Ivanildo Soares de Lima

Volatile substances from male Anastrepha fraterculus wied. (Diptera: Tephritidae): identification and behavioural activity

Volatile compounds produced by calling males of Anastrepha species have previously been reported from A. ludens and A. suspensa. Both species mate in the afternoon, release a similar range of compounds in different proportions, and only differ in the production of monoterpenes. When calling, male A. fraterculus releases two isomers of the sesquiterpene a-farnesene, three lactones (anastrephin, epianastrephin and (E,E)-suspensolide), and two monoterpenes (limonene and (Z)-b-ocimene). The dimorphic male salivary glands produce and/or store the same isomers of a-farnesene and suspensolide, and four pyrazines. Two of these compounds have been previously reported from male A. ludens and A. suspensa. Salivary glands from virgin calling male A. fraterculus showed behavioural activity when bioassayed with virgin mature female flies, but immature females were not attracted.

Mortalidade de larvas de Plutella xylostella tratadas com extratos etanólicos de Aspidosperma pyrifolium

The objective of this work was to assess the effects of Aspidosperma pyrifolium ethanol extracts on cabbage moth (Plutella xylostella) larvae. The ethanol extracts of the stem bark, fruits and roots of A. pyrifolium were obtained by classical phytochemical methods, and the resulting subfractions were tested on P. xylostella, using 4 and 5 mg L-1. The crude ethanol extract of the stem bark was more lethal. The alkaloid-rich aqueous subfraction derived from the stem bark extract caused 100% larval mortality at 4 mg L-1. Insecticidal activity was associated with the presence of the monoterpenoid indole alkaloids aspidofractinine, 15-demethoxypyrifoline, and N-formylaspidofractinine. These alkaloids presented excellent insecticidal properties against P. xylostella.

Captura de Rhynchophorus palmarum L. (Coleoptera: curculionidae) em armadilhas iscadas com o feromônio de agregação e compostos voláteis de frutos do abacaxi

O objetivo deste trabalho foi determinar os indices de captura de Rhynchophorus palmarum em armadilhas iscadas com o feromonio de agregacao, 6-metil-2(E)-hepten-4-ol (rincoforol), associado a toletes de cana-de-acucar, a pedacos de frutos do abacaxi e a seis compostos volateis isolados de frutos do abacaxi. Os compostos volateis do abacaxi sao caracterizados por uma mistura de esteres metilicos e etilicos, sendo o octanoato de metila e o octanoato de etila os mais abundantes. As armadilhas iscadas com o rincoforol associado a toletes de cana-de-acucar e as iscas com rincoforol associado a pedacos de abacaxi nao apresentaram diferencas significativas no numero de besouros capturados. No entanto, ambas apresentaram indices de captura superiores aquelas em que o rincoforol foi utilizado em associacao com volateis do abacaxi. Nao se observaram efeitos significativos do local e epoca de captura, nem no numero de machos e de femeas capturados.

Aspectos práticos relacionados ao uso do Rincoforol, o feromônio de agregação da Broca-do-olho-do-coqueiro Rhynchophorus palmarum L. (Coleopterate: Curculionidae) no controle de pragas do coqueiro: análise de sua eficiência em campo

Rhynchophorol (6-Methyl-2-hepten-4-ol) is the major constituent of the aggregation pheromone of Rhynchophorus palmarum L. (Coleoptera: Curculionidae), which is released by males of this species. The racemic mixture has been produced in one step-simplified preparation. The pheromone is placed into ampoules and furnished to coconut farmers. In the field, traps baited with Rhynchophorol and pieces of sugarcane attract both males and females, reducing the population of R. palmarum. The best conditions for field application are showed.

Eficiência de diferentes taxas de liberação do feromônio de agregação na captura de Rhynchophorus palmarum L. (Coleoptera: Curculionidae)

The American palm weevil Rhynchophorus palmarum L. (Coleoptera: Curculionidae) is the most important pest of the coconut palm tree. Its larvae feed on plant tissues and the adult is the main vector of the red ring disease caused by the nematode Bursaphelenchus cocophilus (Cobb) Baujard. The aggregation pheromone 6-methyl-(2E)-hepten-4-ol (Rhynchophorol) has been used as part of the integrated pest management of coconut in several countries, including Brazil, where the pheromone is synthesized and distributed to coconut producers. The use of imported reagents makes the synthesis of the pheromone very expensive. Therefore, this work aimed to verify the efficiency of different release rates of the pheromone in capturing adults of the American palm weevil in the field. When kept inside Eppendorf vials, containing a small hole on the lid (1 mm), the mean release rate of the pheromone was 4.3 mg/day. Weevil catches by pheromone traps baited with pieces of sugar cane and Rhynchophorol at release rates of 4.3 mg/day; 8.6 mg/day; 17.2 mg/day; 34.4 mg/day and 68.8 mg/day, during 60 days, showed that the release rate of 4.3 mg/day was the most economic because all the release ratesdid not capture, but allowed the capture of equal number of weevils. Weevil catches by pheromone traps baited with Eppendorf vials without a hole on the lid, were significantly lower than those traps baited with vials containing a hole. Vials without holes on the lid release 2.2 mg/day of Rhynchophorol in the environment.

Disposição do nematóide Bursaphelenchus cocophilus (Cobb) baujard, em coqueiros portadores da doença anel-vermelho

The aim of this work was to investigate how the nematode Bursaphelenchus cocophilus tends to distribute itself inside the coconut palm trees in advanced stages of the red ring disease. In the samples of the roots collected at the base of the stem of sick trees, the number of nematodes was considerably higher when compared to the number found in the roots situated between one and three meters away from the stem. It was observed that, as it stands back of the sick plant, the possibility to find nematodes in the root is remote, so that the chances of transmission of the disease, from one plant to another, by means of the roots are minimal. At the top part of the stem, where the tissue is softer, it is possible to find the nematode both in the discolored areas and in the adjacent tissues, apparently healthy. In the tissues of the petioles, nematodes were found in small amounts. Therefore, the practice of the scythe disinfections used in the harvesting and leaf pruning should be recommended with the purpose of decreasing the possibility of transmission of the disease. None of the obtained samples from tissues of the rachis and leaves were contaminated. The population of nematode is higher in the excrements of larval tunnels of the apical parts of the plant, which provide higher chances of being transported, from one plant to another, stuck on to the body of its main vector, the coconut palm weevil Rhynchophorus palmarum.

Caracterização morfológica dos imaturos de Hyponeuma taltula (Schaus) (Lepidoptera, Noctuidae, Herminiinae)

Hyponeuma taltula (Schaus, 1904) is a borer that feeds on sugar cane plant in Brazil. In the decade of 1970 were reported damages in sugar cane fields in the states of Santa Catarina, Sao Paulo and Pernambuco. Most recently, in 2005, were observed sugar cane plants hosted by this species in the State of Alagoas. The aim of this work is to describe morphologically the immature stages of H. taltula, mainly aspect of the eggs micropila, the chaetotaxy of the caterpillar and the position of pupa appendages.

Evidence of an attractant from virgin females of Bephratelloides pomorum (Hymenoptera: Eurytomidae): Possible role of cuticular compounds

The Annona seed borer, Bephratelloides pomorum (Hymenoptera: Eurytomidae), is the most important insect pest of soursop, Annona muricata L. The female lays eggs directly into the most recently formed seeds of developing fruit where the larvae remain feeding until pupation. When fully developed, the young wasps make a channel to emerge from the fruit, ready to copulate. Males are attracted to females and display a peculiar behaviour which consists of three steps: antennation, lateral bouncing and wing vibrations. Experiments carried out in semi-field and laboratory conditions showed that males also behave similarly in the presence of filter paper impregnated with a hexane extract of the females body, suggesting that female B. pomorum produce an attractant which enables males to find them. The hexane extracts of females, analysed by GC-MS, were shown to consist mainly of a mixture of straight- and branched-chain hydrocarbons and esters.