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(BASIC) August 2 & 3 Report
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For All Growers: Trip Report August 2 & 3, 2001

Kern County BASIC Pilot Program

Deke and Francisco Cornejo made and compiled the report.

 

Kevin Antongiovanni – August 2 & 3, 2001

P. O. Box 78790, Bakersfield, CA 93383

The biological control of cotton pests is progressing very well. The safflower field is plowed, the old melon field land has been prepared for planting, the watermelon patch is covered with weeds, the machinery yard and the border along the road to the south of the cotton block is still an attractive refuge for biological control. We discussed planting a permanent refuge hedge in this area. The north border road has some weeds and Sudan growing as a habitat enhancement to separate from cotton. The cotton to the west has been treated with growth regulator which will slow down whitefly reproduction. We will be watching to see if the adult whitefly that are not killed seek refuge in Kevin’s field. Whitefly are not strong fliers and only get transported by air when there is little or not wind.

Eretmoscerus, Trichogramma and one gallon of Hippodamia ladybugs were released to help the resident natural enemy complex suppress the whitefly population growth. There is little else for predators to eat since the worms are almost gone and no lygus or spidermites threaten. General predators are forced to forage on whatever prey they can find when faced with starvation. The D–Vac samples continues to show a very favorable ratio of beneficials to pests, except for the whitefly adults harvested in the samples.

The D–Vac sweep samples detect whitefly adults reliably as soon as they arrive. Turning leaves and counting adult whitefly can give the standard economic threshold of an average of 10 per leaf taken at the top of the plant. Such a rating does not take into account any biological suppressive forces, for which the D–Vac accounts correlated with the whitefly adult measure. The level of whitefly population has not reached this level on any leaves yet.

One event happened that we have not previously seen. A Calosoma carabid beetle was surprised and took flight like a bird when the noise of the motorfan startled it. It flew with difficulty, more like throwing a stone. We have seen them before in the walks through the cotton. They are very strong, long–lived beetles that feed on all kinds of cotton worms and the adults. They climb the plants at night, accumulating around nightlights. There are also a lot of tachinid flies, particularly Voria ruralis active at dusk. The highest density of beneficials of the five fields is now faced with the prospects of feeding on whitefly or starving or eating each other. We will try and monitor this war among the bugs, the good guys vs. the pests.

 

Ray Banducci – August 2, 2001

10747 Taft Rd. Bakersfield, CA 93311

Aphids:

The sudden rise in the population of aphids seen in the samples last week, July 26 & 27, were harvested from the northwest corner in the most mature cotton plants located between the road and the sweet corn has been controlled by the very large populations of ladybugs (all growth stages present). Green lacewing larvae which were difficult to find before are now present in high numbers. We also have syrphids, parasitic wasps of aphids and others. We think that this hot spot of aphids may have immigrated from alfalfa and ensilage corn fields being harvest in the plantscape. Most of the aphids were not cotton aphids, but displaced other species particularly corn aphids. In any case the resident predators and those individual predators from the source of any migration quickly turned a generation of aphids into more predators that will help sustain biological control of cotton pests such as the whitefly whose populations are rising each week.

Whitefly:

The beneficials are overwhelming the whitefly population. The whitefly is the primary potential pest and it will depend upon the general predators and honey–dew clean–up scavenger insects to keep the cotton healthy. Generally they can control whitefly, but at a higher threshold than is desirable. Hot spots will develop but they will feed more and more predators in the process. We are bringing Eretmoscerus parasitic wasps that kill immature whitefly in the attempt to get them established in your cotton, but they are not enough to make much difference this year. If we can get them to overwinter in habitat plantings, they will hole a lot next and the following seasons.

Lygus, etc:

Lygus, worms, spidermites and other insects are being controlled by beneficials from alfalfa hay that appear during hay harvesting. The three adjacent alfalfa hay fields are being cut one at a time and therefore hay insects seek and migrate to alfalfa and are only visitors to cotton until the hay grows and forms a new food supply that they like better than cotton.

Worms:

Sampling the alfalfa butterfly eggs that are present at a very high level shows that many predators and parasites are feeding on the eggs and small larvae. Most of the worms hatching from 3 to 5 eggs per stem average density are killed in the egg or 1/2 inch length, (1st and 2nd instar). Trichogramma released in the cotton are attacking these butterfly eggs at the edge of the alfalfa. The earlier heavy populations of cabbage loopers and other worms have declined except for the corn earworm in the sweet corn.

 

Bill DeStefani Cotton – August 2, 2001

2112 24th Street, Suite 3 , Bakersfield, CA 93301

The biological control of cotton pests is progressing very well. Eretmoscerus , Trichogramma and one gallons of Hippodamia ladybugs were released to help the resident natural enemy complex suppress the growing whitefly population. Since over half of the field was under water, we concentrated the releases on the west side.

We are still seeing a lot of blackbirds flying around. This must be the reason it is so difficult to find worms. There is little else for predators to eat since the worms are almost gone and no lygus or spidermites threaten. The alfalfa hay field has been plowed driving all surviving insect that could fly, including the alfalfa butterflies into the cotton. Many tachinid and hymenoptera parasites have been grown in the field while helping to clean up the worms. Trissolcus parasites of stinkbug eggs are found in the samples.

This field has the second largest population of natural enemies of the five fields in this demonstration experiment. These general–feeding predators that fed upon the hoard of worms that the cotton survived are now forced to forage on whatever prey they can find when faced with starvation. The D–Vac samples continue to show a very favorable ratio of beneficials to pests, except for the whitefly adults showing up in the samples. The D–Vac sweep samples detect whitefly adults reliably as soon as they arrive. Turning leaves and counting adult whitefly can give the standard economic threshold of an average of 10 per leaf taken at the top of the plant. Such a rating does not take into account any biological suppressive forces, for which the D–vac accounts correlated with the whitefly adult measure. The level of whitefly population has not reached this level on any leaves yet.

Many tachinid flies and parasitic wasps, particularly Voria ruralis are observed searching for prey when we force our way through the cotton that is taller than the other fields, (over Francisco’s head). These beneficials are now faced with the prospects of feeding on whitefly or starving or eating each other. We will try and monitor this war among the bugs, the good guys vs. the pests. Big–eyed bugs are present in three species, Geocoris pallens, G. punctipes and G. atricolor. The larger, light grey G. punctipes has replaced the more common early season species G. pallens, possibly due to an egg parasite, Telenomus sp.

 

Bob Reynolds–Cotton – August 2, 2001

22520 Copus Rd., Bakersfield, CA 93391

Whitefly:

The D–Vac samples no threatening pest population increase except for the increasing numbers of whitefly adults in the vacuum sweeper. When we arrived the air was very still and whitefly could be seen reflected in the light at the north west corner of the field. They are not strong fliers and are dispersed by eddies of air movement. This is the start of a new generation possibly the 2nd or 3rd. They seek new growth in the terminal leaves to lay their eggs. The level of adults per leaf is still very low and not honeydew is accumulating.

The D–Vac sweep samples detect whitefly adults reliably as soon as they arrive. Turning leaves and counting adult whitefly can give the standard economic threshold of an average of 10 per leaf taken at the top of the plant. Such a rating does not take into account any biological suppressive forces, for which the D–Vac accounts for, correlated with the whitefly adult measure. The level of whitefly population has not reached this economic level on any leaves yet.

There continues to be a high density of beneficials compared to pests except for the whitefly, which are now faced with the prospects of feeding on whitefly or starving or eating each other. On the northwest corner there is a highly dense concentration of green lacewing and big–eyed bug. We will try and monitor this war among the bugs, the good guys vs. the pests.

Lygus:

The ratio of beneficial insects to pests is very favorable for lygus. Lygus have not been as much of a threat as we expected. Sanders alfalfa sample show a reduction in lygus despite the seed development in the border that was left uncut. However, some lygus have drifted across the north side of the field ending up in the northwest corner. Only two nymphs were harvested along with less than five adults even in this hot spot. The few lygus that left the alfalfa hay have not found their way back to the alfalfa. A row of alfalfa and corn habitat along the west drive road would have trapped them out of the cotton. and provided food and space for more natural enemy to reproduce. This year, the big–eyed bugs were the main control factor.

Spidermites:

Predatory thrips are keeping mites under control. The mites have not developed in the cotton thus far.

Mr. Reynolds advises us that he will fly on a growth regulator, PIX, to try and set more bolls. He wants 20 bolls per plant with Pima. We will adjust our plant mapping to meet his information needs.

 

Rodger & Sandy Sanders Cotton – August 2, 2001

9201 Lindsay Rd. Bakersfield, CA 93311

The D–Vac samples are clear of any pest population except for the increasing numbers of whitefly adults in the vacuum sweeper. The ratio of beneficial insects to pests is very favorable for lygus and spidermites.

Plant Growth:

The internodes space between boles is short and the boll load is crowded. The cotton plants are shorter when compared to most other fields. Whether the cotton bolls are smaller is a question, but there are as many bolls. We will adjust the plant mapping protocol to give more details about plant growth as requested by Reynolds.

Lygus:

Have not been a threat and even the alfalfa sample show a reduction in lygus despite the seed development in the border that was left uncut. The natural enemy complex has suppressed lygus so that a heavy seed crop has set in this border. The few that left the hay have ended up on the east side of our plot where they are still too few to bother the cotton.

Spidermites:

have not developed in the cotton thus far. The high populations of predatory thrips are probably accountable for this control.

Whitefly:

The D–Vac sweep samples detect whitefly adults reliably as soon as they arrive. Turning leaves and counting adult whitefly can give the standard economic threshold of an average of 10 per leaf taken at the top of the plant. Such a rating does not take into account any biological suppressive forces, for which the D–Vac accounts correlated with the whitefly adult measure. The level of whitefly population has not reached this level on any leaves yet. There continues to be a high density of beneficials compared to pests except for the whitefly, which they are now faced with the prospects of feeding on whitefly or starving or eating each other. We will try and monitor this war among the bugs, the good guys vs. the pests.

Status of the Hedge:

The habitat enhancement plants are growing very well, but the irrigation lines are broken at several places so we are having some plants with water stress. It would help if George would instruct the crew to walk carefully over the hedge and irrigation lines. Our top priority for next trip is to repair the lines, but we need for the crew to accept responsibility for maintenance of the irrigation lines in order to both save water and put the water where it is needed. We mulched almost half of the perennial plants with alfalfa hay mulch to test a hypothesis that microbes in the soil food web can correct the root zone for excess sodium and protect the plant against water loss. the Lavatera plants are starting to blossom with colorful yellow flowers. The mulch is spread next to the plants leaving the annual insectary plants growing space. The corn is starting to silk and no bollworms (corn earworms) are seen. Wolf spider are becoming very common when observed while tending weeding the plants in the habitat. Tiger beetles are also seen in sandy areas. Dust control from the Sudan can be seen to be effective when observing through the rear view mirror when driving along this heavily used road to and from the alfalfa hay and the cotton field to the north.

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