Uninvited Holiday Guests: Part 1
Christmas
trees like other crops have many pests that feed on them. Also like
other crops, they are grown outside. Thus, many insect species may be
unfortunate enough to stop for a rest just as the tree is bundled up and
trucked to your local box store. Every year people report arthropods
that have hitchhiked into their house on a Christmas tree. Here are a
few of the most common.
Cinara sp. aphids feed on Christmas trees and are sometimes present at harvest time (http://www.freshfromflorida.com/pi/pest-alerts/christmas-tree-aphids.html).
These critters feed on tree sap and are often mistaken for ticks once
inside a house. They are easily distinguished from ticks because they
have 6 legs whereas ticks have 8. In addition they are round whereas
ticks are flat. These aphids cannot survive long without a living tree
and will soon fizzle out as the tree dries.
Spruce
spider mites are another Christmas tree pest that could come in on your
tree. You would have to be looking very hard to see these guys. They
are very small.
Cooly spruce gall adelgids are Christmas tree pests and super interesting (http://www.bugoftheweek.com/BugOfWeek_52C.html).
They have a complex life cycle in which they alternate between two
hosts. The produce galls that look like cones that actually contain
hundreds of young aphids.
It
is important to remember that all of these pests feed on live trees.
The will not set up shop under your couch or on your dog. As the tree
dies so will they. If there are more than you can handle then return the
tree and pick a new one. It is very unlikely you would get another
infested tree even from the same dealer.
Uninvited Holiday Guests: Part 2
We
discussed arthropod pests of Christmas trees that people find once they
bring trees into their home. In this article we will discuss arthropod
hitchhikers that do not feed on Christmas trees but were unlucky enough
to be on one when it was cut, bundled, and shipped. When you get home
with your tree these critters may wander off and startle the kids or
amuse your cat but will not cause harm to people or become permanent
residents of your home. They do not want to be there any more (probably
way less) than you want them there.
Many
arthropods spend the winter as eggs that their parents laid in the
fall. The eggs typically hatch when warm weather comes in the spring.
However, if the eggs are on a tree that you place in front of your warm
yuletide fire they will hatch (please don’t put your Christmas tree near
a fire, yuletide or otherwise).
Spiders
frequently lay eggs on trees and hitchhike into homes on Christmas
trees. Spider hatchlings get around in nature by climbing to the top of
plants and ballooning on silk threads. Essentially they get blown around
and hope to land in a good spot. In your living room there is probably
not much wind (though Grandpa always complains about the draft) but they
will still string silk around the tree as they try to catch a breeze.
Eventually they will give up and crawl off the tree where you might spot
them on the wall.
Praying
mantids are a fun insect to rear. The egg case looks like brown foam
from which hundreds of small mantids emerge. The young mantids are an
inch or so long and very quick. They climb all over and really freak
people out who aren’t expecting them. Young mantids are hungry,
voracious predators so maybe they will eat the other bugs you didn't
know you had. A lot of bugs live in your home no matter how clean it is.
Our friends at http://www.yourwildlife.org can tell you all about this.
People
also report adult and larval lady beetles or green lacewings. Of course
people often find Asian multicolored lady beetles in their house that
come in through vents and cracks to spend the winter. It is possible
that adult or larval lady beetles of other species could be hunkered
down for the winter on your Christmas tree along with green lacewings
and their larvae. Green lacewings are beautiful delicate insects as
adults and predators as larvae. They are very cool to watch and to feed
if you happen to have some other bugs lying around.
