Sexual behavior and diel activity of citrus fruit borer Ecdytolopha aurantiana

Mating behavior and oviposition of Palpita forficifera (Lepidoptera: Crambidae)

Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is considered the main pest of the olive tree (Olea europaea L., Oleaceae) in Brazil and Uruguay. The aim of this work was to study the mating and oviposition behavior of P. forficifera in the field and laboratory. In the field, the sex emitting the mating pheromone was determined and in the laboratory, the rate of emergence of males and females; the age, time and duration of mating; number of copulations and oviposition time of P. forficifera were recorded. The field results showed that it was possible to capture up to five males per trap in just one night in traps with the presence of female P. forficifera. Copulation occurs between the seventh and twenty-third day of life and is most frequent during the third and sixth hours of scotophase. The average duration of the first copulation was 174 min, with 35% of couples recopulating, and there were cases of up to five copulations. Oviposition times were concentrated between 20:00 and 02:00. The results obtained provide insight into the reproductive behavior of P. forficifera and are useful for future studies aimed at identifying the sex pheromone to improve monitoring of the pest in olive orchards.

Gymnandrosoma aurantianum (Lepidoptera: Tortricidae): Calling Rhythm and Effect of Age on Female Sex Pheromone Titer and Male Antennal Responses

The macadamia nut borer, Gymnandrosoma aurantianum Lima (Lepidoptera: Tortricidae), is the main pest of Macadamia integrifolia Maiden & Betche (Proteales: Proteaceae) in Central America. Despite its importance, there is little information on its reproductive behavior. We studied the calling behavior and effect of age on female sex pheromone production and male antennal response to the pheromone. Calling behavior of G. aurantianum females occurred at the onset of scotophase, between 17:00 and 20:00 h. The mean time spent calling was 64 min. It was observed that 30% of the 50 females exhibited a calling posture characterized by extrusion of the pheromone gland from the tip of the abdomen and they spread their wings slightly. Female age had no influence on the sex pheromone production, while male antennal response increased with age and pheromone dosage. The information obtained in this work contributes to understanding the sexual behavior of G. aurantianum and thus to the creation of strategies to control this important pest in macadamia.

Circadian rhythms of insect pheromone titer, calling, emission, and response: a review

Many insect species have circadian rhythms of pheromone production/titer, calling, emission, and response that are involved in intraspecific communication and impact pest management practices. Rhythms of pheromone biosynthesis, most studied in moths affecting forestry and agriculture, contribute to a periodicity of pheromone concentration or titer within glands or hemolymph. Calling rhythms by the pheromone-emitting sex are physical movements (pumping, vibrating wings) that aid in release and dispersion of the volatile pheromone components attractive to the opposite conspecific sex or both sexes. Circadian rhythms of emission of pheromone also occur as a result of an interaction between calling and the titer of pheromone available for release. Responding individuals usually show a coincidental rhythm of dispersal flight while seeking pheromone plumes in which, by orienting upwind, the insects find mates or food resources. However, some species begin searching an hour or more before the emitting sex initiates calling and emission, which benefits mass trapping control programs because the baited traps do not compete initially with natural pheromone sources. In our review, data of daily rhythms of moths and other insects were extracted from the literature by screen capture software to calculate mean time of activity and standard deviation and fit to normal curves. These methods are illustrated for various insects and as a basis for discussion of interactions of pheromonal circadian rhythms of the well-studied gypsy moth Lymantria dispar, spruce budworm moth Choristoneura fumiferana, turnip moth Agrotis segetum, and cabbage looper moth Trichoplusia ni. The various circadian rhythms are discussed in relation to application of species-specific sex and aggregation pheromones for benign biological control and management of pest insects.

Platynota rostrana (Walker) (Tortricidae) and Phidotricha erigens Raganot (Pyralidae): artificial diet effects on biological cycle

The lepidopterans Platynota rostrana (Walker) (Tortricidae) and Phidotricha erigens Raganot (Pyralidae) have been found frequently in citrus groves in São Paulo State in recent years. Since in Brazil, the fertility cycle of these two species is largely unknown, as are details of the damage wrought by them in crops, this research studied these aspects of the two species, which were kept under laboratory conditions (temperature 25 ± 2 °C, 70 ± 10% RH, 14 h photophase) and on an artificial diet. The duration of the biological cycle (egg-adult) for P. rostrana was 38.3 days and total viability was 44.0%; for P. erigens these values were 32.5 days and 63.6%, respectively. Both species showed five larval instars. Females of P. rostrana laid an average of 308 eggs, whereas those of P. erigens laid an average of 106 eggs. In both species, female pupae were heavier than males. Male and female longevity for both species was nearly 10 days. Based on the data obtained, the artificial diet produced better results in P. rostrana than in P. erigens. If these species, which have the potential to reach pest status in the citrus groves of São Paulo State, could be reared on an artificial diet, research on their control by alternative methods would be easier.

EFEITO DA ALTURA DE POSICIONAMENTO E DA COR DE ARMADILHAS DE FEROMÔNIO NA CAPTURA DE ARGYROTAENIA SPHALEROPA (MEYRICK, 1909) (LEPIDOPTERA: TORTRICIDAE) NA CULTURA DO CAQUIZEIRO

RESUMO Argyrotaenia sphaleropa (Meyrick, 1909) (Lepidoptera: Tortricidae) é uma das principais pragas do caquizeiro na região da Serra Gaúcha, principal pólo produtor da fruta no Rio Grande do Sul, onde danifica também as culturas do pessegueiro e da videira. O monitoramento da praga nos pomares pode ser realizado com armadilhas de feromônio. Entretanto, para implementar um programa de monitoramento da praga nos pomares é fundamental disponibilizar informações sobre a influência da altura de posicionamento e da cor das armadilhas sobre a captura de A. sphaleropa. Neste trabalho foi avaliada a captura de adultos de A. sphaleropa em armadilhas delta brancas posicionadas a 0,5, 1,0, 1,5, 2,0 e 2,5 m acima do nível do solo, e em armadilhas das cores branca, amarela, vermelha, azul e verde, posicionadas a 1,8 m acima do nível do solo. Pelos resultados obtidos constatou-se que as armadilhas posicionadas a 2,0 e 2,5 m acima do nível do solo capturaram um número maior de indivíduos quando comparadas com aquelas posicionadas a 0,5, 1,0 e 1,5 m. As armadilhas das cores verde e azul foram mais eficientes que as das cores branca, amarela e vermelha, proporcionando maior captura de A. sphaleropa. Em função dos resultados obtidos neste trabalho, recomenda-se a utilização de armadilhas delta da cor verde ou azul, instaladas a 2,0m acima do nível do solo, para o monitoramento de A. sphaleropa na cultura do caquizeiro.

Identification, synthesis, and field evaluation of the sex pheromone of the citrus fruit borer Ecdytolopha aurantiana

The sex pheromone of the citrus fruit borer Ecdytolopha aurantiana has been identified by gas chromatography coupled to an electroantennographic detector (GC-EAD). The electron impact mass spectral (EI-MS) fragmentation of the major EAD-active peak gave identifying features for a monounsaturated acetate. Further analyses by chemical ionization mass spectrometry (CI-MS), vapor-phase infrared spectroscopy (GC-IR), along with chemical derivatization (DMDS reaction), led to full characterization of the major component as (E)-8-dodecenyl acetate (E8-12 : Ac). The second constituent was identified as the related alcohol, (E)-8-dodecenol (E8-12 : OH). The two compounds were indistinguishable from the authentic synthetic standards in chemical and EAD analyses. Samples of the two compounds were obtained by a facile synthesis utilizing lithium chemistry. Field tests showed that captures in traps baited with a mixture of E8-12 : Ac and E8-12 : OH at 100 : 1 and 10 : 1 ratios were not significantly different from the catches in traps having two virgin females. Dosage tests showed better performance of traps baited with 1 mg than those with 0.1 mg of the pheromone blend, either in 100 : 1 or 10 : 1 ratio.