RESUMEN
Laelaspis loeckii Duarte Moreira sp. nov. is described based on the morphology of adult females and males collected from soil in a survey carried out in southern Brazil, in the temperate Pampa biome. This is the first species of this genus described from this country. A key to the species that have so far been reported from the Western Hemisphere is provided.
Asunto(s)
Ácaros , Estructuras Animales/anatomía & histología , Animales , Brasil , Ecosistema , Femenino , Masculino , SueloRESUMEN
The sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) is considered the main sugarcane pest in many countries. The use of plant genotypes less preferred by insects are among the alternative methods to control this species which can be used alone or associated with other control methods such as biological control in Integrated Pest Management (IPM) programs. We assessed if the nonpreference for oviposition of D. saccharalis in sugarcane genotypes established by seedlings is different according to ripening group and plant age. For that purpose, four experiments were performed: 1) seedlings of early-ripening genotypes, 2) seedlings of late-ripening genotypes, 3) and mix of early- and late-ripening genotypes, seedlings, and 4) plants. There were least preferred genotypes for oviposition by D. saccharalis among seedlings of early-ripening (RB965902 and RB966928) and late-ripening (RB987935) genotypes. It was also observed when the groups were mixed as seedlings (RB965902) or plants (RB925345). The nonpreference for egg deposition in different ripening groups and plant age might be useful to integrate with other strategies for the management of D. saccharalis. Moreover, results of egg distribution might indicate the likely position of resistance factors on leaves, whether morphological or chemical.
Asunto(s)
Mariposas Nocturnas , Saccharum , Animales , Femenino , Larva , Oviposición , Hojas de la Planta , PlantonesRESUMEN
Stratiolaelaps scimitus (Womersley) and Cosmolaelaps brevistilis (Karg) (Acari: Laelapidae) are predatory mites of soil-inhabiting pests, mainly small insects. Fungus gnats fly species are found in greenhouse strawberry production and may be controlled with predatory mites, being important to know their compatibility with the pesticides used in strawberry crops. In this study, the compatibility of seven commercial pesticides used in strawberry cultivation with the predatory mites S. scimitus and C. brevistilis was assessed in laboratory conditions. Survival and oviposition rates were evaluated between 0.5 and 120 h after treatment (HAT). The results demonstrate that lambda-cyhalothrin treatment resulted in the lowest survival rate for both mites in the first evaluations, being moderately harmful, while spinetoran was slightly harmful to C. brevistilis. On the other hand, abamectin, azadirachtin, azoxystrobin + difenoconazole, iprodione and thiamethoxam were harmless for both mites and, oviposition rate was significantly different only at 72 and 120 HAT for S. scimitus and C. brevistilis respectively. These results may be used to develop guidelines for the adoption of selective pesticides in integrated pest management programs that conserves predatory mites.
Asunto(s)
Fragaria/fisiología , Ácaros/fisiología , Control Biológico de Vectores/métodos , Plaguicidas , Animales , Conducta Predatoria/efectos de los fármacosRESUMEN
We report on the Tydeidae and Triophtydeidae associated with grapevine (Vitis labrusca L. and Vitis vinifera L.) in Rio Grande do Sul State, Brazil, and describe a new species of Prelorryia, Prelorryia labrusca sp. nov., and two new species of Tydeus, Tydeus manoi sp. nov. and Tydeus riopardensis sp. nov. Brachytydeus formosa (Cooreman), B. podocarpa (Baker), Neolorryia pandana (Baker), Tydeus californicus (Banks), Pretydeus henriandrei Kazmierski and Triophtydeus lebruni (André) are recorded and illustrated. A key to species of Tydeidae and Triophtydeidae from Brazil is provided.
Asunto(s)
Ácaros y Garrapatas/clasificación , Enfermedades de las Plantas/parasitología , Vitaceae/parasitología , Ácaros y Garrapatas/anatomía & histología , Distribución Animal , Estructuras Animales/anatomía & histología , Animales , Brasil , Ecosistema , Femenino , MasculinoRESUMEN
BACKGROUND: The spider mite, Tetranychus urticae, is the major strawberry pest in Brazil. The main strategies for its control comprise synthetic acaricides and predatory mites. The recent register of a commercial formula of azadirachtin (Azamax(®) 12 g L(-1) ) can be viable for control of T. urticae. In this work, the effects of azadirachtin on T. urticae and its compatibility with predatory mites Neoseiulus californicus and Phytoseiulus macropilis in the strawberry crop were evaluated. RESULTS: Azadirachtin was efficient against T. urticae, with a mortality rate similar to that of abamectin. In addition, the azadirachtin showed lower biological persistence (7 days) than abamectin (21 days). Azadirachtin did not cause significant mortality of adult predatory mites (N. californicus and P. macropilis), but it did reduce fecundity by 50%. However, egg viability of the azadirachtin treatments was similar to that of the control (>80% viability). The use of azadirachtin and predatory mites is a valuable tool for controlling T. urticae in strawberry crop. CONCLUSIONS: Azadirachtin provided effective control of T. urticae and is compatible with the predatory mites N. californicus and P. macropilis. It is an excellent tool to be incorporated into integrated pest management for strawberry crop in Brazil.