Factors affecting inundative releases of Trichogramma minutum Ril. against the Spruce Budworm¹

Abstract

29Maiszunslers, Ostriniu nubikzlis Hbn., mit der Verwirrungstechnik. Mitt. Schweiz. Ent. Ges. DAUMAL, J.; VOEGELE, J.; BRUNETTI, P., 1975: Les trichograrnmes. 11. Unite de production massive et quotidienne d'un hBte de substitution Ephestia kuehniellu Zell. Ann. Zoo1.-Ecol. Amin., 7, 45-59. MEIER, W.; ANDRESXA, S.; KOLAR, O., 1972: Neuere Beobachtungen zurn Auftreten des Maiszunslers. Mitt. Schweiz. Landw. 20, 151-163. MEISSELI~RE, C. de la, 1982: Methodes d'ivaluation des risques. Agromais, 8, 27-29. MURBACH, R.; HACHLER, M.; GOY, G., 1973: La pyrale de rnds (Ostriniu nubilalis Hbn.) en SUTER, H.; RAMSER, E., 1978: Auftreten und biologische Bekampfung des Maiszunslers (Ostriniu J4, 87-98. Suisse romande. Rev. suisse Agric., 5, 108-111. nubilalis Hbn.) in der deutschsprachigen Schweiz. Mitt. Schweiz. Landw. 26, 57-65. AbstractInundative releases of Trichogrurnmu minuturn Riley for biological control of the spruce budworm, Choristoneuru furniferunu (Clemens), were investigated in Canada's boreal forest during 1982 and 1983. The most significant factors affectin the level of egg mass parasitism were the time of release, the density of the parasitoids, and the focal weather conditions. Food supply to the female parasitoids, vertical location of the host egg mass in the stand, intensity of solar radiation, and density of the host insect were less im ortant. Parasitism was not affected by the tree species on which budworm e g masses were laid: Parasitoids reared at different temperatures and on different host eggs differed in biological characteristics and could influence the success of field releases. Geographical strains of T. minuturn were not considered as important in subsequent releases as the rearing conditions because of the high degree of individual variation within each strain.

Assays with Commercially Produced Trichogramma (Hymenoptera: Trichogrammatidae) To Determine Suitability for Obliquebanded Leafroller (Lepidoptera: Tortricidae) Control

“…Although laboratory results do not always predict accurately the outcome of field trials (Smith et al 1986), our laboratory results did indicate that T. platneri would parasitize more obliquebanded leafroller egg masses than T minlltllm (Rv). However, the magnitude of difference between parasitism rates caused by the 2 species in the field was not indicated by our assays.…”

“…Trichogramma spp. have different host preferences which may be inherent or influenced by the host on which they were reared (Smith et al 1986;Hassan 1989Hassan , 1990. Host age can have a pronounced effect on parasitism levels, with younger eggs generally more heavily parasitized than older eggs (Houesweart et al 1982, Yu et al 1984a.…”

“…In the current study we released only 1 density of parasitoids from 1 canopy location; the effect of modifying these are .unknown. Increased parasitism of spruce budworm egg masses has occurred by releasing more T. minutum, but the relationship was not linear (Smith et al 1986). Releases of T. minurum into apple at different canopy positions had no effect on the location of parasitized codling moth eggs, which were parasitized to the greatest extent near the bottom of the tree (Yu et al 1984b).…”

Effect of host availability and egg load in Trichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) and its consequences on progeny quality

“…They have revealed the importance of feeding the wasps a carbohydrate (Yu et al, 1984;Smith et al, 1986;Hohmann et al, 1988Hohmann et al, , 1989McDougall and Mills, 1997), exposing them to their target hosts before releasing them (Bergeijk et al, 1989), and timing their release (Volkoff and Daumal, 1994;Smith, 1996). The adoption of these recommendations along with maximizing wasp size would certainly improve current biological control programs that use Trichogramma spp.…”

The Release of the Parasitoid Trichogramma evancens to Control the Pink Bollworm Pectinophora gossypiella (Saunders) and the Side-Effect of Certain Insecticides on It

“…Practical uses of Trichogrammatid (egg parasitoids) are worldwide utilized against many lepidopterous pests on several key crop i.e. ; corn, sugar-cane, cotton, fruit trees and vegetables (Smith et al, 1986;Tuhan et al, 1987;Hassan, 1993;Smith, 1994;Wang, 1997;Shalaby et al, 2002;Abd El-Hafez et al, 2002;Khidr et al, 2003;Abd El-Hafez et al, 2004;El-El-Wakeil and Vidal, 2005;El-Bassouiny, 2006 andAgamy, 2010). The wide use of Trichogrammatids is mostly due to the easy mass production techniques of these parasitoids on numerous hosts which are mainly the lepidopterous insect-pests of stored products, such as Sitotroga cerealella, Ephestia kuehniella and Plodia interpunctella.…”