Monday, August 29, 2016

Velvet Ant

Velvet Ants in the family Mutillidae are commonly found in August and September as they erratically crawl around on bare spaces in pastures, fields, yards and other areas where grass is sparse or nonexistent. There are 3,000 known species found worldwide, and most are easily recognized by the ant-like female. She is covered in dense hairs, in either reddish-orange & black, gold, black & white or yellow. They get their common name from their resemblance to ants. They are not ants at all, but wasps. They do have a somewhat constricted waist like ants, but they lack the curved antennae of ants. These wasps also possess something that the majority of ants do not, a very powerful stinger. Many species of velvet ants have a stinger that is half the length of their body. It is tucked underneath out of sight and only brought out when mishandled or provoked. These wasps try to avoid confrontation, but if mishandled they will sting and it will be an experience you won't soon forget. This painful sting has earned the species pictured here, Dasymutilla occidentalis, the nick-name Cow Killer. The name comes from reports that the sting is so horrible it could kill a cow. Obviously this is an exaggeration, but still we should respect anything that is reportedly so foreboding that it carries the moniker of Cow Killer. Thankfully they're not super defensive or prone to aggressiveness                                                                                                                  
Males do not look anything like the females. They have black-brown wings that the females lack. They do not possess stingers, but that doesn't deter them from attempting to defend themselves with a stinger-like projection on their gentalia. I suppose a penis-poke that feels like being jabbed by a straight pin would cause a person to drop him in a hurry. 

The male and female pictured here were found in Branson, MO. I spotted the female first as she was walking in circles on a leaf next to a walking trail I was on. I stopped to watch her and take a few pictures and tried to figure out what her odd behavior meant. Then I spotted the male nearby. When the male would come closer to her she would bob her abdomen up and down as if to attract the males attention. He seemed quite interested in her. I am assuming she was somehow releasing pheromones which attracted this male that was in the vicinity. Not sure what the abdomen bobbing was all about, but apparently shaking your booty brings the boys. 

Every time in the past when I have tried to photograph these wasps it has proven impossible. They are quick and always on the move. This female sat still for seconds at a time which allowed for a few quick pictures. The male on the other hand never stopped long enough to manage a decent, clear image. 

Velvet Ants are not colony wasps and do not create hives, nests or burrows. After mating, the female will seek out the nest of solitary wasps or bees, like bumble bees, and enter the nest and lay an egg on larvae therein. The newly hatched velvet ant larvae will burrow into the larvae of the bumble bee (or other host) and feed on the innards of the unfortunate victim until they are ready to pupate. Pupation will take place inside the burrow of the bumble bee or other host. The larva that was fed on will not survive. 

These wasps rarely occur in large numbers and are usually encountered randomly. I've only found 5 or 6 of them in the last 10 years. I am fascinated by them, but careful to never try and handle one!



Tuesday, August 9, 2016

Colorado Potato Beetle

Colorado Potato Beetles (Leptinotarsa decemlineata) are endemic to Colorado as well as a few neighboring states where they feed on native plants in the genus Solanum. These include horse nettles and nightshade. With the expansion of potato, tomato, and eggplant crops these beetles made a natural jump from their native host to these cultivated, garden favorites in the same genus. With this expansion in the cultivation of food crops in the genus Solanum this beetle also expanded it's reach and now can be found throughout much of the United States and parts of Canada.

They are considered to be a serious pest of potato, tomato, eggplant and pepper crops and their feeding habits can drastically reduce yield or even kill the plants. Because of this potential harm to food crops people are often dependent on insecticides to control them. Unfortunately, this beetle shows an extraordinary ability to develop resistance to insecticides developed to control it. This falls in line with what I have been saying for years and have mentioned numerous times in various posts on this very blog. Insecticides only work for a short period of time, before the insect you are targeting develops resistance and passes that resistance onto their offspring. Within a few generations they will have nearly complete resistance to the chemical cocktail and your spray will have no ill effects on them. Then you have the added concern of the spray you are using causing the unintended death of beneficial bugs like bees, butterflies and ladybugs. Insecticides are not pest specific. They routinely kill all insects they come in contact with. Care should always be exercised when using insecticides, and always follow the directions to the letter. Using more than is necessary causes more harm than good and can actually cause the resistance to insecticides to be exacerbated exponentially.

Larva feeding on potato
CPB overwinter as adults and become active again in the spring when the temperatures warm up. They will feed on weeds, volunteer potatoes and other volunteer plants within the genus Solanum. About 3 or 4 days after feeding they will mate and within days of mating the female will begin laying clusters of up to 24 eggs on the underside of the leaves of the host plant. I've read differing accounts of how many eggs they can produce in their short window of 4 to 5 weeks of ovipositing. Some say 400-500 and still others claim they may lay up to 800 eggs. Whichever number is correct, they obviously lay a tremendous amount of eggs and are quite adept at populating an area where food sources meet their needs.  It takes up to 9 days for the eggs to hatch, depending on how warm the temperatures are. Within 3 weeks they will burrow into the ground to form a pupal chamber and remain there for up to 10 days before emerging as adults. These new females will feed for a few days and seek out mates and the cycle begins again. There may be up to 3 generations per year. With such prolific reproduction it is no wonder there are so many and they can quickly become pests.

Colorado Potato Beetles are also known by other names such as Potato Beetle, Ten-lined Potato Beetle, Ten-Striped Spearman, and Colorado Beetle. They measure up to 1/2 inch in length (or 30 mm)....and their wings are yellow-orange with 10 dark brown stripes. They are often confused with the False Potato Beetle. The false potato beetle has a distinctive brown stripe down the center of their wings. The false potato beetle and the Colorado potato beetle are not able to cross breed. The Colorado potato beetle is the only one considered a pest.

We are familiar with unwanted 6 legged invaders in the United States that have made their way here via cargo shipments from other countries. Think Mutlti-Colored Asian Lady Beetle, or the Japanese Beetle, and a whole host of other destructive little blighters. The Colorado Potato Beetle is native to the US, but has spread it's reach to include Asia, and Europe. It is spreading exponentially and could end up in northern Africa, as well as Japan and other nearby countries sooner rather than later. With so much travel and trade taking place across all borders and with so many different countries its no wonder the entire World experiences an onslaught of 6-legged menaces. Truthfully it's a wonder there isn't more of a problem than there is.

If you find your garden being invaded by this hungry little bug it can be very frustrating. There are options available for organically controlling it, or you can manually remove them from the leaves. Rotating the area where you grow your crops each year can also help control them. Just keep in mind any chemicals you use may not work long term as they are notorious for building up resistance to most all chemicals designed to kill.