Gardening 101 - Part Three : Good Bugs vs Bad Bugs and Common Diseases

In the last installment of Gardening 101 we discussed soil profiles, compost and germination. So now your garden is growing, you have flowers all over your plants and even little fruits here and there when suddenly you spot a huge hole in a leaf on your eggplant, you lean in a little closer and OH MY GOD THAT IS A GIANT GRASSHOPPER. It is easy to see a bug in your garden and get spooked or totally grossed out but learning about what insects are visiting your garden is not only a great way to work on those phobias but it's also a great way to quickly spot problems and beneficial insects can even help you increase your harvest! Insects do a multitude of different things for our environment; they pollinate our plants, areteriate the soil, break down waste and serve as food for wildlife. Today we will discuss non-beneficial insects and beneficial garden insects as well as common diseases that may be plaguing your garden!

Bad bugs and creepy crawlies!

GRASSHOPPERS. Grasshoppers consume approximately one-half of their body weight per day so they can easily decimate an entire crop in one evening . Both adults and nymphs cause damage by chewing on the leaves and stems of plants, and if infestations are severe, may defoliate entire fields. 

Adults (1-2 inch long) are brown to reddish yellow or green in color with prominent jaws, fully developed wings and short antennae. They have enlarged hind legs and can jump great distances. Immature stages — nymphs — are similar in appearance to adults, but are smaller and have wing buds instead of wings. Control: Row covers are the best defense against these pests, I found they only attacked my garden at nighttime and that was also the best time to find them chewing away. Garlic spray and garlic plants are also good deterrents to put in place to ward off grasshoppers. You can also dust the plants with all purpose flour, this gums up the grasshoppers mouths preventing them from eating. 



APHIDS. Aphids are small (1/8 inch long), soft bodied, pear-shaped insects that may be green, yellow, brown, red or black in color depending on species and food source. 
They tend to group together toward the base of the plant and on the underside of leafs as pictured left. Aphids secrete a a sticky fluid called honeydew as they eat your plants. This fluid drips onto plants, attracting ants and promoting mold growth on leaves. 
Control: Pruning off affected areas of the plant is an effective removal method if you've found them before the infestation has gotten bad. Another effective method is to turn your hose to its strongest setting and blast the plants with water, follow up with a soap spray and repeat as necessary every few days. Ladybugs also love to pest on this common pest.

FLEA BEETLES. These bugs cause damage to plants by chewing  small holes in the leaves, which make them look as if they have been shot with a buckshot. They feed most on hot sunny days and attack a wide variety of plants, most plants actually.
Adults are small brown or black beetles with large hind legs that allow them to jump when disturbed much like the common house flea. Flea beetles transmit viral and bacterial diseases so wear gloves when tending to the pest and shake off clothing before entering your home. 

Control: The best way to eliminate these pests is with food-grade diatomaceous earth, this is a nontoxic compound that scorches the body the beetle as it crawls through the fine powder - you can also use this on household fleas and most beetle type pests. Row covers and sticky traps are also very effective in protecting plants from this pest.

SQUASH VINE BORERS. If one day your squash is suddenly wilted and limp, you might have some of these pests in your garden. Larva overwinter in the soil and can work their way into your plants stems, alternatively the adult moth (pictured left) will lay eggs at the base of the plant.
The adult is a moth about ½ inch long that looks a bit like a wasp with a black body, marked with orange-red. The hind wings are transparent and the front wings are metallic green. If you slit open a stem lengthwise with a sharp knife, you will see the borer larva. It resembles a maggot with its fat, white, wrinkled body and brown head; it can grow to about an inch long. 

TOMATO HORNWORMS. Don't let their name fool you, these little jerks will destroy much more than your tomato plants - they also feed on peppers, eggplant and other soft leaf fruit bearing plants. Unfortunately most gardeners don't realize this pest has made its way into the garden until they find a large patch of damage, these guys eat fast. Tomato hornworms are the caterpillar stage of the Sphinx moth (the same type on the cover of Silence of the Lambs) so if you see these moths fluttering around your garden - take action immediately! The caterpillars are 3-4 inches long,  they are green with seven diagonal white strips and a black or red horn projecting from the rear.  In their moth stage they are large (4-5 inch wingspan), heavy-bodied moths. They are gray or brown in color with white zigzags on the rear wings and orange or brownish spots on the body - they fly quickly and are able to hover like a hummingbird over flowers and plants. 

Tip from PlanetNatural: To find the larvae hidden among plants, look for black droppings (frass) on the leaves and ground and spray the foliage with water. The caterpillars will thrash about and give away their hiding spots.

Control:  The best method for removal of this pest is to simply pick it off your plants and either crush it by hand or toss the caterpillars into a bucket of soapy water. (If you have chickens, they love these as a treat!) A very effective caterpillar killer is bacillus thuringiensis (marketed as BT), this organic compound usually comes in powder form and you simply sprinkle it over the plant - however this kills ALL caterpillars and not just pests so if for example you have some lovely monarch caterpillars on your milkweed make sure to keep BT very far away.
My favorite method for dealing with this pest is, we will go into more detail on these wasps in the benefinical section of this article, to use these for prevention you release them early in the the season. The wasps lay their eggs on the hornworm which then feed on the insides of the hornworm until the wasp is ready to pupate, when the wasp bursts from inside the hornworm they will seek out other hornworms to infect and kill. So if you see a hornworm covered in little white bumps (photo right), do NOT kill or remove it from your garden - let the wasps do what they do best! 

Good Bugs! 

BEES. These little guys are easily the most important insect on the planet earth,without bees to pollinate we wouldn't have any of the fruits or vegetables we love so dearly. There are over 20,000 different species of bees in the world and each region has a host of different species native to their area. Bees live in colonies called hives and can fly as far as 2 miles (3 km) from their hive to collect pollen though some beekeepers have seen their bees as far as 4 miles from the hive foraging. 
The honey bee is responsible for approximately 80% of the pollination of fruits, nut, grains, and vegetables in the United States today. Honey bees are not native to North America; they were brought here by European settlers in the colonial days to pollinate their crops and for the products created or gathered by the honey bees-honey, propolis, royal jelly, pollen, and beeswax. Some plants to help attract bees to your garden are; lavender, sage, thyme, mint, sunflowers, rosemary, chives, beebalm, basil, catnip and any other herb or brightly color flowers.

LADYBUGS. These brightly colored insects are every gardeners favorite, instead of feeding on your crop ladybugs feed on aphids, mites, the eggs of pest insects and other various small soft-bodies creepy crawlies. You can buy live ladybugs at almost any organic gardening center or you can order live ladybugs offline for usually less than $20.00 - generally they come in a plastic or cotton container filled with hay, woodchips or straw and to release them into your garden gently shake them loose during a time of day when pest activity is high (usually early morning or early evening as the sun sets), if you are lucky they will thrive in your garden and lay eggs and continue to act as pest-control. Ladybug eggs are bright yellow balls clustered together on the bottom of a leaf or near the plants stem, their larva and pupa are brownish black with yellow spots - leave them be! 

Note from PlanetNatural: Larvae will eat approximately 400 aphids prior to pupating. Adults will consume more than 5,000 aphids during their lifetime. 

What is a Asian ladybug? These are pest insects that are cousins of the common ladybug. It can be hard to tell the difference between the Asian ladybug and beneficial common ladybugs, they are very similar in color though Asian ladybugs have a wilder variety of color in all shades of yellow to orange to red, if you look closely, you will see the Asian lady beetle has a white marking behind its head in the openings of what looks like a black M. Some also have dark black spots like common ladybugs, but  on many their spots are very light or they have none at all. 

During the 1980-90's the USDA released a very large amount of these Asian ladybugs in Southern United States and they reproduced and spread like wildfire. Unlike common ladybugs these Asian beetles can and will occasionally bite humans. These pests also like to find their way into your home and hide in cracks, crevices, drawers and pretty much anywhere they can fit which is everywhere - it is important to avoid smashing them if possible, they release a gooey yellow substance that smells fowl and will attract more Asian ladybugs, some people also are allergic to this substance and can have mild to severe reactions from hives to asthma attacks. 

Here is a fun story from my personal experiences with Asian ladybugs; back in my teenage years, I went on vacation to North Carolina with my then (now ex) boyfriend and his family. His family owned a small cabin up in the smoky mountains and to get to the cabin you must drive up the mountain it's settled on at a 70 degree angle (or at least it felt that way!) all the way until you reached a large gate, it wasn't until you walked around the cabin to the front porch, which all but sat hanging off the side of the mountain, that you realized how high up and tucked away you really were. The cabin was beautiful, wild blackberries grew along the sides of the mountain and when it rained you could watch the dense puffs of steam rise off the mountains, at the time the inside was mostly finished but it was clear there were renovations being done, regardless it had all the charm and coziness you dream of when you think about a tiny mountain cabin. 

So where do the asian ladybugs come in? During the drive from Tennessee to North Carolina, at some point, his mother turned around in her seat and ominously questioned me "have you ever seen 1,000 dead ladybugs?" I, of course, told her no and she explained the mass release by the USDA, how they've become such pests in the region and how without fail every spring when they returned to vacation at the cabin virtually every surface was covered in Asian ladybugs corpses from the winter - the problem is so common that most residents of the area keep their bedding and chairs covered in plastic! I thought this was an exaggeration until I saw it with my own eyes, hundreds of dead ladybugs. They were built up around the windows, in corners and mostly floating in anti-freeze filled toilet and sink. I recall it taking several hours to clean up and each day we were greeted by new ladybugs - probably seeking revenge, if I had to guess. Moral of this story? These things get out of hand quick! Always make sure whatever you plant or release is native to your area and will not overwhelm the local ecosystem. 

NEMATODE. The question you're probably asking yourself right now is; what the heck is that photo of and what the heck is a nematode? Firstly, those a nematodes under a microscope. Secondly, a nematode is a microscopic parasite closely related to roundworms and threadworms. These little guys are EVERYWHERE, from the lowest valley to the tops of the highest mountains. While some types of nematodes do cause sickness and diseases in humans and animals, the type we are discussing today do not. 

Beneficial nematodes work by actively seeking out and attacking pests that harm plant life, nematodes destroy over 150 different types of insects that live in soil or mature in the ground. These include weevils, beetles including roaches, fleas, borers and gnats.  Beneficial nematodes do not attack earthworms or most other beneficial insects. They’re excellent for use in lawns, in gardens and around trees and shrubs. They need generally moist condition to facilitate their movement. 

PRAYING MANTIS. 

Large, green or tan praying mantis are most often sold as egg cases which can yield up to 200 and more small adults (some pet stores carry single mature adults for housing in terrariums and other enclosed environments). Two to three weeks of warm temperatures allow the eggs to hatch. The newly hatched insects squeeze through the egg sac, leaving it intact and disperse quickly without leaving behind a clue that hatching has occurred. It takes as much as five months for mantises to reach full size.  These critters feed on pests such aphids, leafhoppers, mosquitoes, caterpillars and other soft-bodied insects when young. Later they will eat larger insects such as beetles, roaches, grasshoppers, crickets, moths and even locusts! 

TIPS ON RELEASE FROM PLANETNATURAL:

• Use 3 egg cases for small areas — under 5,000 sq ft — and increase the amount accordingly for larger areas. 
• Tie each egg case to twigs or branches about three feet above the ground. Birds and rodents will feed on egg cases. 
• Placing them in a container with holes large enough for the nymphs to escape — 1/4 to 1/2 inch diameter — will provide protection.

PARASITOID WASPS. Just like there are thousands of different types of bees, there are thousands of different types of wasps. When a gardner refers to parasitoid wasps they could be referring to several different kinds depending on what their pest problem is. Generally speaking these tiny wasps, which are not harmful to humans at all and do not sting, reproduce and act in the same manner. They infect the larva of immature stages of various pests with their own eggs and those eggs feed off the pest until they themselves mature then the adult wasps will seek out more pests to continue the cycle.

Common Plant Diseases   

There are many times when the problems you'll encounter in your garden are not the cause of pests but of different fungi sapping the life from your plants. Here are few of the most common plant diseases and some simple remedies. 

BLOSSOM END ROT: This is a common disease most gardeners, especially busy gardeners, will encounter at least once. This generally occurs on tomatoes but can also affect peppers and other fruits in the nightshade family. 

Blossom end rot is caused by a few different things; a lack of calcium, too much salt, lack of/over watering or rapid growth. This disease manifests itself on both ripe and unripe fruit, soggy spots will appear at the bottom of the fruit (where the blossom was) and will eventually turn brown and ruin the fruit by causing mold or attract pests. This disease will not spread from plant to plant so focus on treating the affecting plants only. To treat and prevent this disease you can; till eggshells or bone meal into the soil before planting (you can purchase calcium sprays from your local garden center too), use chopped leafs, straw or undyed wood chips as mulch to prevent moisture from leaving the soil, and avoid over fertilizing with commercial brand fertilizers that are high in nitrogen.   

RUST: Rust affects many different vegetation, flowers and trees. There are over 4,000 different varieties of rust, rust first appears on the underside of leafs and toward the lower parts of the plant. It is a raised bright golden or orange spots that appear very much like rust, as the fungi grows spores small fuzzy spots in red or black may appear and then will spread via wind to other nearby plants. 

Rust likes warmth, humidity and darkness so making sure your plants get plenty of light and are pruned so air can flow freely is a big help to preventing this fungi. Water in the morning to prevent excess moisture retention and water only at the base of the plant, do not soak the leafs. You should prune off and dispose of effected leafs and stems - DO NOT COMPOST THEM. You can also purchase organic sprays and powders if the disease has gone unchecked for too long. 

POWDERY MILDEW: This is probably the most common fungi in North America, it affects almost all types of plants and is easily identified by powdery white areas on the top of young leafs. The fungi begins as tiny raised bumps near the edges of the leaf causing it to warp and curl before the white powder mildew appears. Prune and destroy effected leafs and plants and make sure plants have good ventilation and air flow to prevent further development. Keep excess yard and plant debris away from young susceptible plants and water in the morning before the heat of the day.

FUSARIUM WILT: I wanted to cover this disease because it is every gardeners worst fear. This disease generally will go unnoticed until it is too late for you to do anything and it can survive for years in the soil. Fusarium wilt is a soil borne pathogen that affects potatoes, tomatoes, peppers and other members of the nightshade family. It enters your plants through the roots and causes the plants leafs to yellow, wither and die. It then slowly works its way up your plant from larger mature leafs to younger leafs. This disease is spread by wind, water, pests and infected gardening tools - unlike some of the other diseases we covered today this one thrives in dry weather with hot temperatures. 

When you notice this disease you should immediately prune effected areas away and sterilized your pruning sheers before using them again - throw the clipping away or destroy them. DO NOT COMPOST FOR ANY REASON. You can purchase sprays and compounds to combat the disease but if you are unable to destroy the disease you should replace the soil in your garden beds or solarize your garden soil. 

VERTICILLIUM WILT: This disease is very similar to fusarium wilt in appearance but unlike fusarium wilt this disease is much more persistent and can survive cold weather and overwinter much more easily. Study has shown that crop rotation is very helpful in the prevention of this disease, since the pathogen develops in the soil it will grow in strength in the same unaltered environment so by rotating crops with more resistant varieties the disease cannot thrive.