Right after identifying the Mexican Bean Beetles, we were introduced to their larvae who decimated half  of our Jacob Cattle Beans plants in a day.

To protect our other bean plantings, we immediately harvested all of the beans, cut off all of the plants at the root, and composted them.

This what our plants looked like before we cut them down…

More information on these pests can be found here…

Today two new beetles showed up on our beans.  They look a lot like lady beetles (beneficial), however their arrival coincides to some significant leaf damage.  Are they here to save the plants from some unseen threat or are they themselves the ones to blame?

According to Avant-Gardening they are most likely the culprits:

MEXICAN BEAN BEETLE
These are related to ladybugs but are not beneficial. The adults have sixteen black spots on their back and the Larvae are fat, spiny yellow grubs 1/3 inch long. Both feed on foliage, leaving plant leaves a skeleton of veins. Adults overwinter on plant leaves, in late spring or early summer lay clusters of yellow eggs on the undersides of leaves, and there can be one to four generations a year depending on different climates.

More information from North Carolina Integrated Pest Management Information.

For now, it seems we will have to settle for picking them off and destroying their eggs.

Today when we arrived, we were panicked by the sight of one of the corn stalks covered in these black insects.  They leaves and tassels were ensconced in these little black aphids.  Strangely, out of the entire block of corn, it was only one plant that was infested.  There are far too many to pick off.  The debate quickly turned to whether we should cut the entire plant and remove it, spray, or just wait and see.

A bit of research revealed:

Aphids do not interfere with pollination unless most corn tassels are heavily covered with aphids and their honeydew secretions. Feeding by large colonies of aphids can reduce yields significantly. Aphid colonies can slowly kill the tassel and top few leaves of a corn plant. The plant responds by shunting nutrients to the feeding area and not to the developing ear, resulting in stunted ears or even barren plants. ( read more )

Further observation also revealed that they were not spreading.  After a few days, the population reduced dramatically and the plant seems no worse for wear.  It will be interesting if the yield is affected.  It appears the worst case would be that we lost 2-3 ears of corn.

As cute as this little guy looks, he is bad news.  They are tiny – about the size of a grain of rice – and chirp like a cricket when threatened.  A small colony has taken up residence on our potatoes.  They appear harmless and so far the potatoes don’t seem to be adversely affected by them.  However, they are here for leaves.

Rutgers University offers a free guide to the Three Lined Potato Beetle here.

Management of Three-lined Potato
Beetles:
1. Hand picking of eggs, larvae, and adults is effective but difficult due to their size and activity. Eggs may be difficult to find, and adults and larvae can migrate large distances, even across rows to other plants. Also, they will readily climb back up the plant and resume feeding if just knocked off and not destroyed.
2. Floating row covers, cheesecloth, or other similar materials are an effective barrier to the beetles while the plants are small. However, these materials can be expensive and are generally not economically justified.
3. Because damage is sporadic and population levels seldom reach economic levels, pesticides are usually not necessary for this pest. However, if an insecticide is used, obtain thorough coverage of foliage to ensure adequate control of both adults and larvae. Pesticides used for other insects, such as the Colorado potato beetle, are also effective against the three-lined potato beetle. Read and follow all pesticide label directions, restrictions and precautionary statements. Days to harvest after last application varies depending on crop and pesticide—refer to label for appropriate time intervals.

Public Enemy #1: The Colorado Potato Beetle

Unchecked,  these guys have are able to strip entire potato plants a couple of days putting the plant into irreversible shock.  Incredibly efficient eaters, the only thing with which they are more industrious is reproducing.

They lay yellow/orange eggs on the underside of leaves.

If given the chance, they hatch into these horrible looking larvae:

The best defense?  Hand picking off the beetles and larvae and squishing the eggs on sight.  At first I was squeemish about it, but after seeing what they did to our potato plants a couple of years ago it was all out war.  There are several insect predators.  Most garden centers sell products containing “Bt”, the bacterium Bacillus thuringiensis.

The Bt toxin dissolve in the high pH insect gut and become active. The toxins then attack the gut cells of the insect, punching holes in the lining. The Bt spores spills out of the gut and germinate in the insect causing death within a couple days. University of California.

This year, they seem under control.  The potatoes have full leaves and flowers are blooming.  So far, picking has been the best method.