Parasitismo natural, produção e liberação de parasitoides para o controle de Lepidópteros desfolhadores de eucalipto

Abstract

Tetrastichus howardi (Olliff, 1893), Trichospilus diatraeae (Cherian & Margabandhu, 1942) and Palmistichus elaeisis (Delvare & LaSalle, 1993) (Hymenoptera: Eulophidae) are endoparasitoids, with potential to be used in biological control programs for eucalyptus defoliating caterpillars. In view of the above, in view of the biological potential of the studied parasitoids, it is proposed with the works of this thesis, to record the natural parasitism of Brachymeria annulata (Hymenoptera: Chalcididae) and T. diatraeae in pupae of Iridopsis panopla Prout, 1932 (Lepidoptera: Geometridae) in eucalyptus (Myrtaceae) in Mato Grosso do Sul. Select the best breeding host, for each species of parasitoid, among P. elaeisis, T. howardi and T. diatraeae, in order to optimize the technique of breeding these parasitoids on a large scale, as well as raising the cost of production of these eulophids. Finally, to promote the inoculative release of P. elaeisis, T. diatraeae and T. howardi, aiming to reduce the infestation of and Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae) in eucalyptus. Therefore, the bioassays were carried out at the Laboratory of Biological Control of Insects (LECOBIOL) at UFGD and the parasitoid releases were carried out in commercial eucalyptus plantations, by foresters associated with REFLORE-MS (Associação Sul-Mato-Grossense of producers and consumers). of planted forests), in Mato Grosso do Sul. In the first work, we recorded the natural parasitism of pupae of I. panopla, in eucalyptus in Mato Grosso do Sul. Pupae of I. panopla were collected naturally in a commercial plantation of Eucalyptos grandis, in Ribas do Rio Pardo, Mato Grosso do Sul, were individualized, sent and kept in a laboratory to investigate possible emergence of parasitoids or the moth. After 18 days, two species of parasitoids emerged, namely: B. annulata and T. diatraeae, whose biological aspects were evaluated under laboratory conditions, which is the first record for eucalyptus in Brazil. In the second work, the biological characteristics of the parasitoids, T. howardi, T. diatraeae and P. elaeisis, were evaluated in the hosts Diatraea saccharalis (Fabricius 1794) (Lepidoptera: Crambidae), Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae), Bombyx mori Linnaeus 1758 (Lepidoptera: Bombycidae) and Tenebrio molitor (Linnaeus 1758) (Coleoptera: Tenebrionidae), with the proposal of a new methodology, in order to optimize large-scale creations in the laboratory. In general, specifically with the method used, pupae of D. saccharalis and A. gemmatalis were the best hosts for rearing the three parasitoids T. howardi, P. elaeisis and T. diatraeae, with 100% parasitism and emergence. in all. Considering the proposed methodology and the evaluated biological characteristics of the parasitoids, the host T. molitor is the most suitable for breeding P. elaeisis. In the third work, the production cost of host pupae and T. howardi, P. elaeisis and T. diatraeae parasitoids when reared in different hosts was determined. It was found that the pupae of B. mori and T. molitor were the lowest cost hosts, being suitable for optimizing breeding of P. elaeisis and T. howardi, without affecting the quality, on the other hand, these hosts should not be used for breeding. of T. diatraeae, exclusively with this methodology. A. gemmatalis pupae have a great cost benefit, being adequate to create the three species of parasitoids, however, it presented a slightly higher cost. Finally, it was found that D. saccharalis pupae had the highest production cost, which were suitable for rearing the three species of parasitoids. Finally, the ability of P. elaeisis, T. howardi and T. diatraeae to reduce the population of T. arnobia in eucalyptus plantations was evaluated, which proved that, in general, the three species of parasitoid had good results, which P elaeisis, T. diatraeae and T. howardi parasitize and develop in pupae of T. arnobia, with T. diatraeae being the parasitoid that presented the best biological characteristics when raised in this defoliator lepidopteran under laboratory conditions. After 15 days of release, it was certified that there was parasitism of 23.60; 18.00 and 25.10% by females of P. elaeisis, T. howardi and T. diatraeae, respectively, in eucalyptus plantations. After 30 days of release, there was a decrease in the adult population of this lepidopteran and practically null after 45 days of release, considering the release in the amount of 15,000 parasitoids of each species separately per hectare. The unpublished results obtained in this thesis serve as subsidies for applied biological control programs of eucalyptus defoliating lepidopterans, mainly I. panopla and T. arnobia, using the parasitoids P. elaeisis, T. howardi and T. diatraeae as management agents. In addition, to assist biofactories in order to optimize the mass creation of the three main parasitoids of eucalyptus defoliating lepidopterans.