Insect Pest - Invasive

Agronomy News IPM Insect Scouting Tips

If you grow leeks or onions or other Allium species, now and for the next few weeks is the time to watch for the tell-tale marks left by Allium leaf miner. Allium leaf miner Phytomyza gymnostoma tell-tale marks consist of several small round white dots (made by the female’s ovipositor) in a row that appear on the middle towards the end of leaf blades (fig. 1) of their preferred hosts of leeks, onions, garlic and other Allium species.

I have seen and have gotten reports of (and some really nice pictures of) stinkbug damage in tomatoes over the past few weeks from all over Maryland including the Eastern Shore. Stinkbug feeding damage is called cloudy spot in tomato fruit (fig. 1). It occurs when the adult or immature stinkbug puts its needle-like mouth parts into the fruit and removes material from a large number of cells. On green fruit the damage appears as whitish areas with a black dot in the center and indistinct borders (fig. 2) on ripe fruit the spots are golden yellow (fig. 1).

Parasitic wasps are beneficial wasps that generally lay their eggs inside the egg, immature or adult stage of another insect commonly called its host. Eggs of these wasps then hatch, leaving the larval wasp which resembles a maggot to consume the contents of the host egg.

This has been a bad year for stink bug damage in tomatoes. Just about every field I walk into has at least some damage while others have moderate to heavy damage (>20% tomatoes not marketable). Cloudy spot of tomato fruit is caused by the feeding of various species of stink bug (SB). On green fruit the damage appears as whitish areas with indistinct borders (Fig. 1).

All adult stink bugs are shield shaped. Phytophagus: Green and southern green stink bugs are light green and measure ½" to ¾" long. The green stink bug is bordered by a narrow, orange-yellow line around most of its body (Fig. 1). Brown stink bugs are dull brownish-yellow in color and about ½" long (Fig. 2). The Brown Marmorated stinkbug is a newly introduced pest to the Mid-Atlantic area and can be distinguished from other brown stink bugs by their lighter bands on the antennae and darker bands on the overlapping part at the rear of the front pair of wings (Fig 3).

There has been a large and rapid increase in brown marmorated stink bug BMSB) in some pepper fields in the past week in central Maryland. Numbers just two weeks ago in these areas were very low with just a few nymphs observed. We know that BMSB populations tend to increase in August and through the fall into the first frost, but this was such a rapid increase that a great deal of damage was done to bell and banana peppers.

The Brown marmorated stink bug (BMSB) Halyomorpha halys (Figs. 1 and 1a) was accidentally introduced into the United States in shipping containers arriving from Asia. The first confirmed specimen was collected in Allentown, PA in October 2001, although there is evidence that it was collected from black light traps in New Jersey as early as 2000.

The News and Notes roundup for this issue features a way to get caught up on this fall's Woodland Wildlife Wednesday webinars, a way to remove adult Spotted Lanternflies using an empty water bottle, how to have your business listed in our new Natural Area Management Services Providers Directory, and how to order seedlings for spring planting projects from the Maryland State Nursery.

The spotted lanternfly (SLF) is a colorful non-native, invasive pest native to Asia that was first detected in the United States in 2014 in Berks County, Pennsylvania. In addition to Pennsylvania, it has been confirmed in Maryland, Delaware, New Jersey, West Virginia, and Virginia. In Maryland, Cecil and Harford Counties are under a quarantine. The first instar hatch was recorded in Cecil County in May 2020.