Morphometric variation within apterous females ofSchizaphis graminum biotypes
Tóm tắt
The occurrence of greenbug,Schizaphis graminum (Rondani), biotypes is a constant threat to the development and stability of pest-resistant cereal crop varieties. Of the five biotypes (A, B, C, D, E) reported, only biotype B can be differentiated in life from the others by the physical characteristics of color. The other biotypes are differentiated on the basis of their ability to kill certain hosts or to withstand selected insecticides. The purpose of this research was to differentiate biotypes of apterous viviparous female greenbugs by multivariate techniques. Appendages from individuals of biotypes B, C, and E were measured. Some of the characters including the length of first and fourth flagellar segments, profemur, mesofemur, mesotibia, metafemur and metatibia differentiated the biotypes in multiple comparisons in univariate analyses. Using discriminant functions based on within-group covariance matrices, all greenbugs were classified into their correct group. The shortest Mahalanobis distance was between biotypes B and C. This suggests that biotype B is more closely related to biotype C than it is to biotype E. The coefficients of variation in the body measurements of biotype E were higher as compared to those of the other biotypes, indicating that a new biotype may evolve from biotype E in the future.
Tài liệu tham khảo
Bey-Bienko, G. Y. (1958) The principle of change of stations and the problem of initial divergence of species.Proc. 15th Int. Congr. Zool. Section, II,Paper No. 31: 1–3.
Eastop, V. F. (1973) Biotypes of aphids. 40–51. InA. D. Lowe (ed) Perspectives in aphid biology.Bull. No. 2, Entomol. Soc. N. Zeal. Caxton Press, Christchurch.
Kim, K. C., H. C. Chiang andB. W. Brown, Jr. (1967) Morphometric differences among four biotypes ofOstrinia nubilalis (Lepidoptera: Pyralidae).Ann. Entomol. Soc. Am. 60: 796–801.
Kindler, S. D., S. M. Spomer, T. L. Harvey, R. L. Burton andK. J. Starks (1984) Status of biotype E greenbugs (Homoptera: Aphididae) in Kansas, Nebraska, Oklahoma, and Northern Texas during 1980–1981.J. Kans. Entomol. Soc. 57: 155–158.
Kirkland, R. L., I. D. Peries andG. C. Hamilton (1981) Differentiation and developmental rate of nymphal instars of greenbug reared on sorghum.J. Kans. Entomol. Soc. 54: 743–747.
Morrison, D. F. (1976) Multivariate statistical methods. McGraw-Hill, New York.
Murdie, G. (1969) Some causes of size variation in the pea aphid,Acrythosiphon pisum Harris.Trans. R. Entomol. Soc. London 121: 423–442.
Overall, J. E. andC. J. Klett (1972) Applied multivariate analysis. McGraw-Hill, New York.
Rochow, W. F. andV. F. Eastop (1966) Variation withinRhopalosiphum padi and transmission of barley yellow dwarf virus by clones of four aphid species.Virology 30: 286–296.
Sana, D. L. andJ. T. Schulz (1967) Identity of instars of apterous viviparae ofRhopalosiphum fitchii (Sanderson) andToxoptera graminum (Rondani), (Aphididae, Homoptera).Pak. J. Sci. Res. 19: 108–112.
SAS Institute (1982) SAS user's guide: statistics, 1982 ed. SAS Institute, Inc., Cary, North Carolina.
Saxena, P. N. andH. L. Chada (1971a) The greenbug,Schizaphis graminum. 1. Mouth parts and feeding habits.Ann. Entomol. Soc. Am. 64: 897–904.
Saxena, P. N. andH. L. Chada (1971b) The greenbug,Schizaphis graminum. 2. The salivary gland complex.Ann. Entomol. Soc. Am. 64: 904–912.
Saxena, P. N. andH. L. Chada (1971c) The greenbug,Schizaphis graminum. 3. Digestive system.Ann. Entomol. Soc. Am. 64: 1031–1038.
Saxena, P. N. andH. L. Chada (1971d) The greenbug,Schizaphis graminum. 4. Central and stomatogastric nervous systems.Ann. Entomol. Soc. Am. 64: 1038–1044.
Saxena, R. C. andL. M. Rueda (1982) Morphological variation among three biotypes of the brown planthopperNilaparvata lugens in the Philippines.Insect Sci. Appl. 3: 193–210.
Singh, S. M. andT. K. Cunningham (1981) Morphological and genetic differentiation in aphids (Aphididae).Can. Entomol. 113: 539–550.
Starks, K. J., R. L. Burton andO. G. Merkle (1983) Greenbugs (Homoptera: Aphididae) plant resistance in small grains and sorghum to biotype E.J. Econ. Entomol. 76: 877–880.
Thottappilly, G. V. F. Eastop andJ. E. Bath (1971) Morphological variation withinAcyrthosiphon pisum and in ability to transmit broad bean severe chlorosis virus.Entomol. Exp. Appl. 22: 29–34.
Wool, D. andJ. Koach (1976) Morphological variation of the gall-forming aphid,Geoica urticularia (Homoptera), in relation to environmental variation. 239–272. InS. Karlin andE. Nevo (eds) Population genetics and ecology. Academic Press, New York.