Mike:

I live in the Rocky Mountains near Loveland, Colorado. I seem to be getting 2 to 3 Western Conifer Seed bugs in my house every day. The “stink” is pretty potent. I have tried everything I know to seal up all cracks and spaces in my log home. I haven’t done anything with my chimney. What else can I do? Thanks, Mike

Picture courtesy of Cornell Cooperative Extention

Unfortunately all you can do to keep these guys out of your house is seal up cracks and gaps around your house. There are no pesticides (not that I would reccommend that anyway) registered for these bugs. You could try screening your chimney. Otherwise it sounds like you are already doing everything that I would have suggested. If it gives you any more peace of mind, they are not harmful or anything

Maybe another reader has some clever suggestions?

Theresa:

“Can we please have the picture of Aphodinae(subfamily) Aphodiini(tribe), Aphodius sp., which has nesting type of a dweller”

I don’t personally have any pictures of that species of beetles, but you can find some here at BugGuide.net. Maybe someone else who reads this blog will want to share some pictures if they have some.

PJ:

“How do isopods differ from insects?”

Well isopods are not insects at all (they are crustaceans), they still belong to the same phylum as insects though.

Just based on morphology isopods have 2 pair of antennae while insects only have one pair. They have simple eyes while insects have compound eyes. They have 7 pairs of legs where as insects only have 3 pairs.

There are some other differences too…but these are probably the biggest differences between isopods and insects from an outward appearance.

Virginia:

I found what looks like an antlion larva in a puffball (mushroom). Any idea what this might be? In a nearby puffball there were numerous spheroids each containing its own small white pupa a little over a mm in length. Any idea what these might be? I collected one of the puffballs and have it in a container and I took some pictures.

To be honest I don’t know much about insects that are associated with mushroom fruiting bodies. But I do know that there are beetles called ‘puffball beetles’. There is a picture here at BugGuide.net of the different life stages, does this match what you saw?

Unfortunately, I have not been successful in finding information about this species’ biology, but perhaps someone else who visits this site will be able to chime in.

Luis:

What goes on inside a pupa?

There are three different types of insect metamorphosis (ametabolous, hemimetabolous, and holometabolous). Insects that are holometabolouss have a complete metamorphosis and go through a pupal stage.

The pupal stage is often referred to as the inactive phase in the insect life cycle because the insect isn’t moving or eating, however, physiologically speaking there is much internal activity taking place. Most internal reconstruction occurs in this stage.

I’ll just stick to the holometabolous insects for simplicity sake. Once the larva molts to the pupa, histolysis (the breakdown of tissues) and phagocytosis (the ingestion of bacteria and foreign bodies) takes place.

During this time (when the larva molts to a pupa) the developing wings, which have been developing internally in the larva, become everted and visible. Reconstruction begins to take place after histolysis, and the adult appendages begin to develop from epidermal thickenings called imaginal buds/discs. The details of the imaginal disc development vary between insects.

The muscular system goes through a lot of modification and the different muscles’ fate can either:

1. Pass through the pupal to adult molt unchanged,

2. Be destroyed and not replaced,

3. Destroyed and replaced,

4. Existing muscles reconstructed,

5. New muscles formed that weren’t previously there (formed by free myoblasts)

The alimentary canal (which is the esophagos, forgut, midgut, and hindgut) is remodeled differently depending on whether the insect eats a different diet as an adult compared to when it was a larva. Generally the forgut and hindgut are formed from imaginal rings, the midgut is reformed by regenerative cells in the epithelium.

The trachea (breathing tubes) shows almost no change, with the exception of new branches. The circulatory system also shows little change during the larva-to-pupa-to-adult molt. The central nervous system becomes more concentrated, the nerve cells and glial cells increase in number.

The control of metamorphosis (i.e., all of this stuff I have been talking about concerning the larva to pupa molt and the molt to adult) is controlled by hormones, including juvenile hormone, and ecdysone.

To escape from the pupal cuticle, hemimeabolous insects swallow air to increase volume and split the cuticle along a line of weakness. The adult pulls itself out, often with the help of gravity, and begins to expand its wings by pumping them. For holometabolous insects, escape from the pupal cocoon is a bit trickier. Different insects have developed different ways to escape, some have mandibles to chews through the pupal case, some have spines on their abdomen that help break through the case as they moved back and forth, and some produce softening secretions that actually break down the case.

Much cooler though are of course the cyclorrhapha flies. They have a structure called a ‘ptilinum’, which is a membranous sac (or basicaly a balloon) that is everted by pumping blood. The balloon presses against the puparium wall and splits the line of weakness.

Picture courtesy of http://entomology.unl.edu

Whew! So, all of that is going on during the ‘inactive‘ stage of the insect.
If you’d like to read a more detailed description, “The insects: Structure and Function” by Reggie Chapman, is the book I used as a reference for this post.

Luis:

I’ve always been interested in biology, so I take organisms in often. One day I brought in a caterpillar, it pupated, and on a dark summer night, I noticed that it was eclosing! I hurried to get my camera, I positioned it, and started taking pictures. Suddenly, without any warning, it’s little shriveled wings started to expand at an AMAZING rate. It was done “inflating” it’s wings in about 3 seconds, and was pretty much able to fly just as fast. Admittedly it was a small moth, with a wingspan of about two inches, but I was still amazed. (I tried to video tape it, but by the time I had switched to the “video” mode, it was done). [Note: See pictures above taken by Luis]

Here’s my question: I rarely get to see my lepidoptera eclose, so what would you say is the average span of time in which lepidoptera (or other insects) “inflate” their wings? Thanks!

Many people may be unaware that this behavior (wing pumping) takes place. So what happens is, as the butterfly or moth emerges/ecloses from their chrysalis, it must enlarge its new cuticle and expand its wings before the epicuticle hardens. See, when they emerge their cuticle (insect ’skin’) is very soft and the insect is very vulnerable, which probably explains why most people do not see this behavior take place because the bugs tend to hide. The insect pumps up its wings by swallowing in air and forcing hemolymph (insect blood) into the wings. Supposedly, if you cut the tips of the wings off of a dragonfly once it has emerged, hemolymph will drip from the tips as it pumps its wings, and as a result the wings will never expand completely.

What is the average span of time in which leps “inflate” their wings? Honestly, I don’t know of a very academic answer to provide because I think it is highly variable, depending on the environmental conditions, pre-programmed motor output, hormones (i.e., busicon, a cuticle-hardening hormone) among other things. For example, you noted that it only took about 3 seconds, but in the tobacco hornworm I think they have documented that it takes about 30-75min for wing expansion. Experiments performed by Truman and Endo (1974) showed that if you decapitated a tobacco hornworm as soon as it eclosed there was no wing pumping. But if you decapitated the moth 5 seconds after emergence the moth continued wing pumping. Similarly, if you cut off the abdomen the moth still continued to pump its wings. Injections of bursicon into moths who had their abdomens cut off showed a reduced amount of time in wing expansion. So the authors determined that bursicon had some role in the termination of wing pumping.

Image courtesy of eNature.com (John Coffman)

I’m sorry I can’t give a better, more conclusive answer. Perhaps another reader will have more insight into this and will comment.

Neshan:

Can June bugs see? Why do they crash into things, etc? My friends and I cannot figure it out or find it on the internet.

Image courtesy of bugguide.net

“June bug” is a common name given to the beetles (mostly of the genus Phyllophaga and Polyphylla) in the Scarabidae family. They are a well known insect and can be seen bouncing off screens and porch lights in early summer.

They can indeed see (note the compound eyes in the picture above). In fact, that is why most people see them at night around their porch lights…because they are attracted to light. It is probably fair enough to say that their sense of smell is better than vision. Their antennae are quite distinctive, they are club-shaped and made up of plates (lamellae). The antennae can be folded in together (as in the picture above) or fanned out. (Note: In the picture above, the antennae are the big, orange-ish structures that might be mistaken at first glance as the first pair of legs.)

So, why do you always see them bumping into things? Well, as a general observation, beetles are fairly clumsy fliers. In that respect, june bugs kind of remind me of myself on rollerblades…once I get going, I pretty much need to just roll smack-dab into something in order to stop or slow down

K. Downz (a.k.a., my baby sister):

Why the heck do we have bugs? They’re gross, they’re hairy, they’re ugly, and they are just plain annoying!!!!

Haha, well unfortunately a lot of people share the same sentiment towards insects. A lot of our ill-conceived notions and even phobias of insects come from 3 main reasons.

Are insects all that bad and deserve the reputation they have?? Nope. At least not in my opinion. They are hairy and “ugly” for functional purposes, not as a scare tactic, per se. The hairs are actually sensilla, or sense organs, and help relay information from the environment (tactile, olfactory, auditory) to the insect’s central nervous system. I don’t know that I have ever seen an ugly bug, but the big eyes, big jaws, the spines and horns…all functionally based (i.e., better hunting, protection, and camouflage).

As far as insects being annoying and pesty, well, they are just going about their business. Trust me, they waste no time playing…each day is about finding food, finding a mate, producing offspring, and making it to the next day. Most insects really can’t even harm you. We would be very much out of luck without insects carrying about their daily routines as pollinators of most of our crops and plants or decomposers of decaying animal and plant matter. Insects serve as food for many animals and even many human cultures, past and present. So without them, many food chains would collapse.

We need insects, despite whatever fears they evoke in us.