Influences of host age, sex ratio, population density, and photoperiod on parasitism by Trichogramma evanescens Westw. (Hym., Trichogrammatidae)

Abstract

Moth species Ephestia kuehniella and Sitotroga cerealella are serious pests in cereal-based food processing facilities and stores in Turkey. Control of these pests is undertaken by regular space treatment of infested areas with pesticides. An alternative control method could be the release of parasitic wasps of the genus Trichogramma. In laboratory tests, we use T. evanescens as a parasitic wasp reared on the eggs of Ephestia kuehniella. Adult wasps emerging from the host were maintained in glass tubes at 27 ± 1°C, 60-70 ± 5 % r.h and L14:D10 and fed on honey solution. Adults of T. evanescens in vials without food enclosed from host eggs and all died within 1.8 days; in comparison, in vials with honey, live adults were evident for 15.2 days. Fresh (6-48 h) and old (72-96 h) host eggs were offered to T. evanescens and fresh eggs were more accepted than old. Host acceptance of females with males in vials was better than without males. The number of females in the vials also influenced the parasitization rate and single female parasitized more eggs. Adults living in light regime (L14:D10 and L6:D18) parasitized more eggs than in total darkness. Results are discussed with relation to enhancing parasitoid effectiveness in biological control in processing facilities and mills.

Effect of fertilized, unfertilized, and UV‐irradiated hosts on parasitism and suitability for Trichogramma parasitoids

“…Recently, fertilization of the host is also reported to affect host selection and suitability of some parasitoid species. In addition, most Trichogramma species prefer parasitizing newly laid eggs (Pak, 1986;Hintz & Andow, 1990;Reznik & Umarova, 1990;Tuncbilek & Ayvaz, 2003;Pizzol et al, 2012;Zhang et al, 2014;Song et al, 2015). Furthermore, some Trichogramma parasitoids were found to prefer parasitizing fertilized over unfertilized striped rice stem borer, Chilo suppressalis (Walker) (Yang et al, 2016).…”

“…Furthermore, some Trichogramma parasitoids were found to prefer parasitizing fertilized over unfertilized striped rice stem borer, Chilo suppressalis (Walker) (Yang et al, 2016). In addition, most Trichogramma species prefer parasitizing newly laid eggs (Pak, 1986;Hintz & Andow, 1990;Reznik & Umarova, 1990;Tuncbilek & Ayvaz, 2003;Pizzol et al, 2012;Zhang et al, 2014;Song et al, 2015). It is unclear whether Trichogramma parasitoids have similar parasitism preference on alternate hosts like the rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae).…”

Capacidade de paralisação, parasitismo e viabilidade de Habrobracon hebetor sob o efeito do fotoperíodo

“…Parâmetros reprodutivos de fêmeas de Habrobracon hebetor (± DP) nos primeiros 11 dias de idade, em larvas de Ephestia kuehniella em nove diferentes combinações de fotoperíodos (n = 15) (28 ± 2°C e 50 ± 20% UR) A maior concentração de parasitismo foi nos primeiros dias de idade, sendo que o maior número de larvas parasitadas em 24 horas foi obtido entre o 2º e 4º dia de idade nos diferentes tratamentos, com média de 4,2 ± 2,36 no tratamento T2 e 7,0 ± 1,51 no tratamento T5 (Figura 1). No entanto, diferente desse estudo, Tunçbilek & Ayvaz (2003), avaliando Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae), mostraram que existia tendência de parasitismo mais forte no primeiro dia do que nos dias seguintes. Essas diferenças, entretanto, são previstas, já que trata de um parasitoide de ovos e de outra família, com comportamento distinto e ciclo de vida mais curto.…”

Effect of host egg age on preference, development and arrestment of Telenomus remus (Hymenoptera: Scelionidae)

“…Most studies indicate that old eggs are poor quality hosts for egg parasitoids (Souza & Spence, 2001;Tunçbilek & Ayvaz, 2003). However, there are reports that old eggs do not have any deleterious effect on preference or offspring performance (Pak et al, 1986;Jacob et al, 2006).…”