Saturday, September 29, 2012

Black Blister Beetle

This matte black beetle is a Black Blister Beetle (say that fast three times). These beetles are in the family Meloidae. They are quite common around here, especially in the fall. I find them frequently on the goldenrod around our farm. Some plants will have dozens of these beetles on them.Many of them are mating and creating mirror images of themselves for the next generation. With nearly 7500 species of blister beetles found throughout the world there is no shortage of these noxious bugs to be found. 

(This particular beetle seems to have an injury. Not sure what caused it. I can't imagine that anything would chose to feed on these beetles, but perhaps some predators don't mind the nasty taste. Or maybe the predator discovered the noxious taste after biting a wing off and decided that was enough)

 They have an elongated body with a very narrow thorax. This cylindrical shape is very typical of blister beetles. They are commonly found in  vegetable and flower gardens. Look for them near croplands, especially forage crops. The adults feed on a wide variety of foods like clover, alfalfa, soybean, radish, carrot, beans, cabbage. In the wild they will feed on pigweed. They also will feed on ornamental plants like Hostas. The black variety is especially fond of goldenrod. After mating, the females will lay eggs in clusters in the soil. After the larvae hatches it will seek out grasshopper eggs and young grasshopper nymphs that are beginning to surface from underground. Sometimes they will also feed on bee larva. This makes them an important natural control measure for these often time invasive insects. Blister Beetles aren't always the "good guy" however. They have a dark side. Blister beetles contain a chemical in their legs called cantharidin. This chemical is extremely toxic, especially to horses. The horses come in contact with the beetles in their feed. The beetles feed on alfalfa, then the horses also feed on the alfalfa. As few as 550 beetles can kill a young horse weighing 275 pounds. This chemical is also found in the controversial drug called "date rape drug". 

I myself have had a run-in with these beetles. Several summers ago we had 100's of these beetles all over our farm. They were in the gardens, in the flowers beds. They were feeding in large numbers on my hostas, and had nearly defoliated the hostas before the summer was over. At night they were around the pole lights. I also spent a lot of time near the pole lights, looking for bugs to photograph, or capture for my collection. One night I felt one of these beetles land on my neck, as I went to brush it off me it released some of this awful chemical and blistered my skin. This blister hurt for days and left a welt for over a week. These beetles mean business, this is chemical warfare at its finest.

These beetles are best looked at and not touched. They are common and easily found, some years there seems to be more of them, than other years. In the past two years I've not seen populations of them anywhere near like what I had several summers ago

Friday, September 21, 2012

Spotted Cucumber Beetle

Spotted Cucumber Beetles(Diabrotica
undecimpunctata), are small (3 or 4 mm) in size, but bright in color. They superficially resemble ladybugs with those spotted wings, but instead of bright red, pink or orange like ladybugs they are a lemon-lime green. Their head is black as are their legs. Don't let their diminutive size fool you though, these beetles are extremely destructive.They overwinter in leaf litter near fence rows, wood lots and areas near protected buildings. In the spring with the return of warm weather they will become active again. They will seek mates in early spring and the female will lay her eggs in the soil near the base of host plants. When the eggs hatch the young larvae will burrow into the soil to feed on the roots of various plants. It is this activity that has earned them the common name of Southern Rootworm.  After a few weeks they will emerge as adults and it is these grown up beetles you will find in your gardens feeding on the leaves of cucumbers, as well as squash, melons, beans, beets, tomatoes, potatoes, eggplants, cabbage and a host of other garden favorites. 

As adults they prefer to nectar at flowering plants, but will feed on nearly anything they can find. Although it isn't the adults that wreck havoc, it is the wormlike larvae of this beetle that causes so much irritation and expense to farmers and growers everywhere. Their burrowing action damages the root systems of a vast amount of grain crops, especially corn. They are even known vectors of bacterial wilt. Millions each year in crop loss are attributed to these little spotted beetles. There are two other subspecies of this beetle and each are equally problematic to farmers and growers; Western cucumber beetle (Diabrotica undecimpunctata tenell) and the Western spotted cucumber beetle (Diabrotica undecimpunctata undecimpunctata). They aren't typically found in our region, you will instead find them out west as their names indicate. 

As a farmers wife I can sympathize with the farmers in their constant battle to stay one step ahead of an often times unseen enemy. The farmers job is to grow a good healthy crop, and get it to market (hopefully for a profit) so he and his family can make a living. So when these unwelcome visitors make themselves at home in the crops, often times drastic measures have to be taken. All too often this in the form of pesticides. While I am a farmers wife I am far from an advocate of pesticides. All too often they are used in ways that cause more harm than good. Pesticides do not differentiate between helpful insects or harmful insects. So many times the insects that actually benefit us are killed in the line of fire.I will never encourage anyone to use pesticides as I feel the damage they can cause far outweighs the benefits. Often if we will allow mother nature to do her job she will surprise us in many ways. Many other beneficial insects, birds, spiders and other known predators of insects will step up their game and consume the problematic insects. If we spray these chemicals and kill off all our beneficial insects we are defeating our purpose. Approximately 5% of the harmful insects will survive the onslaught of chemicals. These insects will now have a small resistance to the insecticides designed to kill them. They will pass this resistance off to their offspring and within a few generations these harmful insects will have total resistance to the chemicals. Now the chemical companies have to create new insecticides to kill the same insects. We essentially accomplish making the chemical companies richer. Bats, birds and the surviving beneficial bugs will leave your area because it has now become a wasteland of death and there is no longer anything for them to eat.These chemicals leach themselves into our soil and make their way into the water systems, whether that is in the form of ponds, lakes, rivers, or the well water we drink and cook with. What impacts will that have on other wildlife? On humans?

 We have 66 acres of row crops here on our farm. We rotate corn and soybeans each year and we have not used a pesticide, insecticide or fungicide in over 15 years. We have experienced no crop loss due to bugs, because we recognize that there are many insect predators out there taking care of it for us. 

The drought heavily impacted the plants and animals in our region this year. We received early rains, then no rain throughout the summer and some late rain in the past couple of weeks. It seemed to create a perfect situation for these beetles, as I've seen record numbers of these beetles this year. All feeding on the tomatoes and melons in our garden. Thankfully the remaining veggies are not good for human consumption so the bugs can have them.