Archive for June, 2012

Battle of the Bugs: Tomato Fruitworms/Corn Earworms

 

 

 

Most gardeners have experienced damage caused by this destructive insect.  In fact, it is one of the most costly pests in the United States as it attacks many important field and vegetable crops.  Corn, tomatoes, pepper, cotton, sorghum, beans, and lettuce are seriously damaged, but Heliocoverpa zea also attacks other fruits, flowers, and weeds.  This single insect pest is called by many common names, but the most popular are the tomato fruitworm, the corn earworm, sorghum headworm, and the cotton bollworm.  

 

Close to 3000 eggs are laid by the female moth close to a full moon.  Target sites are on the silk of corn or on new leaves near fruit of tomatoes and peppers.  The corn earworms develop for about 4 weeks, becoming cannibalistic on others worms in the same ear of corn.  Then they drop to soil to pupate for a couple of weeks and emerge as adults.  Adults mate then live two weeks to distribute eggs. The moths have been found at 10,000 feet as they disperse up into Canada to Mexico. Three generations are produced per year with the overwintering limit occurring around Interstate 70. 

 

Natural control of the tomato fruitworm is by parasitism with tachinid flies, trichogamma wasps, and naturally occurring Bacillus thuringiensis (Bt). 

 

For organic control, a drop or two of mineral oil on the corn silk right after pollination will trap the young caterpillar before it reaches the ear.  Other strategies are to dust with diatomaceous earth, spray with Bt in the evenings, introduce parasitic wasps (Campoletis sonorensis and C. nigriceps), plant resistant corn hybrids, and apply beneficial nematodes to the soil and to simply plant corn early.  Some cotton farmers have had success with evening garlic sprays to control this and many other insect pests.

 

For specific chemical control recommendations, go to the LSU AgCenter website.

 

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Carpenterworm Moth: Pest of Stressed Trees

Carpenterworm Moth

Battle of the Bugs by George Giltner, Louisiana Master Gardener

The carpenterworm moth larvae, Prionoxystus robiniae, feeds on local species of oak, locust, maple, willow, ash, walnut, American elms, fruiting pears, and ornamentals.  Therefore if you observe a weeping ooze and brownish frass from these trees you should have concern.  If the caterpillar has been active for an extended period of time, the tree will be deformed due to tunneling damage.  The ¼ – 3 inch larvae are greenish white to pinkish with a dark brown head.  Other identifying features are the prominent hairs on their body, hooked legs on their thorax, and distinctive abdominal prolegs.  The adult moths have a mottled black and gray wing span of 3 inches.  The male has orange and brown hind wings while the female’s hindwings are white.

Images 1 & 2: Adult moth on left & larva on right.

The adult moths mate from late April to early June, then lay 3-6 oblong olive green eggs in crevices or wounds of the tree.  Within the two weeks the eggs hatch, then the larvae feed on the inner bark to the sapwood for 2-4 years.  Pupation is in the heartwood.  In 20 days, the adult moth emerges in daylight, leaving the pupal case on the outer bark.

How do you control these boring caterpillars?  With early detection and a light infection site, your best bet is to use beneficial nematodes, Steinernema feltiae and S. carpocapsae.  A squeeze bottle, syringe, or an oilcan makes a good application device for a water injection at the bark tunnel entrance.  Any extra nematodes can be used to control fungus gnats, leaf miners, domestic flies, Japanese beetles, and sweet potato weevils.  Websites for ordering the nematodes are: www.gardeningzone.com/products/nematodes, www.bugsforgrowers.com/products/steinernema-feltiae, www.groworganic.com/parasiticnematodes

Nematodes are live worms that do not do well with shipping in our hot summer climate or cold winters.  The best time for ordering is in the fall and spring when temperatures are moderate (60 to 70 deg. F) nationwide.  Schedule quick delivery.  Pick up quickly from the mail box. Then apply soon after arrival in the evening.  Seal the tunnel entrance of caterpillars with caulk.

Chemical insecticide applications of carbaryl or permethrin are not effective or are partially effective.  The best way to control heavy infections is to cut and burn the tree.  The females are not good fliers, thus the infection range tends to be more localized.

If you suspect you have carpenterworm moth in your trees, call the LSU AgCenter in DeRidder, LA at 337-463-7006.

 

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Notes of a Beginning Beekeeper

Notes of a Beginning Beekeeper

by Jimmy Earl Cooley & Keith Hawkins

      Mr. Jimmy Earl Cooley recently acquired beekeeping equipment and, with the help of Mr. Richard Hebert, a local experienced beekeeper, placed a swarm of captured bees in his beehive.  Here are his early notes regarding his experience so far.

Notes from JEC Bee Book

 Received my box and suit from Mann Lake April 16th.

Richard Herbert installed bees in box on Wednesday, April 25th.

Added feed bottle on April 28th following a storm and heavy rain storm , felt sorry for bees.

Viewed, with top and inner cover off, every few days and added liquid water and sugar when needed.  Did not remove any frames but noted beeswax on some frames.

On May 17th, did a through inspection and took photos,  removed only 1-7 frames, 8, 9, 10 looked same as 6 and 7.  Did not locate queen.   Will send photos to Richard for his review and explanation as to how hive is progressing.  Did not receive a response from Richard. 

June 1, 2012, 9am, removed top, inner cover, and inside 10 frame size top feeder with super to expose top of 10 frame (9 5/8 inch) bottom super.  Bees very active and working.  Noted that the inner cover had been sealed to several of the frames – Comb and honey could be seen here.  What does this mean?  Assume material is overflowing from the frames 8, 9, and 10 which were basically full on May 17th.  Noted that now even frame 1 has comb on one side as was 2-through 5.  So now all 10 frames are being worked on.  So reached a decision if anything should be done.  One thought was to leave everything as is and take a chance that, now that all frames are being filled, they may decide that hive is filling up and start making new queen and pack bag to split off or reduce work and collection.  Another thought was to add a second super on top of the present one to give more space and frames to encourage more building.  Decided to add another super, put one shallow super, 10 frames (5 3/8 inch) on top of existing 10 frames (9 5/8) super.  Put a queen extruder between lower and new super to keep queen in lower box.  Then put inner cover on top of shallow super, then added the 10 frame size top feeder and then the top cover.

Top Cover

Top Feeder

Inner Cover

Shallow Super

Queen Extruder

Hive Body 10 X 9 5/8

Bottom Board 

                Hive Arrangement

Beekeepers, Appreciate if you please send me any comments or errors that I may have made.  I’m just a novice and learning.   JEC

 Mr. Jimmy is a member of the SW LA Beekeepers Association and is starting his first beehive. SW LA Beekeepers meets the first Monday of each month at 7 PM in the War Memorial Civic Center, 250 West 7th Street, DeRidder, LA. For more information, please call the LSU AgCenter at 337-463-7006.

 

 

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Battle of the Bugs: A Hymenopteran Garden?

 

Battle of the Bugs    A Hymenopteran Garden?

By George Giltner                                           

 

Search the web for a butterfly garden and you probably will get around a million hits, but try to find info on gardens for bees, wasps, and ants, and you will be mainly out of luck.  And the next thought in the general public’s mind is who in their right mind would want a garden for these stinging and biting insects?

 Probably everyone is aware of pollinators, mostly bees, providing an enormous benefit to farmers.  The values are quite variable but range up to 40 billion dollars plus within the United States.  Pollination is just the tip of the value “ice berg”. 

Hymenopterans supply a large amount of biomass as they are eaten by other animals from lizards and frogs to skunks to birds, bears, and even armadillos. Therefore, these bugs are an important part of the food chain of nature.

 Many species are predators and parasitoids of other insects.  89,000 species are parasitic forms and 18,000 species are predatory forms.  Thus they play a significant function in nature as natural and biological controls.  One example in our local area is the dirt dauber.  Its primary food is spiders including black widow spiders as a favorite.  Inspect the mud nest and you will find paralyzed spiders that serve as food for developing dauber larvae.  Another solitary wasp, the sphecid wasp provisions its nest with cutworm larvae.  Paper wasps, a social species, carry masticated prey (mostly caterpillars) back to its paper nest.  They regurgitate the chew food, much like birds.  Ichneumonid wasps are known as endoparasites as its larvae lives inside its caterpillar hosts.  Brachonid wasp larvae live inside of moth caterpillars leaving nothing but a shell of the former host. 

Ants occupy nearly every possible niche within our gardens, fields, and forests where they perform unheralded and valuable environmental services to the soil.  Their far extended tunnels function to aerate the soil.  Movement of organic matter from the surface to below functions like plowing.  Also ants are great seed dispersers of cordalis, delphinium, bloodroot, trillium, viola and many other plants.

Therefore, hymenopterans have value and play important roles in the balance of nature.  If you don’t want to have a hymenoptera garden, at least consider a tolerance when possible for these bugs.  They will be in the pea patch and around flowers searching for prey and also feeding on nectar and pollen.  No need to carry a can of “Raid” to the garden as they go about their routine without regard to humans unless a nest is around.

If you wish to attract hymenopterans, then have an ample supply of water in shallow dishes of water with gravel.  These insects require water in late hot afternoons just like we do.  A diverse habitat of nectivorous plants will provide shelter and food. The extrafloral nectaries that attract bees and wasps are located on leaf margins, petioles, leaf and flower buds and on hairs of the plant stem.  You may have seen wasps looking for nectar along the pod petiole of field peas during summer.  Block nests attract many predatory wasps.  Tolerating low levels of pests provide food for the reproduction of predators and parasitoids.  Also short pistillate flowers supply a vegetarian meal with nectar and pollen.  Be very careful with broad range insecticides like Sevin which can kill many bugs for up to two weeks.  A spot target spray with low toxicity to beneficial insects should be used instead.

Plant sunflowers, asters, cosmos, dill, mints, oregano, zinnias, and other flowers around your veggie gardens and you will have both, a Lepidopteron (butterflies and moths) and a Hymenopteran (bees, wasps, etc.) garden.

Editor’s Note: George Giltner is a Louisiana Master Gardener Beauregard Parish. He is a self-taught entomologist and writes the “Battle of the Bugs” series.

 

 

 

 

 

 

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