As the flies emerge from the galls in May, they are collected and redistributed to new Canadian thistle-infested sites. Velvetleaf, a persistent weed with a seed dormancy of up to 50 years, can cause substantial crop losses, especially in field crops, and is difficult to control with herbicides. Weed control efforts are further hampered by the seed's ability to germinate throughout the growing season and withstand periods of reduced rainfall when herbicide effectiveness is lowered. Scentless plant bugs, which feed on the reproductive parts of the weed, were laboratory-reared for field release trials to evaluate their ability to reduce the weed population. In this, the third year of the trial, it was determined that velvetleaf seed germination was reduced by 100 percent when the scentless plant bugs are released at the proper rate and time during the season.
Euonymous scale is a predator of ornamental plants in New Jersey.
The department has established a ladybug throughout the state that preys on the scale while three additional beneficial insects, two parasitic wasps and a tiny predatory beetle, are now being laboratory-reared for field release against Euonymus scale. The beetle was released in seven counties this year, the parasites in four counties. Recoveries of overwintering beetles have been made in Mercer and Cape May Counties. The department continued its delineation survey of an established parasite which feeds on tarnished plant bug nymphs, a pest of fruits, vegetables and field crops. The parasite was originally released in Warren County by the USDA and has been recovered in Warren, Sussex, Morris and Hunterdon Counties.