Friday, October 28, 2016

Widow spiders

Information just in time for Halloween where spider webs and spooky spiders are a common sight.

There are four species of widow spiders found in Texas, with the best known being the black widow.  Coloration can vary, but they are typically jet black with two reddish-orange triangles on the underside of the abdomen, forming an hourglass shape.  The triangles sometimes do not touch each other creating a broken hourglass shape.  Males and juveniles are smaller and often are more colorful, with bright markings on their sides or back.

Females lay eggs in an oval sac which can hold from 25 to over 900 eggs.  Depending on temperature and time of year, eggs usually hatch after about 20 days.  Spiderlings stay near the egg sac for several days where they can be seen consuming their brothers and sisters.  The survivors throw a thread of silk to the wind and are carried off in a process called “ballooning”.  They eventually locate a sheltered spot where they build a loosely woven web and remain for the rest of their lives.  As time progresses, the spiders build larger webs to capture larger prey.  Males eventually leave their webs to find females for mating.  In natural settings, most females do not eat males after mating.

Widow spiders do not like being in the open.  They can often be found outside in protected areas such as rainspouts, shrubbery, firewood piles or unused BBQ pits.  It is also possible to find them in garages, cellars, attics, furniture or electric or water meter boxes.  Widows are shy creatures and often people are bitten when a web is accidentally disturbed.

The bite of a black widow sometimes is not noticed, but when it is, it often feels like a pin prick.  The bite location will have two red marks surrounded by redness and swelling.  The bite reaction is systemic and intense pain usually occurs within 1-3 hours and continues for up to 48 hours.  Other symptoms include tremors, nausea, vomiting, leg cramps, abdominal pain, profuse perspiration and rise in blood pressure.  It is also possible for breathing difficulties and unconsciousness to occur.  If bitten by a black widow, immediately seek medical attention.

When working around the house or in the yard, it is best to wear leather gloves to avoid being bitten by venomous arthropods.

Friday, October 14, 2016

Fun facts about bugs

I'm feeling a bit blue today, so I thought I would do something a bit lighter.  Here are 10 fun facts about insects!

  • Insects are on every continent except Antarctica.
  • The fear of cockroaches is called Katsaridaphobia.
  • Mexican jumping beans are seed pods that have been inhabited by the larva of a small moth and are native to Mexico.
  • Adult ladybugs will eat more than 50 aphids per day.
  • Throughout history, species of biting ants have been used as sutures to close wounds.
  • Blow flies find dead bodies using body fluids and gases; they lay their eggs within 2 days after death.
  • Silk comes from the cocoon of a silkworm (a type of caterpillar).  Each cocoon is made up of a filament around 2000- 3000 feet (600-900 meters) in length.  They use 5-8 of the filaments twisted together to make one thread.
  • Peanut butter can have an average of 30 or more insect fragments per 100 g in it  (see website here).
  • A group of fruit flies were the first animals launched into space.
  • Bed bugs have also been known as Cimex, red coates, mahogany flats and wall-lice.