RESUMEN
To further the use of local parasitoids to control the spotted wing drosophila suzukii (Matsumura) in Mexico, three treatments were implemented by sextuplicate in commercial berry fields of Colima and Jalisco from June 2017 to May 2018: single release of Trichopria drosophilae Perkins (pupal parasitoid), combined release of T. drosophilae + Leptopilina boulardi Barbotin, Carton & Kelner-Pillault (larval parasitoid), and a no release control. Compared with the no release sites, parasitism by T. drosophilae increased 4 and 4.1-fold at the single and combined release sites, respectively, and parasitism of L. boulardi increased 2.8-fold at the sites where it was evaluated. Additionally, it was registered a 50 and 55% reduction of D. suzukii at the sites with single and combined releases, respectively; in other words, supplementing T. drosophilae with L. boulardi provided little benefit compared with the release of T. drosophilae alone. These results indicate that single release of local T. drosophilae is a more cost-effective option to reduce D. suzukii populations, and that such activity can contribute significantly to the phytosanitary management of this invasive pest.
Asunto(s)
Drosophila/parasitología , Control Biológico de Vectores/métodos , Avispas/fisiología , Animales , México , Pupa/parasitología , RubusRESUMEN
Cry proteins from Bacillus thuringiensis have insecticidal properties. The function of domains I and II has been described but domain III has so far eluded understanding. Domain III from Cry1Ab and Cry1Ac has been cloned, expressed in E. coli and injected to rabbits with the aid of characterizing them immunologically. Interestingly, polyclonal antibodies against Cry1Ab fragment did not recognize either the native Cry1Ab toxin or the Cry1Ac fragment while those against the latter did recognize either the native Cry1Ac toxin or the Cry1Ab protein fragment. A combination of information from sequence comparison and hydrophobicity profile indicates that these protein fragments possibly adopt different spatial dispositions within the respective toxins.
Asunto(s)
Bacillus thuringiensis/química , Proteínas Bacterianas/química , Toxinas Bacterianas/química , Endotoxinas/química , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Toxinas Bacterianas/genética , Toxinas Bacterianas/inmunología , Clonación Molecular , Endotoxinas/genética , Endotoxinas/inmunología , Ensayo de Inmunoadsorción Enzimática , Proteínas Hemolisinas , Estructura Secundaria de Proteína , Proteínas Recombinantes/química , SolubilidadRESUMEN
Bacillus thuringiensis is a Gram-positive bacterium, widely used in agriculture as a biological pesticide. The biocidal activity mainly resides in a parasporal protein inclusion body, or crystal. The inclusion is composed of one or more types of delta-endotoxins (Cry and Cyt proteins). Cry proteins are selectively toxic to different species from several invertebrate phyla: arthropods (mainly insects), nematodes, flatworms and protozoa. The mode of action of the insecticidal proteins is still a matter of investigation; generally, the active toxin is supposed to bind specific membrane receptors on the insect midgut brush-border epithelium, leading to intestinal cell lysis and subsequent insect death by starvation or septicemia. The toxin-encoding cry genes have been extensively studied and expressed in a large number of prokaryotic and eukaryotic organisms. The expression of such genes in transgenic plants has provided a powerful alternative for crop protection.