Over the past few years, harvesting of some Maryland and Eastern U.S. grapes has been complicated by the presence of Multicolored Asian Ladybeetles (MALB - Harmonia axyridis). The adult beetles can damage fruit in the field but most importantly, acts as a contaminant of the harvest, “fatally” tainting the wine made from the grapes.
The previous “Timely Viticulture” addressed some basic information on MALB and this message will concentrate on management tactics. Some sections of this message were intentionally repeated, but there is new information throughout.
Entomopathogens are bacteria, fungi, protozoans or viruses that can infect and subsequently cause disease in insects and other arthropods. They can indirectly impact cropping systems by serving as naturally suppressors of insect and mite pests. When there are epizootic outbreaks, entomopathogens are capable of causing rapid declines in large populations of their arthropod hosts. Many of these naturally occurring pathogens have been formulated and commercialized as insecticides.
Potato production in Maryland continues to grow and has more than doubled in the last 5 years, while in surrounding states it has declined. About 50% of the potatoes harvested in Maryland are for the fresh market while the other half goes for processing. Because of its value growers frequently apply pesticides too often in order to protect their investment. This often leads to the development of insect resistance, environmental contamination, worker and food safety concerns and poor management of pests.
I visited a few tomato fields this week and found 2-4-week-old tomato plants with some early blight (Alternaria solani) and in some cases bad early blight lesions. This is very early in the season to be seeing this level of early blight. Many of the plants had a few flea beetle adults on the plant (fig 1) and in the areas where the early blight was found also had moderate to high flea beetle feeding (fig 2).