An invasive pest new to the United States was discovered for the first time on a farm in Lancaster County and has been found to have spread to at least four other counties, according to officials at the Pennsylvania Department of Agriculture.
The invasive pest, known as allium leafminer Phytomyza gymnostoma, infects crops such as leeks, onions, garlic, chives, shallots and green onions. While researchers are still working to understand this invasive species, previous research suggests that the pest can be more damaging in organic, non-commercial farms or homeowner gardens.
“There is indication that the movement of plant crops impacted by this pest could result in transport of the pests,” Redding added. “That’s why it is of the utmost importance that we provide education and awareness about the leafminer and stop it from spreading anywhere else in Pennsylvania or beyond our state lines.”
The adult leafminer are about three millimeters in length and appear to be gray or black flies with a distinctive yellow or orange patch on the top and front. The yellow coloring is also present on the side of the abdomen. When resting, the wings are positioned horizontally over the abdomen. The eggs appear white, about 0.5 millimeters in length and slightly curved. The larvae are white, cream or yellowish in color and up to eight millimeters in length.