Posts Tagged ‘agronomic crop insect scouting’

Agronomic Crop Insects – July 6, 2012

Friday, July 6th, 2012

Alfalfa
With the recent weather, leafhopper populations have significantly increased so be sure to keep a close watch for adults and nymphs. We are seeing economic levels in fields throughout the state and in a number of cases yellowing has already occurred. Remember, the nymphs can quickly cause damage and once yellowing is present significant damage has already occurred both in season as well as to the long term health of the stand. With the hot, dry weather, you should consider reducing treatment thresholds by at least one-third.

Field Corn
We are starting to see an increase in Japanese beetle and have found the first rootworm beetles feeding on corn silks. Although beetles feeding on silks can potentially interfere with pollination, research indicates that silk feeding does not reduce pollination if they cut the corn silks after pollination has already taken place. As a general guideline, an insecticide treatment may be needed if two or more Japanese beetles and/or corn rootworm beetles are present per ear and silks are clipped to less than ½ inch prior to pollen shed.

Soybeans
We continue to see a wide variety of defoliators present in full season soybeans including Japanese beetles, yellow striped armyworm, green cloverworm and grasshoppers. The best way to make a treatment decision in full season soybeans is to estimate defoliation. Before bloom, the defoliation threshold is 30%. As full season beans enter the reproductive stages, the threshold drops to 15% defoliation. Remember that double crop soybeans can not tolerate as much defoliation as full season beans so be sure to watch newly emerged fields carefully.

Continue to scout for spider mites in full season and double crop soybeans. Economic levels can be found in fields throughout Kent and Sussex Counties. With the current hot, dry weather, economic populations are being found field wide so be sure to scout the entire field because edge treatments may not be effective. At this time of year any rains we receive will allow beans to grow and then allow treatments to be more effective. If egg populations are high at the time of application, a second application will mostly likely be needed. Labeled materials include dimethoate, Lorsban (chlorpyrifos), Hero (zeta-cypermethrin + bifenthrin) as well as a number of stand-alone bifenthrin products. All of these products need to be applied before mites explode. Be sure to read all labels before making an application since there are restrictions on the total number of applications allowed, rotation between materials as well as the minimum number of days needed between applications.

Agronomic Crop Insects – June 22, 2012

Friday, June 22nd, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Soybeans
Early in the season there were a few reports of millipedes feeding on field corn and this week we have received reports of millipedes feeding on soybeans. In some cases, these same fields were also affected earlier by slugs. Similar to slugs, millipedes can feed on the cotyledons and stems prior to emergence resulting in death of seedlings. Unfortunately, there is little information available on the efficacy of chemical controls. Please refer to the following link for pictures and comments on what has been observed in other areas of the country. http://cropwatch.unl.edu/web/cropwatch/archive?articleID=4837611

With the recent hot weather, be sure to watch for an increase in both grasshopper and spider mite activity. Early control is needed with both of these pests. Some consultants are also seeing an increase in leafhopper populations in seedling stage soybeans. As a general guideline, a control may be needed for leafhoppers if you see plant damage and you find 4 leafhoppers per sweep in stressed fields and 8 per sweep in non-stressed fields.

Agronomic Crop Insects – June 15, 2012

Friday, June 15th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Continue to sample for potato leafhoppers on a weekly basis. We can find both adults and nymphs in fields at this time. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
In recent years, we have seen an increase in native brown stinkbug damage to developing corn ears, especially when fields are adjacent to wheat fields. Remember, corn is most susceptible to this type of stink bug injury during ear formation before the tassel stage (VT). Bugs feed through the sheath, causing a dead spot on the ear. As the ear expands it becomes distorted and curves usually outward. In the last 2 years, we have also seen kernel damage, not distorted ears, on the edges of corn fields resulting from Brown Marmorated Stink bug (BMSB) feeding. We are continuing to survey fields to evaluate the extent of the damage from all species this season. This past week we have observed low levels of native brown stink bugs present in whorl stage corn. We also found the first BMSB eggs on corn in New Castle County.

We also observed and received a few reports of heavy aggregations of Japanese beetle adults in the whorls of field corn in New Castle County. Other areas of the country are also reporting earlier than normal emergence of beetles. Currently, they do not appear to be feeding on the plants. As a general rule, whorl stage corn is very tolerant to defoliation. The following link provides information on the potential for yield loss in bushels per acre from whorl stage defoliation.

http://www.caes.uga.edu/commodities/fieldcrops/gagrains/documents/Buntin_InsectControlinFieldCorn.pdf

As we indicated earlier this season, we were able to confirm the presence of Western Bean Cutworm moths in pheromone traps for the first time in 2011. The counts were extremely low and no damage was observed to corn ears, but this is a pest we will need to watch for in both field corn and sweet corn. Adult moths generally fly in mid-summer (we could see earlier flights in 2012) and females lay eggs on the upper surfaces of corn leaves. Unlike black cutworm that feeds on seedling stage corn, this is a later season corn pest, which feeds on tassels, silks, and developing kernels and can cause severe damage. Factors that contribute to the risk of potential problems include: (a) sandy soils, (b) a high percentage of acres in reduced and no-till production, (c) high humidity, and (d) presence of multiple host crops. Since these conditions fit Delaware, we will need to watch and see if this insect becomes a serious pest over the next couple of years. We have expanded our survey this year and will keep you updated if we see an increase in populations.

Soybeans
Be sure to sample fields for bean leaf beetles, potato leafhoppers, thrips, grasshoppers, green cloverworm and spider mites. Grasshopper populations have increased, especially in no-till fields. As barley and wheat are harvested and soybeans are planted, these fields will be susceptible to attack and grasshopper feeding can often cause stand loss. If stand reductions are occurring from plant emergence to the second trifoliate, a treatment should be applied. Although no precise thresholds are available, a treatment may be needed if you find one grasshopper per sweep and 30% defoliation from plant emergence through the pre-bloom stage. Numerous products are labeled for grasshopper control including a number of pyrethroids, dimethoate, Lorsban (chlorpyrifos), Orthene 97 (acephate) and Sevin XLR (carbaryl). Be sure to check all labels carefully before combining insecticides and herbicides since there are a number of restrictions on the labels.

Continue to watch carefully for spider mites. Be sure to scout the entire field for mites since windy conditions can result in mites being found throughout a field. Labeled materials include dimethoate, Lorsban, Hero (zeta-cypermethrin + bifenthrin) as well as a number of stand-alone bifenthrin products. All of these products need to be applied before mites explode. Be sure to read the labels for use rates and restrictions – including but not limited to combinations with herbicides, number of applications as well as the time between applications.

For those who read Weekly Crop Update, you know that the presence of soybean vein necrosis virus was confirmed for the first time in 2011 in Delaware soybean fields. The following link provides pictures and more information on this virus. http://agdev.anr.udel.edu/weeklycropupdate/?p=3727 . Although we do know that thrips transmit this virus, we do not know which species transmit the disease or when transmission occurs. Work is being done in the Midwest to identify the thrips vectors and possible other hosts of the virus that may harbor it and allow thrips feeding to move it to soybeans. In 2011, it did not appear that yield loss occurred; however, more information is needed to determine if it will cause yield reductions or lower seed quality in our area. In 2012, we will include thrips monitoring in our soybean surveys as well as look for virus symptoms.

By now, most growers should also be aware of another potential new soybean insect pest, the Kudzu bug. It has not been found in Delaware as of this date. In 2011, this bug was found as far north as one southern county in Virginia near the North Carolina border. It was first found in Georgia in 2009 and within two years made its way through North and South Carolina. We have received funding from the Delaware Soybean Board to survey for this pest so we will be able to alert you if it makes it to Delaware in 2012.

Agronomic Crop Insects – June 8, 2012

Friday, June 8th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Continue to sample for potato leafhoppers on a weekly basis. We continue to find adults and nymphs in fields. Although both life stages can damage alfalfa, the nymphs can cause damage very quickly. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
In addition to thrips feeding, we are finding a few fields with cereal leaf beetle adult feeding. Although cereal leaf beetle problems were low in most small grain fields this season, beetle adults can be found moving out of untreated small grains and feeding on the edge of corn fields. Although we do not have any firm thresholds for this insect on corn, as a general guideline controls may be needed on corn if you find an average of 10 beetles per plant and 50% of the plants exhibit feeding damage. In the Midwest, it has been reported that the adult beetle is a vector of maize chlorotic mottle virus (MCMV) that causes corn lethal necrosis disease. Thresholds for beetle feeding would be much lower if this disease is an issue. As of last season, we have not seen this virus in Delaware corn fields. However, please let us know if you suspect a problem.

We are continuing our stink bug survey of corn fields next to wheat to evaluate movement of stink bugs from wheat into corn. Just this past week, we have found a few stink bugs in corn along field edges adjacent to wheat. Although we have not developed thresholds for our area, the following information developed in the South (North Carolina and Georgia) should provide guidance for management in our area:

(a) Until the V6 stage, the economic threshold is four stink bugs per plant.

(b) “Corn is most susceptible to stink bug injury during ear formation before the tassel stage (VT). Bugs feed through the sheath, causing a dead spot on the ear. As the ear expands it becomes distorted and curves, usually outward. Feeding during silking and pollen shed (R1) will also kill kernels on the ear. Once the ear has elongated, stink bug feeding during the blister and milk stages can blast individual kernels usually causing them to abort.”

(c) When the ear is forming, during ear elongation, and during pollen shed, the treatment threshold used in the South is one stink bug per four plants (25% infested plants).

(d) From the end of pollen shed to blister/milk stage, the threshold is one stink bug for every two plants (50% infested plants).

Soybeans
Be sure to sample seedling stage beans for bean leaf beetles, grasshoppers, thrips and spider mites.

Grasshoppers: Population levels are starting to increase, especially in full season no-till soybeans. As barley is harvested and soybeans are planted, these fields will be especially susceptible to attack by grasshoppers which can cause stand loss. If stand reductions are occurring from plant emergence to the second trifoliate, a treatment should be applied. Although no precise thresholds are available, a treatment maybe needed if you find one grasshopper per sweep and 30% defoliation from plant emergence through the pre-bloom stage.

Bean Leaf Beetle: As a general guideline, a treatment may be needed for bean leaf beetle if you observe a 20 – 25% stand reduction and/or 2 beetles per plant from cotyledon to the second trifoliate stages. These treatment thresholds should be reduced if bean pod mottle virus is present in your area or you suspected virus the previous season.

Thrips: At this time, soybean thrips and other thrips species are present in seedling stage fields. Thrips can feed and reproduce on the leaves and buds of soybean seedlings. Their feeding creates bleached-out lesions along the leaf veins and gives a silvery/bronzed appearance to the leaf surface when damage is severe. These insects are very small (less than 1/10 inch) and are torpedo shaped. While thrips always occur on seedling stage soybeans, it is only during outbreak years that they cause concern. In particular, during dry weather and on earlier planted full-season soybeans, thrips populations can explode when plants are growing slowly. Under these circumstances thrips injury will occasionally kill seedlings. Other stressors, such as nutrient deficiencies and herbicide injury, can add to thrips damage and cause plant loss. Yellowing can occur from thrips but there are also a number of other factors that can cause yellowing so it is important to scout fields to identify what is causing the yellowing. Although no precise thresholds are available, as a general guideline, treatment may be needed if you find 4-8 thrips per leaflet and plant damage is observed.

Spider Mites: The first spider mites have been found in seedling stage soybeans so be sure to scout fields as soon as plants emerge. Early detection and control is needed to achieve spider mite suppression. Dimethoate, Lorsban (chlorpyrifos), Hero (zeta-cypermethrin + bifenthrin) as well as a number of stand-alone bifenthrin products are available for spider mite control in soybeans. All of these products need to be applied before mites explode. Be sure to read the labels for use rates and restrictions – there is a limit on the number of applications as well as the time between applications on all of the materials labeled for spider mite control.

Agronomic Crop Insects

Friday, June 1st, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Continue to sample for potato leafhoppers on a weekly basis. Although adults are the main life stage present, we are starting to see the first nymphs. Both life stages can damage alfalfa but the nymphs can cause damage very quickly. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

If you have planted a glandular haired variety, we do not have any local data but here is some information from Ohio State regarding treatment thresholds on these varieties:

“If the alfalfa is one of the glandular-haired, leafhopper-resistant varieties of alfalfa, the economic threshold is three leafhoppers per inch of growth (24 leafhoppers for 8” tall alfalfa, for example). However, if the resistant alfalfa is a new planting this spring, growers should use thresholds meant for regular alfalfa during the first growth from seeding. Because resistance improves as the seedling stand develops, research suggests that the threshold for a resistant variety can be increased after the first cutting.”

This past week we received a few reports of high thrips populations in alfalfa. In past years, we have seen increases in thrips during hot, dry weather conditions. Reports from other areas of the country indicate that thrips feeding on developing leaf tissue can cause the leaves to distort as they emerge. Leaves may also be curled, with a cupped or puckered appearance. Since there are no thresholds for thrips in alfalfa, the following information from other areas of the country may be helpful when considering the need for thrips management: (a) high populations of bean or onion thrips may cause damage, especially in dryland conditions and (b) if a thrips treatment is contemplated, it is best to cut as soon as possible and treat the regrowth if the infestation persists. Thrips are very difficult to control in alfalfa, so excellent coverage is important and two applications may be required for satisfactory results

Field Corn
Since last week, we have had a number of reports of true armyworm moving from barley into adjacent corn fields. In many cases, larvae are large and control will be difficult once larvae move deep in whorls. Remember, worms must be less than 1 inch long – some labels indicate that larvae need to be even smaller – to achieve effective control. The treatment threshold for true armyworms in corn is 25% infested plants with larvae less than 1 inch long.

There have also been a number of reports of thrips feeding on field edges. As small grains dry down, it is not unusual to see thrips populations increase along the edge of a field. In the past, no controls have been needed but it always warrants watching fields to be sure populations and leaf damage does not increase. No thresholds are available.

Although most fields are past the seedling stage, there have been a number of questions this spring about damage caused by seedling stage insect pests. The following posting by Dominic Reisig, North Carolina State University Extension Entomologist, does an excellent job of describing seedling insect pests and their damage: http://www.nccrops.com/2012/05/23/distinguishing-among-insect-injury-types-in-seedling-corn/. One of the insects he describes is the sugar cane beetle. Although I have never encountered sugar can beetle attacking field corn in Delaware, we did receive one question about this insect from a field in southern Maryland. It continues to be a very different year so be on the lookout for unusual insect problems this year.

Soybeans
Be sure to sample fields starting at emergence for bean leaf beetles and grasshoppers. In the earliest planted and emerged fields, we have started to see an increase in activity for both insects. As barley is harvested and soybeans are planted, these fields will be especially susceptible to attack from grasshoppers and feeding can often cause stand loss. If stand reductions are occurring from plant emergence to the second trifoliate, a treatment should be applied. Although no precise thresholds are available, a treatment may be needed if you find one grasshopper per sweep and 30% defoliation from plant emergence through the pre-bloom stage. As a general guideline, a treatment may be needed for bean leaf beetle if you observe a 20 – 25% stand reduction and/or 2 beetles per plant from cotyledon to the second trifoliate stages.

Agronomic Crop Insects – May 25, 2012

Thursday, May 24th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Potato leafhoppers are now present in fields so be sure to sample on a weekly basis. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
True armyworms can now be found in corn fields. There have also been reports of yellow striped armyworm in fields which I have not seen before. As small grain dries down, be sure to watch for true armyworms moving out of small grain and into adjacent corn fields. You should also scout corn for true armyworms in fields that were planted into a small grain cover. Remember, worms must be less than 1 inch long to achieve effective control. The treatment threshold for true armyworms in corn is 25% infested plants with larvae less than one-inch long. Large larvae feeding deep in the whorls will be difficult to control.

Soybeans
This past week we saw a significant increase in slug damage in no-till soybeans, especially in fields planted into heavy corn stalk or double crop soybean stubble. Slugs are extremely difficult to manage in soybeans because the damage can occur below the ground before plants emerge. Damage to soybean can be more severe than damage to corn because the plant’s growing point is within the emerging cotyledons. If soybean plants are able to emerge, the plant may be able to send out the unifoliate leaves where slug feeding will be noticeable. However, slugs often feed on the cotyledons below ground and/or just as the beans are cracking through the surface feeding on the growing point. This type of feeding results in the death of the plant and significant stand loss. In 2010, we saw significant stand losses from slugs feeding below ground before plants emerged. With the continued cool, wet weather in 2010, the only effective control option was to till fields , then wait until fields dried out and the weather was warmer to encourage quick germination before re-planting. In 2010, it was also extremely difficult to time a bait application. This year, a bait application could be an option if you are scouting fields routinely, plants are just emerging and before there is significant feeding on the growing point. We have had very limited experience with bait applications in soybeans, especially with applications ahead of plant emergence. We will be evaluating fields treated recently to determine the effectiveness and timing of the bait applications.

Agronomic Crop Insects

Friday, May 18th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Potato leafhoppers are now present in fields so be sure to sample on a weekly basis after the first cutting. Once the damage is found, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
During the past week, we have seen an increase in the number of no-till fields with economic damage from cutworms. Damage has mainly occurred in fields that were not treated with a cutworm product at planting. Be sure to scout fields carefully for cutworms – in some cases you will need to check fields twice a week to be sure you do not miss an economic population. In addition to cut plants, be sure to watch for leaf feeding which can be an indication of the potential for significant cutting damage and yield loss.

Slugs continue to be a problem in later planted fields. In fields where Deadline MPs have been applied at a rate of 10 lbs. per acre and the distribution of pellets is at 5 per square foot, control has been very good. The best control with the Deadline M-Ps (up to 2 weeks in some cases) has been observed when applications were made and there was at least one day of sunny weather after an application.

Small Grains
We continue to find armyworms and cereal leaf beetles in barley and wheat fields that were not treated. Population levels remain variable throughout the state so scouting fields will be the only way to determine if an economic level is present. Although armyworm can attack both wheat and barley, they can quickly cause significant losses in barley. Heavy defoliation of the flag leaf can result in significant economic loss. Armyworms generally begin head clipping when all vegetation is consumed and the last succulent part of the plant is the stem just below the grain head. Larvae can feed on the kernel tips of the wheat, resulting in premature ripening and lower test weight.

As barley and wheat approach harvest, the treatment options change due to the pre-harvest interval (the waiting period between application and harvest). In addition, not all materials are labeled on both crops so be sure to carefully read all labels – remember the label is the law.

Soybeans
As the earliest beans emerge, be sure to watch carefully for slug damage. Remember, if you had a problem in past years, the slugs may still be present in fields and can quickly damage soybeans if present as plants emerge. Be sure to also watch fields carefully for bean leaf beetles and grasshoppers. Small grasshoppers have already been detected in fields before planting. Early detection and control of small grasshoppers is necessary to achieve control. As a reminder, OP insecticides (examples – dimethoate or Lorsban) cannot be combined with SU/ALS herbicides. Since other materials may also state restrictions regarding combinations of insecticide and herbicides, you should be sure to check all labels carefully before combining insecticides and herbicides.

Agronomic Crop Insects – May 11, 2012

Friday, May 11th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
In addition to checking for weevils feeding on re-growth, be sure to begin checking all fields for leafhoppers within one week of cutting. Spring planted fields should also be sampled since they are very susceptible to damage. Once the damage is found, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
In addition to slugs and cutworms, be sure to sample fields for true armyworm larvae, especially where a grass cover or volunteer small grains were burned down at planting. As a general guideline, a treatment may be needed for armyworms if 25% of the plants are infested with larvae less than one-inch long.

Small Grains
Continue to scout fields for cereal leaf beetles, armyworms and sawflies. In unsprayed fields that have a history of cereal leaf beetle, we have observed a significant increase in activity this week. Cereal leaf beetle can cause the greatest economic loss from flowering through the soft dough stage. Once wheat reaches the hard dough stage, the beetle feeding damage generally has little effect on yield. It is important that you scout fields on a weekly basis until harvest for armyworm and sawfly larvae. We continue to find larvae in fields that have not been sprayed yet. Although sawflies and armyworm can attack and cause economic losses in both wheat and barley, in outbreak years the damage often occurs quicker in barley. Since populations of all of these insects vary from field to field, fields should be scouted to determine if economic levels are present. As a general guideline, if multiple insects are present, the threshold for each insect should be reduced by one third to one half. 

Black Light and Pheromone Trapping Program Has Begun

Thursday, May 3rd, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Our black light and CEW pheromone traps are now up and running for the season. The traps are generally checked on Monday and Thursday and counts are posted by early Tuesday and Friday morning. True Armyworm moth catches will be posted only through the month of May. We will once again check traps for all stink bug species. Please use the following link to access all trap information: http://ag.udel.edu/extension/IPM/traps/index.html. I will also begin the Crop Pest Hotline mid-May (instate: 800-345-7544; out of state: 302- 831-8851).

Agronomic Crop Insects – May 4, 2012

Thursday, May 3rd, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Since weevil populations have been heavier this year and in some cases fields were not sprayed, be sure to check for both adults and larvae within a week of cutting. Feeding from both stages can hold back re-growth. After cutting, there needs to be enough “stubble” heat to control the weevils with a cutting. A stubble treatment will be needed if you find 2 or more weevils per stem and the population levels remain steady.

Field Corn
The recent cooler wet weather in combination with an earlier slug hatch due to the warm winter and March has resulted in an increase in slug damage this past week. We have seen a number of fields with economic levels of slug damage, especially in fields with heavy no-till covers and a history of problems. Options to reduce damage and allow plants to grow ahead of the damage include the use of Deadline M-Ps (or other available metaldehyde baits), Lannate LV ( DuPont issued a 2ee recommendation for slug management in field corn in DE, MD, PA, VA and WV in 2010) or 30% Urea Ammonium Nitrate (UAN) fertilizer. In years past, 30% UAN applied at night when the plants are dry and there is no wind has resulted in variable levels of success (the rate used in past years was 20 gallons per acre of 30% UAN on corn in the spike to one-leaf stage and the mix was cut 50/50 with water to reduce – but not eliminate — plant injury). The best control with the Deadline M-Ps has been observed when there is at least one day of sunny weather after an application. In general slugs stop feeding in 2-3 hours. Although we only have one year of research data with Lannate LV, growers using it this season have reported that they feel it is helping plants to stay ahead of the damage. We are doing a trial again this year to look at application timing. Please see the following link for the Lannate LV 2ee recommendation: http://www.cdms.net/LDat/ld183004.pdf. Remember that when it comes to slug management all of the available control tactics generally reduce the slug activity – buying time to enable the crop to outgrow the problem.

Small Grains
We continue to find armyworms and cereal leaf beetles in barley and wheat fields that were not treated, so be sure to check fields as soon as it is dry enough in the day to do a good job scouting. Population levels remain variable throughout the state so scouting fields will be the only way to determine if an economic level is present. Depending on the temperature, cereal leaf beetle larvae will feed for up to 3 weeks. Research from Virginia and North Carolina indicates that the greatest damage can occur between flowering and the soft dough stage so continue to sample carefully for this insect. Although armyworm can attack both wheat and barley, they can quickly cause significant losses in barley. We are also starting to see an increase in sawfly adults laying eggs in wheat fields so hatch may be delayed. Continue to sample for sawflies, especially in areas with a history of problems. Before treatment, be sure to check all labels for the days allowed between last application and harvest.