Re: What are the purpose of June Bugs?

Jack,
June bugs, or also called 'May beetles' are a type of beetle called a 
Scarab beetle (related to dung-rolling beetles). They are sometimes called 
'humbugs', and I have often wondered if the chunky striped candy called 
humbugs was given that name because they look similar. This nickname is 
perfect because they are so heavy that their wing coverings make a buzzing 
or humming sound when they fly. 
June bugs spend the winter as white grubs buried in the dirt with the roots 
and grass debris they like to eat - and in the spring they pupate and 
become adult beetles. They emerge from the soil when the temperatures 
(and light conditions) are high enough for them to become active - which 
will be the same for all June bugs in the same immediate area. Which is the 
answer to part of your question - they appear earlier in your area (Texas), 
because springtime temperatures must be reached in April. So the 
name June bug does not seem right - these beetles must have been 
originally named by someone living in a climate where they did not appear 
until later in the year. 
Your observation that they all seem to come out and die in one night has 
already been partly explained above, by the fact that they all wait for an 
ideal temperature to emerge from the soil. This can also benefit them by 
increasing the likelihood that they will run or fly into other members of 
the opposite sex in that area at that time. They probably emerge at night 
to prevent from being eaten by predators before they can mate. It may also 
prevent any one individual June bug from being eaten - because any 
predator has so many others to choose from right then. I am curious to know 
if the humming sound they make (just trying to fly) might also help them to 
find a mate in the dark. Things that make you go Hmmm....
Compiled in consultation with Rodney Hallum, Entomology Technician, 
University of Western Ontario, Canada.
-Neala MacDonald