Agriculture: Citrus Pest Management Guidelines

Fuller Rose Beetle

  • Naupactus (=Asynonychus) godmani (syn. Naupactus cervinus, Pantomorus cervinus)
  • Description of the Pest

    Adult Fuller rose beetles are brown, flightless snout beetles and are all females that reproduce without mating (parthenogenetically). They can be distinguished from two other snout beetles that occur in California citrus groves but do not cause damage: viewed from the top the Fuller rose beetle head and bulging eyes are different than the cribrate weevil, which has a teardrop-shaped head with closely spaced eyes, and viewed from the side, the Fuller rose beetle's snout is less sharply pointed to the ground than that of the vegetable weevil.

    The Fuller rose beetle has one generation a year. Eggs are laid in a mass of several dozen on fruit, especially underneath the button, or in cracks and crevices in the tree. When eggs hatch, larvae drop to the ground and live in the soil where they feed on roots of citrus for 6 to 10 months or longer. They pupate in the soil and the adults emerge 1.5 to 2 months later.

    In the San Joaquin Valley, peak emergence is July through September (very high in August), but adults emerge from the soil year-round (in the San Joaquin Valley, roughly 4.3% emerge in June, 14.5% in July, 53% in August, 17.3% in September, 3.7% in October, 2.6% in November, 2.8% in December, and 1.9% for the combined months of January through May). In Southern California, emergence is delayed about a month from that in the San Joaquin Valley and is a bit more spread out with peak months being July through November (very high August through October). Adults are flightless and reach the canopy by climbing up the trunk or branches that touch the ground or vegetation.


    The beetle itself does not generally cause economic damage in citrus but the presence of viable eggs on fruit exported to other countries such as Korea can be a quarantine concern. Since Fuller rose beetle has been found in Japanese citrus groves, it is no longer a concern for fruit exported to Japan.

    Fuller rose beetle adults feed along the margins of citrus leaves, creating notches and leaving a characteristic sharp, ragged appearance. Normally, they are not a concern except on topworked trees where the beetles will feed on new buds or if a young tree is planted in a mature grove and beetles concentrate their feeding on the new growth of that tree.


    If management of Fuller rose beetles is necessary because it has become a quarantine concern there are two management strategies explained in MONITORING AND TREATMENT DECISIONS below that incorporate cultural and chemical control methods: season-long local suppression and pesticide applications to prevent egg laying close to harvest.

    Biological Control

    The internal egg parasite, Fidiobia citri, can parasitize up to 50% of each egg mass. Parasitized eggs are a dark gold color during the parasite's larval stage and a few may persist long after unparasitized eggs have hatched. Once the parasite pupates, the egg appears dark black for several days prior to wasp emergence. While parasites assist with control, they do not reduce Fuller rose beetle numbers enough to enable fruit to be exported to quarantine countries.

    Cultural Control

    If Fuller rose beetle has been a problem in your orchard in the past, an important component of the strategy to prevent the flightless adults from reaching the canopy is using skirt pruning. Organic growers may want to combine skirt pruning with a sticky trunk barrier. Skirt pruning by itself is about 30% effective in reducing the number of beetles that will produce eggs several weeks after feeding on citrus foliage. Skirt prune trees 24 to 30 inches above the ground and apply a sticky material to the trunk to prevent adults from reaching the canopy. Sticky material or spray can be expected to last 2 to 10 months, depending on wash-off by sprinklers and the amount of dirt and leaf contamination. Sticky material will also control ants, and if it contains tribasic copper sulfate, it is effective against brown garden snail as well.

    Some concern has been expressed regarding the application of sticky polybutene materials directly to the trunk of citrus trees, especially if multiple applications are applied to the same area of the trunk. The sticky material can be applied on top of a tree wrap but this is both laborious and expensive. Trials to date on mature trees have failed to show serious phytotoxicity (minor bark cracking has been seen in a very small number of cases) except in situations where damage is associated with sunburn—that is where the banded area is exposed to direct sunlight, as with topworked trees. Young trees have a very thin cambium layer and are more susceptible to damage. On young or topworked trees, apply sticky materials only on top of a tree wrap to protect the tree from sunburn.

    Organically Acceptable Methods

    Use biological and cultural controls, including skirt pruning and the application of sticky materials in organically certified crops.

    Monitoring and Treatment Decisions

    Adult Monitoring

    If fruit may be exported to countries prohibiting fruit with unhatched Fuller rose beetle eggs, sample the orchard starting in June. Previous-year damage to foliage low and inside the tree canopy provides past evidence of Fuller rose beetle. Current-year numbers can be monitored from a minimum of 20 trees per 10-acre block by shaking or beating branches to knock adult beetles onto a sheet or tray. If low Fuller rose beetle numbers are found in a grove and it is likely fruit will go to Korea, apply insecticides two to three times per year (discussed in SEASON-LONG LOCAL SUPRESSION) to suppress Fuller rose beetle numbers.

    Season-Long Local Suppression

    The goal is to reduce the beetle numbers by skirt pruning combined with one or more bifenthrin ground (soil) or trunk sprays, or foliar insecticide sprays applied during the period of time when adults might lay eggs that remain viable at harvest. In the San Joaquin Valley, more than 50% of the beetles emerge from the soil in August so that is a key month for control. Apply a ground or trunk bifenthrin spray before peak emergence (June or July). Foliar sprays are more important to apply August through October after peak emergence, because the eggs deposited earlier in the season hatch before harvest. When practicing season-long suppression, follow these guidelines in the San Joaquin Valley (in Southern California, a similar strategy should be used but applications should be applied one month later):

    • If three insecticide applications are planned, they should be applied in June (soil), August (foliar) and October (foliar).
    • If two insecticide applications are planned, then apply a ground (soil) or foliar spray in August and a foliar spray in October.

    A substantial reduction in beetle numbers will likely take several years with two to three applications per year. It is essential to combine skirt pruning with one or more of the other strategies (ground sprays, trunk sprays, foliar insecticide sprays, or a combination of these) to improve effectiveness.

    Skirt Pruning and Ground (Soil) or Trunk Sprays

    To reduce egg laying on fruit, skirt prune trees to a height of 24 inches or more by late May and apply repeated bifenthrin ground or trunk sprays starting in early June (San Joaquin Valley) or July (Southern California). Monitor the orchard every 4 to 6 weeks and remove weeds growing upward or branches and suckers bending downward that beetles can use to access the tree.

    Apply bifenthrin to the ground with a weed or other sprayer using low pressure so the spray does not splash on fruit. Cover the entire area under the tree canopy from the trunk to the drip line. Consult the insecticide label for details. Apply trunk sprays with a shielded sprayer or with a home-built U-shaped hand wand.

    • Use low pump pressure and a shielded sprayer so the insecticide does not splash onto the foliage or fruit.
    • Do a test application with water only to determine the amount of solution that is needed per acre for thorough coverage of the soil under the tree or trunk and to make sure the spray does not contact foliage or fruit.
    • Keep the solution thoroughly mixed during application.
    Treatments to Prevent Egg Laying Close to Harvest

    If skirt pruning and ground or trunk sprays have not been fully effective (adults are laying eggs under the button of the fruit) also apply one or two foliar insecticides during the period 600 degree-days (accumulated above the 51°F lower threshold) before harvest to kill adults that would lay eggs that would be viable (unhatched) at harvest.

    Typical degree-days per month above the Fuller rose beetle egg development lower threshold of 51°F.
    Modified from Morse, J. G. and K. R. Lakin 1987, "A degree-day model for Fuller rose beetle," Citrograph 72(11): O-P.

    Month Madera, Madera Co. Orange Cove, Fresno Co. Lindcove*, Tulare Co. Lindsay-Strathmore, Tulare Co. Porterville*, Tulare Co. McFarland, Kern Co. Lamont, Kern Co. Maricopa, Kern Co.
    January 22 28 68 52 55 42 52 40
    February 93 101 124 126 113 126 135 128
    March 184 188 224 219 219 237 233 206
    April 310 303 326 335 318 372 365 345
    May 517 506 541 528 524 600 610 600
    June 707 724 730 708 693 784 811 812
    July 876 899 929 882 874 956 1010 984
    August 834 843 882 838 827 909 973 938
    September 661 688 692 662 660 729 790 764
    October 414 429 448 425 421 469 525 515
    November 136 156 175 163 158 168 184 173
    December 19 33 66 50 54 39 52 44
    Yearly total 4,772 4,899 5,205 4,989 4,915 5,429 5,739 5,546

    Month Santa Paula, Ventura Co. Ojai, Ventura Co. Riverside, Riverside Co. Indio, Riverside Co. Niland, Imperial Co. Valley Center, San Diego Co.
    January 197 170 170 236 219 229
    February 193 176 186 307 270 209
    March 235 219 239 470 396 297
    April 294 292 340 659 545 373
    May 348 376 474 876 782 460
    June 425 496 634 1117 1015 537
    July 541 654 813 1291 1224 663
    August 555 677 832 1269 1222 740
    September 509 581 708 1058 1028 661
    October 411 440 512 789 724 500
    November 269 265 278 394 361 315
    December 202 180 182 241 211 200
    Yearly total 4,178 4,524 5,367 8,706 7,994 5,183
    Weather data were obtained from UC IPM Online (UC Statewide IPM Program) at The above data are EXPECTED degree-days each month of the year for the indicated location based on average weather data over the past 30 years.
    * for Lindcove and Porterville, data were based on average weather data for two nearby weather stations for a total of 25 and 29 years respectively.

    With this treatment strategy, only unhatched eggs (eggs deposited before the 600 degree-days point in time) are present at harvest. For example, if harvest was at the end of January, insecticide applications to prevent adults from laying eggs that would be viable at that time would need to start in early to mid-November in Riverside and Ventura counties, and in early October in Kern and Tulare counties. The eggs laid prior to these insecticide applications would have 600 degree-days to complete their development and hatch before harvest.

    To learn more about how to use degree-days to time insecticide applications, see Using Degree-Days to Time Insecticide Applications in Fruit and Nut Orchards. For assistance in calculating degree-days for Fuller rose beetle in your location, see Degree-days: Fuller Rose Beetle in Citrus.

    Examine eggs on fruit to determine if these insecticide applications were successful in eliminating the presence of unhatched eggs.

    Egg Monitoring

    Just before harvest, sample fruit for egg masses, especially in the areas where adults were found during branch shaking or feeding damage was observed. Sample a minimum of 500 fruit in a 10 acre block (5 fruit per tree from 10 trees per acre).

    1. Select fruit at chest height from a different quadrant of the canopy.
    2. Clip the stem 2 inches from the fruit, then hold the stem and twist off the button.
    3. Look for egg masses on the underside of the button and on the fruit where it was covered by the button.

    For fruit to be shipped to a country that requires fruit free of unhatched Fuller rose beetle eggs, infestation levels should be less than one fruit infested with a viable, unhatched egg per 500 fruit sampled at harvest.

    For more information on monitoring and management of Fuller rose beetle see UC Ag Experts Talk: Fuller Rose Beetle.

    Common name Amount to use REI‡ PHI‡
    (Example trade name) (type of coverage)** (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used.
    2- to 4-inch band on trunk NA NA
    RANGE OF ACTIVITY: Pests: narrow (trunk climbers); Natural enemies: few, if any
    PERSISTENCE: Pests: long; Natural enemies: long
    COMMENTS: Combine with skirt pruning. For use on all varieties. Use polybutene-based products only. Do not apply sticky materials directly on the trunk of trees, especially young or top worked trees where the treated area is exposed to the sun—use a 6- to 18-inch wrap under the sticky material to prevent application directly to the trunk and protect the tree from sunburn. Exercise caution in applying multiple applications (more than 3 or 4)—watch for symptoms of bark cracking. Apply the sticky band high enough to avoid sprinklers, dust, and direct sunlight. Reactivate periodically by rubbing with a stick to remove dust. Check to ensure that hanging branches, sticks, weeds, etc. are not allowing Fuller rose beetles access to trees.
    (Brigade WSB) 2.5–5.0 lb/acre 12 See comments
    (Bifenture 10DF) 40–80 oz/acre 12 1
    RANGE OF ACTIVITY: Pests: narrow (insects on trunk or soil); Natural enemies: few, if any with trunk sprays; ground dwelling species with soil application
    PERSISTENCE: Pests: long; Natural enemies: long
    COMMENTS: Combine with skirt pruning. Do not allow the insecticide to contact fruit or foliage. Consult the label for trunk or soil application details. Soil applications of either Brigade WSB or Bifenture 10DF can be made using a total of 0.5 lb a.i. per season. Spray the soil from the drip line to the base of the trunk using 40 gal/acre (or more if needed). Trunk applications of Brigade WSB can be made either with a hand wand sprayer or a shielded sprayer using a total of 2.5 to 5 lb/acre in 10 gal/acre. These applications of Brigade WSB, under the 2ee label, have a 1-day PHI.

    Under a 24(c) Special Local Need (SLN) label, two applications of 5 lb Brigade WSB (0.5 lb a.i.)/acre, applied 12 to 16 weeks apart with a PHI of 63 days, or four applications of 2.5 lb (0.25 lb a.i.)/acre, applied 6 to 8 weeks apart with a PHI of 28 days, are allowed per year. The SLN label expires September 30, 2023. Additional information may be found at California Citrus Quality Council (CCQC). Bifenthrin is both toxic and repellent to adult Fuller rose beetles.

    (Prokil Cryolite 96) 20 lb/acre (IC) 12 15
    (Kryocide) 8–30 lb/acre (IC) 12 15
    RANGE OF ACTIVITY: Pests: intermediate (foliage feeders such as worms, katydids, and Fuller rose beetle); Natural enemies: few, if any
    PERSISTENCE: Pests: long, unless washed off by rain; Natural enemies: none to short
    COMMENTS: Combine with skirt pruning. Check label for variety. Use higher rate for larger trees. Slow-acting stomach poison that may take several days of warm weather to kill Fuller rose beetles. Use of Prokil Cryolite 96 allowed under a supplemental label. There is no cryolite maximum residue limit (MRL) for Korea.
    (Actara) 5.5 oz/acre (IC) 12 0
    RANGE OF ACTIVITY: Pests: broad (many insects); Natural enemies: most
    PERSISTENCE: Pests: long; Natural enemies: long
    COMMENTS: Combine with skirt pruning. For use on all varieties. The minimum interval between applications is 7 days. The 0 day PHI is based on a U.S. tolerance of 0.4 ppm (Korean and Japanese MRLs are 1.0 ppm).
    (Sevin XLR Plus) 5 qt/acre (IC) 72 (3 days) 5
    RANGE OF ACTIVITY: Pests: broad (many insects); Natural enemies: most
    PERSISTENCE: Pests: long; Natural enemies: long
    COMMENTS: Combine with skirt pruning. For use on all varieties. The 5 day PHI is based on a U.S. tolerance of 10 ppm (7 ppm maximum residue level (MRL) in Japan). The MRL for Korea is 0.5 ppm so a 5 day PHI will likely not meet MRLs in Korea.
    (Leverage 360) 3.2–6.4 fl oz/acre (IC) 12 0
    RANGE OF ACTIVITY: Pests: broad (many insects and mites); Natural enemies: most
    PERSISTENCE: Pests: long; Natural enemies: long
    COMMENTS: Combine with skirt pruning. Do not exceed 6.4 fl oz Leverage 360 per season (0.05 lb a.i./acre beta-cyfluthrin and 0.10 lb a.i./acre imidacloprid). Do not exceed 0.05 lb a.i./acre beta-cyfluthrin in all forms per crop season. Do not exceed 0.10 lb a.i./acre cyfluthrin in all forms per crop season. Maximum beta-cyfluthrin plus cyfluthrin allowed in all forms is 0.10 lb a.i./acre. The 0 day PHI is based on a U.S. tolerance of 0.7 ppm imidacloprid and 0.2 ppm beta-cyfluthrin. The MRL for Korea is 0.5 ppm imidacloprid and 2.0 ppm cyfluthrin.
    (Voliam Flexi) 5–7 oz/acre (OC) 12 1
    RANGE OF ACTIVITY: Pests: broad (many insects and mites); Natural enemies: most
    PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
    COMMENTS: Combine with skirt pruning. Do not exceed a total of 14 oz of Voliam Flexi or 0.172 lb a.i. of thiamethoxam-containing products or 0.2 lb a.i. of chlorantraniliprole-containing products/acre per growing season. The 1 day PHI is based on a U.S. tolerance of 0.4 ppm thamethoxam and 1.4 ppm chlorantraniliprole. The MRL for Korea is 1.0 ppm thiamethoxam and 1.0 ppm chlorantraniliprole.
    ** IC - Intermediate coverage uses 250 to 600 gal water/acre.
    OC - Outside coverage uses 100–250 gal water/acre.
    Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI The longer of two intervals is the minimum time that must elapse before harvest.
    # Acceptable for use on organically grown produce. NA = not applicable
    1 Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers (un = unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee).
    * Permit required from county agricultural commissioner for purchase or use.

    Important Links

    Text Updated: 02/17
    Treatment Table Updated: 02/17