Pickleworms in Cucurbits

Large Holes in A Wilting Cucumber Vine

Pickleworms and melon fly larvae have similar characteristics and both go after the cucurbits. The melon flies stick the thin skins of the young fruit and deposit their eggs and the moths lay their eggs on the plants. I've found both types of larvae inside the fruit but the pickle worms also tunnel into the vines.

The section of cucumber vine above was wilting and when I looked closer I saw the holes where the larvae had tunneled inside.

A Pickleworm Inside the Vine

I broke this vine horizontally at the holes and tore it open vertically and found the pickleworm munching it's way down inside the vine. The small green pickleworm was about 3/4 inch long.

A Better Look at the Pickleworm

The green larvae were the most prevalent but I've found larvae that were translucent white with black spots and larvae that were reddish brown. With the exception of the coloration, the larvae had very similar characteristics.

There may be several moths responsible for these terrible pests. I've read that they have a preference for summer squash. In my garden, they seem to do the most damage to the zucchini - they actually massacre the blossoming portion of the plant.

Pickleworm Damage to a Young Squash

(A pickleworm is boring another hole in the blossom end)

Even though the squash above was covered by a paper bag, a pickleworm crawled down the vine and tunneled holes into the fruit.

Melon flies and pickleworms are a problem in Kihei predominately during the spring and summer. From April through September I put white paper lunch bags around the pollinated female cucurbits to protect the fruit. White and brown paper lunch bags are avalable at WalMart.

Bt and spinosad are recommended products to use for pickleworms in an organic garden. I haven't tried either product and I'm not convinced that Bt is truly safe.

Following is a link with additional information and product recommendations for pickleworms. http://www.gardeners.com/on/demandware.store/Sites-Gardeners-Site/default/Page-Show?cid=5293&utm_term=PDD

 If the pickleworms become a serious problem, parthenocarpic varieties of cucumbers and zucchini can be grown under light row covers. These are F1 hybrid cucumber seeds that produce only female flowers and don't require pollination. These types of seeds are commonly grown in greenhouses. Johnny's Select Seeds offers a variety of parthenocarpic cucumber and zucchini seeds. http://www.johnnyseeds.com/

Growing Winter Squash in Kihei

 

Kikuza
(Sweet Kikuza)

Ready to harvest

Winter squash is fairly easy to grow in Kihei. Most heirloom varieties are adaptable to the hot summer sun and 90 degree temps. Powdery mildew is ever present in the air here and it affects many vegetables. Most winter squash are hardy enough to withstand the negative affects and still produce at least 1 mature squash.

Growing a winter squash in a Smart Pot

I have acidic clay soil that's great for growing bananas but not for growing most vegetables. I double dug and amended a bed in my yard but normal veggies didn't grow very well in it. Then I discovered SmartPots. I've been able to grow all of my squash in 15 gallon Smart Pots filled with an organic potting soil. It doesn't take long before worms begin living in the potting soil and the soil gets even better over time.

Before I direct sow the seeds, I amend the potting soil with green sand and an organic or natural all-purpose fertilizer. Then I add additional fertilizer after 1 month and continue to add fertilizer at a minimum of 1 month intervals until the plant starts to die back.

Kikuza

Protected from melon fruit flies

The melon fruit flies and pickleworms have been the greatest challenge to growing melons, summer and winter squash in Kihei. Mosaic virus has also been a challenge that surfaces during the summer months.

As soon as the female flower closes, I cover it with a paper lunch bag. When the fruit begins to grow, I replace the paper bag with a fabric shopping bag and keep the squash covered until it's close to maturity.

Most winter squash develop thicker skins as they grow. After they thicken, the melon fruit fly larvae and pickleworms tend to be less successful in penetrating beyond the skin and into the fruit or stems. If you miss covering them right away and the melon flies attack the fruit the holes will be microscopic. As the fruit grows the holes become visible. Pickleworms bore large, very noticeable holes into the stems and vines. Wilted vines are sometimes evidence of pickle worm activity.

The melon fruit flies attacked the stem of this Kikuza but the vine and fruit survived and continued to grow to maturity.

Unless it's obvious that the fruit has been damaged, if you notice small holes give the squash more time before you cut it from the vine. If the larvae have been unsuccessful at penetrating into the fruit, the holes will dry and the squash will continue to grow. If larvae have penetrated into the fruit, it will eventually begin to rot.
 

Black Futsu, Marina di Chioggia, Australian Butter (in the center),

Chiriman and Shishigatani Squash

I've found that January and February are ideal planting months for squash as the melon fruit fly mating seems to be inactive until late April and pickleworms aren't normally at infestational levels until June. By the end of April, I have to keep all the young squash covered and cover the pollinated females as soon as the flowers close. Sometimes the melon fruit flies will attack the females before the flowers open.

There are lures for the male melon fruit flies and a bait for the females - they do help but they haven't eliminated the problem. The lures and bait are available from the Univ. of Hawaii College of Tropical Agriculture, Cooperative Extension Office in Kahului (808) 244-3242. They offer a free 2 hour education program about fruit flies. Fruit fly bait and lures can also be purchased from Crop Production Services in Kahului.

More information about fruit fly infestation in Hawaii can be found here:

http://www.fruitfly.hawaii.edu/

http://www.ctahr.hawaii.edu/oc/freepubs/pdf/IP-4.pdf 

Fruit fly larvae look like maggots and can be seen in photos on the first linked website. Information about pickleworms and mosaic virus can be found in the Growing Tips - Pests & Diseases section on my side bar.

Greek Sweet Red

I've trialed many different varieties of winter squash and I'll continue to trial different seeds as well as experiment with earlier and later planting dates.

Greek Sweet Red was the variety I chose to trial for late summer planting. Seeds were planted in August and September with good results. Although I did find a few pickleworms in late September and early October, the damage was minimal. 

I've been able to grow winter squash successfully from seed when planted from late January through September. I haven't tried planting earlier or later but other gardeners on Maui tell me squash can be grown all year.
 

Buen Gusto de Horno

(Good taste of the oven)

 

Buen Gusto is so far the only variety I've planted that was too big and aggressive to grow in a 15 gallon Smart Pot. I planted it in a garden bed and it grew fairly well.

Seeds for all of the squash in this post are available from

Baker Creek Heirloom Seeds.

Winter Squash Favorites of 2010 

- a blog post highlighting the tastiest winter squash from my 2010 garden.

Waltham Butternut

In American cuisine, squash and pumpkins are most commonly used at Thanksgiving. But squash is a popular year round vegetable in European and Southeast Asian cuisines. Following are links to recipes, with detailed instructions, that feature squash. Butternut is the most common winter squash available from the market but any sweet winter squash can be substituted in these recipes.

 

Smoked Squash, Herb Marinated Feta, Garlic Dressing

Thai Fish & Kabocha Coconut Milk Soup
Butternut Squash Soup with Prosciutto
Wood Grilled Butternut Squash Puree

Butternut Squash Coconut Soup

Thai Butternut Squash Soup

Pumpkin & Crab Chowder
Butternut Squash Ravioli 

Asian Style Roast Duck with Roast Pumkin
Butternut Squash Lasagna with Infused Bechamel

Almost Raw Butternut Squash Pie

Raw Pumpkin Recipes - Part 1

Raw Pumpkin Recipes - Part 2

Kabocha Turkey Pasta
Pumpkinpalooza