Elm Seed Bugs are the worst, they really are. They invade by the thousands, smell gross when crushed, and get into everything. Every June or so (at least since 2009) when the weather gets hot, Elm Seed bugs invade Treasure Valley homes en masse. Trying to escape the heat, they are driven indoors to air conditioned kitchens, living rooms, and bedrooms.

Elm Seed Bugs are a recent addition to the list of unwelcome pests in the area. We first started becoming aware of these bugs during the summer of 2012. We started getting calls from customers complaining of an insect that looked a lot like a Box Elder Bug, but much smaller. When our technicians went out to do inspections, that’s just what they thought as well: Immature Box Elder Bugs (not in the sense that they like Justin Bieber, say socially inappropriate things, etc….immature as in smaller).

Later that year, they were identified as Elm Seed Bugs. They originate from south-central Europe, and they (for whatever reason) came to Ada & Canyon counties. How they got here remains a mystery. Nevertheless they are here now, and here to stay. Since then, Elm Seed Bugs have spread in Idaho and even into Eastern Oregon & Utah. Idaho (to the chagrin of other states I’m sure) has the wonderful distinction of being the first place in the United States for the Elm Seed Bug to appear.

Elm Seed Bugs have piercing/sucking mouthparts, and they feed on both Elm seeds, and the sap of the Elm tree. Consequently, they live near Elm Trees! Coincidentally, this is why I live near a refrigerator.

They have one generation per year. This means that males and females mate only once, and females lay only one set of eggs per year in the spring. The newly hatched young immediately begin to feed throughout the summer and fall, then overwinter beneath leaf litter, bark, or other protected places, and the process starts over again.

Elm Seed Bugs are distinguishable from Box Elder Bugs in 3 important ways: At around a third of an inch long they are much smaller than Box Elder Bugs. There is a dark triangle spot on their backs that points backwards. They have white bands on their abdomens.

Eliminating their habitat is one of the big things you can do to get rid of these pests. If you can’t get rid of the Elm Trees, you can certainly rake up Elm seeds, leaves, and branches. You can do your best to ‘pest proof’ your homes and businesses by calking, weather stripping, and otherwise sealing up your structure as well.

Regular exterior treatments with a safe residual pesticide around the perimeter, doors, windows , and other opening or protrusions are a must in combatting this seasonal pest.


CC Image by PermaCultured at Flickr.