Identificação, comportamento e multiplicação de himenópteros parasitoides de Phenacoccus solenopsis (Hemiptera: Pseudococcidae) nas culturas do algodoeiro e gergelim

Abstract

Cotton and sesame are plant species of great agricultural importance, being cultivated in several countries around the world, playing an essential role in the global economy, including Brazil. These plant species are attacked by various insect pests, which can cause severe damage if control measures are not adopted. Among these pests, the scale insect Phenacoccus solenopsis (Hemiptera: Pseudococcidae) deserves special mention. Controlling this insect is made difficult not only by the waxy layer that covers its body, but also by its behavior of colonizing areas of the plant that are difficult for the insecticide spray to reach. This has encouraged the use of biological control instead of chemical control. The objective of this work was to identify, study the behavior and multiplication methods of these parasitoids in nymphs and females of P. solenopsis in cotton and sesame. The occurrence of Aenasius sp. was evaluated, as well as the characterization of P. solenopsis nymphs mummified by this parasitoid collected on cotton plants. In addition, the parasitism of P. solenopsis, reared on cotton and sesame, by Aenasius sp., Aprostocetus sp. and Cheiloneurus sp. was evaluated, and a methodology for rearing Aenasius sp. in the laboratory on P. solenopsis nymphs and females reared in a greenhouse was developed. Chapter II evaluates which parasitoids parasitize nymphs and females of P. solenpsis when it has cotton or sesame as its host, and Chapter III presents a methodology for rearing Aenasius sp. in the laboratory. Mummified nymphs of P. solenopsis presented coloration ranging from ochre-brown to olive-brown and the emerged parasitoid was identified as Aenasius sp. (Hymenoptera: Encyrtidae). The specimens of parasitoids emerged from P. solenopsis mummified in cotton and sesame plants were identified as Aenasius sp., Aprostocetus sp. (Hymenoptera: Eulophidae) and Cheiloneurus sp. (Hymenoptera: Encyrtidae) with similar parasitism among hosts fed on these plants, but with greater emergence of the first parasitoid from both plant species. Finally, the rearing methodology developed here is efficient and the Aenasius sp. rearing system developed in this study makes it possible to obtain 6,271.37 parasitized scale insects and 2,719.01 emerged parasitoids during a period of 15 days after the exposure, respectively, of 15,207 scale insects to the parasitism of ̴ 1,521 pregnant females of the parasitoid.