Wednesday, November 25, 2015

Home Invasion - Fall Insect Pests

To survive the winter insects have developed different strategies to survive.  Some insects lay eggs and die when temperatures fall below freezing.  Other insects burrow in the ground or under piles of decaying plant material.  Still others avoid the cold by migrating to warmer climates.  As the temperature begins to fall, insects begin to look for a warm place to overwinter.  One of the places where they can overwinter is in your home.  Some of the most common overwintering insects that tend to invade homes are listed below.


Boxelder bug (Leptocoris trivittatus)


Boxelder bug adult surrounded by nymphs. William M. Ciesla
Forest Health Management International

The adult boxelder bug gets its name from their host plant the boxelder (Acer negundo). The boxelder bug is about 1/2 inch in length, and dark gray to brownish-black in color, with three red stripes on the thorax and wing margins.  The body is bright red.  They have piercing-sucking mouthparts and feed mainly on seeds produced by female boxelders.  Eggs are straw-yellow to rusty-red in color and are not often seen, as they are deposited on boxelder trees or other maples, or near the trees.  The nymphs, which are found on the trees, are bright red in color with the front half darker. Nymphs resemble adults but do not have fully developed wings and are not able to reproduce.


Multi-colored Asian lady beetle (Harmonia axyridis).


Asian lady beetles vary in color. Note the whitish area
with M-shaped marking behind the head.
University of Kentucky

The Asian lady beetle (Harmonia axyridis), is common throughout the United States. Adult Asian lady beetles are oval, convex, and about 1/4-inch long. Their color can vary widely from tan to orange to red. They often have several black spots on the wing covers. On some beetles the spots may be indistinct or entirely absent. Multi-spotted individuals tend to be females while those with few or no spots tend to be males. Most beetles have a small, dark "M" or "W"-shaped marking on the whitish area behind the head. The Asian lady beetles are beneficial insects. The use of lady beetles as a natural control of aphids in some crops like pecans has decreased insecticide use against those pests. Additionally, lady beetles have  been used to controlled aphids on some ornamental plants.


Cluster fly (Pollena rudis)


Cluster Fly - Colorado State University Extension

Cluster flies are named for their habit of overwintering in large clusters within the attics or upper walls of homes and buildings. They are black and a little larger than house flies, from 3/8- to 1/2-inch long, with short, yellow hairs on the thorax. Their wings overlap when at rest.
Cluster flies are unique because they are parasites of earthworms. In summer they can be seen flying around yards just above the ground. They lay their eggs in cracks in the soil and the eggs hatch in about three days. The newly hatched maggots grab onto earthworms as they slither by and burrow into the worm to feed. The fly completes a life cycle in four to five weeks.



Brown marmorated stink bug (Halyomorpha halys)


University of California

The brown marmorated stink bug (BMSB), Halyomorpha halys, is a pest whose first officially reported appearance in the United State was in Allentown, Pennsylvania in 2001. Adult bugs are 14-17 mm (about a 1/2 inch) in lenght and dark mottled brown. The last 2 antennal segments have alternating light and dark bands. The exposed edges of the abdomen also have light and dark banding. Stink bugs get their name from the scent glands located on the dorsal surface of the abdomen and the underside of the thorax.

Management

Repair torn screens and close up places where the insects can enter the house, such as cracks around doors and windows and attic or basement vents. Use caulk, weatherstripping, fine-mesh screen or expandable foam as appropriate. Overwintering insects that enter the home may be controlled by hand-collecting or vacuuming. Repeat as needed. 

Eliminate hiding places such as piles of rocks, boards, leaves, and general debris close to houses. Rake leaves and remove weeds and grass from a 6- to 10-feet wide strip around the foundation, particularly on the south and west sides of the house.   A weed and debris-free area tends to reduce the congregation of insects near the foundation. 


Additional Information


Cluster Flies - Pennsylvania State University

Boxelder Bug - University of Idaho

How to Identify the Brown Marmorated Stink Bug - Rutgers University

Flies in the Home - Colorado State University Extension

Asian Lady Beetle Infestation of Structures - University of Kentucky

Brown Marmorated Stink Bug - Featured Creatures - University of Florida