How to: help the bees!

An article I saw yesterday about how bees might be harmed by neonicotinoid pesticides reminded me to put up my wild bee house in my front yard.

This is an easy thing you can do at your home to help some of the wild bees in your neighborhood. If you live somewhere with four seasons, early spring is the best time of year to put out a bee house, but you can really do it any time of year, anywhere. Then enjoy watching as bees start to fill it up with nests!

This type of nest will only attract certain kinds of bees called stem-nesting or cavity-nesting bees, but its a great start to your home pollinator protection program. Stem-nesting bees are solitary bees, which means that they don't make large nests like the social bees (e.g. honey bees and bumble bees). 

Honey bee Apis mellifera

Honey bee hives in a blueberry field

Bumble bee Bombus sp.

A solitary bee entering her nest

Solitary bees also don't aggressively defend their nests, which means that they are much less likely to sting you or your family. I made my bee house out of an empty steel can, but any container that is impermeable to water and open on one end will work just fine. Size doesn't matter much either, although it should be at least 15 centimeters (6 in.) long or a little bit longer to protect the nest entrances from the rain. One important consideration is the direction that the nest faces. It is best if the open end or the bee house faces toward the east so that the sun warms it in the morning. However, if its not convenient to hang yours facing due east don't worry about it, the bees will probably still use it. I filled mine with a variety of nesting options to increase the diversity of the bees that will nest there. Bees can be pretty picky about their nesting sites, so if you only have one size nest hole you might only get one kind of bee. Easy options for nesting sites are sections of hollow reeds (e.g. bamboo) or blocks of wood with holes drilled in them. The tunnels for the bees should be about 15 cm (6 in.) deep and anywhere from 3 to 7 mm (1/8 to 1/4 in.) in diameter. If you're feeling really ambitious you can create a bee hotel with a variety of different nesting options.

Now if this post has piqued your interest, I recommend that you look at a couple of fact sheets that were produced by the Xerces society and provide more detailed information on Nests For Native Bees and Tunnel Nests For Native Bees. Good luck and have fun!

Flying scorpion? No.

I'm sure this has happened to you. You're walking along in the woods and you see something black and wispy go by out of the corner of your eye. You naturally think, "Oh, there goes a damselfly, a mayfly, or a crane fly," but when it lands on a nearby plant you realize that its something much more sinister. That happened to me in late September this year and all I could get was this fuzzy photo before it flew away.

Fortunately, I was gardening a few weeks later, in October, and my friend found another one. This time it was not flying because it was probably too cold outside, so I was able to get in close for a really nice picture.

These are pelecinid wasps (Hymenoptera: Pelecinidae) in the genus Pelecinus and they are actually not that sinister...unless you are a june beetle (Coleoptera: Scarabaeidae Phyllophaga). That long "tail" is really just their abdomen, which all insects have. Their abdomen is longer and skinnier than most because they use it to dig into the soil in search of june beetle larvae (AKA white grubs). Once they find a white grub, they lay an egg on it. Eventually the egg hatches and the wasp larva attacks and kills the grub, feeding off of its corpse until it matures.  Then the wasp larva will pupate right there in the soil and emerge next summer as an adult wasp. 

Because of their long curved abdomen, pelecinids do sort of resemble scorpions which has led some people to call them scorpionflies. However, that name belongs to another group of insects in the order Mecoptera, the true scorpionflies. Of course, neither are flies (order Diptera) or scorpions, and scorpions are not even insects. Scorpions are arachnids (like spiders, harvestmen, and mites). Whew, glad we cleared that up. 

Regardless of how scientists classify them, pelecinid wasps attack and kill white grubs, which can be a nuisance to gardeners and homeowners, so we here at Crunchy Segments classify them as beneficial insects. Keep up the good work pelecinids!

Aphids, what the heck are aphids?

I have written about aphids before, but never dedicated a post to them. Aphids are in the insect order Hemiptera. Aphids feed almost exclusively on plants so they fall solidly under the category of pests in the garden. 

Annoying as they may be to gardeners and farmers, aphids are very interesting creatures. 

Aphids often live in colonies where the mother or fundatrix gives live birth to many genetically identical offspring. Most of the time they are just feeding on the phloem (AKA sap) of plants, which is where they get most of their nutrients. 

Individual aphids are fairly sedentary creatures, but every once in a while, the colony produces winged aphids that go off in search of new food plants. Ants will also sometimes carry aphids to new plants (e.g. see this article about the corn root aphid). Ants and aphids sometimes form a symbiotic relationship where the ants protect the aphids from predators and the aphids provide the ants with honeydew. The aphids secrete honeydew as a byproduct of their feeding on the carbohydrate rich but nutrient poor plant sap. For the ants, the honeydew is an important source of carbohydrates (sugars). 

If you have ants tending aphid on a plant in your garden, one solution is to create a sticky barrier around the stem of the plant. This will prevent the ants from protecting the aphids, and the aphids' natural enemies will be able to attack them. Aphids have many natural enemies, including lacewing larvae, lady beetles, and parasitoid wasps.

Flying Tigers

This seems to be the summer of predatory flies. I have written about long-legged flies, robber flies, and now tiger flies (AKA hunter flies). Tiger flies are in the family Muscidae, which is the same family as the common house fly and at first glance they are very similar in appearance to a house fly.

If you look closer at this photo though you will see a very important difference.

This tiger fly is eating an insect that it has just caught. Tiger flies sit and wait on vegetation for a potential prey item to fly by. Then they will take off, catch the prey,  and return to the perch to eat it. This is very similar to the predatory behavior of the robber flies that I wrote about a few weeks ago. 

Tiger flies are interesting also because of their apparent tameness. I was able to get very close to this fly with my camera without disturbing it. One researcher has even developed a technique for using these flies to gather insects much like a falconer uses birds of prey to catch game.

Tiger flies can be very helpful to us in the garden, vineyard, and orchard. They are known to eat economic pests such as leafhoppers, whiteflies, and aphids.

Tree crickets are awesome!

This is a tree cricket (Orthoptera: Gryllidae Oecanthus sp.). 

Tree crickets, like all crickets, are closely related to grasshoppers and katydids (see this previous post for some info on how to tell them apart). You may not see tree crickets as often as some other kinds of crickets because they usually blend in with the vegetation that they hang out on. I was lucky enough to find this one on a pink flower. Tree crickets are very interesting but poorly understood insects. Here is a link to a great website created by an amateur entomologist that is very enthusiastic about them. Tree crickets feed on a variety of things from plants to other insects and even fungi. Some species are more predaceous than others, but they are rarely considered pests in the garden.
Tree crickets hear through special membranes on their forelegs.

Hearing is very important for crickets, because they use sound to find their mates. In tree crickets, the male calls females by chirping with his wings. Once, the female locates a male, they engage in some very interesting mating behavior.

Robber Fly

I caught this robber fly (Diptera: Asilidae) with my camera a few days ago. 

Robber flies are predators of a lot of other insects. They aren't particular about what they eat, if they can catch it they'll eat it. They sit and wait for prey to fly by and then attack them on the wing. 

They kill their prey by injecting them with a toxic saliva. The robber fly's mouthparts fit together to form the proboscis that they use to inject the saliva. Robber flies can be distinguished from other similar flies by the distinctive notch on the top of their heads between the compound eyes. There is a great deal of variation in body shape, size, and color among the species of Asilidae. For example, some robber fly species are excellent mimics of wasps or bees, which helps protect them from predators. Robber fly larvae can be found in the soil or in decaying wood where they feed on the larvae of other insects.
In the garden, robber flies are generally considered beneficial predators of pests. However, they are not picky about diet choices and will sometimes be seen eating other beneficial insects such as honey bees, wasps, spiders, and even other robber flies.

Dance Fly! Dance!

This is a long-legged fly (Diptera:Dolichopodidae), so named because their legs are rather long in proportion to their bodies compared to other flies. 

My friend sent me this picture of one the other day. 

Unfortunately, that one was deceased. 

Long-legged flies are beneficial insects that you have probably seen around your yard or garden this summer. They are predators of insects and other small invertebrates. They are pretty easy to identify since they are shiny green and metallic with very prominent compound eyes and a thinner body than other green metallic flies. You can tell them from green metallic bees by the fact that they only have one pair of wings. I sometimes confuse them with closely related fly family called dance flies (Diptera: Empididae or Hybotidae), because I see them "dancing" on leaves more often than I see "dance flies". Long-legged flies are very fast runners and you may see them scooting quickly around on leaves in search of their tiny prey. Dance flies on the other hand, got their name from the aerial maneuvers that the males perform in mating swarms.

Some members of these fly families have very interesting courtship behavior. For example in some species the male will kill another insect, bundle it up and bring it to a female as a gift. Biologists call this a nuptial gift and if the female accepts it she will often allow the male to mate with her and use the nutrients in the gift to nourish her offspring. Like many insects, they also perform elaborate behaviors that resemble dances during courtship. Here is a video of the courtship behavior of one species that I downloaded from the Dolichopodidae Wikipedia page.

Long-legged flies are one of my favorite insects to see during the summer and I hope that you will enjoy seeing them too! 

Finding a place to spend the winter

Well, its that time of year again. The leaves are falling from the trees in the Northern hemisphere. Some of us are heading South for the winter and some of us are seeking shelter and preparing to hibernate.

Insects are getting ready for winter as well. Some insects overwinter in self-constructed shelters called cocoons.

This cocoon (above), contains a Green Lacewing pupa (Neuroptera: Chrysopidae). Pupa is the life stage between larva and adult during which some insects undergo complete metamorphosis. The Green Lacewing larva looks something like this:

They use those sickle shaped mouthparts to pierce the exoskeletons of their insect prey and suck their insides out. Once they are fully grown and ready to become adults they curl up into a tight ball and spin this cocoon.

The cocoon is made of silk, a material that is produced by most insects and serves a variety of purposes throughout their lives. Once the cocoon is complete, the larva transitions into the pupa stage. Since it is so late in the year, this lacewing will not emerge as an adult until next spring.
This is what a Green Lacewing adult looks like:

As you can see, they get their name from the lacy appearance of their wings.



These Brown Lacewings (Neuroptera: Hemerobiidae) are also getting ready for the winter.

They don't spin their cocoons nearly as densely as the Green Lacewings do so you can clearly see the pupa inside.

Brown lacewing larvae sometimes cover themselves in debris to camouflage themselves from predators. you can read more about this in my previous post, but here is what they look like:

Brown lacewing adults look pretty much like Green Lacewing adults except that they are brown and quite a bit smaller. 

Next spring as the temperatures start to warm, we'll start seeing both kinds of lacewing adults flying around as they search for places to lay their eggs. Hopefully enough of them will survive the winter to help us control those nasty aphids and scales in our gardens next year!

Sugar Fix

I noticed that this trumpet vine (Campsis radicans, Bignoniaceae) was covered with ants the other day. Ants are usually on plants for one reason and that is to get a sugar fix.

Often they are getting their fix from aphids or other herbivorous insects that produce honeydew (see a video here). Sometimes they are getting the sugar from the flowers of the plants in the form of nectar, just like bees, butterflies, and hummingbirds do. You can see clearly in this photo that they are entering the flower's corolla to access the nectar inside. There is, however, another way for ants and other insects to obtain nectar from flowers.

As you can see, the ants are also foraging on unopened flowers and flower buds. This is because trumpet vines, like a surprising number of other plants, produce nectar in special glands outside of the flowers. These glands are called extrafloral nectaries. They are the little circular structures seen here on the calyx of the flower.

Extrafloral nectaries produce nectar that is attractive to a variety of insects, most of which are beneficial to the plant by defending it from its enemies.
The next time you see ants on a plant in your garden don't just assume that they are harming it. A closer inspection may reveal that they are actually defending it. If you see them tending aphids though, there may be cause for concern!

Yikes!

Cute bug?

I saw this Pandorus sphinx caterpillar (Eumorpha pandorus) on a grape vine last weekend. 

These caterpillars belong to the Sphingid family (Lepidoptera: Sphingidae), which includes the infamous tomato and tobacco hornworms. Although the caterpillars are often referred to as hornworms because of the "horn" at the tip of their abdomen, the adult moths carry the more attractive names of Sphinx or Hawk Moth. This caterpillar doesn't have a horn though. Instead it has a thin curved hook and an eye-spot on the tip of its abdomen. As they get older they lose the hook altogether, leaving only the eye spot.

This caterpillar was an amazing dark red color, but I saw others that were a much lighter rusty-orange.

When they feel threatened Sphingid caterpillars often rear up and tuck their heads back, in a motion that is reminiscent of a serpent preparing to strike.

But let's face it. It just makes them look ridiculous and...kind of cute. In fact, I think they ought to be put in the running for cutest bug. Or at least be in the top 10.

Pollinator Pit Stop

I took a break from my bike ride the other day to see what insects were visiting this patch of wildflowers.

Flowers that bloom late in the summer are often teeming with insects. This is an important time of year for them to stock up on pollen and nectar to help them or their offspring survive the long winter.
Many of the insects on flowers have black and yellow stripes, which make them easily mistaken for bees or wasps. This syrphid fly (Diptera: Syrphidae) for example, is a fly, not a wasp, and it couldn't sting you if it tried!

Syrphids are actually very beneficial insects in the garden. They lay their eggs near aphid colonies and when the syrphid larvae hatch out, they devour the aphids one after another.

Here is another fly that could be mistaken for a bee. This is a bombyliid fly or "bee fly" (Diptera: Bombyliidae).

Some members of this fly family are parasites of bees and wasps. They attack their hosts insects by flicking the eggs into their nests. The bombyliid eggs then hatch and the larva eats the host larva as well as the food that the host's mother provided for it in the nest. Its a pretty nasty strategy, but bombyliids are pollinators too, so they're not all bad.

Speaking of pollinators, there were honey bees visiting this flower patch as well.

Honey bees (Hymenoptera: Apidae) are the #1 insect pollinator of our food crops and they are also important for honey production.
Honey bees are not the only bees that pollinate our food crops though. There are hundreds of other bee species that help with the pollination.
This is a sweat bee or halictid bee (Hymenoptera: Halictidae).

They are called sweat bees because of their habit of landing on our skin to drink droplets of sweat. Many people find this irritating so they have a bit of a reputation as a nuisance, but they are important pollinators. They can sting people too, but will only do so in defense and their sting is fairly mild. Next time you have a sweat bee on your arm try just shooing it away rather than swatting it. Sweat bees come in a variety of shapes, sizes, and colors. The green metallic one above, is one of the largest ones in our area (Northeastern United States).
Here is a much smaller one on a goldenrod flower.

As you can see halictids tend to carry pollen on their hind legs. The pollen is held in place by tiny hairs on their legs. They are gathering pollen to take back to a nest where they form it into a ball for their offspring to feed off of while they grow. Halictids usually nest in burrows in the ground, sometimes in large groups. If you ever come across a cluster of tiny holes in the ground with sweat bees bees going in and out you may have found a colony of halictids.
Halictids are just one of the many important bee pollinators of our wild and cultivated plants. I will hopefully get to cover other groups in future posts. You can also follow this link to all of my previous posts about bees. Thanks for reading!

Bee-ka-boo!

Its that time of year again!


The flowers are blooming,

and the bees are hard at work to collect all that pollen!

These bees pack their pollen into little balls and put it in these hollow reeds for their offspring to feed on.

This photo is of a bee habitat made by someone who wanted to attract bees to their garden! If you look really close you might be able to see some bee faces poking out.
Flowers produce two types of food that bees need: pollen and nectar. Nectar is the sweet sugary (mostly fructose) liquid that honey bees use to make honey. Nectar is an important source of carbohydrates for bees and it gives them the energy they need to fly around from flower to flower all day. Pollen on the other hand is the bees' main source of protein.  They feed the pollen to their young to help them grow. If you look closely at a bee foraging on a flower you can usually see the pollen stuck to hairs on their legs,

or underneath their abdomen.

Grasshoppers, katydids, and crickets. Oh my!

Grasshoppers, katydids, and crickets are all closely related insects in the insect order Orthoptera. It can be a little tricky to know which is which sometimes, but one easy way is to look at their antennae. Grasshopper antennae are generally shorter and even when they are very long they don't get longer than their body.

A very young grasshopper

An adult grasshopper

Katydid and cricket antennae are often longer than their bodies.

An immature katydid

An adult katydid

I don't have any good pictures of a cricket, but here is a video of one. 

Another difference between grasshoppers and katydids and crickets is that katydids and crickets rub their wings together to "sing" or chirp.  Grasshoppers rub their hind leg against their wing to "sing". If you are looking for more detailed info here is a good article by Debbie Hadley at about.com. The Orthoptera have gotten a bit of a bad rep due to the infamous nature of a few members of the group (e.g. the desert locust). However, the vast majority of grasshoppers, katydids, and crickets are not economic pests and at worst are just a nuisance. The fact is that not much is known about the behavior and feeding habits of the orthopterans that are not economic pests. They are mostly lumped into the herbivore category, but the amount of omnivory and predation that they do is probably grossly underestimated.