess midge lar-vae, while midge adults were surveyed using sticky traps.

a strong correlation between midge catches and weath-er conditions was obtained; as well a coincidence between pheromone catches and wheat midge infestation in the sus-ceptible growth stages (gS 47–65) was recorded. insecti-cide applications to fields of midge-infested winter wheat significantly reduced the wheat midge damage. There were significant differences in wheat midge numbers between treated and untreated; wheat midge numbers were lower in the treated than in control. the results proved that both

Karate and biscaya caused more mortality to wheat midges than neemazal t/S.

Keywords Wheat blossom midges · Pheromone traps · insecticides · Water traps · Winter wheat

Zur Bekämpfung von Weizengallmücken in Winterweizen in Mitteldeutschland

Zusammenfassung Weizengallmücken sind ökonomisch bedeutsame Schädlinge im Winterweizen und können in ab-hängigkeit vom befallsbeginn in der Weizenähre verschie-dene Schadsymptome (z. b. Kümmerkörner) verursachen. Zur etablierung einer bekämpfungsstrategie wurde im Jahre 2012 in der Leipziger Tieflandsbucht ein Insektizidversuch auf einem Praxisschlag durchgeführt. Die Zielstellung des sogenannten „On–Farm-experiment“ war es, eine bewer-tung direkt im Produktionsfeld vorzunehmen und Hinweise zur entscheidungsunterstützung der landwirte zu formulie-ren. Der methodische ansatz berücksichtigte den einsatz von Pheromonfallen, gelbtafeln und Wasserschalen zur Überwachung der Flugaktivität der Mücken und zur erfas-sung des abwanderungsverhaltens der larven. Die bekämp-fungsstrategie orientierte sich am derzeitigen Wissensstand und terminierte einen Spritztermin zum Ährenschieben. es wurden zugelassene insektizide hinsichtlich ihrer effektivi-tät gegenüber Weizengallmücken in einem Zeitfenster von fünf Wochen getestet. Die ergebnisse 2012 zeigen eine gute Korrelation zwischen Mückenaktivität und den Wetter-bedingungen. Die Pheromonfallenfänge signalisieren unter den Feldbedingungen eine enge Koinzidenz zwischen dem Flughöhepunkt und dem kritischen Pflanzenstadium (BBCH 55–65). Der bekämpfungstermin war somit optimal auf die Schädlingsaktivität abgestimmt. Die Feldstudie belegt signi-

Gesunde Pflanzen (2013) 65:7–13DOI 10.1007/s10343-012-0289-7

Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter WheatNabil E. El-Wakeil · Abdellah S. H Abdel-Moniem · Nawal Gaafar · Christa Volkmar

n. e. el-Wakeil () · a. S. H. abdel-Moniem · n. gaafar · C. Volkmarinstitute of agriculture and nutritional Sciences, Martin-luther-University Halle-Wittenberg, germanye-mail: [email protected]

n. e. el-Wakeil · a. S. H. abdel-Moniem · n. gaafar Pests and Plant Protection Department, National Research Center, Cairo, Dokki, Egypt

Received: 21 November 2012 / Accepted: 21 December 2012 / Published online: 5 January 2013© Springer-Verlag Berlin Heidelberg 2012

1 3

8 N. E. El-Wakeil et al.

fikante Unterschiede zwischen den Varianten. Die höchsten Wirkungsgrade erzielte der einsatz von Karate Zeon, gefolgt von biscaya und neemazal t/S. Die Datenanalyse des ex-periments zeigt ein hohes Schadpotential von Weizengall-mücken auf dem Kontrollschlag und unterstreicht die not-wendigkeit diese versteckt lebenden Ährenschädlinge exakt zu überwachen.

Schlüsselwörter Weizengallmücken · Pheromonfallen · gelbtafeln · Wasserschalen · insektizide · Winterweizen

Introduction

Wheat (Triticum aestivum l.) is one of the most important cereal grain crops in the world and it is cultivated over a wide range of climatic conditions (Varshney et al. 2006). Yields can be improved if producers take time to inspect their fields and control the insect pests during the growing season. important pests that may reduce wheat yields are wheat blossom midges (WbM). the orange wheat blossom midge Sitodiplosis mosellana (géhin) and the yellow wheat blossom midge Con-tarinia tritici (Kirby) (Diptera: Cecidomyiidae), have a very patchy spatial distribution and infestations vary from year to year, because they have the capacity for extended diapauses and only a portion of the larvae in the soil develop and pupate each spring, depending on climatic conditions (Oakley 1994; bruce et al. 2007; gaafar 2010; Gaafar and Volkmar 2010). During the past decade, infestations of wheat midge seriously reduced the yield and quality of wheat in the major wheat-pro-ducing provinces in germany (el-Wakeil et al. 2010; gaafar et al. 2011), Finland (Kurppa 1989), UK (Oakley et al. 2005), and Canada (Dexter et al. 1987; lamb et al. 2003; Olfert et al. 2009).

Pheromone traps gave a reliable indication of peak midge emergence, onset of flight and abundance of midges throughout the season. the wheat plants are susceptible growth stages (GS) from the flag leaf sheath opening up to the flowering half complete (GS 47–65) (Olfert et al. 2004). also weather conditions have to be favorable for the insect to lay eggs within the florets (Pivnick 1993; Oakley et al. 1998; Oakley et al. 2005). the critical risk factors are the proportion of diapausing midge larvae that might develop in any given season, the coincidence between emergence of adult midges and susceptible stages (basedow and gillich 1982; gaafar 2010) and the suitability of the weather dur-ing adult midge activity coinciding with susceptible growth stages for flight and oviposition (Gries et al. 2000; Smith and lamb 2001). a strong correlation between maximum trap catches and crop infestation levels has resulted in many studies (bruce et al. 2007; gaafar et al. 2011).

Water traps are often used to sample migrating and flying insects. larvae are caught in their migrating way from wheat ears to soil at the end of the season. insects are attracted visually by colour of the traps and are then captured in the

water. Studies have demonstrated the preferences of a cer-tain cultivar of insect to a particular coloured trap, as well as weather condition, especially rainfall (barker et al. 1997).

the highest wheat midge populations can be found in fields where wheat was grown in previous years and in the neighbor fields. Coupled with this pressure is the demand for minimizing damage of insects as well as for the decreas-ing insecticides uses. an insecticide application is recom-mended when there are 30 midge adults/pheromone trap/day or one adult midge for four to five wheat heads (Ellis et al. 2009; gaafar 2010; el-Wakeil et al. 2010); at this level of infestation, wheat yields will be reduced by approxi-mately 15 % if the midge is not controlled. Higher midge densities will reduce yields even further (lamb et al. 2000). insecticide applications should be applied in the evening when female midges are most active at the top of the crop canopy. However, early morning applications may also pro-duce acceptable results. application should be made within 24 h of reaching the action threshold with the proper doses (elliott and Mann 1997), while the adults are still active (elliott 1988; JianCheng et al. 2000). if adult midge persist, a second application may be required, provided the crop has not started to flower (Oakley 2008). application during the advanced stages of flowering is discouraged because plants in this growth stage are no longer susceptible to attack, and any larvae already inside the florets are unlikely to be affected by an insecticide. the insecticide will have a nega-tive impact on midge parasites (Shanower 2005).

the objective was to determine the abundance of orange wheat midge in large scale wheat field through pheromone traps to survey wheat midge adults to decide whether chem-ical control is needed or no. after treatments, yellow and white water traps were used to assess wheat midge larvae as well using sticky traps to count the wheat midge adults.

Materials and Methods

Winter Wheat Field

the experiments were conducted at vegetation period 2012 in central Germany (in Bad Lausick- Latitude: 51.15 and Longitude: 12.63); the wheat variety Kerubino was selected (anonymous 2011). the experimental plots were designed as a randomized completed block experiment (four blocks); three replicates were repeated in each block; plot size was 16 m (long) and 24 m (wide).

Survey S. mosellana adults Using Pheromone traps

the pheromone traps Suterra® were set up at growth stages 45–77. Two traps were placed at ca. 20 m from field borders and distance between two traps was 10 m. the traps were positioned at the same height as the ears of the wheat plants.

Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter Wheat

1 3

9

trap catches were recorded once a week (bruce et al. 2007). Date of wheat midge control was determined based on pheromone trap results. each trap consists of a pheromone lure; Dispenser: Septa; Material: Natural rubber; Packaging: Individually Sachet Packed; Sachet Material: Foil Lined laminate.

Chemical Control

the wheat midge management was conducted by using Karate (lambda cyhalothrin), a pyrethroid insecticide, at a rate of 0.75 l/ha (anonymous 2012), and biscaya a neonic-otinoid insecticide containing 240 g/L thiacloprid (22.97 % w/w) at rate of 0.4 l/ha and neemazal t/S a botanical insecticide at rate of 3/500 L water/ha. The tested com-pounds were sprayed on 6th June 2012 at heading stage (gS 55) (tottman 1987). the control plots were only sprayed with water. insect populations were sampled before the insecticide application, thereafter, 7, 15, 21 and 28 d after treatment. the presented results will be mean of four dates after treatment. the mortality or reduction percents were calculated based on abbott (1925).

where: n insect populationt treatedC Control

Surveying Wheat Midge Larvae Using Water Traps

White Water traps

White water traps are often used to sample migrating both orange and yellow wheat midge larvae. the migrated midge larvae from wheat ear were monitored during their wander from ears to soil as expectation factor for the following year. the traps consisted of white plastic dishes; 12.5 cm diam-eter and 6.5 cm deep. in each plot, three traps were placed and partly filled with water plus drops of detergent at GS 71 till 85. The traps were observed weekly; and the caught larvae were counted using a binuclear in the lab (barker et al. 1997).

Yellow Water traps

three yellow water traps per plot were placed on the ground between wheat plants. these traps consist of yellow square dishes 30 × 30 cm with the front grille. The trapping fluid consisted of water with a drop of detergent. this method is designed to identify larvae of orange and yellow wheat midges. the collected samples were transferred in 100 ml

Corrected % =(

1 −n in T after treatment

n in C after treatment

)× 100

plastic cups with ethanol; these traps were gathered weekly and identified in the lab.

Inspecting Wheat Midge Adults Using Sticky Traps

Sticky traps (Pherocon aM no bait traps, trece inc., Sali-nas, CA, USA) are fastened onto bamboo stakes with the long axis of the card vertical. the paper covering one of the sticky surfaces is peeled off to expose the sticky sur-face. traps are placed at the same height as the wheat heads (lamb et al. 2002). three traps were placed in each plot in winter wheat field. Weekly, traps were collected, and adult of wheat midges on each trap was counted.

Statistical Analysis

numbers of captured insects either in pheromone or water traps and sticky traps were analyzed by factorial design with General Linear Model (GLM- ANOVA Statistix 9) (Thomas and Maurice 2008). tukey test was used to compare means of treatments. Significances were noted at P < 0.05 for all trials.

Results

Pheromone Trap Catches

Orange wheat midge males (OWbM) (S. mosellana) adult population increased with days to reach the first peak on GS 59–63 (230 midges/trap) on 4th June (therefore the midge management was applied on 6th June); while the second peak was recorded on GS 75–77 (134 midges/trap). Tem-poral overlap between adult OWBM flight and the suscep-tible growth stages of wheat (gS 47–65) allowed a higher infestation to develop of OWbS population levels, as shown by the oval shape in Fig. 1. there was a strong correlation between the catches of OWbS in pheromone traps and the mean daily temperature and rainfall (r = 0.73). A coinci-dence between catches of pheromone traps and infestation of wheat midges in the susceptible growth stages (heading and flowering stages) was found.

Effects of Insecticides on Orange and Yellow Wheat Midge Larvae

White Water traps

both orange and yellow wheat midge larvae were surveyed by white water traps during their way immigrating to the soil at end of wheat season. generally, the results showed

1 3


that midge larvae in control plots were significantly differ-ent (P = 0.001) than treatments, within the different treat-ments were Karate and Biscaya had a good influence on wheat midge populations than neemazal t/S treatments (Fig. 2).

Yellow Water traps

in general, the results proved that larvae of midges in treat-ments plots were significantly lower (P = 0.0011) than con-trol plots. Within the treatments, Karate caused the highest percent mortality of wheat midges than other both treat-ments (Fig. 3).

Effect of Insecticide Application on Wheat Midges Using Sticky Traps

both adults of orange and yellow wheat midges were surveyed by sticky traps. generally, the results showed that midge adults in control plots differed significantly (P = 0.0022) than treatments, within the different treatments, midge adults were higher in neemazal t/S than Karate and biscaya (Fig. 4).

Effect of Insecticides (Mortality %- Abbott Value) on Wheat Midge Larvae and Adults

There were considerable significant differences in the impact of insecticide on wheat midge larvae and adults as shown in table 1. in white water trap results, Karate caused the highest percent larval mortality (72.8 %), followed by

Fig. 1 Mean ± Se of Sitodiplo-sis mosellana adults catches in pheromone traps and their relation to temperature and rainfall in winter wheat 2012. Oval refers to coincidence of adult activity and susceptible growth stages. Dif-ferent letters indicate significant differences

Fig. 2 Mean population ± Se of orange and yellow wheat midge lar-vae cached by white watertraps (n = 12) after insecticides application. Different letters indicate significant differences

Fig. 3 Mean population ± Se of orange and yellow wheat midge lar-vae cached by yellow watertraps (n = 12) after insecticides application. Different letters indicate significant differences


1 3

11

Biscaya (57.2 %) then came NeemAzal T/S (46.8 %). While in yellow water traps, the larval mortality percents differed significantly (P = 0.001); they were recorded as the fol-lowings: 66.7, 54.5 and 45.5 % in Karate, NeemAzal T/S and biscaya, respectively. the reduction percents in wheat midge adults were significantly different (P = 0.002), these percents reached to 45.4 % in neemazal t/S, 57.4 % in biscaya and 66 % in Karate as found by using sticky traps.

Discussion

large variations in adult midge numbers caught in the pheromone traps and in timing of peak catches were found between dates in large scale studies undertaken in central germany in region named “leipzig lowlands”. this suggests that it is more useful for farmers to put traps in neighboring fields which were cultivated wheat in the year. The peak of midge flight synchronized with the susceptible stage (GS 59) of winter wheat, because there was correlation between total numbers of males caught during the susceptible period and infestation as confirmed by Gaafar and Volkmar (2009) ellis et al. (2009) and el-Wakeil et al. (2010). Pheromone traps were very valuable in indicating midge emergence and for decision making to determine the proper date for wheat midge management. This is a significant benefit with other systems for monitoring wheat midges as mentioned by gaafar et al. (2011). there was also a strong correla-tion between peak pheromone trap catches and temperature and high rainfall. these results agree with those obtained by Pivnick and labbe (1993); Oakley et al. (2005); bruce et al. (2007); Volkmar et al. (2008); Gaafar and Volkmar (2009), who studied pheromone traps in different sites.

there is a constructive relation between pheromone trap catches and wheat midge infestation. therefore, chemi-cal control was applied on 6th June in case of high level

of midge infestation in pheromone traps (230 midge/trap/week) after heading (GS 59–65). These results are consis-tent with those observed by Oakley (2008), ellis et al. (2009) and el-Wakeil et al. (2010), who determined the economic threshold at 30 or more midges caught per pheromone trap per day. this study suggest that a trapping program based on pheromone and sticky traps for midge adults and both water traps for midge larvae is a good way of sampling wheat blossom midges, in early of the season for adult and late of the season for larvae. a monitoring technique is necessary at the beginning of season in the study region such as central germany and also where the wheat grown; this gives a reli-able base for decision making to midges control. routine use of all trap types to monitor wheat midge would elimi-nate most unnecessary applications of insecticide and assure that benefits of insecticide application usually exceed costs.

the numbers of orange wheat blossom midge lar-vae in either water trap types or sticky traps were higher in untreated than treated plots. Karate caused the highest reduction percents, followed by biscaya, then neemazal t/S. the high catches of WbM in the water traps may be attributed to weather conditions, especially rainfall, which had a direct effect and facilitated the migration of midge lar-vae to the soil. Similar results were recorded in winter wheat by gaafar (2010), gaafar et al. (2011) who noted increases in catch densities after heavy rainfall. this is important for crop rotations; insect densities can easily surpass threshold densities if wheat is grown after wheat.

to reduce the economic impact of wheat midges; wheat farmers must be aware of all suitable management strategies. Forecasts and risk warnings, monitoring tools, chemical control, biological control and plant resistance are all avail-able for the industry to manage wheat midges. although, neemazal t/S treatment caused adequate mortality of wheat midges not high as Karate, but it is still safer to the natural enemies (elliott and Mann 1996; Olfert et al. 2009). an insecticide application is recommended when the crop is heading but not full flowering and wheat midge density is more than 30 midge/pheromone trap/day. Late insecticide applications should be avoided as it is not cost effective and may adversely affect biological control agents. results of water traps is considered as forecasting method for the next year when it intend growing the wheat after wheat.

Fig. 4 Mean population ± Se of orange and yellow wheat midge adults surveyed by sticky traps (n = 12) after treatments in winter wheat 2012. Different letters indicate significant differences

Table 1 effect of botanical and synthetic insecticides (abbott values in %) on wheat midge population surveyed by white and yellow water traps as well sticky trapstreatments White water

trapsYellow water traps

Sticky traps

neemazal t/S 46.8 Ca 54.5 b 45.4 CKarate 72.8 A 66.7 a 66.0 abiscaya 57.2 b 45.5 C 57.4 baDifferent letters indicate significant differences (P = 0.002)

1 3


Acknowledgements Our deep thanks are due to trifoloio for pro-viding us neemazal t/S. We are also greatly indebted to Prof. M. Saleh for his helpful comments on the manuscript. this research was supported financially by DFG in Martin Luther University in Halle, germany.

References

Abbott WS (1925) A method of computing the effectiveness of an insecticide. J Econ Entomol 18:265–276

anonymous (2011) beschreibende Sortenliste getreide, Mais, Ölfrüchte, leguminosen (großkörnig), Hackfrüchte (außer Kar-toffeln). Bundessortenamt, Osterfelddamm 80, 30627 Hanover ISSN 0948–4167, pp 86–120

anonymous (2012) list of authorized plant protection products in ger-many with information on terminated authorizations. bundesamt für Verbraucherschutz und Lebensmittelsicherheit. www.bvl.bund.de/infoppp.

Barker AM, Sanbrooke KJ, Aebischer NJ (1997) The water trap colour preferences of farmland sawflies. Entomol Exp Appl 85:83–86

Basedow T, Gillich H (1982) Untersuchungen zur Prognose des auftretens von Contarinia tritici und Sitodiplosis mosellana. ii. Faktoren, die ein Schadauftreten der Mücken verhindern können. Anz Schädlkunde Pflschutz 55:84–89

bruce tJa, Hooper aM et al (2007) Development of a pheromone trap monitoring system for Sitodiplosis mosellana, in the UK. Pest Manag Sci 63:49–56

Dexter JE, Preston KR, Cooke LA, Morgan BC, Kruger JE, Kilborn RH, Elliott RH (1987) The influence of orange wheat blossom midge Sitodiplosis mosellana damage on hard red spring wheat and the effectiveness of insecticide treatments. Can J Plant Sci 67:697–712

Elliott RH (1988) Evaluation of insecticides for protection of wheat against damage by the wheat midge, Sitodiplosis mosellana (Géhin). Can Entomol 120:615–626

Elliott RH, Mann LW (1996) Susceptibility of red spring wheat, Trit-icum aestivum l. cv. Katepwa, during heading and anthesis to damage by wheat midge, Sitodiplosis mosellana (géhin) (Dip-tera: Cecidomyiidae). Can Entomol 128:367–375

Elliott RH, Mann LW (1997) Control of wheat midge, Sitodiplosis mosellana at lower chemical rates with small-capacity sprayer nozzles. Crop Prot 16:235–242

Ellis SA, Bruce TJA, Smart LE, Martin JL, Snape J, Self M (2009) integrated management strategies for varieties tolerant and sus-ceptible to wheat midge. HGCA Project Report number 451 May 2009, p 148

El-Wakeil NE, Gaafar N, Volkmar C (2010) Susceptibility of spring wheat to infestation with wheat midges and thrips. J Plant Dis Prot 117:261–267

Gaafar N (2010) Wheat midges and thrips information system: moni-toring and decision making in central germany. PhD Diss Martin- Luther- Uni Halle, p 109

Gaafar N, Volkmar C (2009) Monitoring system of orange wheat blos-som midge, Sitodiplosis mosellana using pheromone trap in the central Germany. Mitt Dtsch Ges Allg Angew Ent 17:221–225

Gaafar N, Volkmar C (2010) Evaluation of wheat ear insects in large scale field in central Germany. Agric Sci 1:68–75

Gaafar N, El-Wakeil NE, Volkmar C (2011) Assessment of wheat ear insects in winter wheat varieties in central germany. J Pest Sci 84:49–59

gries r, gries g, Khaskin g, King S, Olfert O, et al (2000) Sex phero-mone of orange wheat blossom midge, Sitodiplosis mosellana. Naturwissenschaften 87:450–454

JianCheng L, Gang W, Jun D, QingWen Z (2000) Study on the tech-niques for control of wheat midge by chemicals. Plant Prot 26:30–32

Kurppa SLA (1989) Wheat blossom midges, Sitodiplosis mosellana géhin and Contarinia tritici (Kirby) in Finland during 1981–1987. Ann Agric Fenniae 28:87–96

lamb rJ, tucker Jr, Wise il, Smith MaH (2000) trophic interac-tion between Sitodiplosis mosellana (Diptera) and spring wheat: implications for yield and seed quality. Can Entomol 132:607–625

lamb rJ, Wise il, gavloski Je, Kaminski la, Olfert OO (2002) Making control decisions for Sitodiplosis mosellana in wheat using sticky traps. Can Entomol 134:851–854

Lamb RJ, Sridhar P, Smith MAH, Wise IL (2003) Oviposition pref-erence and offspring performance of a wheat midge Sitodiplo-sis mosellana on defended and less well defended wheat plants. Environ Entomol 32:414–420

Oakley JN (1994) Orange wheat blossom midge: a literature review and survey of the 1993 outbreak. Res Rev No. 28. Home-Grown Cereals Authority London, p 51

Oakley JN (2008) Control needs for changing pest distribution. Arable cropping in a changing climate: Proc HGCA Conf United King-dom: HGCA, pp 87–92

Oakley JN, Cumbleton PC, Corbett SJ, Saunders P, et al (1998) Predic-tion of orange wheat blossom midge activity and risk of damage. Crop Prot 17:145–149

Oakley JN, Talbot G, et al (2005) Integrated control of wheat midge: variety choice, use of pheromone traps & treatment thresholds. HGCA Project Report (363) 65

Olfert OO, elliott rH, Hartley S, Zeleny K (2004) Forecast of wheat midge in Alberta and Saskatchewan for 2004, 2003 Crop variety highlights and insect pest forecasts. Saskatoon Res Centre Tech-nical Bull No. 2004–01:14–15

Olfert OO, Elliott RH, Hartley S (2009) Non-native insects in agri-culture: strategies to manage the economic and environmental impact of wheat midge, Sitodiplosis mosellana, in Saskatchewan. Biol Invasions 11:127–133

Pivnick KA (1993) Response of males to female sex pheromone in the orange wheat blossom midge, Sitodiplosis mosellana. J Chem Ecol 19:1677–1689

Pivnick KA, Labbe E (1993) Daily patterns of activity of females of the orange wheat blossom midge, Sitodiplosis mosellana. Can Entomol 125:725–736

Shanower tg (2005) Occurrence of Sitodiplosis mosellana and its parasitoid, Macroglenes penetrans in northeastern Montana. Can Entomol 137:753–755

Smith M, Lamb R (2001) Factors influencing oviposition by Sitodip-losis mosellana (Diptera: Cecidomyiidae) on wheat spikes. Can Entomol 133:533–548

Thomas CR, Maurice SC (2008) Statistix 9, Ninth Edition, Manage-rial Economics McGraw-Hill/Irwin. (ISBN: 0073402818). More information at http://www.statistix.com. Accessed 28 Sept 2012

Tottman DR (1987) The decimal code for the growth stages of cereals, with illustrations. Ann Appl Biol 110:441–454

Varshney RK, Balyan HS, Langridge P (2006) Genome mapping and molecular breeding in plants. Cereals & Millets 1:79–134

Volkmar C, Werner C, Matthes P (2008) On the occurrence and crop damage of wheat blossom midges Contarinia tritici (Kby.) and Sitodiplosis mosellana (geh.) in Saxony-anhalt. Mitt Dtsch ges Allg Angew Ent 16:305–308


1 3

13

Dr. Nabil E. El-Wakeil is work-ing as an assistant Professor at the National Research Centre, Cairo, egypt; currently he works as Post doc fellow at Martin luther Halle University since July 2010.

Dr. nabil el-Wakeil was born in Egypt in 1969. He completed his academic degree in agri-cultural sciences in Menofyia University in 1991, Egypt with a major in Plant Protection and minors in economic entomology. He conducted his Master research on “ecological studies on certain natural enemies of maize and sor-ghum pests’’ in Cairo University,

Egypt and obtained his Master in 1997. Dr. El-Wakeil completed his doctorate in 2003 at the Department of Entomology, Crop Sciences, University of göttingen, germany. the topic of his dissertation was “new aspects of biological control of Helicoverpa armigera in organic cotton production”. He had started working at the national research Center (Pests and Plant Protection Dept.) in Egypt since 20 years ago.

Documents

Effectiveness of Some Insecticides on Wheat Blossom Midges in Winter Wheat