Sri Lanka Weevil

On a recent visit to Florida’s Manatee county, this poor Crepe myrtle was brought to my attention.

A branch from a crepe myrtle eaten up by the weevil

The owner of the plant said that white insects were found on it. Sure enough in a few seconds of searching, a white weevil was found. Here you can see him pinned down for a really awful picture.

The perpetrator pinned down on the countertop by a shish-kebab skewer. They are not much for flying away.

After a few minutes search on the internet, I think this insect is probably the “Infamous” (heh-heh) white weevil from Sri Lanka. As one of the many invasive insects coming into the USA each year, this one is without natural predators or diseases and has been increasing in Florida and other places. This insect has a very wide range of plant hosts so it will probably be successful all over the place. It seems to eat everything and the kitchen sink. Unfortunately, it seems to eat citrus plants which will cause Florida some problems. Obviously, it likes Crepe Myrtle too.

I do not know anything about this insect in particular since it is a relatively new import, but I know about a cousin of it, the Black Vine Weevil. I can tell you about its life cycle and how nurserymen have been handling it.

The Black Vine Weevil is primarily a root feeding insect. Most of their lives they exist as immature grubs that eat roots of susceptible plants. They overwinter in the soil, moving downwards as the soil temperature drops in the fall. After winter, they warm up and rise shallower and shallower in the soil until they are just under the surface by spring. Here they pupate and turn into adult beetles. If you are a curious human, your best bet is to find them in the shallow soil or leaves on top of the ground. The Black Vine Weevil is nocturnal in its adult form.

The adults emerge when the weather turns warm and they begin to feed on the foliage. All weevils have a snout with a little mouth at the tip. It is characteristic of the Family. The little mouth chews a smile shaped bite out of the leaves of its host. You can pretty easily look at a weevil-eaten leaf and say it was done by a member of the Weevil family. The only other insect making even close to this feeding pattern is the grasshopper and their feeding is quite rough-looking in comparison. Anyway, the feeding damage occurs at night and is sometimes quite heavy. Our little friend on the Crepe-myrtyle make a big mess of the leaves. In the day, weevils of the Black Vine type sleep down in the shade under the plant. That is where I found the Sri-Lankan one too, so it may be nocturnal also.

Something very strange occurs with the Black Vine weevil. There are no males. Only females exist. Females spontaneously create parthenogenic eggs and lay them in the soil under host plants. I do not know why they never have any males, but there it is, ladies. A species of complete feminists for you. I am not sure how common this is in weevils but there are a few other insects that do this durung certain times of the year, like aphids. I do not know of any other completely female species, but, like I always say, I don’t know much.

As far as control, they Black Vine Weevil can be treated by dosing the soil around the affected plant with a water can full of pesticide. This is best done in early summer as you notice the first little bit of adult notching on the new leaf growth. Then spray the foliage once per month during the summer. The first drenching in the soil will kill active grubs that are root-feeding. Then the adults eating the leaves get knocked off from their lunch. If you are into this sort of thing, you can easily flashlight your way around the garden at night and hand-pick hundreds of them. They are slow and non-flying. Hand collection is not a good control measure because they hide in the shadows and are pretty sneaky. Weevils also walk into homes pretty frequently on cold nights. They come in and get lost and never get out. If you have weevils in your foundation plants, you will probably find a few lost in your garage!

Are there Moles in Florida?

“Are there moles here?” I once asked as a child visiting my Grandma in Florida. My Grandpa over heard us and immediately saw a teachable moment. He offered to show me a real mole. What kid could resist? Out we went to the backyard with shovels and visions of cute beaver-toothed hamsters in my head. As soon as we got out there a couple of other-people’s Grandpas came over to help with the search and some tentative digging ensued. Confused, I dug in and chunked out a huge shovelful. I examined the spadeful of soil for big game. Another chunk out of the grass. And another. “Not so deep!” the Grandpas exclaimed in unison. I was deeply confused. I was going for a six inch long animal about the size of a slicked down chipmunk-squirrel. Something like this:

A horrible vicious beast, all rubbery whiskers and spade-like paws

The Grandpas were picking around so tentatively, I thought they were nuts. “Ah, here is one” one of the Grandpas declared and held out his hand.

Really?!? Is that all you got? That thing is just a CRICKET!

I was kind of angry that a bunch of Grandpas did not even know that a mole was a furry mammal that was like a subterranean squirrel with interesting rubbery nose things and were trying to trick me with a joke of a big grasshopper. As you can see, I never quite got over it. In hindsite, I can see they were talking about creatures they referred to as “moles” in their neighborhood and really had no idea what a real mole was. I remain appalled that the Average Grandpa had so little knowledge of insects/moles/mammals vs. cold blooded beasts. Was the public school system so bad in their day that they really got these things mixed up? Sigh.

For all you gardeners out there fighting real moles, here is a link to the Extension Service. They never get mammals and insects confused.

http://edis.ifas.ufl.edu/uw080 link to the Florida Extension Service’s info on moles in lawns.

Stinkbugs

Infamous recently traveled to the Garden State, New Jersey, for a family get-together. It was not too long before I saw my first stinkbug flying around. My relatives told me the Marmorated Stinkbug Halyomorpha halus, has become a pest to crops and homeowners in new Jersey in 2010. The stinkbugs were so prevalent in the fall, they congregated on the sunny exterior walls of the house sunbathing. As the weather became cooler, they infiltrated into homes and come flying around lazily even in winter.

This is not too different from ladybugs and many other casual home invaders. They come seeking shelter as winter closes in. Some species come in by the thousands and have to be vaccuumed up. The stinkbugs were found all aver the window sills making quite a mess.

Stinkbugs as a group are members of the true bug family, the Hemiptera. The word Hemiptera means half-wing in Latin. They hold the wings over their back in a characteristic crosswise fashion, making the appearance of an “X”. Their wings are half heavy leathery upper parts and clear, veined lower tips. They usually have a broad shoulder look to the collar behind the head. Once you see a few examples of insects in this Order, it is easy to classify Hemiptera whenever you see them because of the big “X” on their backs.

This particular species is an exotic import from China and was first found in Allenton, Pennsylvania in 1998. Rutgers University first trapped some in 2000, so they are successfully spreading. In Japan and China they are responsible for damaging soybeans, corn, green beans and many types of fruit. They have a piecing mouthpart that pokes into the plant and allows them to suck juices out. They make numerous tiny holes all over the plant they are feeding on and cause damage to the fruits especially by wounding the ripening fruit. So far this insect has spread into several states on the east coast and seems destined to keep going across the country.

When an insect comes to our country from another environment, it leaves behind the natural checks and balances that keep it under control in its home. The diseases and predators that attack it either are not present in the new home or need several years to ramp up their levels to control the population. Apparently in its native country several predatory spiders, wasps and other insects are known to feed on them.

This story is just another reminder that imported goods from other countries may harbor hitch hikers that can cause damage to our agricultural crops. Good shipping practices are essential to avoid scenarios like this.

Woolly Aphids

Our pest today is an unusual version of a common insect. Most people know what an aphid looks like. They are soft bodied tiny insects that suck plant juices by inserting a pointed snout into the plant. They are very common in most gardens. Colonies of mothers and daughters are fairly well known on the new growing tips of plant shoots like roses. One other kind of aphid that is not so well known is the woolley aphid. They are called woolley because of a white waxy covering on their backs that keeps them protected from the elements. When giant colonies of these insects cover twigs it can look like the branches are coated with snow. When you take a closer look it is appalling how many thousands of individual insects are attacking the plant and sucking plant juices. The branches can be overwhelmed and dry up and die. This is a picture of a fine big colony attacking my ornamental cherry tree.

The white stuff on these branches is wall-to-wall insects attacking the twig.

Although I may have been a little late discovering what was going on, they have now all been sprayed with Orthene insecticide. I hope they are incapacitated and I will not lose this branch.

Bee’s Genetics

Bee genetics

One of my favorite people is taking genetics in school now. That class can tell you some weird biology. One of my favorites is the fun facts of bee genetics and sex. Bees live in a social colony with only one queen laying eggs. The workers scatter throughout the hive taking care of it.  They fly out gathering nectar and pollen to provide for the members of the hive. Workers are aptly named because they do all the work and the queen does nothing except have babies (eggs). The queen has a full complement of chromosomes, 2X. One X comes from her mother and one X comes from her father. She has 2x and when she is ready to mate, as in all most animals, she makes eggs by meiosis which are 1X. She needs a mate to supply the other half of the chromosomes, (1X) . Where does her mate come from? Well, from the previous queen usually. When virgin queens fly out of the hive on mating flights, they are looking to mate with a boy bee called a drone. The queen only flies and mates once for her whole life. She then stores the sperm in her body and uses a little at a time as she cooks up eggs that need it. She only lives a year or two, but that is still some impressive longevity for an insect. As she uses up her stored sperm, workers are created. The egg has half the chromosomes and the sperm has the other half. The fertilized eggs grow up to become worker bees. They stay worker bees unless they are fed royal jelly as infants by the workers. So the queen and the workers are both genetically diploid organisms. Now for the males. The queen makes males when her supply of sperm gets depleted. Her eggs are 1X and if they are not fertilized by any sperm, she lays them anyway as 1X organisms. In insects, 1X, or haploid organisms occur sometimes. These are the drones or boy bees. The guys are only made of half the normal chromosone number, so when they make sperm, they do not do meiosis or reduction division, they just do gametogenesis by mitosis, or regular cell division. When the queen begins laying drones, the workers take a cue and start making a bunch of new queen cells because they know the end of the current queen is near. The new queen cells grow and hatch. New queens must fly and mate before they can lay eggs. One hive may produce numerous new queens who either fly away and make a new colony or fight with each other for dominance of the current colony. Summary: Queen=2x, make eggs by meiosis. Eggs=1x Drones=1X, make sperm by mitosis Sperm=1x Eggs 1X+sperm 1X =2X workers= BEES! Cool genetics, huh?