Stink

September 27, 2022

When I opened my News Break app the lead story concerned a bug rapidly multiplying throughout the US.  Now with winter fast approaching the bugs are going to be moving inside your home.  The insect is originally from Asia and researchers think it came over on shipping crates from China or Japan.  It was first spotted in 1998 and has already taken over 44 states (including Arkansas) and four provinces in Canada.  Even though they do not bite, they are a nuisance when hundreds or thousands of them come inside your house.  The bug survives the winter as an adult by entering houses and structures when autumn evenings become colder.  In one home, more than 26,000 stinkbugs were found overwintering.  While we have a few hundred different indigenous species of stink bugs these are different.  If you try to kill, squash, or even vacuum them they will spray and make a vile smell.  The brown marmorated stink bug is more likely to invade homes in the fall than others in the family.

When I looked online, I found the brown marmorated stink bug (Halyomorpha halys) is an insect in the family Pentatomidae, native to China, Japan, Korea, and other Asian regions.  The adult brown marmorated are approximately 0.67 inches (1.7 cm) long and about as wide, forming the heraldic shield shape characteristic of bugs in the superfamily Pentatomoidea.  They are generally dark brown on top with a creamy white-brown underside, but individual coloration may vary.  “Marmorated” means variegated or veined (like marble), which refers to the unique markings to this species that include alternating light-colored bands on the antennae and alternating dark bands on the thin outer edge of the abdomen and brown legs with faint white mottling or banding.  The nymph stages are black or dark brown with red husks (integument) between the body plates (sclerites).  First instar nymphs (larval stages) have no white markings, but second through fifth instar nymphs have black antennae with a single white band.  The nymphs’ legs are black with varying amounts of white banding.  Freshly molted individuals of all stages are pale white with red markings.  Eggs are laid on the underside of leaves in masses of 28 eggs.  They are light green when laid, slowly turning white.

Like all stink bugs, the glands that produce the defensive chemicals (smell) are located on the underside of the thorax, between the first and second pair of legs.  The species was first collected in the US in September 1998 in Allentown, Pennsylvania, where it is believed to have been accidentally introduced in shipping crates.  The nymphs and adults of the bug feed on over 100 species of plants, including many agricultural crops.  By 2010–11 the bug had become a season-long pest in orchards in the Eastern US.  In the Mid-Atlantic States during that year, US$37 million in apple crops were lost, and some stone fruit growers lost more than 90% of their crops.  This stink bug is established in many parts of North America and has recently become established in Europe and South America.

THOUGHTS:  Several wasps and predators indigenous to North America and Europe have been reported to attack stink bug eggs, nymphs, and adults.  Researchers have experimented with predators like the spotted lady beetle (Coleomegilla maculate), the spined soldier bug (Podisus maculiventris) who is another stink bug species, and the common green lacewing (Chrysoperla carnea) in the US.  The Samurai Wasp (Trissolcus japonicus) is the primary predator of the bugs in China and the species has self-introduced to North America.  The Joro spider is another invasive Asian species, and a natural predator of the stink bug, and was identified in Georgia in 2015.  It seems invasive predators attacking invasive pests is the approach taken by researchers.  What happens after the “spider swallows the fly.  Don’t ask me why”?  Act for all.  Change is coming and it starts with you.