Sugarcane stem borers of the genus of Diatraea (Lepidoptera: Crambidae) form a species complex that causes serious economic losses to sugarcane production in the Cauca River Valley and other regions of Colombia. Two primary species, Diatraea saccharalis (F.) and D. indigenella Dyar and Heinrich, have been effectively managed for more than 4 decades through augmentative releases of the tachinid flies Lydella minense (Townsend) and Billaea claripalpis (Wulp) (Diptera: Tachinidae) and the egg parasitoid Trichogramma exiguum Pinto & Platner (Hymenoptera: Trichogrammatidae). Here we review the current pest status of Diatraea species, damage assessment protocols, management tactics, and the environmental factors and cultural practices that can affect biological control outcomes. Recent changes in the cultivars grown have the potential to increase pest populations and diminish biological control efficacy. Additionally, recent outbreaks of new Diatraea species may further increase overall pest pressure. Thus, there is a need to develop supplementary tactics for the management of these pests that will be compatible with biological control, as well as more reliable protocols for assessing host plant resistance against the increase in infestation intensity.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

No abstract

S U M M A R YThe presence of free water on both surfaces of the leaves of shaded and unshaded coffee trees was evaluated at Cenicafe, Colombia. Rainfall was the main source of humidity and dew was not registered during the experiment. Five mm of rain caused canopy saturation and water began to reach the underside of the leaves. The period of wetness lasted 9.7 hours on average and no significant moisture differences were found between leaves on east or west facing branches, at different levels within the tree, or externally or internally positioned on the branches, either for exposed or shaded trees. Between 1700 and 0500 h (local time), a close relation was found between the time of rain initiation and the duration of the period of wetness. Leaves dried out at approximately 1000 h.O. Guzman y L. Gomez: La permanencia del agua libre en hojas de cafe.R E S U M E N La presencia de agua libre en ambas superficies de las hojas de cafetos sombreados y no sombreados fue evaluada en Cenicafe, Colombia. La fuente principal de la humedad era la Uuvia, y no se registro roci'o durante el experimento. El follaje se saturo con 5 mm de Uuvia, y el agua comenzo a alcanzar la parte inferior de las hojas. El periodo de humedad duro un promedio de 9,7 horas, y no se vieron diferencias significativas en la humedad entre hojas de ramas de orientacion este u oeste a diferentes niveles dentro de la planta, o de posicion externa o intema en las ramas, ni para plantas expuestas ni sombreadas. Entre las 1700 y 0500 h (hora local), se vio una relacion estrecha entre el momento del comienzo de la Uuvia y la duracion del periodo de humedad. Las hojas se secaron a las 1000 h (hora local) aproximadamente.Coffee leaf rust (Hemileia vastatrix Berk, and Br.) was first detected in Colombia in September 1983. This event, a real threat to the Colombian economy, created a need for research into the different aspects concerning the development of the fungus.Climatic conditions can affect the geographical distribution and seasonal severity of plant diseases. Therefore, a knowledge of the conditions prevailing during the course of a specific disease can lead to a better understanding of its nature and behaviour and at the same time contribute to more economic and efficient control. Although the relation between climate and disease is complex, there are two stages in the life cycle of the majority of pathogenic fungi that are very susceptable to environmental conditions, namely: spore dispersion which requires a minimal amount of water, and spore germination which is a function of temperature and humidity (Waller, 1973).

No abstract