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Advantages and Disadvantages of Haplodiploidy on Whitefly By Alan Soffan Normally individuals, including insect has males and females that arise from fertilized eggs, each sex is diploid, that is possesses two sets of genes, one from each parents, But in some insect such as hymenoptera, the fertilized eggs become female and unfertilized eggs becomes male, so female has normal set of genes diploid, while male are haploid, this pattern of reproduction called as haplodiploidy (Horn, 1976; Mathews and Mathews, 1978). This female insect can lay either fertilized or unfertilized egs by controlling a sphincter muscle that permit the release of sperm from the spermathecal duct, so the female has an ability to determine the sex of their offspring (Evans,1984). Advantages The sex ratio desired in a colony can be determined by female by controlling a sphincter muscle that allow sperm release Since female are more important to support the colony such as make a nest, feeding the young etc, so in order to build up the colony they can determine to have more female (Evans, 1984). The female may have a greater tolerance to the environmental factor by reproducing male parthenogenetically when there are no males (Adamson and Ludwing, 1993; Atkins, 1978) Producing males can be regulated until time of production of a new brood of potential queen (Evans, 1984) The intrinsic rate of increase of a haplodiploidy species would be 1.43 times greater than diploid species (Adamson and Ludwing, 1993) Disadvantages To have a female offspring, the mother/female must wait to mate with her parthenogenetically produced sons/male (Adamson and Ludwing, 1993) There is an increasing expression of deleterious alleles in male (Thornhill,1993) Reference Adamson, Martin., Donald ludwing.1993 Oedipal mating as a factor in sex allocation in haplodiploids.Pkil.Trans.R.Soc.Lond.B (1993) 341, 195-202 Atkins, Michael D.1978.Insects in Prespective.Mac Millan Publishing Co.Inc.New York.513p. Evans, Howard, E.1984. Insect.Addison-Wesley Publishing Company.London.436p. Horn, David J. 1976. Insect Biology.W.B.Saunders.Philladelphia.439p Thornhill , Nancy Wilmsen.1993.The Natural History of Inbreeding and Outbreeding: Theoretical and Empirical Perspectives. University of Chicago Press.575p. By Arya Widyawan In most insects, male and female arise from fertilized eggs; each sex is diploid, that is posses two sets of genes, one from each parent. However, in some insects such as whitefly, all fertilized eggs become females and unfertilized eggs become male. In this case, male are haploid, that is have only one set of gene. Being male haploid has some consequence. He intends to increase the number of population in order to keep his gene in the population. Male haploid will never have son but have grandfather. He receives all his gene-in one of two alleles from his diploid mother. He shares an average of one half of his gene with his brother but possesses only an average of one fourth of his gene with his sister. This condition make male haploid to have more to gain by fathering daughters, with whom they share an average one half of their genes than by assisting in the production of more sisters, with whom they share an average of only one fourth of their genes (Mathews and Mathews 1978). Another advantage of producing a male haploid is on the point of view of the parent female. By producing male haploid, maternal alleles are twice as frequent in gametes of haploid Sons as in gametes of diploid son. This means that female may contribute more to the F2 generation (Bull 1979). Pedigree with diploid son A1 A2 (female) A3 A4 (male) A1 A3 A2 A4 A1 A3 A2 Pedigree with haploid son SONS A4 A1 A2 FEMALE PARENTS A1 A1 A2 A1 THEIR GAMETE Figure 1. Maternal alleles (a1 and a2) appears 2 times in the gametes of sons. (Bull 1979) A2 A2 In other case, there is also a possibility of disadvantage of having male haploid in a population. If there is a aneuploid sperm (abnormal number of chromosome) in the male haploid, all female will suffer proportionally (Bull 1979). Reference Mathews, R.W. & J.R. Mathews, 1978. Insect behavior. John Willey and Sons, New York. Bull, J.J. 1979. An advantage for the evolution of male haploidy and system with similar genetic transmission. Heredity (3), 361-381 By Boy Valenza Based on their ploidy levels in sex determination, arthropods can be grouped into four groups: diplo-diploidy, arrhenotoxy, thelyotoxy, and parahaploidy (Hoy, 2003). Both sexes of many arthropods are diploid (2n, diplo-diploidy), whereas others have haploid males and diploid females (n and 2n, haplodiploidy or arrhenotoxy). Other species consist primarily of diploid females where haploid males rerely are produced (thelytoxy). In some species, haploid males are produced by the loss of paternally derived chromosomes after fertilization (parahaploidy) (Hoy, 2003). Most of whitefly species are arrhenotoky, where females are diploid which are produced from fertilized eggs and males are haploid which come from unfertilized eggs (Hoddle, 1999 ; Henter, 2003). In other words we can say that female whitefly has complete number of chromosomes, twenty two chromosomes, while the male only has half number of chromosomes, eleven chromosomes (Mittler, 1946). There are advantages and disadvantages of being haplodiploidy on whitefly. The first advantage is the female whitefly, the mother, able to control or manipulate the sex ratio of her progeny (Werren, 1980 in Thornhill and Alcock, 1983 ; Wrensch and Ebbert, 1992). If the number of males in white fly population are very low, the female need only lay unfertilized eggs to produce the males to maintain the continuity of their population. The second advantage of being haplodiploidy on whitefly is the female can escape from the problem of mate finding for doing copulation and also reducing the competition in mating process (Wrensch and Ebbert, 1992). It means the female can save their energy for waiting or searching the male, because she can produce another male parthenogenetically. By this condition a new population can be established despite her failure to mate prior to dispersal (Wrensch and Ebbert, 1992). The disadvantage of being haplodiploidy on whitefly is the female whitefly can not produce the female offsprings parthenogenetically looklike the aphids do. Female whitefly will absolutely rely on the presence of male whitefly for producing new generation of females. References: Henter, H. J. 2003. Inbreeding Depression and Haplodiploidy: Experimental Measures in a Parasitoid and Comparisons across Diploid and Haplodiploid Insect Taxa. Society for the Study of Evolution. □ Hoddle, M. S. 1999. The Biology and Management of Silverleaf Whitefly, Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) on Greenhouse Grown Ornamentals. Article. Department of Entomology. University of California. o Hoy, M. A. 2003. Insect Molecular Genetics: An Introduction to Principles and Applications. Academic Press. □ Mittler, S. 1946. Production of Female Offspring by Virgin Females in the Greenhouse Whitefly, Trialeurodes vaporariorum, Under the Influence of High Temperatures. The University of Chicago Press. Δ Thornhill, R and Alcock, J. 1983. The Evolution of Insect Mating Systems.Harvard University Press. London. □ Wrensch, D. L and Ebbert, M. A. 1992. Evolution and Diversity of Sex Ratio: In Haplodiploid Insects and Mites. Springer Publisher. □ By Haris Setyaningrum An insect like another animals has specially character which can differentiated them to each character. One of the character that can be differs is genomic character. In insect we know that some of insect have haploid chromosomes and another have diploid chromosomes. It sure that all type of these chromosome will impact to individual it self. The famous condition in insect are the male haploid insect. It happen like in diptera, hymenoptera, Lepidoptera, orthoptera and coleopteran (Capinera, 2008). But generally we can separated then into advantage and disadvantage: Advantage: balance the population of insect it self in some condition it as strategy to response the threshold condition(unsupported condition) its as resulted from inbreeding that unsuccessful but can resulted the male haploid. Because in normal condition unsuccessful inbreeding not give the individual. generally haploid generation is unfertile and use for protection of colony as mechanism to control of diversity genetic Disadvantage : the male losses the ability to fertilized the egg from the female. production fertile generation is low more sensitive to radiation of light as case in Drosophila melanogaster generally haploid generation shorter life span than diploid ( Capinera, 2008; Cowan & Stahlhut, 2004 ; Crozier & Pamilo, 1996; Kanungo, 1994) References: □Capinera, John L. 2008. Encyclopedia of Entomology. Springer. UK ΔCowan, David P and Stahlhut, Julie K. 2004. Functionally reproductive diploid and in an inbreeding hymenopteran with complementary sex haploid males determination. Proc Natl Acad Sci U S A. 2004 July 13; 101(28): 10374–10379. □Crozier, Rossiter Henry and Pamilo, Pekka. 1996. Evolution of Social Insect Colonies: Sex Allocation and Kin Selection. Oxfor University press. Oxford. □Kanungo, Madhu Sudan. 1994. Genes and Aging. Cambridge University Press.Cambridge .