Drawer CC, College Station, TX 77841, Download a printer-friendly version of this publication: Controlling the Pecan Weevil, View more Farming and Ranching information ». the monitoring trees. inspection of damaged pecans will reveal a puncture the size of a straight pin that can be traced through shuck and shell to the liquid endosperm area of the nut (Fig. Hard soil acts as a physical barrier to adults moving from their soil cells to the soil surface. SE Region Row Crop Initiative Grain and Cotton Marketing Update: Online Zoom, https://www.youtube.com/watch?v=Wc8xY2YuOfM. Feeding rates for males and females prior to shell hardening are low. Insecticides labeled for control of pecan nut casebearer (PNC), hickory shuckworm (HSW), pecan weevil (PW) and pecan phylloxera (PP). This emergence pattern is typical across the pecan belt. Our work makes a difference, in the lives of Texans and on the economy. To control the weevil, it is recommended to target with specific methods during particular life cycle stages. During drought conditions in 1977 -78, almost 30 percent of the adult weevils emerged after an October 19 rain. If trees are large, it may take two or more traps to encircle the tree. Weevils can be controlled with surveillance of traps throughout late nut development through harvest,. The remaining 10 percent delay pupation until the second year. Wire cone traps have been used for many years to monitor adult pecan weevil emergence. Your name. Pecan weevil management is a crucial management technique. To properly manage a successful pecan orchard, a well-developed plan should be implemented. Abstract. COMMERCIAL PECAN INSECT CONTROL. Therefore, their life cycle can take two or three years to complete one generation. These publications are available at the Texas Cooperative Extension Bookstore, http://tcebookstore.org. What can be done to prevent this? Go to www.noble.org/pecan-management-calendar​ to view our pecan management calendar for the month of June and July. 4). Many attempts have been made by independent researchers and industry representatives to control weevil larvae in the soil using an insecticide. The pecan weevil burrows into the nut before the shell hardens and lays eggs, then worms hatch from the eggs and devour the nut. The pecan, Carya illinoensis Koch, is the most important native horticultural crop in the United States; however, the pecan industry is new compared to other orchard crops with commercial pecan production developing largely during the 20th century (Brison 1974). Relying on information from a neighbor’s orchard will likely result in poor weevil control. 4). In the first wave, adult weevils puncture the developing immature pecans (water stage), causing the nuts to drop. The most effective control for pecan weevil is the use of insecticides to prevent adult weevils from feeding and adult females from laying eggs. Abstract. Also, the large brown adults are very secretive when they emerge and any eggs or larvae … By Clint Thompson for CAES News. Pecan weevils can be controlled by spraying liquid applications of carbaryl (commonly sold as Sevin) on the ground underneath trees out to the drip line, as well as up the trunks of pecan trees as far as you can reach, beginning in mid August and continuing every … The adult emergence period lasts for several weeks so time sprays to prevent oviposition rather than to protect a few nuts that will be lost to the small number of early emerging adults that feed during the water stage. Movement over longer distances results from transport of infested nuts by  humans. Planning will help growers and managers be prepared for tasks that will need to be addressed throughout the year. Because the larvae, pupae and adults are covered with 4 to 12 inches of soil and pesticides cannot reach larvae inside the nuts, management of these life stages is not practical. Even in years where drought delays emergence and traps fail to collect adults, some pecan weevil adults will emerge through soil cracks before gel formation and this justifies the initial treatment. The trap is painted a, dark color and fitted with a boll weevil trap to collect adults. K. Koch) (Fagales: Juglandaceae). To prevent weevils from laying eggs, pecan producers must do the following: Monitoring Kernel Development: Pecan kernel development must be in the gel or dough stage for oviposition, larval hatch and development to be successful. A treatment program for the pecan weevil requires at least two properly timed insecticide applications. Acramite 4SC Unclassified 12-16 oz 12 H/ – Mites, especially the pecan leaf scorch mite, are normally … Adult female pecan weevils do, not begin to lay eggs until 5 days after emergence, so the earliest time to retreat will be 10 days after the initial application. Orchards under drip irrigation will have normal weevil emergence near water emitters but, under drought conditions, also will have delayed emergence from hard soils under the canopy but away from emitters. 2). Nuts are susceptible to oviposition from the gel stage up to shuck split. Proper soil preparation and planting can prevent most weevil infestations, but control pea weevils with natural means or pesticide applications if they are causing serious damage. At least two sprays are needed to control established pecan weevil infestations. The objective in a pecan weevil integrated pest management (IPM) program is to prevent female weevils from laying eggs in nuts. The remaining 10 percent delay pupation until the second year. Drought conditions and clay soils delay emergence of adults by a month or more. In late 2016 and Janu-ary 2017, pecan weevil was … atmospheres of 21% oxygen (02) and 30% CO2, pecan weevil mortality was 100%, total mycoflora isolated from kernels was significantly reduced, and off-flavors had not yet developed in the kernels. Trap placement on the tree allows use with grazing livestock. Weevils can cause two types of damage to a pecan crop, occurring at two stages of pecan development. Female weevils bore through the shuck and shell of a nut to lay 5-7 eggs. 2020 Commercial Pecan Spray Guide. Any. $36.00–$270.00 This eradication program requires a minimum 3-year period when no larval infestations appear in the harvests. Often this feeding puncture or egg laying site will be surrounded by a circle of tracks created by the adult (Fig. By Will ChaneySr Pecan Operation Associate 2. Read and follow label directions. Adults emerge from the soil where they have spent 2 or 3 years in soil cells located 4 to 12 inches beneath the soil surface. Even though damage can occur from the time of adult emergence to shuck split, the key to weevil control is to prevent egg lay or oviposition. Sort by. Since most of the life stages of the pecan weevil inhabit protected environments, applications used to control this pest are generally targeted at the adult stage. Since this trap works as a visual preference, the tree trunk next to the trap should be painted white to a height of 6 to 8 feet. The arid Southwest (West Texas, New Mexico, Arizona and California) has not yet had an established population of weevil develop. This prevents weevils that live in the infested orchard from causing economic damage. Root Weevils. CD-ROM, Pecan Pest Management. Application of 2 to 3 acre inches of water in mid-August should prevent most soils from being drought-hardened during the critical August 20 to September 10 emergence period. For additional information, review our Privacy Policy. She will avoid any pecans in which eggs already have been laid by other females. At the present time, the most effective control measure for the pecan weevil is the use of insecticides directed at the adult weevils in the trees to prevent feeding and, more importantly, egg laying by the females. The pecan weevil (Curculio caryae [Horn]) is a key pest of pecan in the United States and portions of Texas. A female will lay approximately 75 eggs in her life at a rate of 2.6 to 3.8 eggs per day. 8). However, soils hardened by drought delay adult emergence. These adults remain in the soil for another year, which results in a 3-year life cycle. : There are several monitoring techniques to detect adult pecan. The emergence of adult pecan weevils is directly related to the type of soil and soil. K. Koch) (Fagales: Juglandaceae). Pecan weevil biology, management and control strategies. Do not use spreader stickers with the treatment. However, these traps are expensive, labor intensive and cannot be used with livestock unless the trap area is fenced. Unlike treatment for the pecan nut casebearer, where infestations can vary from year to year by several weeks or more, the initial insecticide application for pecan weevil is applied around August 20 to 22. Of these techniques, the wire cone trap, pyramid or “Tedders” trap, and the Circle trap are commonly used. If adult pecan weevils are found in an orchard, economic damage will occur if the orchard is not treated. Check out our So You Want to Grow Pecans event on Sept. 3. Once the larvae are on the ground, they burrow into the soil and construct an almost impenetrable earthen cell underground. As of 1999 , pecan weevil had been found in 131 Texas counties (Fig. These eggs hatch into legless larvae which completely devour the kernel of the nut. This emergence pattern is typical across the pecan belt. The time period from egg lay to larval emergence is approximately 42 days. Adults typically emerge over a two-month period (August to September); however, depending on weather, emergence can occur even up to harvest. The presence of punctures and tracking confirm weevil presence.