I= EFFECTS OF CHLORFULAZURON ON THE GROWTH OF COMMON LITURA (F.) (LEPIDOPTERA: NOCTUDIAE) WITH SPECIAL REFERENCES TO THE MORPHOLOGY AND HISTOLOGY OF THE REPRODUCTIVE SYSTEM
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Title of Thesis
EFFECTS OF CHLORFULAZURON ON THE GROWTH OF COMMON LITURA (F.) (LEPIDOPTERA: NOCTUDIAE) WITH SPECIAL REFERENCES TO THE MORPHOLOGY AND HISTOLOGY OF THE REPRODUCTIVE SYSTEM

Author(s)
Farzana Perveen
Institute/University/Department Details
Department of Zoology/ University Karachi
Session
2004
Subject
Zoology
Number of Pages
444
Keywords (Extracted from title, table of contents and abstract of thesis)
embryogenesis, hatchability, insemination, malformations, oogenesis, oviposition stimulating factors, reproductivity, spermatogenesis, toxicity, viability

Abstract
Chlorfluazuron was applied to newly moulted fifth-instar larvae or .newly ecdysed pupae of the .common cutworm, Spodoptera litura (F.) by topical application. The values of LD50 and LD95 of pupae were higher than those of larvae. Sublethal doses (LD10: .1.00 ng/larva; 0.12 ng/female pupa;' 1.23ng/md.le pupa or L030: 3.75 ng/larva) were applied to females. and males and subsequent adults were mated in three different treatment combinations. First, treated females were mated with untreated males, for both doses (LD10♀x U♂; LD30♀x U♂) Secondly, untreated females were mated with treated males for both doses (U ♀x LD10♂; U♂ x LD30♂). Finally, treated both sexes were mated ,for both doses (LD10♀x LD10♂; LD30♀x LD30♂). The fecundity was reduced by 35 - 44% for all combinations of both doses. With both Sublethal. doses the fertility was reduced to 49 - 58% when females were treated, 65 - 81% when males were treated and 68 - 83% when both sexes were treated. The subsequent hatchability was reduced to 22 - 26% when females were treated, 44 - 66% when males were treated and 45 - 72% when both sexes were treated with both Sublethal doses. However,. there were no significant differences between larval and pupal treatments in the above mentioned parameters. .Moreover, there were no significant differences in daily patterns of them when compared with controls. The body weight reduction occurred during the development of larvae and pupae when treated with LD30 and in adults when. treated with LD10 or LD30. The duration of larval and pupal stages, the life-spans of male and female adults and the number of matings per pair remained unaffected by the larval or pupal treatments.

Sublethal doses of Chlorfluazuron significantly reduced ovarian weight and number of mature eggs in pupae and adults compared with controls, but their ratios were unaffected by the both treatments. In treated adults, the germarium was significantly longer than the pedicle and vitellarium, whereas in controls the vitellarium was significantly longer than the germarium and pedicle. The number of nuclei was also significantly reduced in the germarium. These results indicate delayed maturation of ovarioles in treated insects. These doses also disrupted growth and development of 06cytes by significantly affecting the size of basal oöcytes and the thickness of the follicular epithelium. The thickness of the follicular epithelium of basal oöcytes reached a maximum one day later in treated common cutworms. In newly emerged treated adults, the protein and nucleic acid (DNA and RNA) content of ovaries were significantly reduced, but the carbohydrate and lipid content were not significantly effected Ovarian ecdysteroid titres were low during pre-vitellogenesis, increased during vitellogenesis, peaked at the time of choriogenesis and decreased when insects started to deposit eggs and decreased thereafter. Ecdysteroid titres significantly decreased in LD10-, and ;more 'significantly decreased in LD30-treated females. However, the patterns of ecdysteroid titre secretion were the same as in controls.

Sublethal doses disrupted growth and development of the testes by decreasing the volume, weight and thickness of the sheath. The protein and nucleic acid (DNA and RNA) content were significantly reduced in the testes, but carbohydrate and lipid content were unaffected, Three peaks of testicular ecdysteroid were obtained during pupal development. The ecdysteroid titre was significantly reduced by Sublethal doses during larval, pupal and adult development.

Additionally, theses doses disrupted spermatogenesis by reducing the number and size of eupyrene and apyrene sperm bundles in the testes. Very few or no eupyrene sperm bundles were observed in the vas deferens of pre- and newly emerged adults. This shows that the transfer of sperm bundles from testis to vas deferens was delayed in treated males.

Male adults multiple-mated 10 times during the whole life-span of 13 days, when paired.each day with a new virgin female of the same age. A complete spermatophore was transferred through the male aedeagus and endophalus into the bursa copulatrix of the female after 50 min of copula formation. The number of inseminated eupyrene sperm decreased 66% or 88 %, respectively, in LD10 or LD30 treated males. However, no significant reduction in inseminated eupyrene sperm was observed when females were treated, The ratios .of eupyrene and apyrene sperm were unaffected, but the first mating was delayed by one day when males were treated with LD10 or LD30,

In addition, examination of the unhatched eggs revealed that the number of unfertilized eggs was greater than those that were fertilized. The greater number of unfertilized eggs was the result of treatments, The major; cause of failure in the number of hatchings was, therefore, a lack of fertilization, Interference by Chlorfluazuron, which was transferred by copulation through sperm fluids or ova, seems highly improbable. All these fertilized unhatched eggs in the treated crosses died. at an earlier stage than those of controls. In the female-treated crosses, the egg size was significantly reduced, compared with male-treated crosses. During mating, the treated males transferred significantly lower-weight spermatophores into the females.

In S. litura, two factors are involved in activation of oviposition. The first one obtained from virgin female haemolymph and the second one found in the haemolymph obtained from mated females. Sublethal doses of Chlorfluazuron significantly decreased their activities.

Download Full Thesis
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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
345.73 KB
2 1 Introduction 1-40
317.44 KB
  1.1 Toxicity 10
  1.2 Effect Of Sublethal Doses On Reproductivity And Viability 09
  1.3 Effect Of Sublethal Doses On Ovarian Development And Oögenesis 19
  1.4 Effect Of Sublethal Doses On Insemination 26
  1.5 Effect Of Sublethal Doses Insemination 26
  1.6 Reduction In Hatchability By Sublethal Doses And Transfer Of Chloruazuron 29
  1.7 Biochemical Analyses 30
  1.8 Chlorfluazuron As Reproductive Inhibitor 37
3 2 Review Of The Literature 41-101
511.67 KB
  2.1 Toxicity 41
  2.2 Chlorfluazuron 55
  2.3 Effect On Reproductivity And Viability 57
  2.4 Effect On Ovarian Development And Oögenesis 71
  2.5 Effect On Testicular Development And Spermatogenesis 75
  2.6 Effect On Insemination 78
  2.7 Effect On Embryogenesis 83
  2.8 Biochemical Analysed 87
4 3 Materials And Methods 102-137
288.72 KB
  3.1 Insect Rearing Procedure 102
  3.2 Chlorfluazuron 104
  3.3 Method Of Treatment 106
  3.4 Effect On Reproductivity And Viability 108
  3.5 Effect On Sublethal Doses On Ovarian Development And Oögenesis 111
  3.5 Effect Of Sublethal Doses On Testicular Development And Spermatogenesis 115
  3.6 Effect Of Sublethal Doses On Insemination 119
  3.7 Reduction In Hatchability By Sublethal Doses And Transfer Of Chlorfluazuron 121
  3.8 Determination Of Oviposition Stimulating Factors 124
  3.9 Biochemical Analyses 126
5 4 Results 138-303
1864.37 KB
  4.1 Toxicity Determination 138
  4.2 Morphological Effects, Malformations And Development Of Abnormalities 145
  4.3 Effects Of Sublethal Doses On Reproductivity 155
  4.4 Effects Of Sublethal Doses On Viability 161
  4.5 Effects Of Sublethal Doses On Testicular Development And Spermatogenesis 192
  4.6 Effects On Hatchability From Sublethal Doses And Transfer Of Chlorfluazuron 227
  4.7 Effects On Oviposition Stimulating Factor 257
  4.8 Biochemical Analyses 262
  4.9 Comparison Of Causes And Effect Of Reduction In Reproductivity 292
6 5 Discussion 304-379
606.71 KB
  5.1 Toxicity Determination 304
  5.2 Effects Of Sublethal Doses On Reproductivity And Viability 313
  5.3 Effects Of Sublethal Doses On Ovarian Development And Oögenesis 323
  5.4 Effects Of Sublethal Doses On Testicular Development And Spermatogenesis 331
  5.5 Effects Of Sublethal Doses On Insemination 336
  5.6 Reduction In Hatchability By Sublethal Doses And Transfer Of Chlorfluazuron 342
  5.7 Embryogenesis And Effects Of Sublethal And Doses 346
  5.8 Effects Of Sublethal Doses On Oviposition Stimulating Factors 349
  5.9 Biochemical Analyses 355
  5.10 Comparison Of Causes And Effects On Reduction In Reproductivity 374
7 6 Conclusion 378
21.73 KB
8 7 Summary 380
626.93 KB
  7.1 Future Research 387
  7.2 References 389-444