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1.
Uzi Nur 《Chromosoma》1972,39(4):381-401
Parthenogenesis is reported in three soft scales with 2n=16. In the unfertilized eggs of all three, oogenesis is normal and diploidy is restored by the fusion of the division products of the haploid female pronucleus. In Lecanium putmani Phillips 12 of 13 uninseminated females collected in the wild produced only males. The 21 inseminated females produced 15% males. The males were diploid but contained one euchromatic (E) and one heterochromatic (H) chromosome set. Most of the eggs produced by the inseminated females contained sperm but a few did not. It was concluded, therefore, that females develop from fertilized eggs and males from unfertilized eggs and that the species was diploid arrhenotokous. In L. cerasifex Fitch only 18 of 56 females collected in the wild had been inseminated. The frequency of males among their embryos was 22%. The males were again diploid with one E and one H set of chromosomes. Among the 38 uninseminated females, 27 produced only males, and 10 produced only females. All the female producers contained needle-like bacterial symbionts. Most of the male producers, and most of the inseminated females contained no symbionts; the rest contained rod-like symbionts. It was concluded, therefore, that the females of L. cerasifex studied belonged to two races, a diploid arrhenotokous race and an obligate automictic thelytokous race. Eucalymantus tessellatus (Signoret) is obligate automictic thelytokous. All the females examined were uninseminated and produced only females.Supported by Grant GB 23665 from the National Science Foundation, Washington, D.C. 相似文献
2.
Both thelytokous and arrhenotokous Trichogramma minutum were collected from eggs of the spruce budmoth, Zeiraphera canadensis in New Brunswick, Canada and their phenotypic traits compared for use in biological control. The lower threshold temperature for development of thelytokous and arrhenotokous parasitoids was 9.7 and 10.1 °C, respectively; the former required significantly higher degree-days for development from egg to adult (–x±SE=165.1±5.8 °D) than the latter (128.1±4.9 °D). Thelytokous and arrhenotokous parasitoids had similar forewing length (0.49±0.01 vs. 0.49±0.01 mm) and adult lifespan (13.3±0.7 vs. 14.0±1.1 days), but significantly different fecundity and sex ratios. Thelytokous females produced fewer offspring (89.5±6.6 vs. 173.9±6.4) and fewer female progeny (77.2±5.4 vs. 109.8±3.3) despite an overall higher proportion of females (91.6±1.1% vs. 65.4±2.8%) than their arrhenotokous counterparts. Ovarian dissections showed that the number of eggs increased with parasitoid age in arrhenotokous parasitoids but remained steady in thelytokous parasitoids. The variation in ovarian development of the two forms was the major factor contributing to the differences in fecundity. Thelytokous parasitoids were more host-specific than arrhenotokous ones; when offered eight host species, the former rejected three whereas the latter rejected only one. Thelytokous parasitoids survived better than arrhenotokous ones when stored from 30 to 150 days at 4 °C. Thelytokous females were slower at initiating flight after emergence than arrhenotokous females but maintained flight activity longer (6 h). These results indicate that thelytokous T. minutum are different from their arrhenotokous counterparts physiologically, biologically and ecologically and that they may play different roles in the field. The potential for using thelytokous parasitoids in biological control programs is discussed. 相似文献
3.
Hymenopteran parasitoids generally reproduce by arrhenotoky, in which males develop from unfertilized eggs and females from
fertilized eggs. A minority reproduce by thelytoky, in which all-female broods are derived from unfertilized eggs. Thelytokous
populations are potentially of interest for augmentative biological control programs since the exclusive production of females
could significantly lower the costs of mass rearing. Behavioral traits are a major component of parasitoid efficacy. Here,
we examined orientation and host searching behavior in thelytokous and arrhenotokous populations of the fruit fly parasitoid
Odontosema anastrephae Borgmeier (Hymenoptera: Figitidae). Orientation behavior to various odorant sources was studied in a two-choice olfactometer.
No major differences were found between thelytokous and arrhenotokous wasps for this behavior. However, when host-searching
behaviors were analyzed, some differences were found. Thelytokous females arrived sooner, foraged longer, and remained longer
on non-infested guavas than arrhenotokous females. Individuals of both forms exhibited similar stereotyped behavioral sequences
vis-à-vis guava treatments, with only slight deviations detected. Our results suggest that individuals from selected thelytokous
and arrhenotokous O. anastrephae populations have similar abilities to search for tephritid larvae, supporting the use of thelytokous strains for augmentative
releases. 相似文献
4.
M. Wysoki 《Genetica》1973,44(1):139-145
Chromosome studies were made on embryonic tissues of eggs of 15 species of predaceous mites of the family Phytoseiidae belonging to six genera: Amblyseius Berlese, Seiulus Berlese, Typhlodromus Scheuten, Phytoseiulus Evans, Phytoseius Ribaga and Paragigagnathus Amitai et Grinberg. In 14 species, the chromosome numbers n=4, 2n=8 were found. In cytological studies of post-embryonic stages based on these results, the haplo-diploid (arrhenotokous) mechanism was established. In the species Amblyseius deleoni Muma et Denmark, which was found to be thelytokous, only metaphases with 8 chromosomes were found. 相似文献
5.
赤眼蜂部分蜂种或品系受Wolbachia侵染营孤雌产雌生殖。 通过室内试验分析了在4个恒温(20, 25, 30和35℃)下松毛虫赤眼蜂Trichogramma dendrolimi两性生殖品系和孤雌产雌品系对米蛾Corcyra cephalonica卵的寄生功能反应, 旨在比较不同温度两品系的寄生功能反应差异, 评价孤雌产雌品系在生物防治中的应用潜力。 结果表明: 松毛虫赤眼蜂两个品系对米蛾卵寄生作用均随寄主密度的增加而增大;随温度的升高松毛虫赤眼蜂两品系的功能反应类型由Ⅲ型改变为Ⅱ型。孤雌产雌品系以30℃的处置时间最短(0.0207 d), 最大日寄生量为48.31粒卵, 其次是25℃, 35℃最小;两性生殖品系以25℃的处置时间最短(0.0188 d), 最大日寄生量为53.08粒卵, 其次是30℃, 20℃最小; 松毛虫赤眼蜂两品系的寄生功能反应存在显著差异, 30℃下孤雌产雌品系为Ⅱ型功能反应而两性生殖品系为Ⅲ型。 从处置时间来看, 20℃时两品系无显著性差异(P≥0.05), 在25℃和35℃孤雌产雌品系寄生米蛾卵时花费的时间显著长于两性生殖品系(P<0.05), 而30℃却相反。 可见, 寄主密度、 温度和Wolbachia影响松毛虫赤眼蜂功能反应。 相似文献
6.
7.
Misato Aizawa Takeo Watanabe Akemi Kumano Kumie Tamagaki Shoji Sonoda 《Applied Entomology and Zoology》2018,53(1):11-17
Two distinct reproductive types of Thrips tabaci Lindeman, one thelytokous and one arrhenotokous, have been shown to develop target-insensitive cypermethrin resistance conferred by sodium channel mutation (T929I). In this study, we examined the relation between cypermethrin resistance and biotic performances of these reproductive types. Among the T. tabaci strains examined, resistant arrhenotokous strains became adults more quickly after hatching than resistant thelytokous strains. Female adults of resistant thelytokous strains exhibited shorter longevity and oviposited fewer eggs than those of susceptible strains of the same reproductive type. Resistant arrhenotokous strains exhibited similar longevity and fecundity to susceptible thelytokous strains. We further examined the relation between reproductive types and T929I using a total of 85 strains. All 53 arrhenotokous strains encoding T929I were judged to be cypermethrin resistant. Among 32 thelytokous strains with T929I, only four were regarded as cypermethrin resistant. Based on the results, we discuss possible mechanisms accounting for the recent prominence of arrhenotoky T. tabaci in Japan. 相似文献
8.
We investigated population genetic structure, mating system, worker reproduction and thelytokous parthenogenesis in the desert
ant Cataglyphis livida. Pedigree analyses at polymorphic microsatellite loci show that colonies are headed by a single queen, and that queens are
mated with two to eight males. No inbreeding was found in the population sampled. Colonies are genetically differentiated
and exhibit no isolation-by-distance pattern, consistent with independent foundation of new colonies. Workers do reproduce
and lay haploid (arrhenotokous) eggs in queenless colonies; conversely, we found no evidence of worker reproduction in queenright
nests. In contrast with C. cursor, where new queens are produced by thelytokous parthenogenesis, female sexuals and workers of C. livida arise from classical sexual reproduction. We discuss the parallels and contrasts between the mating system and population
structure in C. livida and the other Cataglyphis species studied so far. 相似文献
9.
The host preferences and sex ratios ofMesochorus biotypes from Sweden and Colorado (U.S.A.) were studied in the field and laboratory. TheseMesochorus are secondary parasites ofBathyplectes spp., parasites ofHypera postica (Gyllenhal). The Colorado biotype is 100% thelytokous, and clearly prefersBathyplectes stenostigma (Thomson) as a host. Only an arrhenotokous biotype was positively detected in Sweden, and it appeared to preferB. curculionis (Thomson). However, some of the data suggest that the thelytokous biotype was probably also present in Sweden, at least inB. stenostigma. The behavioral differences and reproductive isolation of the thelytokous and arrhenotokous biotypes indicate that they are
separate sibling species, even though they cannot yet be separated morphologically, and isozyme analyses were inconclusive
(possibly due to a mixture of biotypes in Sweden).
相似文献
10.
Maurilia M. Monti Francesco Nugnes Liberata Gualtieri Marco Gebiola Umberto Bernardo 《Entomologia Experimentalis et Applicata》2016,160(3):292-301
All Hymenoptera have a haplodiploid mode of sex determination. Although most species reproduce by arrhenotokous parthenogenesis, there are many thelytokous species, in which unfertilized eggs develop into diploid females. Thelytoky can be genetic or due to microbial infection. In the large Chalcidoidea superfamily, thelytokous parthenogenesis is almost always associated with infection of endosymbionts of the genera Wolbachia, Cardinium, and Rickettsia. Thripoctenus javae (Girault) (Hymenoptera: Eulophidae) is a larval parasitoid of the greenhouse thrips Heliothrips haemorrhoidalis (Bouché) (Thysanoptera: Thripidae), an important worldwide pest. Both the host and its parasitoid reproduce by thelytokous parthenogenesis. The main goal of this study was to test whether endosymbiotic bacteria, either those known to induce thelytokous parthenogenesis or other sex‐manipulators, are responsible for thelytoky of two geographically distinct populations of T. javae. We used sequencing of ribosomal ITS2 and 28S‐D2 and mitochondrial COI genes to molecularly characterize the two populations, antibiotic and heat treatments, and FISH of ovaries, for thelytoky studies. It was impossible to revert thelytokous individuals back to sexual reproduction and no evidence of bacterial infection was found in parthenogenetic T. javae females. This makes T. javae the second chalcidoid in which thelytokous reproduction appears not to be associated with the presence of bacterial endosymbionts. 相似文献
11.
Isabel M. M. S. Silva Marnix M. M. Van Meer Michel M. Roskam Aldo Hoogenboom Gerrit Gort Richard Stouthamer 《Biocontrol Science and Technology》2000,10(3):223-238
The effects of thelytoky-inducing Wolbachia ( f -proteobacteria) on Trichogramma cordubensis and T. deion (Hymenoptera, Trichogrammatidae) were studied in laboratory and greenhouse conditions. One infected (thelytokous, all female) line of each wasp species was compared with its conspecific uninfected (arrhenotokous, sexual) counterpart for several fecundity and dispersal traits. Arrhenotokous lines had a higher fecundity than their thelytokous counterparts, which suggests that Wolbachia negatively affect the fecundity of Trichogramma females. The arrhenotokous females dispersed more in the laboratory than their thelytokous counterparts. In the greenhouse, the opposite effect or no difference between lines was found, indicating that the laboratory set-up used to measure dispersal is not useful to predict relative dispersal of the females in the greenhouse. Calculations show that by releasing 100 adult wasps of both lines, thus including arrhenotokous males in the sexual line, more eggs are parasitized by the thelytokous wasps. Therefore, in spite of their lower individual female fecundity, thelytokous lines have a better potential for biological control than their arrhenotokous counterparts. 相似文献
12.
Sympatric speciation is strictly defined as the emergence of two species from a population in which mating has been random with respect to the place of birth of the mating partners. Mathematical models have shown that sympatric speciation is possible, but very few examples have been documented in nature. In this article, we demonstrate that arrhenotokous and thelytokous strains of a parasitic wasp, Neochrysocharis formosa, speciated sympatrically through infection by a symbiotic bacterium Rickettsia for the following reasons: First, Rickettsia infection was detected in all of the thelytokous strains collected throughout Japan. Second, the arrhenotokous and thelytokous strains have been collected sympatrically. Third, crossing experiments between the two strains did not result in fertilized offspring. In addition, the two strains were genetically isolated at the nuclear and mitochondrial genes. Fourth, the two strains showed a sister relationship in nuclear 28S rRNA gene. Finally, thelytokous females treated with antibiotics produced Rickettsia-free male offspring of the same reproductive form as arrhenotokous females indicating that the thelytokous strain could have speciated sympatrically from an individual of the arrhenotokous strain. 相似文献
13.
Dao-Hong Zhu Yi-Yuan He Yong-Sheng Fan Ming-Yong Ma & De-Liang Peng 《Entomologia Experimentalis et Applicata》2007,124(3):279-284
The alpha‐proteobacteria of the genus Wolbachia is a widespread group of maternally inherited endosymbionts of arthropod and nematode hosts. Wolbachia infection induces a range of host phenotypes, including cytoplasmic incompatibility, male killing, feminization, and induction of thelytokous parthenogenesis. Heterogony (cyclical parthenogenesis) is a remarkable characteristic of oak gallwasps, Cynipini, the largest tribe of the Cynipidae. A few species of Cynipini are exceptional in that they are univoltine and exhibit thelytokous parthenogenesis, probably because they lost the arrhenotokous generation of their heterogonic ancestor species due to Wolbachia infection. In this study, the presence of Wolbachia was detected using polymerase chain reaction primers for the wsp genes in a thelytokous parthenogenetic species [Dryocosmus kuriphilus (Yasumatsu)] (Hymenoptera: Cynipidae: Cynipini). Approximately 29.8 and 87.1% of adults of the Zhuzhou and Fuzhou strains, respectively, were infected with Wolbachia while all females of the remaining four strains collected from other localities in China were Wolbachia free. The length of the wsp fragment of Zhuzhou and Fuzhou strains was found to be 573 and 561 bp, respectively. The nucleotide sequence of the bacterial wsp fragment indicated that the endosymbiotic bacteria of the Zhuzhou and Fuzhou strains are members of supergroup A, but belong to different clades; they probably originated from two independent infection events. In conclusion, thelytokous parthenogenesis of D. kuriphilus is not caused by Wolbachia infection and the deletion of the arrhenotokous generation is thus not associated with such an infection. 相似文献
14.
Thelytokous reproduction, where females produce diploid female offspring without fertilization, can be found in many insects. In some Hymenoptera species, thelytoky is induced by Wolbachia, a group of cytoplasmically inherited bacteria. We compare and contrast early embryonic development in the thelytokous parthenogenetic species Muscidifurax uniraptor with the development of unfertilized eggs of the closely related arrhenotokous species, Muscidifurax raptorellus. In the Wolbachia-infected parasitic wasp M. uniraptor, meiosis and the first mitotic division occur normally. Diploidy restoration is achieved following the completion of the first mitosis. This pattern differs in the timing of diploidy restoration from previously described cases of Wolbachia-associated thelytoky. Results presented here suggest that different cytogenetic mechanisms of diploidy restoration may occur in different species with Wolbachia-induced thelytoky. 相似文献
15.
Barbara M. Reumer Jacques J.M. van Alphen Ken Kraaijeveld 《Entomologia Experimentalis et Applicata》2014,153(1):47-54
Wolbachia are endosymbiotic bacteria known to manipulate the reproduction of their hosts by, for example, inducing parthenogenesis. In most cases of Wolbachia‐induced parthenogenesis, the infection is fixed and the entire host population consists of females. In the absence of males and sexual reproduction, genes involved in sexual reproduction are not actively maintained by selection. Accumulation of neutral mutations or selection against maintenance of sexual traits may lead to their loss or deterioration. In addition, females may lose the ability to reproduce sexually due to ‘functional virginity mutations’ that may spread concomitantly with the Wolbachia infection through a population. The parasitoid wasp Tetrastichus coeruleus (Nees) (Hymenoptera: Eulophidae) forms an ideal model to study the decay of sexual functionality, because it has both Wolbachia‐infected, parthenogenetic populations and uninfected, sexual populations. We compared several components of sexual functionality of arrhenotokous (sexual) and thelytokous (parthenogenetic) T. coeruleus females. First, we tested whether arrhenotokous and thelytokous females were equally attractive and receptive to males. Second, we examined whether mating is costly to females by measuring the life span of mated and virgin females. Last, we studied the morphology of the spermathecae of arrhenotokous and thelytokous females. Mated females had shorter life spans than virgin females, showing that mating carried a fitness cost. Two sexual traits of thelytokous females have degraded compared to arrhenotokous females. Arrhenotokous and thelytokous females were equally attractive to males, but thelytokous females were unreceptive to males. Furthermore, there was a clear difference in spermathecal morphology between arrhenotokous and thelytokous females. Our data do not allow distinction between the various potential causes of such degradation. Although the longevity cost of mating may indicate selection against the maintenance of costly sexual traits, accumulation of neutral mutations, functional virginity mutations, manipulation by Wolbachia, and/or the genetic distance between the two populations may all have contributed to the decay of sexual traits in thelytokous females. 相似文献
16.
The chromosomes of 13 species of spider mites (Tetranychidae) are determined using the aceto-orcein squash technique in order to establish the haplo-diploid sex-determination. 12 species showed the existence of haploid and diploid eggs:Neotetranychus rubi (Trägårdh) with 7 and 14 chromosomes;Eurytetranychus buxi (Garman) with 5 and 10;Bryobia sarothamni (Geijskes),Eotetranychus tiliarium (Joh. Hermann) andE. carpini (Oudemans) with 4 and 8;Panonychus ulmi (Koch),Schizotetranychus schizopus (Zacher),Oligonychus ununguis (Jacobi).Tetranychus hydrangeae Pritch. & Baker, T.pacificus McGregor,T. urticae Koch andT. cinnabarinus (Boisduval) with 3 and 6 chromosomes.The progeny of virgin females in 7 different species consisted of eggs with the haploid complement. One species was shown to be thelytokous, viz.Tetranycopsis horridus (Canestrini & Franzago), having a diploid number of 4 chromosomes. Some eggs of an inbred line ofT. urticae showed a patchwork quilt of odd polyploidy in embryonic tissue. 相似文献
17.
Both arrhenotokous and thelytokous reproduction are known to occur in the parasitoid wasp Venturia canescens. The cytological mechanism of thelytoky was previously reported to involve the formation of a restitution metaphase after the reduction division, but the exact nature of the subsequent divisions, whether reductional or equational, remained unclear. We reinvestigated the cytological mechanisms in a thelytokous strain collected in France. Our observations confirm previous results, but an equational and not a reduction division was observed after restitution. This type of reproduction can be classified as central fusion automictic parthenogenesis. In two arrhenotokous strains the normal pattern of oogenesis and syngamy of Hymenoptera was observed. In addition, we used PCR amplification to show that thelytoky in V. canescens is not caused by Wolbachia bacteria. The results are discussed in relation to maintenance of heterozygosity and female sex. 相似文献
18.
Biological and morphological characters of the thelytokous and arrhenotokous forms ofA. mytilaspidis and their hybrids were investigated. Some biological differences between the thelytokous and arrhenotokous forms were found. The former is adapted to warmer condition and will parasitizeHemiberlesia lataniae as well asDiaspis echinocacti, while the latter will not parasitizeH. lataniae. The overall fecundity of the thelytokous form is lower than that of the arrhenotokous form, whereas the “effective fecundity”, female progeny per female parent, is higher in the thelytokous form. Apart from the no. of setae in the wings delta, there are no distinguishing morphological characters between the arrhenotokous and thelytokous forms. 相似文献
19.
Divergent reproductive interests of males and females can lead to sexually antagonistic coevolution (SAC). In the absence of males, adaptations evolved under SAC are released from selection and expected to deteriorate. In this study, we investigated this prediction using two populations of the parasitoid wasp Leptopilina clavipes, one arrhenotokous and one thelytokous. Thelytokous females were induced to produce sons by curing them of their Wolbachia-infection. We examined whether thelytokous males were less able to inhibit female remating than arrhenotokous males and whether thelytokous females were more susceptible to male-induced longevity reduction than arrhenotokous females. The results showed that females were monandrous, regardless of whether mated with an arrhenotokous or thelytokous male. While ongoing courtship of males reduced female life span, there was no longevity cost of mating for either arrhenotokous or thelytokous females. Our results therefore do not support the idea that adaptations evolved under SAC deteriorate under prolonged female-only selection. 相似文献
20.
D. A. POLLOCK B. B. NORMARK 《Journal of Zoological Systematics and Evolutionary Research》2002,40(2):105-112
Micromalthus debilis 33 ), has one of the most bizarre life cycles of any metazoan. Reproduction is typically by thelytokous, viviparous, larviform females, but there is also a rare arrhenotokous phase. The active first‐instar (triungulin) larva develops into a legless, feeding (cerambycoid) larva. This form either pupates, leading to a diploid adult female, or develops into any of three subsequent types of reproductive paedogenetic forms: (1) a thelytokous female that produces triungulins via viviparity; (2) an arrhenotokous female that produces a single egg that develops into the short‐legged (curculionoid) larva, eventually devouring its mother and becoming a haploid adult male; or (3) an amphitokous female that can follow either of the two above reproductive pathways. We speculate that Micromalthus is dependent on maternally transmitted bacteria for the ability to digest rotting wood, and that these bacteria are senescent in males, causing males to be obligately cannibalistic. Obligate male cannibalism, in turn, would have dramatically increased the cost of males, and have created a strong selective advantage for cyclic thelytoky and the other features of the Micromalthus life cycle that minimize the role of the male. 相似文献