A PRACTICAL RESEARCH DIGEST FOR TURF MANAGERS TurfGrass TRENDS Volume 6, Issue 1 January 1997 Managing Mole Crickets: IN THIS ISSUE Developing a Strategy for Success Managing Mole Crickets: Developing a Strategy for by Rick Brandenburg Success North Carolina State University Mole Crickets: The Problem Mole Crickets: The Problem The Challenge of Management Mole crickets have firmly established themselves as a major turfgrass pest, not Mole Cricket Life Cycle only in the Southeastern United States, but throughout the world. Concerns A Mole Cricket Management Plan over the potential damage from this pest range from Spain and Italy in Europe to South Africa and Southeast Asia. While different species are responsible for Five Steps to Effective Mole these infestations, they all-regardless of where they occur-are capable of Cricket Management. ... 7 causing severe damage and are difficult to control. Back to Basics - Insecticide The consistent themes of serious damage and expensive control measures have Primer, Part Two: Chemical moved this pest to the number one status for many turfgrass managers in Classes of Turfgrass affected areas. In the United States, the problem extends from eastern Texas Insecticides 9 across Louisiana, Mississippi, Alabama, Georgia, and Florida and north up the coast through South Carolina and North Carolina. Small pockets of infesta- Genetic Resistance to Mole tion have been reported in other southern states further to the west. Crickets in Turf Bermudagrass 17 Planning Ahead to Minimize reprinted America. Insecticide Impacts on Golf are of Courses 18 article Society this Entomological the accompanying of illustrations permission by All TurfGrass TRENDS «1775 T Street NW • Washington, DC 20009-7124 Phone: 202-483-TURF • Fax: 202-483-5797 • Internet: [email protected] The predominant species throughout reside mostly in the soil, we do not the southeastern United States have know what they are doing, and it is been the tawny mole cricket more difficult to manage control of the TurfGrass (Scapteriscus vicinus) and the southern pest. This major difference between mole cricket (Scapteriscus borelli). In insect pests that reside in the soil and TRENDS addition, South Florida also has to deal those that spend much of their time on with the short-winged mole cricket. the foliage means a different approach Maria L. Haber Throughout the rest of the United must be taken for effective manage- States, turfgrass managers will on rare ment. Since much of a soil insect's Publisher occasions have to battle the northern activity occurs out of sight, we need to Dr. Richard J. Hull mole cricket (Neocurtilla hexadactyla). have a solid working knowledge of its Editor biology and ecology. This is true for Michael Heacock The tawny mole cricket feeds primarily mole crickets, but is an essential com- Field Editor on turfgrass roots and is very destruc- ponent for the effective management Dr. Richard J. Hull tive through its feeding and tunneling of any turfgrass soil insect pest. By activities. Southern mole crickets are knowing what the pest is doing in the Science Advisor more a predator and most of their diet soil, we can apply control strategies at Anna Schotanus consists of other creatures in the soil. the most susceptible stage of the insect Circulation Manager The southern mole cricket is still quite life cycle and maximize our chance of THE DESIGN GROUP damaging due to its extensive tun- success. This is, of course, what Layout & Production neling for food just below the surface. everyone desires. Given the difficulty in obtaining effective mole cricket TurfGrass TRENDS The fact that the northern mole cricket control, it is essential that we have this 1775 T Street NW is native to the U.S. and rarely causes understanding. Washington, DC 20009-7124 serious turf damage is important. The Phone: 202-483-TURF other mole cricket species are not The three most important aspects of Fax: 202-483-5797 native to the U.S. They were acciden- mole cricket management are: the 76517.2451 # CompuServe.com tally introduced approximately 95 timing of application, the timing of Abstracts: 800-466-8443 TGIF years ago. Like other insects intro- application, and the timing of applica- duced to the United States from Reprint Permission: 202-483-TURF tion. While this may sound like a abroad, they have gained pest status rather silly overstatement of common TurfGrass TRENDS is published because they had no natural enemies knowledge, I cannot overemphasize monthly. ISSN 1076-7207. The annual subscription price is $180.00. when they arrived here. Given an the importance of appropriate applica- abundant and ever increasing supply tion timing for effective mole cricket Copyright 1997, TurfGrass TRENDS. Ail of high quality turfgrass feed and no control, regardless of your location. Rights Reserved. Copy permission may be granted to turf management natural control agents, mole crickets This will be as true in South Africa as schools. have rapidly earned the reputation of a it is in South Carolina. major turfgrass pest. Information herein has been obtained by TurfGrass TRENDS from sources To facilitate this timing and to target deemed reliable. However, because control strategies to those sites which of the possibility of human or need the greatest level of protection, a mechanical error on their or our part, The Challenge of plan is needed. Mole cricket manage- TurfGrass TRENDS or its writers do not guarantee accuracy, adequacy, or Management ment requires a commitment. It completeness of any information and cannot be an afterthought. Turf pro- are not responsible for errors or omis- Perhaps the greatest challenge we face tection from mole crickets cannot be sions or for the results obtained from the use of such information. with mole crickets is not all that dif- accomplished after insects are large and ferent from what we see for other soil creating extensive surface damage. I insect pests of turfgrass. Since they will spend the rest of this article focusing on two areas: first, our knowledge of the flights begin a month earlier in Florida than in biology and ecology of mole crickets (a necessary North Carolina. The two major species in the component of any management plan) and second, U.S., the tawny and southern mole cricket, have a rather general management strategy for keeping one generation per year. Southern mole crickets mole crickets in check. may have two generations per year in South Florida, while the short-winged mole cricket appears to breed continuously with all stages Mole Cricket Life Cycle present at all times. The northern mole cricket has one generation per year in the southern U.S. but may require more than one year to complete a gen- My discussion here will focus on our knowledge of eration in the north. The life cycles of other mole the mole cricket life cycle in North Carolina. The cricket species in various parts of the world are gen- exact dates of specific stages will vary slightly erally not as well understood, especially as relate to throughout the southeastern U.S., but the basic life their presence in turfgrass and the use of this infor- cycle is generally the same. For example, spring mation to manage their control. However, this southern mole cricket tawny mole cricket mole crickets does not mean that they cannot be managed effec- lay eggs, they probably ensure a better chance of tively. A simple technique, that will be discussed egg and small nymph survival. shortly, allows an individual to monitor cricket development rather easily. Knowing the timing of Most of the eggs are laid in May and June with egg local population cycles is essential for developing hatch beginning in June. Most of the adult crickets effective management programs for specific sites. then die shortly after egg-laying. Each female will lay 30 to 60 eggs in the soil which will hatch in Mole crickets have three stages in their life cycle: about 20 days. Egg hatch continues well into July. eggs, nymphs, and adults. The nymphs are like Nymphs large enough to cause obvious damage miniature versions of the adults but without wings. occur as early as late July. As nymphs continue to The nymphs pass through anywhere from 7 to 12 grow through August and September and turf instars, or developmental stages, as they grow damage becomes increasingly apparent, the crickets toward adulthood. In North Carolina, the tawny become harder to control. This is due in part to the mole cricket overwinters as large nymphs or adults. cricket s larger size, but also to an enhanced ability The percentage of overwintering crickets that are to avoid control measures. Recent research studies adults varies from year to year. During the winter have documented that mole crickets can detect of 1995-96 the percentage of adults was very high. various insecticides and pathogens and avoid them. We do not understand what affects the overwin- The larger the cricket, the greater its capacity to tering developmental stage, nor what influence it tunnel and escape any management efforts and the has on the initiation of egg-laying in the spring. As longer it can stay deep in the soil and "wait out" the soil temperatures begin to warm in March, the residual activity of control practices. This directs us mole crickets become quite active after a period of back to my previous statement about the impor- reduced activity. Any remaining nymphs complete tance of timing control strategies. development and the adults prepare for a period of mating and dispersal flights in April. Warm nights The tawny mole crickets continue development in April bring about increased activity. Damage to until the soil temperatures begin to cool in turf becomes quite noticeable when adult mole November and December when they overwinter in crickets begin to build "calling chambers".