Weekly Update and Insect Pests at the Garden
Hi everyone! It’s Gabriel again with my last blog post for the summer, but don’t worry there will be more posts from our other interns. Next week is my last week at the garden and I am so grateful to have been a part of the garden for the summer! I had a wonderful time planting, caring for, and harvesting all the fruits and vegetables that we have at Morven and giving them out to people to enjoy.
This week was a relatively quiet week. More planting, weeding, and harvesting, so business as usual. On Monday the interns were left to care for the garden on their own as a test for this upcoming week, when their fearless leader, Steph, will be on vacation. They did a great job making sure that all the plants were watered and cared for and the garden was still standing at the end of the day. The interns visited Bellair farms again on a rainy Tuesday and stayed inside most of the time cleaning vegetables to get ready for their CSA.
On Weed Wednesday, an official holiday at the garden, you guessed it, we spent time weeding. We weeded the peppers which are starting to come in nicely and they should be ready to give to our CSA very soon. We also planted some more squash and zucchini to fill in the holes where the plants did not seem to germinate. Thursday we prepared for our CSA by cleaning harvesting materials and deciding which vegetables we should give out that week. On Friday we harvested for our CSA and delivered the tasty fruits and veggies to our subscribers.While in my last blog post I talked about some ways we can control pests, with companion planting, row cover, and organic sprays, this week I am going to talk about specific pests in our garden, where to find them, and how we try to get rid of them.
Hopefully this will help everyone better understand the insects we are fighting every day and give all the home gardeners a way to combat them too. If you are not familiar with plant families check out our post from two weeks ago where our intern Julia gives us an in depth look at all the plant families that are present at Morven, because I will use some plant family names.Cabbage Worm - Pieris rapaeAppearance and life cycle:
Egg stage: White rock shaped eggs they hatch in about 7 days.
Larval stage: Light green in color, about one inch long, they are in this stage for 2-3 weeks and feed on plants during this time, then go into pupa form.
Adult Stage: Emerge from pupa as a white butterfly with black splotches on wings, wingspan one to two inches long. These adults then lay eggs on underside of leaves.
Preferred Crop: Brassica familySigns of Pest:
Holes chewed through leaves of the Brassica family.
Tiny dark green pellets (excrement).
Preventative Measures and Removal:
Row cover over the plants.
Handpicking the pests off and killing them or putting them in soapy water.
Sprinkling rye flour or corn meal on the crops, waiting for the worms to eat it which kills them.
Spraying Bacillus thuringiensis (Bt), a naturally occurring soil bacteria, it is only poisonous to certain caterpillars and does not harm beneficial insect, animals, or humans.
Harlequin Bug - Murgantia histrionicaAppearance and life cycle:
Egg stage: Resemble tiny white kegs laid on the bottom side of leaves, can hatch between 4-29 days depending on temperature.
Nymph stage: This stage consists of 5-6 instars (phase between two periods of molting) and they can take anywhere from 4-9 weeks before they reach sexual maturity. The head of the nymph can range from orange to black depending on what instar they are on. During this stage they feed by sucking the sap out of the plants.
Adult stage: In this stage they resemble stink bugs, but with red and black spots, the identifying feature of this bug is the X or hourglass shape on their back while they are at rest. They also feed on plants, but are the only stage to survive through the winter.
Preferred Crop: Brassica familySigns of Pest:
White or brown spots on leaves of plants where the bug has sucked the sap out of the leaf.
Wilting and death of plant.
Preventative Measures and Removal:
Handpick bugs off leaves.
Row cover.
Weeding in winter time to get rid of cover for hibernating bugs.
Insecticidal soaps, but be careful it can also kill beneficial insects.
Squash Bug – Anasa tristisAppearance and life cycle:
Egg stage: Small brown eggs on underside of leaves, egg laying usually starts early summer and goes to midsummer. They take about 1-2 weeks to hatch.
Nymph stage: About 1/10th of an inch long and spider like, they feed in groups on leaves. They have five instars and take about 6 weeks to become adults.
Adult stage: They are about 5/8ths of an inch long and have a shield like shape with a hard shell. When young they are a green or gray with red heads and legs, but as they get older they become whitish gray with dark legs. They overwinter and take shelter under dead leaves, rocks, and debris.
Preferred Crop: Cucurbit familySigns of Pest:
Yellow and brown spots where the bug has injected a toxin when sucking the sap out of the plant.
Wilting, crispy black leaves, called “anasa wilt,” can resemble bacterial wilt caused by cucumber beetles, smaller plants may die while bigger ones can recover if feeding stops.
Preventative Measures and Removal:
Plant resistant varieties.
Hand pick bugs off plants at all stages.
Place boards on ground near plants with wilt, at nighttime they are used as shelter by the bugs so they can be used as traps to be collected in the mornings.
Row cover.
Organic insecticides.
Cucumber Beetles - Acalymma vittatum(striped) and Diabrotica undecimpunctata(spotted)Appearance and life cycle:
Egg stage: Unlike other insects we have covered, these lay their eggs in the soil at the base of the host plant and they take about 2-3 weeks to hatch.
Larval Stage: The larvae of this bug are small and white, they feed on the plants roots for 2-3 weeks before pupating in the soil.
Adult stage: The only stage of the bug we can see easily, the bugs are about 1/5th of an inch long and are yellow with either black stripes or 12 spots on their backs. They overwinter in protected areas and become active in mid to late May.
Preferred Crop: Cucurbit familySigns of Pest:
Holes in leaves, yellowing and wilting leaves.
Bugs can spread disease called bacterial wilt which can spread through the bugs feces or mouthparts. The bacterium can cause blockage of vessels in the plants causing it to wilt and eventually die.
Preventative Measures and Removal:
Practice crop rotation with cucurbits and plant them in a different place.
Check newly planted cucurbits for signs of beetle, especially when plants are seedlings.
Use sticky traps to catch the cucumber beetles, could catch other insects that can be beneficial, but it is an effective way to slow down the cucumber beetle.
Pull up plants infected by bacterial wilt to stop the spread of the disease.
Could hand pick bugs off, but much harder than other bugs because they are very fast.
Plant nasturtiums next to cucurbits because they have shown evidence of reducing cucumber beetle populations.
Tomato Hornworm - Manduca quinquemaculataAppearance and life cycle:
Egg stage: Spherical green eggs laid on the underside of leaves, laid about midsummer and take about 5 days to hatch.
Larval stage: This is the most harmful stage to the plants. They are likely to be the largest caterpillars you see in your garden and can be 3-4 inches in length. They are bright green in color with white stripes, false eyes, and a blackish red horn on its tail end. They have 5-6 instars and take 3-4 weeks to grow to full size. After this they burrow in the ground and go into their pupal stage.
Adult stage: They take 2-4 weeks to develop from the pupal stage and then make their way to the surface to mate and lay eggs on leaves.
Preferred Crop: Solanaceae familySigns of Pest:
Stripped of leaves at the top of tomato plant.
Chewed fruit.
Droppings from the caterpillar look like dark green or black pineapples, if seen look directly upwards to find the worm. They are very difficult to find because they blend in very well with the leaves.
Preventative Measures and Removal:
Good to practice crop rotation because they pupate underground.
Handpicking might be the most effective way because they are so big.
Introducing beneficial insects such as parasitic wasps to help control the population.
Could use Bt spray for younger worms, but might not be enough to kill larger ones.
Rototill after the harvest to kill the overwintering pupae in the soil.
Thanks for stopping by to see what is going on at the garden and have a wonderful week!
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