Effect of ionizing (gamma) and non-ionizing (UV) radiation on the development of Trichogramma euproctidis (Hymenoptera: Trichogrammatidae)

The potential of using gamma and ultraviolet radiation as an alternative treatment to increase the efficiency of Trichogramma euproctidis (Girault 1911) (Hymenoptera: Trichogrammatidae) was investigated in the laboratory. The developmental and adult stages of T. euproctidis were exposed to gamma radiation of different doses (0-30 Gy) and ultraviolet radiation of 254 nm wavelengths (UV-C) for different durations (0-10 min) to assess their effect on each of the instars and their potential in breaking the developmental cycle of the egg parasitoid. The LD50 values for eggs, prepupae, pupae and adults were 8.1, 10.0, 22.7 and 9.5 Gy for gamma radiation and 9.5, 0.12, 2.0 and 11.9 min for UV radiation, respectively. The pupa and adult stages were more radioresistant to both gamma and UV radiation. The most interesting and unexpected result obtained for the prepupal stage was that UV radiation has a greater effect on prepupal stages than gamma radiation

Effects of artificial diets and floral nectar on longevity and progeny production of Trichogramma euproctidis Girault (Hymenoptera: Trichogrammatidae)

Trichogramma species are the most widely used biological control agents against lepidopteran pests. They prefer sugar-based substances as foods, especially plant nectar. Flowering plants have been shown to differ with regard to their attractiveness to parasitoids and nectar accessibility. The value of floral nectar and laboratory diets as food sources for Trichogramma euproctidis (Girault) (Hymenoptera: Trichogrammatidae) was assessed in the laboratory by testing the effects of different floral nectars (dandelion, dog-fennel, dead nettle, willow, plum) and artificial diets (honey, grape molasses, raisins, beet molasses, glucose and sucrose syrups, and egg yolk) on the longevity, capacity for parasitism and adult emergence. Trichogramma euproctidis females that fed on honey 10.5 days) and dandelion flowers (8.7 days) lived significantly longer than females that fed on other floral nectars and artificial diets. The females fed on raisins (2.9 days) and water alone (2.6 days) had the shortest longevity. Trichogramma euproctidis females that fed on sucrose syrups (30.9 eggs), honey+egg yolk+water (29.13 eggs) and honey (28.0 eggs) parasitized significantly more hosts than females that fed on other floral nectars and artificial diets. The females fed on raisins (18.5 eggs) and plum flowers (15.5 eggs) were shown to have the least parasitizing ability. The results indicate that carbohydrates such as dog-fennel nectar or honey can increase the performance of the wasp parasite. Although floral nectar qualities may be of greater importance to parasitoid longevity when selecting floral resources for conservation biological control, the artificial diets proved to be suitable foods for sustaining the development and reproduction of T. euproctidis

Effects of artificial diets and floral nectar on longevity and progeny production of Trichogramma euproctidis Girault (Hymenoptera: Trichogrammatidae)

Trichogramma species are the most widely used biological control agents against lepidopteran pests. They prefer sugar-based substances as foods, especially plant nectar. Flowering plants have been shown to differ with regard to their attractiveness to parasitoids and nectar accessibility. The value of floral nectar and laboratory diets as food sources for Trichogramma euproctidis (Girault) (Hymenoptera: Trichogrammatidae) was assessed in the laboratory by testing the effects of different floral nectars (dandelion, dog-fennel, dead nettle, willow, plum) and artificial diets (honey, grape molasses, raisins, beet molasses, glucose and sucrose syrups, and egg yolk) on the longevity, capacity for parasitism and adult emergence. Trichogramma euproctidis females that fed on honey 10.5 days) and dandelion flowers (8.7 days) lived significantly longer than females that fed on other floral nectars and artificial diets. The females fed on raisins (2.9 days) and water alone (2.6 days) had the shortest longevity. Trichogramma euproctidis females that fed on sucrose syrups (30.9 eggs), honey+egg yolk+water (29.13 eggs) and honey (28.0 eggs) parasitized significantly more hosts than females that fed on other floral nectars and artificial diets. The females fed on raisins (18.5 eggs) and plum flowers (15.5 eggs) were shown to have the least parasitizing ability. The results indicate that carbohydrates such as dog-fennel nectar or honey can increase the performance of the wasp parasite. Although floral nectar qualities may be of greater importance to parasitoid longevity when selecting floral resources for conservation biological control, the artificial diets proved to be suitable foods for sustaining the development and reproduction of T. euproctidis

Suitability of irradiated and cold-stored eggs of Ephestia kuehniella (Pyralidae: Lepidoptera) and Sitotroga cerealella (Gelechidae: Lepidoptera) for stockpiling the egg-parasitoid Trichogramma evanescens (Trichogrammatidae: Hymenoptera) in diapause

The use of irradiated and cold-stored host eggs could be one option to facilitate the mass rearing of egg parasitoids to control lepidopteran pests. The effect on Trichogramma evanescens (L.) wasp quality after 3-month storage of host eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechidae), that had previously been irradiated with gamma radiation, was investigated. Efficiency of T. evanescens was studied by measuring parasitization, adult and female emergence. There was no significant difference in parasitization and in adult and female T. evanescens emergence between gamma radiation doses and the untreated control for up to 30 days for E. kuehniella eggs and, thereafter they decreased drastically as the storage time increased for up to 60 and 30 days for E. kuehniella and S. cerealella eggs, respectively. No parasitization was observed when the eggs were stored longer and then offered to T. evanescens females. Data obtained from diapaused T. evanescens stored at 3 degrees C for 20, 70, 100 and 150 days indicated that pre-storage temperatures affected the induction of diapause. It was possible to induce diapause in developmental stages of T. evanescens by exposing the immature stages (prior to the pre-pupal stage) inside host eggs to 10 and 12 degrees C for 30 days. Under these conditions, parasitoids could be stored for a period of 50 days without adverse affects on emergence. Emergence appeared to decrease with an increase in the duration of storage for a period up to 150 days for the eggs of E. kuehniella. Parasitoids failed to enter diapause when pre-storage conditions were 3 and 7 degrees C for host eggs of both E. kuehniella and S. cerealella. The long-term storage of parasitoids in diapause improved the mass rearing potential for lengthened releases of this species.The use of irradiated and cold-stored host eggs could be one option to facilitate the mass rearing of egg parasitoids to control lepidopteran pests. The effect on Trichogramma evanescens (L.) wasp quality after 3-month storage of host eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechidae), that had previously been irradiated with gamma radiation, was investigated. Efficiency of T. evanescens was studied by measuring parasitization, adult and female emergence. There was no significant difference in parasitization and in adult and female T. evanescens emergence between gamma radiation doses and the untreated control for up to 30 days for E. kuehniella eggs and, thereafter they decreased drastically as the storage time increased for up to 60 and 30 days for E. kuehniella and S. cerealella eggs, respectively. No parasitization was observed when the eggs were stored longer and then offered to T. evanescens females. Data obtained from diapaused T. evanescens stored at 38C for 20, 70, 100 and 150 days indicated that pre-storage temperatures affected the induction of diapause. It was possible to induce diapause in developmental stages of T. evanescens by exposing the immature stages (prior to the pre-pupal stage) inside host eggs to 10 and 128C for 30 days. Under these conditions, parasitoids could be stored for a period of 50 days without adverse affects on emergence. Emergence appeared to decrease with an increase in the duration of storage for a period up to 150 days for the eggs of E. kuehniella. Parasitoids failed to enter diapause when pre-storage conditions were 3 and 78C for host eggs of both E. kuehniella and S. cerealella. The long-term storage of parasitoids in diapause improved the mass rearing potential for lengthened releases of this species

PNS Limits for Human Head-Size MPI Systems: Preliminary Results

Magnetic Particle Imaging (MPI) utilizes kHz-range sinusoidal drive fields to excite the magnetic nanoparticles. These time-varying magnetic fields form electric fields within the human body, which in turn can induce peripheral nerve stimulation (PNS), also known as magnetostimulation. In this work, we report the preliminary results of human subject experiments for human head-size MPI systems. These experiments were performed on a solenoidal head coil that achieved an order of magnitude reduction in the voltages needed to generate the targeted magnetic fields