Sex allocation and effects of superparasitism on secondary sex ratios in the gregarious parasitoid, Trichogramma chilonis (Hymenoptera: Trichogrammatidae)

Suzuki, Yoshito; H, Tsuji; Sasakawa, Mitsuhiro

doi:10.1016/s0003-3472(84)80284-5

Cited by 174 publications

(146 citation statements)

References 21 publications

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“…Consistent with that, observations of oviposition behaviour in parasitoid wasps have shown two distinct behavioural sequences in the laying of male and female eggs: the deposition of fertilized (female) eggs is associated with a pause in abdominal contractions, during which sperm is supposed to be released (e.g. [20][21][22]; but see Lee et al [23], who found that in the sawfly Athalia rosae, females exhibited a longer pause when laying an unfertilized egg). However, this kind of study is rare, and in most cases the precise mechanism by which sex ratio is adjusted remains unknown.…”

Section: Introductionmentioning

confidence: 58%

Sex-ratio adjustment in response to local mate competition is achieved through an alteration of egg size in a haplodiploid spider mite

et al. 2012

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Sex-ratio adjustments are commonly observed in haplodiploid species. However, the underlying proximate mechanisms remain elusive. We investigated these mechanisms in Tetranychus urticae, a haplodiploid spider mite known to adjust sex ratio in response to the level of local mate competition (LMC). In this species, egg size determines fertilization probability, with larger eggs being more likely to be fertilized, and thus become female. We explored the hypothesis that sex-ratio adjustment is achieved through adjustment of egg size. By using spider mites from a large population, we found that females produced not only a higher proportion of daughters under high levels of LMC, but also larger eggs. Moreover, in populations experimentally evolving under varying levels of LMC, both the proportion of females and the egg size increased with LMC intensity. These results suggest that sex-ratio adjustment in spider mites is mediated by egg size, although the causal relationship remains to be tested.

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Section: Introductionmentioning

confidence: 58%

Sex-ratio adjustment in response to local mate competition is achieved through an alteration of egg size in a haplodiploid spider mite

et al. 2012

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“…Miura & Kobayashi (1998) observaram apenas desenvolvimento de Trichogramma chilonis em ovos de Plutella xylostella de 24 e 48 horas, sendo que nos de 72 h não houve emergência. Embora, a razão sexual possa variar em função de fatores do ambiente, densidade, tipo de hospedeiro e constituição nutricional do ovo (Suzuki, 1984;Vinson, 1997), neste trabalho, este fator não foi influenciado pela idade do ovo. Este resultado é corroborado por Pastori et al (2010), os quais verificaram que a razão sexual da prole de Trichogramma maxacalli não foi afetada em ovos de Bonagota salubricola, com idades entre zero e 72 horas.…”

Section: Discussionunclassified

Influência da idade do hospedeiro e da aprendizagem no comportamento quimiotáxico e no parasitismo de Trichogramma pretiosum

Vargas

Sant’Ana

Morais

et al. 2017

Iheringia, Sér. Zool.

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ABSTRACT. Infl uence of host age and learning on chemotactic behavior and parasitism of Trichogramma pretiosum. Trichogramma pretiosum Riley, 1879 reared on Ephestia kuehniella Zeller, 1879 eggs, have been used in biological control of Spodoptera frugiperda (J. E. Smith, 1797). However, host age and experience just after emergence might have some infl uence on parasitism and parasitoid behavior. This study evaluated the infl uence of S. frugiperda host age and egg odor experience, on chemotactic behavior and parasitism of T. pretiosum. Spodoptera frugiperda eggs with 24, 48 and 72 hours were exposed to T. pretiosum females. Parasitoid time experience, in the same host, was evaluated within 1, 3, 4, 5, 6 and 24 hours, as well as, its host exposed time (1, 2, 3 and 24 hours). Chemotactic responses of T. pretiosum (experienced and inexperienced females) to S. frugiperda egg extracts were recorded in Y-tube olfactometer. We also observe parasitism rates (choice tests) in insects with and without experience. The parasitism average was higher in S. frugiperda eggs with 24 hours. Inexperienced females and those experienced for 1, 3 and 4 hours, parasitized less S. frugiperda eggs compared to those for 5, 6 and 24 hours. There was no diff erence in parasitism from females exposed for 2, 3 and 24 hours when compared to those exposed for one hour. Experienced females were more attracted to S. frugiperda eggs odor than to control (hexano). Parasitism percentage, by inexperienced parasitoids, was greater in E. kuehniella eggs (original host) than in S. frugiperda, however it was not observed in experienced females.KEYWORDS: Biological control, egg parasitoid, eggs extract.RESUMO. Trichogramma pretiosum Riley, 1879 mantido em ovos de Ephestia kuehniella Zeller, 1879, tem sido utilizado no controle biológico de Spodoptera frugiperda (J. E. Smith, 1797). No entanto, fatores como idade do hospedeiro e experiência prévia, podem infl uenciar o parasitismo e o comportamento do parasitoide. Esse estudo avaliou a infl uência da idade dos ovos e da experiência em ovos e extrato de ovos de S. frugiperda no comportamento quimiotáxico e no parasitismo de T. pretiosum. Ovos de S. frugiperda com 24, 48 e 72 horas, foram expostos a fêmeas de T. pretiosum. Também foi avaliado o tempo de experiência do parasitoide, no mesmo hospedeiro, por 1, 3, 4, 5, 6 e 24 horas, assim como, seu tempo de exposição (1, 2, 3 e 24 horas). As respostas quimiotáxicas de T. pretiosum (experiente e não experiente) em extrato de ovos de S. frugiperda foram observadas em olfatômetro tipo Y. As taxas de parasitismo foram registradas em teste de escolha, com insetos experientes e inexperientes com ovos e extrato de ovos de S. frugiperda. O parasitismo em S. frugiperda foi signifi cativamente maior em ovos com 24 horas de idade. Fêmeas inexperientes e experientes por 1, 3 e 4 horas, apresentaram uma menor taxa de parasitismo, quando comparadas a fêmeas expostas por 5, 6 e 24 horas. Não houve diferença de parasitismo em fêmeas expostas por 2, 3 e 24 horas, comparadas à...

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“…O experimento foi conduzido de forma a obter a oviposição de um a dois ovos de T. pretiosum por hospedeiro (ovo de S. cerealella). Para isto, foi utilizada a técnica desenvolvida por Suzuki et al (1984), em que se reconhece o momento exato da oviposição através dos movimentos da genitália da fêmea, ao introduzir o ovipositor, o que permite quantifi car o número de ovos depositados por hospedeiro. A deposição de um e dois ovos de Trichogramma por hospedeiro foram os tratamentos, com 10 repetições cada.…”

Section: Methodsunclassified

Parasitismo e superparasitismo de Trichogramma pretiosum Riley(Hymenoptera: Trichogrammatidae) em ovos de Sitotroga cerealella(Oliver) (Lepidoptera: Gelechiidae)

Moreira¹,

Santos²,

Beserra³

et al. 2009

Neotrop. entomol.

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-The parasitoid Trichogramma has been used worldwide as biological control agent due to its wide geographic distribution, high specialization and effi cacy against many lepidopteran pests. Biological and behavioral traits of Trichogramma pretiosum Riley parasitizing Sitotroga cerealella (Oliver) eggs were studied aiming to a better understanding of the results from parasitism and superparasitism. The variables investigated were: host acceptance and contact time by T. pretiosum on parasitized host, percentage of parasitoid emergence, number of deformed individuals produced, egg-adult period, sex ratio, offspring female body size and longevity, and number of S. cerealella eggs parasitized/female. Parasitism rejection was observed on parasitized host eggs after 24, 72 and 120h of parasitism. The rejection was higher for eggs parasitized after 72h and 120h of parasitism as compared to the eggs after 24h of parasitism. T. pretiosum contact time on eggs after 24h of parasitism was greater than on 72 and 120h. The offspring produced from hosts from which a single parasitoid emerged were larger, exhibited no deformities and greater capacity of parasitism, different from those produced from eggs where two parasitoids emerged. Offspring longevity, however, was similar for females emerged from hosts from which one or two adults emerged. In conclusion, T. pretiosum was able to recognize previously parasitized eggs and the superparasitism reduced the parasitoid.reproductive success.KEY WORDS: Biological control, egg parasitoid, host compatibility RESUMO -Parasitóides Trichogramma vêm sendo utilizados em todo o mundo como agentes de controle biológico devido à sua ampla distribuição geográfi ca, alta especialização e efi ciência no controle de muitas espécies-praga de lepidópteros. Para o entendimento dos resultados do parasitismo e superparasitismo de Trichogramma pretiosum Riley, estudaram-se os aspectos comportamentais e biológicos desse parasitóide sobre ovos de Sitotroga cerealella (Oliver). As variáveis investigadas foram: aceitação hospedeira e tempo de contato de T. pretiosum com o hospedeiro parasitado, porcentagem de emergência, porcentagem de indivíduos deformados, duração ovo-adulto, razão sexual, tamanho e longevidade de T. pretiosum e número de ovos de S. cerealella parasitados por fêmea descendente. Observou-se rejeição de parasitismo em ovos de S. cerealella previamente parasitados com 24, 72 e 120h de idade. A rejeição foi superior para ovos com 72h e 120h após o parasitismo em comparação com aqueles com 24h. Ovos previamente parasitados com 24h apresentaram maior tempo de contato por T. pretiosum comparados aos de 72h e 120h. Os descendentes oriundos de hospedeiros dos quais apenas um parasitóide se desenvolveu apresentaram-se todos maiores, sem deformidades e com maior capacidade de parasitismo, ao contrário dos indivíduos descendentes de hospedeiros em que dois parasitóides se desenvolveram. Entretanto, a longevidade de fêmeas descendentes não diferiu entre parasitóides oriundos de hospedeiros em ...

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Sex allocation and effects of superparasitism on secondary sex ratios in the gregarious parasitoid, Trichogramma chilonis (Hymenoptera: Trichogrammatidae)

Cited by 174 publications

References 21 publications

Sex-ratio adjustment in response to local mate competition is achieved through an alteration of egg size in a haplodiploid spider mite

Sex-ratio adjustment in response to local mate competition is achieved through an alteration of egg size in a haplodiploid spider mite

Influência da idade do hospedeiro e da aprendizagem no comportamento quimiotáxico e no parasitismo de Trichogramma pretiosum

Parasitismo e superparasitismo de Trichogramma pretiosum Riley(Hymenoptera: Trichogrammatidae) em ovos de Sitotroga cerealella(Oliver) (Lepidoptera: Gelechiidae)

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