June Weekly Field Reports

Mr. Antongiovanni's Cotton

June 6-7

June 13-15

June 21-22

June 28-29

The Sanders' Cotton

June 6-7

June 13-15

June 21

June 28-29

Mr. Antongiovanni's Cotton

This is a record of weekly monitoring during June at a 38 acre field of Riata (Acala) Round-Up Ready cotton located in East Bakersfield. Kevin Antongiovanni manages this and other fields in the area. During June we were counting populations of insects in each quadrant of the field and in the surrounding vegetation by 100 sweeps with the sweep net and 100 standard sucks by the D-Vac vacuum insect net sampling method and visual inspection. Our reports built on those of May in which the key beneficial insects were identified for the growers. We did complete counts of the vacuum samples to determine all of the species present in the natural enemy complex associated with each pest.

Field Observations: Arrived late afternoon and stayed until sun went down at 20:30. Lacewings adults are flying from the Safflower field. More corn mix was planted along the south side of the field and patched on the East Side. Cultivation and fertilization following irrigation is complete. Calasoma adult Carabid beetle seen. The larvae of this predatory beetle species seen last week were not seen this trip.

The limited samples with the sweep net reveal many, many lacewing adults in the Safflower. This field has received another irrigation and continues to blossom. Very few green lacewing eggs and no larvae have been seen so far. This field is starting to cotton blossom, the pollen and cotton nectaries should trigger their reproduction. Nectaries alone do not make them lay eggs. These are mostly last year’s adults that are still in winter reproductive diapause. There are no aphids or whitefly to make them lay eggs. The ladybug populations are not laying eggs much either. Only one egg mass and very few larvae are in the samples. One Syrphid fly was taken in the samples. Most of the ladybugs that we see are Coccinella spp. and not Hippodamia convergens (the only one that migrates to the mountains).

D-Vac samples were taken near the SE corner the evening of the 7th and the NW corner on the morning of June 8. The Trichogramma left from June 7 releases were colonized.

Releases: 200,000 Trichogrammatoidea bactrae (swarming adults in cups with honey paper) were released by Francisco walking the field (middle of the south half of the field. The outside edges were colonized from the truck around the edge of all sides of the field.

Field Observations: This cotton plot has the most diverse set of NEC of the Old River Road group of cooperating farmers. The source of beneficial insects is probably the safflower. The cotton is adjacent to safflower, a water melon field and unknown harvested vegetable crop with lot of weeds and Johnson grass and other plants in bloom on east and south sides. There have been no pests until this week when cabbage loopers swarmed into the cotton from the alfalfa hay harvest. These moths feed in the alfalfa bloom a few days and fly from the stubble after cutting into the cotton to lay their eggs. The high numbers of cabbage looper moths that are flying in all cotton fields at night are depositing eggs and small larvae are hatching. The cotton north of this plot has a spray rig applying CCC (possibly selective Bacillus thuringiensis (Bt) to the cotton on 6/14 &15 while we were making tricho releases. The predator complex is composed of big-eyed bugs, damsel bugs and Hooded beetles all of which will feed on these eggs and small larvae.

D-Vac Samples: We have sampled Hyposoter exigua., a small wasp parasite, that attacks half inch long looper worms. Sixty percent have been reported in the literature. They are Nature’s second line of defense against cotton worms. However, the several species of beneficial tachinid fly, especially Voria ruralis, that yields three to five flies from each large looper worm that it attacks have not been seen so far. These important beneficial flies will be too few and too late for lack of an unsprayed refuge and from pesticide interference.

Habitat: The habitat enhancement blooming plants are necessary for this largest group of beneficial insects that control cotton pests. The habitat refuge planting that we are seeding may be too late to help us at this moment, however, we will be monitoring for the presence of these important biological control organisms to discover when they will discover these looper pests. Monoculture without unsprayed year-round flowering plant sources limits the use of EBPM and IPM pest control strategies.

The reduction of the need for conventional chemical control (CCC) is dependent upon having the natural occurring beneficial organisms close by to where the cotton is being grown. The natural suppression of pests occurs where and when most of the known many sets of beneficial insects are provided for by planting a diversity of habitat enhancement plantings, corn, Sudan, Sorghum, flowering safflower and sunflowers, that act as a trap and a refuge for both the pest or an alternate host species. Diversifying plantscape is to optimize the diversity of insect and mite species growing in the plantscape. The cutting process of alfalfa hay is also somewhat involved. It is a lot like recovery from drug addiction. It takes a change of life style to go through the pain of withdrawing from CCC.

Releases: We made our second release of "tricho" egg parasites. We probably need many more than the 200,000 per week that is scheduled in our budget.

Field Observations: The field was thought to be under the next heaviest looper moth egg laying pressure. Last week, the neighboring cotton field north of our demonstration plot was being sprayed with a ground rig. We assumed that it would be Bt that they were applying. We were concerned about the moth flight and the eggs and small larvae seen last week. There was less concern in this cotton because of the higher and more diverse populations of beneficial predators sampled here in both the cotton, the safflower to the east, the large numbers of Polistes wasps and mud dobbers that gather worms to feed their young and the flocks black birds seen working the cotton for worms. We have seen the Carabid beetle Calosoma affinae in two locations. It is a large black beetle that climbs plants at night feeding on large worms and pupae in the duff/soil interface with above ground plant surfaces.

Surrounding plantscape supports biological control: This larger more diverse set of natural enemies suggests more effective biological control is taking place. Only Hyposoter exiguae has not been seen nor have we seen several tachinid flies, but the safflower with some weedy areas of Johnson grass and other weeds and the melons are all good habitat for most of the natural enemies known to be in alfalfa hay. Watermelons to the south and alfalfa hay south of the melons are evidence that this plantscape has more biocomplexity and less pesticide interference than either the DeStefani or Banducci plantscape.

Our foresight was more accurate than expected. The leaf feeding damage was much less than was observed at DeStefani. We were able to meet Antongiovanni and discuss our findings that we had taken to date. I think that the level of biological control has proven to be sufficient by the speed with which the large numbers of big-eyed bugs control of lygus and leaf feeding cabbage loopers, Trichoplusia ni. The number of large worms (more than half inch long) that escape the predators is far fewer than at DeStefani’s. The lygus counts have never been higher than a 3 count (all adults) migrating from the safflower as it matures. This cotton was the first to blossom and green lacewings are laying eggs and small lacewing larvae are in the D-Vac vacuum insect net samples. Lacewing adults are seen throughout the field. The only looper worms found today were in the sweep net samples at the NW corner where cotton is planted interfaced to the north and west of our block. All other sides have sources of natural enemies moving into Antongiovanni's cotton block.

Sudan habitat slow to come up: Mr. Antoniogvanni reported that he had planted the Sudan and the next irrigation will make it grow. However, the Treflan/ Round-up herbicide combination may prevent it. The corn and flowering plant insect refuges have not germinated in this block thus far. The same insectary mix of seeds and Sudan are already 6 to 8 inches tall at Roger Sanders, planted and irrigated two weeks ago. The Sudan barrier acts as a wall to inhibit the flow of dust and other possible pesticide residues that interfere with biological control of cotton pests where natural enemies are being fostered. There is another benefit of the Sudan barrier as far as protecting against an invasion of mites that are encouraged by the infrared radiation effects from a hot dusty dirt road. The outside rows of many farms are being lined with growing plants to inhibit dust (along with sprinkling the roads with water) particularly in strawberry and both table and wine grapes. Some vegetable and tree fruit orchards are also using plants to cool down the outside rows of their fields as a control for the spider mites that seem to flourish at this infrared "hot" interface. It is also a small cost for a large benefit to help increase the biodiversity of monoculture agriculture and protect against mite invasions. Green lacewings spend a lot of the daylight hours in these plants and fly throughout the field laying eggs during the night hours.

The progress of biological control advances with each growth cycle of the plants. The weather has been favorable and the good bugs are winning as of now and the prospects for continued control look good.

Field observations: This field was sampled just before sunset on Thursday. Several birds were flying from the interior of the field. Hyposoter pupae were found at several locations. In general the crop is very clean at this point. The only worry is the adjacent safflower field is almost ready to be harvested and may cause a large migration of Lygus when it is harvested.

Plant growth: Petiole samples were collected Friday morning. Plant growth in this field is very homogeneous. Plants in some areas are at different growth stages but these differences may be due to different soil zones. The petiole sample analysis will reflect the average on the whole field. High nitrogen input increases the risk of mite and aphids outbreaks as these pests thrive on tender plant growth induced by fertilizer use.

Sweep net samples: Sweep net and D-Vac samples were taken from the four corners of the field.

5 Geocoris

1 Orius

3 Nabis

6 Ladybeetles

6 lacewings

3 Spider

2 Hyposoter

High numbers of thrips, hooded beetles (several species of Anthicids), and minute pirate bug (Orius) were found. The high thrips population is the food source maintaining the minute pirate bug population. The hooded beetles are feeding on looper eggs and larvae. More immature stages of beneficials compared to pests were found indicating these pests will be kept under biological control.

Habitat: Few of the corn seeds that we planted few weeks ago are beginning to sprout. The disappointing growth of the corn may be due to residual herbicide use.

Releases: 100,000 Trichogramma were released through the center of the field. As a proactive measure, lacewing releases should be made next week to reduce the risk of a mite and/or aphid out break. Also these releases would increase the general predation on stinkbug and Lygus eggs and nymphs. The farm manager agrees and would like his people to be involved with the releases so that they learn more about the program.

At Rodger and Sandy Sanders’ Old River Farms on Lindsay Rd in Bakersfield we are observing 60 acres of certified organic Pima cotton grown by low-input practices. During June we were counting populations of insects in each quadrant of the field and in the surrounding vegetation by 100 sweeps with the sweep net and 100 standard sucks by the D-Vac vacuum insect net sampling method and visual inspection. Our reports built on those of May in which the key beneficial insects were introduced. We did complete counts of the vacuum samples to determine all of the species present in the natural enemy complex associated with each pest.

Field Observations: Habitat planting has sprouted, corn Sudan sunflowers etc. Alfalfa hay has been cut leaving 7 strips of uncut alfalfa in bloom starting from the south to half way is solid cut. 5-ft. strip swept with net. Each uncut strip is slightly wider going north until the last strip, which is a full border. The insects have moved away from the cotton plot migrating into strips, 1 through 7 with increasing population density. (most in #1 and least dense in final N Border).

D-Vac sample was taken from the last strip. The larger insects and leaves were sieved out and examined in the field. The tiny immature forms were winnowed through the sieve screen to obtain a alcohol sample to show any Trichogramma egg parasites of moths and butterflies, Scelionids that are known to attack Stinkbug eggs, Trissolcus spp. and Mymarids that attack the eggs of lygus, Anastis aeoli. The sample will also make it easier to find the immature forms of all of the NEC (natural enemy complex) in this organic unsprayed alfalfa ie. the good bugs found and pictures of last weeks report, May 24 &25. Gymnosoma (Tachinid fly)on adult Says Stink bug was seen. Stink bugs were the only potential pest besides lygus. The populations were crowded into the alfalfa strip left standing. This gives the appearance of being a high population in strip #1 but is less in strip # 7 which is wider and at the farthermost end of the 90 acre field.

D-Vac sample was also taken from SE corn planting site and 40 cotton plants vacuumed. There were two species of Trichogrammatidae (wild, natural) in the alfalfa. lygus egg parasite and all stages of big-eyed bugs, damsel bugs, Assassin bugs, ladybugs, etc. chasing the potential pests.

Analysis of effect of hay cutting: Essentially, the cutting process has driven all flying insects away from the sample field. The field east of this alfalfa has not been irrigated (start this week). This north end of this check (non release field) is adjacent to the concentration of insects in the alfalfa. However, this will probably not matter since the lygus like alfalfa better than cotton. Stinkbugs like alfalfa seed and will stay in the alfalfa too. There are no spider mites or aphids and plenty of beneficials to control them as well as the lygus and the other potential pests present in the alfalfa at this time.

Releases: 100.000 Trichogrammatoidea bactrae were colonized in the Sanders cotton field. Corn mix was planted in three corners NW, NE & SE to provide habitat trap for worms and evaluate Trichogramma on corn earworm and green lacewing population density. We are enclosing a picture of Trichogramma life cycle. Flood irrigation started over a week ago on east side is being completed June 7. The drip line to our habitat is turned on each day and off at night.

Field Observations: The cotton is now 6 to 10 inches tall with one full irrigation completed. This is Pima cotton. There is a history of Silverleaf whitefly in this field that never received any pesticides previously except sulfur for mites. This must be a good year for the farmer as far as the whitefly pest, since we have not been able to find any yet this year. We are fortunate to have started our project in a relatively low pest year when there are low populations of thrips, aphids, mites, lygus and worms (except for the cabbage looper leaf feeding worms).

D-Vac Samples were taken to see where the NEC sought refuge from the stubble field. The cotton was being irrigated in the meantime. The alfalfa will be watered after the second cotton field. It appears that the insects that could fly went to the cotton. The concentration in the seven strips forced them to follow the hay before going to the cotton. We have sampled the cotton and the alfalfa adjacent to the cotton through the first cutting of alfalfa and the cotton is ok so far. The extraordinary numbers of cabbage looper moths observed flying and lesser numbers of bollworm and beet armyworm moths is a concern.

Our samples of alfalfa have shown naturally occurring adult Trichogramma not to be present except at Sander's unsprayed alfalfa hay. This important parasite normally over-winters on eggs of the painted lady butterfly (this host is common laying eggs all winter on the Malva weeds) and over-summers on alfalfa butterfly eggs. Both of these alternate hosts are present in higher than normal densities around Old River Road than at Sanders' untreated alfalfa, near Maricopa. The difference appears to suggest that the use of CCC in both alfalfa and other crops and the monocultures created by herbicides (the non-availability of few if any flowering plants) in the plantscape as compared to grains and wild sunflowers and blooming alfalfa hay fields that receive no CCC.

Habitat: Much of the research supporting our point of view about the value of unsprayed alfalfa was carried out in this very area of southern San Joaquin Valley in and around Old River Road. Our experience has shown that alfalfa still supports the necessary natural enemies of all pests of vegetable and field crops, especially cotton in this area.

Insectary Hedge at the Sanders Field: The habitat enhancement planting that is designed to favor biological control of the silverleaf whitefly is now in place. 600 feet of drip irrigation line irrigates the patch in between cotton irrigation schedules. The effort involved was making a trip to the Brawley USDA Conservation Research Station to pick up the plants that Charlie Pickett of California Department of Agriculture arranged for us at no cost. The planting and irrigation system was provided with the farmer's help at minimum cost. Speed was most important in order for observation of the effects of habitat enhancement on EBPM this cotton season. The silverleaf whitefly was heavy last season in this field. We have not been able to find whitefly in either the cotton or the alfalfa so far this year.

One interesting side note is the effect on insect behavior in the insectary hedge of the dripline full of water at all times and some muddy puddles where leaks occurred. Even though the field was being irrigated, the patches of standing water and wet mud attracted many insects--particularly wasps-with concentrations of them at these sites of available water. This may favor the native western fire ant and other predators.

The thesis is clear that small modifications of the farming process and the planting of habitat enhancement patches of plants (an "insectary mix" of plants that provide flowers, nectar, pollen and other nutritional exudates, alternate host species etc., both annual and perennial, that enhance the plantscape). Beneficial insects must have the food required for their reproductive needs.

The difficulty for EBPM is the complexity of the science when dealing with the immense variability of the biocomplexity of the NEC that is difficult for implementing the processes. There isn't any money to be made by monitoring pests and telling the farmer to not spray. The products that are sold will work best when supported by a healthy NEC and will fail when the NEC has been destroyed by excessive exposure to pesticide toxins. It is complicated and it takes a great deal of trust to tell a farmer to not spray when the CCC advocates say to spray. Who does the farmer believe?

Releases: We are colonizing a half million adult Trichogramma (egg parasites of moths and butterflies) within the limits of our budget. Cabbage looper eggs and small looper worms are feeding on the cotton leaves as I write this.

Most of these insectary grown Trichogramma (called "trichos") are released as colonies pre-fed with honey paper in white paper drinking cups, folded to hold them as a colony long enough for mating to occur before they find their way into the cotton. The honey is a substitute food that in a normal year would be supplied by aphids and whitefly, which are absent so far this year.

The Sanders, Thursday, June 21

Sampled 9 - 10:00 AM. The weekly D-Vac sample was taken at the biodiversity habitat planting site in the SW corner of the plot (Drip irrigation line was turned on.) The irrigation of the cotton was completed last week and both the habitat perennial plants that focus on whitefly management, the insectary mix annuals and the cotton show no stress. There are lots of weeds germinating as well. The check cotton field to the west that is being prepared for irrigation shows typical leaf wilt from the heat. Temperatures will reach over 100 degrees each day. The alfalfa hay field has grown back from the cutting that was harvested two weeks ago, is still without irrigation. Irrigation will be completed June 22, in the cotton across to the east from the alfalfa. Sweep samples of the alfalfa and all of the cotton reveal good sets of natural enemies, particularly the big-eyed bugs, the most effective predator control for lygus and many other soft bodied insect pests.

Staggered strip-cutting of the alfalfa planting, starting from the south end of the field advancing to the north end (leaving 7 strips of standing alfalfa spread evenly from the middle to the north end) caused the mature insects to fly into this standing alfalfa and concentrate in these strips. This concentration of adult insects triggers reproduction of both the plant feeding insects (potential pests) and their sets of natural enemies (beneficial biological controls). The D-Vac samples and sweep-net samples revealed that lygus in particular and the predators (big-eyed bugs, damsel bugs, minute pirate bugs) responded to this concentration of lygus prey (food). They increased their reproduction rate in proportion to this concentration of all insect life present within this small amount of alfalfa plants remaining in these strips.

D-Vac Samples: Our observations of insect samples showed a crowding of (wingless) immature insect predators in these strips. Only, the adult insects were able to move with the cutting process. The resident immature (wingless) insects were left in the alfalfa stubble where the removal of growing alfalfa plants concentrated the prey (lygus, aphids, mites, thrips etc.) on the stubble. This increased the searching efficiency, resulting from crowding of all flightless stages of insects onto stubble gave the advantage to the beneficial predators, less food for the pest and less searching for the predators, favoring biological control in the battle of good and bad bugs in the whole alfalfa planting.

Small habitat management decision made big difference in beneficial insect ecology: The combined effects of this slight modification of the alfalfa hay harvest resulted in favoring the reproduction of beneficial insects and reducing the numbers of their prey (all plant feeding species). The process also drove the adult insects (flyers) away from the cotton dispersing them throughout the area. It is documented that the increased reproduction of beneficial predators eventually find their prey. Food drives all of these sets of biological controls and the plant feeders alike.

Thus, this farming process or event demonstrates that small changes in farming practice can be used to increase the effective biological control of all pests of vegetable and field crop pests. Extensive research in ecologically based pest management (EBPM) has proven beyond doubt that cotton can be grown with much less use of pesticides when alfalfa hay production is managed as a resource for beneficial and a trap for potential pests.

This season is unique in that the cotton aphid, thrips and mites as well as less than usual lygus populations reside in all of the cotton blocks. Lygus adults are relatively rare species while all of the cotton worms are high density at the all other farms. We can only guess that the favorable number of big-eyed bugs and the hooded beetles seen in every sample is responsible. Aphid predators are abundant and yet aphids difficult to find. All of these predators overwintered from the large populations that occurred following last season at Sanders Ranch because Silverleaf whitefly was a pest and no pesticides other than sulfur and no herbicides have been used.

Early aphids can be a resource for growing mite predators: The usual process of biological control systems is for the 60 or more species of predators and parasites of aphids to attract and grow the biological controls that clean up of aphids and then mite control follows soon after. All of the aphid predators are hungry and are forced to clean up the mites or starve or migrate. Most of the aphid predators will feed on mites when they no longer can find aphids. The same is true of thrips and their natural enemies. The western flower thrips, a pollen feeder, will eat mite eggs before it resorts to feeding on plant tissues. Our samples reveal many kinds of mite predators and few if any mites at this time. The lygus populations are also no threat.

Keep predators alive longer with carbohydrate food sources in a habitat: There is the chance that many of these predators will die of old age or starvation before any new pests arrive, but we know that they can live longer feeding on plant exudates, nectar and pollen when they cannot find their prey that makes them lay their eggs. Each set of predators reproduces rapidly when their particular prey resource becomes abundant. This is the natural rule that is the basis for the biological control process. It is a "density-dependent" response that speeds the reproduction process of predator and parasite species over the prey.

Keep the insect-plant systems functioning: Successful biological control is based on biodiversity and biocomplexity of both plant and insect species. The principle basis for this demonstration is to find ways to increase polyculture of plants, even non-noxious weeds that provide the food and space (habitat enhancement) to the massive monocultures of agriculture. We must provide non-sprayed patches or crops where "pesticide interference" to biological control systems is prevented. These small unsprayed plantings will keep the full sets of natural enemy complexes breeding in residence and adjacent to the market crops where they can enter the new cotton planting as soon as the first pests arrive. Ways must be found to keep insect-plant systems functioning in between crops. This is the opposite of the present paradigm, the opposite of eradication by broad-spectrum pesticides.

Plant growth: The cotton plants at this field are growing slowly but has strong stems which is characteristic of Pima varieties. The plants have good color and are heavily loaded with flower buds. The plants are noticeably shorter here than elsewhere because they have been grown in sub optimal organic soil. However, these plants have the strongest stems and will likely have higher square/boll retention than the other fields. In general the plants are very healthy

6 Lacewings

6 Lady beetles

4 Nabis

2 Orius

3 spiders

6 Geocoris

Some Lygus and looper larvae were seen on the plants but were not caught in the sweep net.

This sample had the most favorable balance of beneficials to pests. This is due to the diversity of the surrounding plantscape (alfalfa fields, grain fields, and uncultivated rangeland). I did not find any signs of mites or aphids.

Habitat: The nearby alfalfa field is being irrigating to start re growing. There is a good number of beneficials that will move over here.

Releases: I released 100,000 Trichogramma most of which were already emerged.