Maria José Araújo Wanderley

The effect of essential oils of sweet fennel and pignut on mortality and learning in africanized honeybees (Apis mellifera L.) (Hymenoptera: Apidae)

It was recently discovered that exposure to small concentrations of the essential oils of sweet fennel (Foeniculum vulgare Mill) or pignut [Hyptis suaveolens (L.) Poit] can be used to control aphids. What is not known is whether these oils also influence honeybee behavior. Experiments using both harnessed and free-flying foragers at concentrations used to control aphids showed that bees readily associated the odors with a reward, discriminated between them, and were not repelled. Honeybees, however, would not consume the oils when mixed with sucrose to create an unconditioned stimulus. An experiment in which harnessed bees consumed various concentrations showed that concentrations greater than 50% were detrimental. The experiments reported here provide further evidence supporting the use of conditioning techniques to evaluate the use of essential oils on honey bee behavior.

Resistência de cultivares de batata-doce a Euscepes postfasciatus Fairmaire (Coleoptera: Curculionidae)

Universidade Federal da Paraiba Centro de Formacao de Tecnologosa Departamento de Agropecuaria

Resistência de cultivares de batata-doce a Meloidogyne incognita

The objectives of this study were to evaluate the resistance of 35 sweet potato (Ipomoea batatas) cultivars to Meloidogyne incognita and illustrating anatomical changes in tissue of infected plants. The plants were inoculated with 3,000 eggs and juveniles of M. incognita and evaluated at 90 days after inoculation based on the reproduction factor of the nematode (RF). Among the 35 cultivars tested, 15 of them were considered resistant. Anatomical changes in sweet potato roots are illustrated, showing interruption of xylem vessels and progressive suppression of vascular tissues.

Efeito de quatro tipos de mel na longevidade e reprodução de Catolaccus grandis (Hymenoptera:pteromalidae)

O trabalho teve como objetivo conhecer o melhor tipo de mel em relacao a longevidade e fertilidade do parasitoide do bicudo-do-algodoeiro Catolaccus grandis. Adultos recem-emergidos foram transferidos para recipientes plasticos de 500mL, adaptados com tubo para fornecer agua e umidade para os insetos. Um casal do parasitoide foi mantido em cada recipiente em câmara climatizada a 25±1°C, UR = 70±10% e fotoperiodo de 14h. O trabalho constou de 4 tratamentos: mel de flor de laranjeira; mel de flores de plantas silvestres; mel de cana-de-acucar (todos produzidos por Apis mellifera) e mel de flores silvestres produzido por abelha Jatai (Tetragonistica angustula), com 15 repeticoes cada. Adultos recem-emergidos do parasitoide receberam cinco larvas de Euscepes postfasciatus encapsuladas em parafilm. Tres goticulas de mel foram colocadas sobre o parafilm. Calculou-se a longevidade de machos e femeas, numero de ovos dia-1 femea-1 e numero total de ovos femea-1 e construiram-se as tabelas de fertilidade. As melhores dietas para alimentar adultos de C. grandis foram o mel silvestre e o de laranjeira. A melhor fecundidade foi observada na dieta de mel de laranjeira (101,60 ovos femea-1) e os melhores resultados para aumento reprodutivo e populacional deste parasitoide foram obtidos com mel de laranja e com mel silvestre.

Mecanismos de ação de himenópteros parasitóides sobre Megastes spp. (Lepidoptera: Pyralidae) em agroecossistema de batata-doce (Ipomoea batatas L.)

The presence and action of Hymenoptera parasitoids in agroecossystems of sweet potato (Ipomoea batatas L.) in Pedra de Fogo county - PB, Brazil, on Megastes spp. complex were studied, with the objective of identifying parasitoids species and to describe the main aspects on parasitism action on Megastes grandalis Guenee and Megastes pusialis Snellen. On direct evaluation 14% of plants had females of ectopasitoids belonging to the Braconidae family. The indirect evaluation showed the occurrence of 22% of worms attacked by parasitoids. The emergence of parasitoids adults of seven species belonging to the Braconidae, Chalcididae and Ichneumonidae families has been observed. It was concluded that the presence of parasitoids in sweet potato agroecossystem is diversified and important to suppress the insect pest.