Egg parasitoids of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), from south-east Queensland

Field surveys of egg parasitoids of the diamondback moth, Plutella xylostella, were conducted at Redlands and Gatton, south-east Queensland. Eggs of P. xylostella were present all year round in both localities, and parasitized eggs were consistently found between late spring and early winter. Percent parasitism in the range 30-75% was recorded on many occasions, although rates less than 10% were more common. The major parasitoids included Trichogrammatoidea bactrae Nagaraja and Trichogramma pretiosum Riley. Laboratory evaluation showed that the T. pretiosum from Gatton has a high capacity to parasitize P. xylostella eggs under suitable conditions. This study represents the first record of egg parasitoids of P. xylostella from Australia

Influência da fase embrionária dos ovos da traça-das-crucíferas sobre fêmeas de Trichogramma pretiosum com diferentes idades Influence of diamondback moth embrionary egg stage on Trichogramma pretiosum females of different ages

Plutella xylostella é considerada a praga mais importante das crucíferas. O método de controle mais utilizado para essa praga é o químico. Contudo, esta espécie de inseto vem desenvolvendo resistência aos inseticidas aplicados. O controle biológico com espécies do gênero Trichogramma é considerado uma alternativa no controle dessa praga. Porém, poucos são os trabalhos que mencionam aspectos biológicos desse parasitóide sobre esta praga. Neste trabalho avaliou-se a influência da fase embrionária dos ovos do hospedeiro P. xylostella sobre fêmeas de T. pretiosum com diferentes idades. Fêmeas do parasitóide foram divididas em cinco lotes, compostos por espécimes recém-emergidos com 24; 48; 72 e 96 horas de idade. Cada lote continha dez fêmeas de T. pretiosum. Para cada fêmea de cada lote, foi oferecida uma cartela contendo 30 ovos de P. xylostella com um, dois e três dias de idade. As maiores taxas de parasitismo foram observadas em fêmeas com idade superior a 48 horas, independente do desenvolvimento embrionário do hospedeiro. Em ovos com três dias de desenvolvimento embrionário verificou-se que, para fêmeas recém-emergidas e com 48 horas de idade, a taxa de viabilidade foi superior apenas em relação àquelas com 96 horas de idade. Ao se avaliar os descendentes de T. pretiosum provenientes de ovos com um dia de desenvolvimento embrionário, verificou-se que os maiores valores de longevidade foram obtidos quando as fêmeas desse parasitóide eram recém-emergidas.<br>Plutella xylostella is one of the most important pests of Cruciferae. Chemicals have been used to control this insect, but the rapid development of resistance is a serious constraint to this method. Biological control with Trichogramma species has been reported as an alternative to control diamondback moth. However few works report biological parameters of this parasitoid interacting with this pest. This work was carried out to evaluate the influence of egg embryonary stage of P. xylostella on T. pretiosum females at different ages. Females of this parasitoid were organized in five groups. These groups were composed of females just emerged, 24 h; 48 h; 72 h, and 96 hours-old. Each group was formed of ten females. Each female received a card with thirty P. xylostella eggs, one, two and three day-old. Higher parasitism rates were observed with females older than 48 hours, with no influence of host embryonic development. In three day-old eggs it was verified that just emerged females and 48 hour-old, the viability index was superior just to those 96 hour-old. The progeny with one day of embryonary development, presented higher longevity values with just emerged females

The role of glycosylation in IBD

Proteomic