A PRACTICAL RESEARCH DIGEST FOR TURF MANAGERS

Volume 8, Issue 4 • April 1999

ENTOMOLOGY IN THIS ISSUE

Red Imported Fire Red Imported Fire Ants Continue to Spread Continue to Spread North and West North and West ... .1 Friend or Foe

Dr. Beverly Sparks, Professor and Extension Entomologist, Look Inside an Mound The University of Georgia Control Strategies olenopsis invicta (Buren), the red imported , was accidentally brought into Treating Mounds Mobile, AL in the ballast of ships from in the 1930s. Since its intro- S duction, this has spread throughout the southeastern United States and now continues to expand its northward and westward distribution into areas with mild climates and adequate moisture and food. The ants currently infest over 240 million acres and can The Tlirfgrass Ant . .6 be found throughout Puerto Rico, Florida, Georgia, Alabama, Mississippi and Louisiana and in portions of South Carolina, North Carolina, Tennessee, Arkansas, Oklahoma and Texas. Why Ants Succeed In addition, infestations of the red imported fire ant were recently found in Fresno, Kern, Colony Life Cycle and Orange Counties in California. Fire ants disperse naturally through mating flights, through colony relocation over short Ants as Pests distances or by floating to new locations in floodwater. Humans also assist in the distribu- tion or movement into new locations through shipments of ant infested nursery stock, sod, Control Strategies soil, hay, pine straw or beehives. Despite quarantine efforts aimed at preventing the move- ment of fire ants, it is not uncommon to find that imported fire ants "jump ahead" of the natural distribution due to movement of infested products. Using Eto to Improve Irrigation Efficiency .11

Crop Coefficients and Uniformity

Determining Run Times

Catch Can Tests

Optimizing Application

Don't Set and Forget

ET-Based Irrigation Has Arrived

Visit us at Large mound of the imported red fire ants. www. landscapegroup. com TURFGRASS TRENDS

Executive Editor Sue Gibson 440-891-2729; 440-891-2675 (fax) may suffer chest , nausea or lapse into sgibson@advanstar. com Friend or foe? a coma from even one sting. Managing Editor Bruce F. Shank, BioCOM In some settings the red imported fire 805-274-0321 ant is considered a beneficial . The Technical Editor ants feed on just about anything, but their Look Inside an Ant Mound Nancy Stairs preferred source of food is other . In Fire ant colonies consist of the brood 440-891-2623 some agricultural settings they prey on very (eggs, larvae and pupae) and adult ants. The Senior Science Editor destructive insects. They also reduce the Dr. Karl Danneberger various types (castes) of adult ants include populations of many human and winged males, winged females, one or more Consulting Editor Chris Sann pests, such as ticks, fleas and flies. egg producing queens and workers. Within a colony, the worker ants vary a great deal in Group Editor Although fire ants can be considered to Vern Henry be beneficial insects in some settings, when size, but they are all sterile, wingless females.

Production Manager looking at the "big picture," one must con- Workers care for the queen and the brood, Karen Lenzen sider the numerous problems they create. forage for food and defend the colony. 218-723-9129; 218-723-9576 (fax) Once fire ant mounds are exposed to envi- klenzen@advanstar. com Winged adults and queens are responsi- ronmental conditions, the above-ground ble for dispersal and reproduction. The Circulation Manager Frank Christopherson portion of their mounds becomes very winged "reproductives" eventually leave the 218-723-9271 hardened and causes significant damage to mound in large numbers to mate in the air. Croup Publisher turf and farm equipment. Damage to This mating or nuptial flight can take place John D. Payne equipment results in lost time in labor as any time of year, but usually occurs in the 440-891-2786; 440-891-2675 (fax) jpayne@advanstar. com well as equipment repair costs. Adult ants spring or early summer after a rainy period. often move into electrical housing units and Males die shortly after mating. The newly Corporate & Editorial Office 7500 Old Oak Blvd. chew away insulation from wiring. Fire ants fertilized queen can fly for several miles Cleveland, OH 44130-3369 cause numerous power outages or electrical before she falls to the ground, sheds her Mew Subscriptions shortages in air conditioners, irrigation con- wings and begins digging a chamber in 1-888-527-7008 trol boxes, traffic lights and water pumps. In which to start a new colony. Abstracts: 800-466-8443 areas where heavy infestations occur (200- The new queen lays a small cluster of Reprint: 440-891-2744 plus mounds per acre), fire ants have signif- eggs that hatch in seven to ten days. The Permission: 440-891-2742 Single copy or back issues: icant effects on populations of ground nest- queen initially provides nourishment to this Subscription/Customer Service ing birds, deer and other wildlife. Imported first group of larvae, but later on, she lays up 1-888-527-7008; (fax) 218-723-9437 fire ants will also feed on seeds and young Website address: to 200 eggs per day and the care of the eggs www.landscapegroup.com roots, causing significant plant loss in some and larvae is taken over by worker ants. agricultural cropping systems. The larvae develop for six to ten days before w Although fire ants damage equipment, pupating. Adults emerge from the pupae in ADVANSTAR cause electrical problems and harm wildlife, nine to 15 days. The average fire ant colony HOLDINGS, INC. the most significant problem associated contains 100,000 to 500,000 workers and Chairman and with fire ants is their stinging behavior. The up to several hundred winged forms. Chief Executive Officer Robert L. Krakoff ants are very aggressive and will readily Mounds may contain only one egg-laying

Vice Chairman attack anything that disturbs their mound. queen (monogyne colony) or have multiple James M. Alic When a mound is disturbed, large num- queens (polygyne colonies). Single queen VP-Finance, CFO & Secretary bers of worker ants come to the mound sur- colonies will not accept workers from other David J. Montgomery face to defend the colony. An unsuspecting colonies and are defensive of their Executive Vice President, victim can be rapidly covered with ants. territory. Populations of single queen Business Development colonies usually stabilize at 40 to 80 Skip Färber The ants anchor themselves with their mouthparts and then sting repeatedly. mounds per acre. Multiple queen colonies injected through their sting causes a are more accepting of workers from other W burning and itching sensation and often colonies and thus their populations often ADVANSTAR COMMUNICATIONS causes a white pustule to form. Although exceed 200-plus mounds per acre. Executive Vice Presidents fire ant stings are not usually life threaten- The mound of a new colony is not con- William J. Cooke ing and are medically uncomplicated, a few Alexander S. DeBarr spicuous until several months after the people are hypersensitive to the venom and young queen begins egg laying. The size of Vice President & General Counsel Eric I. Lisman

Treasurer and Controller Adele D. Hartwick the mound depends upon soil characteris- tics and land disturbance. In heavy soils the upper portion of the mound is often coni- cal and can reach a height of 12 to 18 inch- es, while in sandy soils the mounds are less well developed. The underground portion of the mound is a series of tunnels and chambers that may extend three to four feet deep.

Fire Ant Control Strategies Total elimination of the red imported fire ant in fully infested areas is not techni- cally, environmentally or economically fea- sible. Temporary control of fire ants can be achieved with the use of chemicals; how- ever they must be periodically reapplied for Although fire ant stings are not usually as long as control is desired. If treatment is life threatening, a few people are hyper- terminated, reinfestation is likely to occur sensitive and may suffer chest pains, as newly mated queens from surrounding nausea or lapse into a coma. areas reinvade the area. Furthermore, it is common for the newly repopulated levels in small areas where there are low popula- to be larger than the population prior to the tions of fire ants (less than 20 mounds per initial treatment! acre). Treating each mound requires more The decision to treat fire ants, once labor and monitoring than other treatment taken, must be accompanied by a long- techniques and is not sug- term commitment to continue periodic gested for areas where fire treatments. Because of this need for a long ant populations are extreme- Time insecticide term commitment, it may be difficult to ly heavy. applications when the economically justify an ongoing control To be effective, it is program in many agricultural settings. In important to time applica- adult ants and their high use areas such as parks, playgrounds, tion of these insecticides to brood are located in recreational turf areas and home lawns, jus- when the adult ants and tification for fire ant control programs is their brood are located in the the top portion of the more subjective. One must decide when top portion of the mound. mound, usually in the fire ants become intolerable and how much Mound treatment is most to invest in control efforts. These decisions effective when applied in the spring or fall or are influenced by potential health risk due spring or fall of the year or following periods of to the presence of fire ants and by the envi- following periods of heavy ronmental impact of chemical applications. rain. This technique of treat- heavy rain. ment selectively controls fire ants but reinvasion of the site Treating Individual by ants is often observed within three to six Mounds months. Common methods used to treat indi- Mound drenches: Most fire ant control vidual mounds include drenching each products are formulated as liquid concen- mound with a diluted liquid insecticide; trates, although a few are ready-to-use application of granular insecticides to the formulations. These concentrated prod- top of each mound; of insecticide ucts may need to be diluted in the into each mound; or application of bait amount of water specified on the around each mound. product's label so care should be taken in The treatment of individual mounds is a handling the concentrate to avoid con- control technique that is best suited for use tact. The solution is poured on top of and around the perimeter of an undisturbed can be applied around individual mounds mound. It is important to deliver the or broadcast over larger areas at specified diluted insecticide to the mound in quan- rates. As an individual mound treatments, tities large enough to reach the queen and bait products are slower acting and often the brood. On larger mounds, up to two more expensive than drenches, granular gallons of diluted insecticide may be or injectable insecticides, but as an area needed. Mound drenches generally do not treatment they offer the advantage of kill ants immediately and may require covering larger areas for moderately several days to be effective. infected sites (greater than 20 mounds Granular products: Several products per acre. containing insecticides have been formu- Using baits as a broadcast application for lated as granules to be applied to indi- infested areas prior to individual mound vidual mounds at a specified rate. To treat treatment can be an effective longer term a single mound, the recommended treatment strategy. This approach is best amount is sprinkled on top of and around suited for larger areas where fire ant popu- the base of the mound without disturbing lations exceed twenty mounds per acre and the mound. If instructed, water the gran- there is little or no concern for preserving ules into the mound without disturbing native ant species. This combined program the colony. Several days may be required of area treatment followed by mound treat- for the entire colony to be controlled. ment provides long term ant suppression Dusts: A few products, such as those and minimizes the necessity of individual containing the active ingredient acephate, mound treatments. are specially labeled for dusting indi- vidual fire ant mounds. The powder is dis- tributed evenly at the recommended rate Application methodology over the mound. Treated mounds should Contact insecticides: Several control be eliminated within one week. Acephate products are labeled for broadcast appli- can also be used as a mound drench. cation. The granular formulations are Injectable products: Products con- usually applied with either broadcast or taining pyrethrins, tetramethrin or chlor- drop- fertilizer spreaders and the pyrifos are manufactured in special liquid formulations can be applied with aerosol containers to which an injection high volume hydraulic or individual back- rod can be attached. The rod is inserted pack sprayers. Once applied, these into the mound in a number of places, contact control materials should be thor- according to instructions on the label, and oughly watered into the soil. the pesticide is injected for a specified Products containing carbaryl, chlorpyri- time into each mound. Smaller mounds fos, diazinon or isofenphos are longer act- may require less insecticide. Products ing, contact insecticides that primarily sup- containing pyrethrins immediately kill press foraging ant activity and can prevent ants in the mound; however, foraging small mounds from becoming established. workers outside the mound are not In some cases and through repeated use, affected. Although these products are these treatments can eliminate colonies. more expensive and time consuming to Bait-formulated insecticides: Bait prod- use, they tend to give faster results than ucts contain different active ingredients mound drenches. Injectable products also that work in unique ways. have the advantage of depositing the pes- Hydramethylnon kills ants that ingest it ticide underground out of reach of people by interfering with the ants' ability to con- and pets. vert food into energy. When applied at the Baits: These products contain pesti- broadcast rate, approximately 80 percent of cides formulated on bait of processed the mounds in the treated area will become corn grits coated with soybean oil. Baits inactive within about five weeks. The active ingredients fenoxycarb, Conclusion abamectin, pyriproxyfen or s-methoprene Managing imported fire ants requires is a act as "insect growth regulators" when multifaceted strategy. applied at broadcast rates. These products do • Managers must decide if the current not kill worker ants or queens; instead, they location of any mounds requires control render most queens incapable of egg pro- efforts. duction and cause the brood to develop into • Once a control decision is made, man- winged males and sterile females. Reduction agers should quantify the level of infestation of mounds within a treated area is slow, at the site. requiring several weeks to many months for • Areas of light infestation can be man- the worker ants to die off. However, during aged with individual mound treatment this period, the weakened mounds in the strategies. treated area apparently prevent recoloniza- • Moderate infestations can be managed tion by newly mated queen ants, providing with broadcast treatments. an extended period of suppression which • Heavier infestations can be managed may last up to a year after treatment. with a combination of broadcast and The time required for ants in treated mound treatments. mounds to die depends on the active ingre- • Extensive site infestations in heavily dient used. Hydramethylnon usually elimi- infested regions of the country usually nates ants in about a week. Avermectin has require some accommodation be made some toxic effect on worker ants at high between human and ant activity, in addition dose, but still requires several weeks to to control measures, for satisfactory results achieve control. Ant activity in mounds to be obtained. treated with fenoxycarb, pyriproxyfen or s-methoprene may be seen for five weeks or Beverly Sparks, Ph.D., is professor of ento- longer following treatment as worker ants mology and extension program coordinator slowly age and die. in entomology for the University of Georgia, Athens, GA.

imported Fire Ant Quarantines

13

S Part of county quarantined H All of county quarantined Puerto Riuu

Kes^ricuons are imposed on me movement OT reguiaxea articles Consort your Slate or t-ederal plant protection inspector frorri the quarantined (shaded) areas Into or through unshaded areas. or your county agent for assistance regarding exact at u«*der regulation and requirements Tor moving regulated article». For detailed information see 7 CFR381.81 for qu« <>! itine and regulations iiune 189» The Türfgrass Ant Lasius neoniger

By Sean F. Werle, University of and this number is probably a good estima- Massachusetts, Amherst tor of the diversity in any temperate area. Ant diversity will increase with decreasing hat are ants? This question has latitude — the closer to the equator one almost as many answers as there looks, the more species of ants one can find. are people who might consider it. WTo your child, ants may be the industri- ous residents of an antfarm on a bookshelf Why Ants Succeed or the fascinating combatants that engage in The reasons for the evolutionary success epic battles on the pavement of your drive- of ants are numerous, but there are several way. To an ecologist, they are members of that stand out. These are eusociality, chem- the insect family Formicidae, and are one of ical adaptation and general hardiness, prob- the most important cogs in the complex ably in that order of importance. biological machinery that Eusociality refers to the fact that ants are they study, exerting an effect social insects, similar to some of the bees and The pest status of ants on every other part of a given . E.O. Wilson defines eusocial insects is a phenomenon ecosystem. as those that possess three traits: cooperative If one is in the business of brood care, reproductive caste differentia- that has developed managing turf however, ants tion and overlapping generations. fairly recently; within are more and more often All ants exhibit these traits. Immature becoming a problem that has ants are completely helpless and depend the last 20 to 30 years. to be dealt with. The pest upon adult "worker" ants to care for and status of ants is a phenome- feed them. These worker ants are incapable non that has developed fairly of reproducing; that is the job of the repro- recently, within the last 20 to 30 years. The ductive castes, which include the queen, or reasons are not quite clear, but some queens, and the winged males. hypotheses have been advanced and this Ant colonies can be monogyne, with article will address those ideas and also try only one queen, or polygyne, with multiple to answer the question posed above. queens. Both of these conditions can occur in the same species, as is the case with Solenopsis invicta, the red imported fire ant, The Ant World a notorious ant pest that is discussed in It has been said that the combined num- another article in this issue. ber of ants on the Earth is greater than all "Overlapping generations" refers to the other land combined, which is fact that ant queens survive for many sea- quite possible. Studies of the turfgrass ant, sons, and thus can produce many genera- Lasius neoniger, reveal populations greater tions of offspring in a lifetime. Wilson had a than 10 million ants per acre in heavily turfgrass ant colony that lived for 30 years infested turf. A single ant colony can have as with a single queen. few as 35 ants, in some species, to as many The extreme chemical adaptation of as 1 million or more in others. ants is another factor in their success. Ants There are over 12,000 described species have evolved many glands to produce of ants; a large proportion of these are trop- chemicals that help the colony function. ical, but there are many temperate and even Some are used to raise an alarm in the case arctic species. The state of Massachusetts is of danger from outside, some are for mak- home to approximately 110 species of ants, ing trails that other ants can follow to a source of food or water and still others are Lasius neoniger, the egg-laying queen spends antiseptic, keeping the colony free of infec- most of the season laying fertilized eggs that tions caused by fungi or bacteria. This will develop into female worker ants. These extreme chemical dependence has given workers comprise the majority of the ants a highly developed sensitivity to many colony and are responsible for all of the chemical compounds and some studies food gathering, defense and have shown that they are capable of detect- brood care for the nest. Many ing and avoiding insecticide applications ants share food within the Late in the summer, (Vittum and Werle, unpublished data). colony through a process The general hardiness of ants is quite called trophalaxis where liq- the queen begins to lay remarkable. Some are able to survive immer- uid food is regurgitated and fertilized eggs. Once sion in water for as long as two weeks and passed between workers or others have been exposed to intense radia- from workers to the queen or hatched, specially tion with no ill effect. This toughness means the brood (larvae). treated larvae develop that, for many species, an established colony Late in the summer, the is unassailable by other insects or animals. queen begins to lay fertilized into large winged Many ants can both bite and sting, and eggs and also to feed some of females called Alates; are very capable defenders of their colony. her female larvae differently The tropical ant ( clavata), from than normal worker larvae. The who will become Central and South America, is commonly unfertilized eggs develop into queens once they mate known as the bullet ant because it is said winged male ants and the spe- that the sting of this ant is more painful than cially treated larvae develop during a nuptial flight, a gunshot wound, though the accuracy of into large winged females. usually in August. this is debatable. These winged ants, called alates, build up in the nest and are prevented from leaving by the workers. Colony Life Cycle Sometime near the end of August, some poor- The life cycle of a colony is roughly sim- ly understood signal causes the workers to ilar for all ant species. In the turfgrass ant, allow the alates out of the nest and they take

Turfgrass Ants and Predatory Beetles in Pitfall Traps m

Ants Beetles

45 feet 30 feet 15 feet Border 15 feet 30 feat 45 feet Fairway Rough flight simultaneously across large regions. This These ants need grasses in order to sur- is called the nuptial flight and it occurs once vive because a large part of their food is every year. During this flight the male and indirectly derived from the grass itself. The female ants mate and, after flying some dis- ants don't consume plant material; instead, tance, settle back to the ground. they tend small aphids [Anuraphis maidi- The males have served their radicis, the corn root aphid), which feed on purpose at this point and are the grass roots and produce a sugar-rich The ants don't doomed, falling prey to other excretion called honeydew which the ants ants or insects or dying of consume. These aphids, in turn, are com- consume plant starvation. The females, now pletely dependent on the ants. material, instead they mated and ready to establish Metcalf described this relationship as new colonies, will fly in follows: "This aphid is rarely found on roots tend small aphids search of an open grassy area. except where attended by the ants and, if which feed on the grass Studies have shown that the placed on the surface of the ground, is queens will avoid entering apparently helpless so far as finding a place roots and produce a wooded areas. Thus, if they to feed is concerned. An ant finding one of sugar-rich excretion, began their flight on a golf these aphids, however, immediately picks it course, they will likely up, carries it underground and places it on called honeydew, remain somewhere on the the roots of one of the aphid's food plants." which the ants course. Once they have In the winter, the ants bring the eggs of found a suitable spot, they the aphid down below the frost line and in consume. will chew off their wings, the spring they place the newly hatched burrow into the ground and aphids back on the roots of the grass. The lay a small clutch of eggs. root zone of ant-infested turf often sup- These eggs develop into undersized work- ports large populations of these aphids, ers called nanitics that immediately begin though seldom enough to cause pathology foraging. Once they have brought back in the plant. enough food, the queen begins laying eggs In addition to this food source, the ants that have enough energy to develop into constantly forage around the nest, preying normal workers. upon other insects and insect eggs. Rolando Despite the ant's reputation for organi- Lopez, a scientist working at the University zation, this whole process is actually rarely of Kentucky, has observed turfgrass ants car- successful. There are many dangers faced by rying away black cutworm eggs. This obser- the foundling queen and her tiny nanitic vation has implications in regard to control workers. But, when she does succeed, a new because it suggests that if ants are com- colony is established. Given the large num- pletely eradicated from an area, secondary bers of alates produced every year, the num- pest outbreaks could result. ber of ant colonies in an area will tend to Turfgrass ants also cause a significant increase over time. amount of soil aeration and their activities move nutrients down below the thatch; activities that can be beneficial to the health Ants as Turfgrass Pests of the turf ecosystem. As turfgrass pests, all of this evolutionary The primary problem with turfgrass ant success can add up to a big thorn in the turf- activity in managed turf is their nest struc- grass manager's side. In New England, the ture. The ants nest in the soil in large com- primary ant problems are caused by the plexes of interconnected tunnels and gal- aforementioned turfgrass ant, Lasius leries that can extend more than three feet neoniger. This is a small light to dark brown into the soil and often have multiple ant, about an eighth of an inch long, which entrances. primarily inhabits open areas such as turf, cornfields and pastures. The ants nest in the soil in large com- plexes of interconnected tunnels and gal- leries that can extend more than three feet into the soil and often have multiple entrances. All of the soil excavated to form these tunnels is brought to the surface. The result is an "anthill" like structure. It is not an ant mound in which the ants actually reside. In an infested area there can be as many as ten of these small ejected mate- rial mounds per square yard.

Anthills and Mounds All of the soil excavated to form these tunnels and galleries is brought to the sur- face and piled around the entrance holes leading into the nest. The result is an on golf course greens, they can detrimental- "anthill" like structure. This term is enclosed ly affect game play, a situation that most in quotes to emphasize the distinction members will find unacceptable. After between an anthill or ant mound in which some time, the small piles of soil will smoth- the ants actually reside, and an anthill which er the grass underneath, resulting in small is simply composed of material ejected dead patches that remain even after the ants from beneath the soil by the ants such as have ceased using that entrance. those constructed by turfgrass ants. In an The most pressing concern, however, is infested area there can be as many as ten of the damage to equipment that results from these small ejected material mounds per mowing over the mounds. The small soil square yard and this causes a number of particles dull mower blades and clog rollers, problems. causing a significant increase in equipment Aesthetically anthills and mounds can maintenance costs. greatly degrade the appearance of turf and, Why ants increase western Massachusetts), timing of applica- tion can be an important factor in control. Among a number of possible causes for If an effective material is applied at this the recent increase of ants as turf pests, the time, the colony will suffer a serious setback two that stand out are decreased mowing in its initiation of warm weather activity height and the loss of organochlorine insec- and this can delay the onset of turf man- ticides. For many years, chlorinated organic agement problems. compounds such as chlordane were used Another possible avenue of control is to extensively in turf to control a number of adjust mowing height in order to mask ant pests, mainly scarab beetles. These com- activity. Fairways mowed at three quarters pounds are highly toxic to ants of an inch are unlikely to exhibit ant prob- and thus ant populations were lems because the soil ejected from the nests The best long-term probably secondarily con- will not reach above the grass. Often solution is probably to trolled by these applications. changes such as this are unacceptable to Since the use of these materi- club memberships and so ants remain a dif- find ways to coexist als was discontinued in the ficult and expensive problem for the people 1970s, ants have possibly been in charge of managing turf. with the ants, using a released from this chemical combination of care- constraint and thus are able to Conclusion fully timed pesticide emerge as pests. Another possibility is the It is appropriate to return to the ques- applications and "Stimpmeter factor." As golf tion posed at the beginning: what are ants? adjustments to fairway courses have competed to Hopefully the point has been made that increase green speed, mowing while ants are a serious problem in many and greens mowing heights have steadily de- turfgrass settings, they are beneficial in heights. creased. Turfgrass ants are sel- other ways also. dom cited as home lawn pests Understanding what ants are and how and their presence is difficult they fit into the local turf ecosystem (i.e., to detect in a golf course rough. This is identifying and controlling food sources) is because the grass is mowed at a height that important for responsible ant management. masks ant activity. On short-mowed fair- However, if all your efforts prove fruitless, ways and greens, this masking is removed then the best long-term solution is probably and ants that may have been present but for turf managers to find ways to coexist undetected at a slightly higher mowing with the ants, using a combination of care- height are revealed as pests. fully timed pesticide applications and adjustments to fairway and greens mowing heights. Controlling Turfgrass Ants Think of it this way: With all of the myr- Lasius neoniger has proven difficult to iad insects out there that eat grass, can control. Many insecticides are ineffective insects that eat other insects be all that bad? against them and, as mentioned before, they are capable of detecting applications and Sean F. Werle is a graduate student of Dr. avoiding materials in some cases. Studies at Pat Vittum in the Department of Entomology Dr. Vittum's lab at the University of Mass- at the University of Massachusetts, Amherst. achusetts have revealed no material that is effective for more than a few weeks in con- trolling mound-building activity. Some patterns have been seen that may be helpful, however. Since the ants spend the winter deep in the soil and move rapid- ly to the surface in the spring (early April in