Study on fluctuation of species composition of corn insect pests in Gia Lam, Hanoi, in 2010 - 2011

JOURNAL OF SCIENCE OF HNUE Chemical and Biological Sci., 2012, Vol. 57, No. 8, pp. 81-89 This paper is available online at STUDY ON FLUCTUATION OF SPECIES COMPOSITION OF CORN INSECT PESTS IN GIA LAM, HANOI, IN 2010 - 2011 Bui Minh Hong1 and Tran Hong Trang2 1Faculty of Biology, Hanoi National University of Education 2Nguyen Van Cu High School, Gia Lam, Hanoi Abstract. The relationship between corn insect pests, geographical location and time of the year was studied. Of the total number of species, 32.26% were of the order Lepidoptera (10 species) and 6.46% were of the order Homoptera. Thirty-one, 28 and 27 species of insects which feed on corn were found in the villages of Phu Dong, Van Duc and Phu Thi, respectively. Autumn-winter, 2010: The number of corn insect pest species was found to be 30 in October, 26 in September and November, and 13 in December. Summer, 2011: The number of corn insect pests in June was 28 species, in July it was 25 species, in August 15 and in May 11 species were found. Keywords: Corn insect pest, species, Gia Lam. 1. Introduction Corn (Zea mays L.), of the Poaceae family, is an important agricultural product in Vietnam. It is grown over a wide area of the country, there is the potential for high yields and intensive farming is possible. Of the corn being grown, 50 - 70% is fed to livestock and the rest are used for industrial purposes or exported [3]. In Vietnam, and particularly in Gia Lam, Hanoi, average yields are low, prices are high, and local demand is not met. Reasons for low yields in Vietnam include climate change, drought, flooding and infestation by new species of insects. This study was done to identify the species of insects which are found in the corn fields of Gia Lam, Hanoi, Received May 22, 2012. Accepted June 26, 2012. Contact Bui Minh Hong, e-mail address: bui_minhhong@yahoo.com 81 Bui Minh Hong and Tran Hong Trang 2. Content 2.1. Collection and identification method * Collection locations: - Areas of corn cultivation: Phu Dong, Van Duc and Phu Thi villages, Gia Lam District, Hanoi. - Species identification was carried out by the Zoology Department and the Faculty of Biology in Hanoi National University of Education. * Species collection methods: Insects were collected using a method of the Institute of Plant Protection [4] and the national technical regulation on identification of plant pests (QCVN 01 - 38 : 2010/BNNPTNT) [1]. * Classification of species: Specimens were classified referring to the identification key developed by Charles A. Triplehorn and F.J. Norman [2]. 2.2. Result and discussion 2.2.1. Species composition of corn insect pests in Gia Lam, Hanoi (2010 - 2011) The species of insect pests collected is presented in Table 1. Insect pests collected were of 31 species belonging to 16 families of 5 orders (Coleoptera, Hemiptera, Homoptera, Orthoptera and Lepidoptera). Table 1. Corn insect pest species in Gia Lam, Hanoi (2010 - 2011) No. Scientific name Order Family 1 Alissonotum impressicolle (Arrow,1908) Coleoptera Scarabaeidae 2 Adoretus sp. Coleoptera Scarabaeidae 3 Cassida circumdata (Herbst, 1799) Coleoptera Chrysomelidae 4 Henosepilachna vigintioctopunctata (Fabricius, 1775) Coleoptera Coccinellidae 5 Epicauta gorhami (Marseul, 1873) Coleoptera Meloidae 6 Hypomeces squamosus (Fabricius, 1792) Coleoptera Curculionidae 7 Leptocorisa varicornis (Fabricius, 1843) Hemiptera Coreidae 8 Cletus punctiger (Dallas, 1852) Hemiptera Pentatomidae 9 Eysarcoris ventralis (Westwood, 1837) Hemiptera Pentatomidae 10 Nezara viridula (Linnaeus, 1758) Hemiptera Pentatomidae 11 Scotinophora lurida (Burm, 1834) Hemiptera Pentatomidae 12 Dirdecus sp. Hemiptera Pyrryhocoridae 13 Rhopalosiphum maidis (Fitch, 1856) Homoptera Aphididae 14 Nilaparvata lugens (Stal, 1854) Homoptera Delphacidae 15 Acrida chinensis (Westwood, 1842) Orthoptera Acrididae 82 Study on fluctuation of species composition of corn insect pests in Gia Lam, Hanoi... 16 Atractomorpha chinensis (Bolivar, 1905) Orthoptera Acrididae 17 Oxya chinensis (Thunberg, 1815) Orthoptera Acrididae 18 Oxya velox (Fabricius, 1787) Orthoptera Acrididae 19 Chondracsis rosea (De Geer, 1773) Orthoptera Acrididae 20 Trilophidia sp. Orthoptera Acrididae 21 Brachytrupes portentosus (Lichtenstein, 1796) Orthoptera Gryllidae 22 Parnara guttata (Bremer et Grey,1852) Lepidoptera Hesperiidae 23 Cnaphalocrocis medinalis (Guenee,1854) Lepidoptera Pyralidae 24 Ostrinia furnacalis (Guenee, 1854) Lepidoptera Pyralidae 25 Leucania loreyi (Duponchel, 1827) Lepidoptera Noctuidae 26 Spodoptera litura (Fabricius, 1775) Lepidoptera Noctuidae 27 Agrotis ipsilon (Rottemburg, 1766) Lepidoptera Noctuidae 28 Helicoverpa armigera (Hubner,1805) Lepidoptera Noctuidae 29 Hyphoraia testudinaria (Fourcroy, 1785) Lepidoptera Arctiidae 30 Amsacta lactinea (Cramer, 1977) Lepidoptera Arctiidae 31 Porthesia scintillans (Walker, 1856) Lepidoptera Lymantridae As shown in Table 1, 31 species belong to 16 families and 5 orders (Coleoptera, Hemiptera, Homoptera, Orthoptera and Lepidoptera) were found and identified. The number of species and the species proportion in the corn fields was determined and the results are shown in Table 2. Table 2. The number posision and proportion of species/family of corn insect pests in Gia Lam, Hanoi (2010 - 2011) No. Order Family Species Number of family Rate of family (%) Number of species Rate of species (%) 1 Coleoptera 5 29.42 6 19.35 2 Hemiptera 3 17.64 6 19.35 3 Homoptera 2 11.76 2 6.46 4 Orthoptera 2 11.76 7 22.58 5 Lepidoptera 5 29.42 10 32.26 Total 17 100 31 100 Of the families of insects pests identified, 31.25% were of the Coleoptera and Lepidoptera orders. Five families of Lepidoptera (including Hesperiidae, Pyralidae, Noctuidae, Arctiidae and Lymantridae) insects were found of 10 species, which was 32.26% of the total number of species. Four species (12.9%) were of the Noctuidae family. In the Coleoptera order were 5 families: Scarabaeidae, Chrysomelidae, 83 Bui Minh Hong and Tran Hong Trang Coccinellidae, Meloidae and Curculionidae, with 6 species, which was 19.35% of the total number of species. Two species were of the Scarabaeidae family. Insects of only 2 families were found of the Homoptera or Orthoptera orders, 11.76% of the species. Two species (corn aphid Ropalosiphum maidis and brown plant hopper Nilaparvata lugens Stal) accounted for 6.46% of the number of species. 2.2.2. Fluctuation of corn insect pest species in Gia Lam, Hanoi (2010 - 2011) Species composition of corn insect pests and their abundance at the locations investigated in Gia Lam, Hanoi were reported in Tables 3 and 4. The number of species of corn insect pests in individual study place were different, these pests distributed with density more or less dependent on crops’ growth-up conditions and other external factors. Rhopalosiphum maidis, Trilophidia sp., Ostrinia furnacalis and Nilaparvata lugens found at three study place. Table 3. Fluctuation of corn insect pest species in the corn fields of Gia Lam, Hanoi (2010 - 2011) No Scientific name Place of study Phu Thi Phu Dong Van Duc n n% n n% n n% I Scarabaeidae 8 0.30 21 0.62 12 0.42 1 Alissonotum impressicolle Arrow 8 0.30 15 0.44 12 0.42 2 Adoretus sp. 6 0.18 II Chrysomelidae 14 0.53 32 0.95 22 0.87 3 Cassia circumdataMerbet 14 0.53 32 0.95 22 0.87 III Coccinellidae 31 1.18 40 1.19 25 0.87 4 H. vigintioctopunctata Fabricius 31 1.18 40 1.19 25 0.87 IV Meloidae 9 0.34 18 0.53 5 Epicauta gorhamiMar 9 0.34 18 0.53 V Curculionidae 26 0.99 30 0.89 11 0.38 6 Hypomeces squamosus Fabr 26 0.99 30 0.89 11 0.38 VI Coreidae 19 0.72 33 0.98 12 0.42 7 Leptocorisa varicornis Fabr 19 0.72 33 0.98 12 0.42 VII Pentatomidae 19 0.72 55 1.63 47 1.64 8 Cletus punctiger Dallas 16 0.47 11 0.38 9 Eysarcoris ventralisWestw 7 0.27 13 0.39 15 0.52 10 Nezara viridula Linnaeus 12 0.45 18 0.53 16 0.56 11 Scotinophora lurida Burm 8 0.24 5 0.17 84 Study on fluctuation of species composition of corn insect pests in Gia Lam, Hanoi... VIII Pyrryhocoridae 9 0.27 12 0.42 12 Dirdecus sp. 9 0.27 12 0.42 IX Aphididae 1680 64.02 2100 62.39 1800 62.91 13 Rhopalosiphum maidis Fitch 1680 64.02 2100 62.39 1800 62.91 X Delphacidae 24 0.91 29 0.86 53 1.85 14 Nilaparvata lugens Stal 24 0.91 29 0.86 53 1.85 XI Acrididae 410 15.62 415 12.33 377 13.17 15 Acrida chinensisWest 47 1.79 15 0.44 25 0.87 16 Atractomorpha chinensis Bolivar 55 2.09 32 0.95 38 1.33 17 Oxya chinensisWalk 58 2.21 40 1.19 50 1.75 18 Oxya velox Fabr 80 3.05 135 4.01 120 4.19 19 Chondracsis rosea De Geer 67 2.55 78 2.31 52 1.81 20 Trilophidia sp. 103 3.92 115 3.42 92 3.21 XII Gryllidae 5 0.19 16 0.48 12 0.42 21 Brachytrupes portentosus Licht 5 0.19 16 0.48 12 0.42 XIII Hesperiidae 74 2.82 98 2.91 37 1.29 22 Parnara guttata Bremer et Grey 74 2.82 98 2.91 37 1.29 XIV Pyralidae 135 5.14 245 7.28 236 8.25 23 Cnaphalocrocis medinalis Guenee 26 0.99 75 2.23 86 3.00 24 Ostrinia furnacalis Guenee 109 4.16 170 5.05 150 5.25 XV Noctuidae 154 5.85 180 5.35 164 5.73 25 Leucania loreyi Dup 85 3.24 96 2.85 70 2.45 26 Spodoptera litura Fabr. 14 0.53 38 1.13 32 1.11 27 Agrotis ipsilon Rott 31 1.18 29 0.87 37 0.24 28 Helicoverpa armigera Hubner 24 0.91 17 0.50 25 0.87 XVI Lymantridae 16 0.61 45 1.34 41 1.43 29 Porthesia scintillanWalker 7 0.27 24 0.71 23 0.80 30 Hyphoraia testudinar Fourcroy 3 0.11 9 0.27 31 Amsacta lactinea Cramer 6 0.23 12 0.36 18 0.63 Total 2624 100 3366 100 2861 100 Total number of insects 2964 3803 3233 Total number of insect species 27 31 28 Fluctuation (%) 87.09 100 90.32 85 Bui Minh Hong and Tran Hong Trang Cassia circumdata andOxya veloxwere found in high numbers in Phu Dong wheras in Phu Thi and Van Duc they were present in a lower density. Henosepilachna vigintioctopunctata, Chinensis Oxya, Chondracsis rosea, Chinensis Acrida, Atractomorpha chinensis, Leucania loreyi, Helicoverpa armigerawere also found. Cletus punctiger only was found only in Phu Dong. Scotinophora lurida, Dirdecus sp. were found only in Van Duc and Phu Dong. A difference in species composition and number of species of corn insect pest species varied among the different place of study in Gia Lam, Hanoi: - Phu Thi village: 27 species were collected, 3 in a frequency greater than 60%, 12 in a frequency of 40 - 60%, 8 in a frequency of 20 - 40% and 4 in a frequency of less than 20%. - Phu Dong village: 31 species were collected, 5 in a frequency greater than 60%, 16 species in a frequency of 40 - 60%, 9 from 20 - 40% and one species less than 20%. - Van Duc village: 28 species were collected, 5 species in a frequency greater than 60%, 15 in a frequency of 40 - 60% 7 species in a frequency of 20 - 40% and 3 species less than 20%. 2.2.3. Fluctuation of species composition of corn insect pests over the months in Gia Lam, Hanoi (2010 - 2011) The composition and abundance of corn insect pest species differ from month to month as the corn grew (Table 4). Table 4. Fluctuation in species composition of corn insect pests over the months in Gia Lam, Hanoi No. Scientific name Order Family The level of encounter frequency over the months In autumn - winter In summer 2010 2011 9 10 11 12 5 6 7 8 1 A. impressicolle Coleoptera Scarabaeidae + ++ + ++ + 2 Adoretus sp. Coleoptera Scarabaeidae + + + + 3 C. circumdata Coleoptera Chrysomelidae ++ ++ + + ++ + 4 H.vigintioctopunctata Coleoptera Coccinellidae ++ ++ + ++ + 5 E. gorhami Coleoptera Meloidae + + 6 H. squamosus Coleoptera Curculionidae + + 7 L. varicornis Hemiptera Coreidae ++ ++ + + ++ + + 8 Cletus punctiger Hemiptera Pentatomidae ++ ++ + ++ + 9 Eysarcoris ventralis Hemiptera Pentatomidae ++ +++ ++ + +++ ++ + 10 Nezara viridula Hemiptera Pentatomidae + +++ +++ + + +++ ++ + 86 Study on fluctuation of species composition of corn insect pests in Gia Lam, Hanoi... 11 Scotinophora lurida Hemiptera Pentatomidae + + + + 12 Dirdecus sp. Hemiptera Pyrryhocoridae + + + 13 R. maidis Homoptera Aphididae ++ +++ +++ + +++ +++ + 14 Nilaparvata lugens Homoptera Delphacidae + ++ ++ 15 Acrida chinensis Orthoptera Acrididae ++ +++ ++ ++ +++ +++ ++ 16 A. chinensis Orthoptera Acrididae ++ +++ ++ ++ + +++ ++ ++ 17 Oxya chinensis Orthoptera Acrididae ++ +++ ++ ++ +++ ++ ++ 18 Oxya velox Orthoptera Acrididae ++ +++ ++ ++ + +++ +++ ++ 19 Chondracsis rosea Orthoptera Acrididae ++ +++ ++ ++ + +++ +++ +++ 20 Trilophidia sp. Orthoptera Acrididae ++ +++ +++ ++ ++ +++ +++ +++ 21 B. portentosus Orthoptera Gryllidae + + 22 Parnara guttata Lepidoptera Hesperiidae ++ ++ + ++ + 23 C. medinalis Lepidoptera Pyralidae ++ ++ + + ++ + 24 Ostrinia furnacalis Lepidoptera Pyralidae + +++ +++ ++ + +++ +++ ++ 25 Leucania loreyi Lepidoptera Noctuidae ++ +++ ++ ++ ++ 26 Spodoptera litura Lepidoptera Noctuidae + ++ ++ + ++ ++ 27 Agrotis ipsilon Lepidoptera Noctuidae ++ +++ ++ + +++ ++ 28 H. armigera Lepidoptera Noctuidae + ++ + ++ 29 H. testudinaria Lepidoptera Arctiidae + ++ + ++ + + 30 Amsacta lactinea Lepidoptera Arctiidae ++ ++ ++ + ++ +++ ++ 31 P. scintillans Lepidoptera Lymantridae + ++ ++ ++ ++ Notes. +: Low encounter frequency (less than 25% total of encounters); ++: Moderately common (25 - 75% total of encounters); +++: Very common (≥ 75% total of encounters) Autumn-winter, 2010: From September to December, we collected 31 species of corn insect pests: Species of Acrididae were found during all the months of investigation but they were most prevalent from mid-September to late October. - Period of 8 to 10 leaves: Oxya velox, C. Rosea, Trilophidia sp., Acrida chinensis, Atractomorpha chinensis were the species present with the highest densities and frequencies. - Period of 9 to 11 leaves: P. guttata, C. medinalis, L. loreyi were found from mid-September to November in high frequency. E. ventralis appeared in October. Stink bugs appeared from September to November. Ostrinia furnacalis were found in October and November. - Period of 8 to10 leaves to flowering: Damage was observed on leaves and stems and appeared to be caused by Lepidoptera species (P. guttata, C. medinalis, Leucania loreyi, A.ipsilon and Spodoptera litura) and Orthoptera species (Oxya velox, C. Rosea, Trilophidia sp., Acrida chinensis and Atractomorpha chinensis). 87 Bui Minh Hong and Tran Hong Trang - Period of corn flowering to harvest: Many species of corn insect pests were observed, including Ostrinia furnacalis, R. Maidis, Ostrii;/pnia furnacalis, Trilophidia sp., Acrida chinensis and Atractomorpha chinensis. September: 26 species were collected. These species appeared in May with low to average frequency, with 17 species at average frequency (25 - 75%) and 9 species at frequencies less than 25%. October: 30 species were collected, appearing at different levels: 12 species appeared at a frequency much greater than 75%, 13 species appeared with an average frequency of 25 - 75% and 5 species appeared at frequencies of less than 25%. November: 26 species were collected of which 4 species appeared at a frequency much greater than 75%, 11 species appeared with an average frequency of 25 - 75% and at least 11 species were seen with a frequency of less than 25%. December: 13 species were collected but not many appeared at a frequency greater than 75%. Seven species appeared with a frequency average of 25 - 75% and 6 species with a frequency of less than 25%. Summer, 2011: During the 2011 summer corn growing season (May to August), we collected 29 species. May: 11 species were collected with low to mederate frequency, with frequency averaging 25 - 75%. Ten species appeared at frequencies of less than 25 %. June: 28 species were collected. Eleven appeared at a frequency much greater than 75%, 13 with frequency averaging 25 - 75% and 4 with a frequency of less than 25%. July: 25 species were collected of which 7 appeared at a frequency much greater than 75%, 9 species with an average frequency of 25 - 75% and 9 at a frequency of less than 25%. August: 15 species were collected, two with a frequency much greater than 75%, 7 with an average frequency of 25 - 75% and 6 species appeared with a frequency of less than 25%. 3. Conclusion 1-Thirty-one species of corn insect pests, belonged to 5 orders (Coleoptera, Hemiptera, Homoptera, Orthoptera and Lepidoptera) were collected. More species were of the Lepidoptera order than any other with 10 species, which is 32.26% of all species collected. Belonging to the Diptera order were only two species. 88 Study on fluctuation of species composition of corn insect pests in Gia Lam, Hanoi... 2-Among seventeen families of corn insect pests, 5 families belonging to the Coleoptera and Lepidoptera orders (29.42%), 3 families to the Hemiptera order (17.64%), 2 families to the Homoptera (11.76%) and 2 families to Orthoptera orders (11.76%). 3-Corn insect pest species differentiation existed among the three places of study. There were 31 species (100%) in Phu Dong village, 28 species (90.32%) in Van Duc village and 27 species (87.09%) in Phu Thi village. 4-In Phu Dong village there was the greatest abundance at 38.03%, in Van Duc village it was 32.33% and in Phu Thi village it was 29.64%. 5-The composition of corn insect pest species found through the months and at different sites also varied: - Autumn-winter, 2010: The greatest number of species, 30, was found in October while in September and November 26 species were found and in December 13 species were found. - Summer, 2011: The largest number of corn insect pest species found was 28 species in June, 25 species in July, 15 in August and 11 species in May. REFERENCES [1] Ministry of Agriculture and Rural Development, 2010. National technical regulations on methods of detection of plant pests. Circular No. 71/2010/TT-BNNPTNT. QCVN 01-38: 2010/BNNPTNT (in Vietnamese). [2] Charles A. Triplehorn and Norman F. Johnson, 2005. Borror and DeLong’s Introduction to the Study of Insects (7th edition). Thomas books/Cole - a Classic textbook in North America. [3] Goodyer G, 1984. Insect pest of maize. Review of Applied Entomology, 72(5), p.330. [4] Nguyen Duc Khiem, 1995. The situation on the maize pest in Hanoi. Journal of Plant Protection, No. 5, pp. 10-13 (in Vietnamese). [5] Institute of Plant Protection, 2000. Research methods in plant protection. Agriculture Publishing House, Hanoi (in Vietnamese). 89