Leaffooted Bug

Integrated Pest Management for Landscape Professionals and Home Gardeners

Leaffooted bugs are medium to large sized that feed on fruits, fruiting vegetables, nuts, and ornamentals. They have piercing-sucking mouthparts that allow them to feed on plant parts, par- ticularly seeds. Leaffooted bugs are in the family and get their name from the small leaf-like enlargements found on the hind leg. They are closely related to other sucking insects, such as stink bugs (family Pentatomidae) that Figure 1. zonatus adult. Figure 2. adult. can also suck juices from plants. The two yellow spots on the pronotum The sharply pointed, thornlike clypeus behind the head are characteristic of at the tip of the head is characteristic of IDENTIFICATION this species. (D. Haviland, UCCE Kern Co.) this species. (J.K. Clark) There are three common species of leaf- footed bugs that are native to California and the western United States. These include , L. clypealis, and L. occidentalis (Figures 1-3). Adults of all three species are about 0.75 to 1 inch long and have a narrow brown body. Adults of all three species are similar in appearance, except that: • L. zonatus has two yellow spots just behind the head (on the pronotum) Figure 3. Leptoglossus occidentalis Figure 4. Leaffooted bug eggs are laid (Figure 1). adult. (L.L. Strand) end to end in one or more strands. • L. clypealis has a thorn-like projec- Holes in these eggs on a tion called a clypeus that extends hull indicate that larvae have already hatched. (D. Haviland, UCCE Kern Co.) forward from the tip of the head (Figure 2). • L. occidentalis has neither of these features (Figure 3). All three species have a white zigzag pattern across the wings: this pattern is prominent in L. zonatus and L. clypealis and is relatively faint in L. occidentalis.

The brown, cylindrical eggs of all three species are laid end-to-end in a string- like strand on the host plant, often along Figure 5. Leaffooted bug . Figure 6. Nymphs of assassin bugs, a stem or leaf midrib (Figure 4). Most (D. Haviland, UCCE Kern Co.) which are beneficial predators, resemble egg masses have 10-15 eggs, though leaffooted bug nymphs but are lighter colored. (J.K. Clark) more than 50 have been reported. Eggs hatch into small nymphs that have dark heads and dark legs on bodies that sassin bug (Zelus renardii) (Figure 6). Nymphs of this beneficial have light-col- range in color from orange to reddish- ored legs and antennae and hatch from barrel-shaped eggs that are grouped together brown (Figure 5). Small leaffooted bugs with a white cone top. As leaffooted bug nymphs become larger, they can easily be can be confused with nymphs of the as- recognized by the development of the leaf-like projection on the hind legs (Figure 5).

PEST NOTES Publication 74168

Statewide Integrated Pest Management Program May 2014 May 2014 Leaffooted Bug

LIFE CYCLE gardeners as a pest of tomatoes (Figure 8) and (Figure 7); farm- Leaffooted bugs overwinter as adults, ers primarily report it as a pest of al- typically in aggregations located in monds, , and pomegranates. protected areas, such as in woodpiles, Other important hosts in California barns or other buildings, palm fronds, include young citrus fruit, cotton bolls, citrus or juniper trees, under peeling watermelons, and several ornamental bark, or in tree cracks. Cold winters kill trees and shrubs. L. clypealis also has a many adults, and major outbreaks often wide host range within gardens, land- occur after mild winters. Overwintered scapes, and farms and is the predomi- adults live from September/October nant species found on desert plants like until late spring. When weather gets palm trees, Joshua trees, and yucca. L. warm, typically in March in the San Figure 7. Aggregations of L. zonatus on occidentalis, also known as the western Joaquin Valley and April in the Sacra- fruit. conifer seed bug, is primarily found in (D. Haviland, UCCE Kern Co.) mento Valley, adults disperse to find association with conifer trees. food sources. Adults are strong flyers that may feed initially on the seeds of winter weeds and later move into gar- DAMAGE dens, landscapes, and farms in search Leaffooted bugs have piercing-sucking of early-season fruit and a place to lay mouthparts that extend more than half eggs. of the length of the narrow body. They use this mouthpart to probe into leaves, Overwintering leaffooted bugs can shoots, and fruit to suck plant juices. lay over 200 eggs during a two-month The depth of the probing depends on period in the spring. Nymphs emerge the size of the bug: small nymphs feed from the eggs about 1 week after being shallowly on superficial plant juices, deposited, after which they develop whereas adult bugs probe deep into into adults in 5 to 8 weeks. Adults are fruit in search of seeds. If a hard seed is Figure 8. Leaffooted bug nymphs on long-lived and can lay eggs over an found, such as an almond kernel or ju- tomato. (R. Ostroff) extended period, so the population can niper berry, the bug excretes digestive consist of all life stages by late June. At enzymes from its mouthparts to liquefy this time, overwintering adults are still a small part of the seed so that it can be alive as the first generation of their off- ingested. Leaffooted bug mouthparts spring develop into adults. During the are also known to carry a fungal yeast, spring and summer, there are typically (formerly known two to three generations of leaffooted as Nematospora). When leaffooted bugs bugs. In the fall, all bugs develop until feed, this yeast can be introduced into they become adults that overwinter in fruit causing a variety of symptoms aggregations (Figure 7). usually related to discoloration. How- ever, the yeast causes no damage that Population levels change from year to would limit the ability of the fruit to be year depending on weather and para- harvested and consumed. This infec- sitism of eggs. Populations are typically tion is most predominant when rains highest after mild winters that allow are abundant. Figure 9. Leaffooted bug excrement on the surface of a pomegranate fruit. high survival of overwintering adults. (D. Haviland, UCCE Kern Co. ) Seasonal fluctuations in the number For most ornamental and many garden of bugs can also be related to rainfall, plants, feeding on the leaves and shoots food availability, and the prevalence of causes no visual damage and is of little spores gain entry into the fruit through natural enemies. concern. The most destructive damage the feeding wound. Large aggregations occurs when bugs feed on fruit. Early- of leaffooted bugs can also leave excre- Host Plants. In the spring, leaffooted season feeding on nuts like almonds bugs often feed on thistles and other and pistachios can cause the kernel to ment on the surface of the fruit that can weeds. Adults migrate from weedy abort and die, and mid- to late-season reduce its aesthetic appeal (Figure 9). areas into gardens and landscapes, feeding on nuts causes a black stain Feeding on small fruit (e.g., tomatoes) particularly when fruits have started on the kernel. On pomegranates, late- can cause the fruit to abort, while feed- to ripen. L. zonatus is the most de- season feeding as the fruit ripens gen- ing on medium-sized fruit can result structive of the leaffooted bug spe- erally causes no external damage but in depressions or discoloration at the cies. It feeds on many types of plants can cause aryls (seed-like structures) to feeding site as the fruit expands and a n d i s m o s t c o m m o n l y r e p o r t e d b y darken and wither, especially if fungal ripens. Feeding on mature tomatoes

◆ 2 of 4 ◆ May 2014 Leaffooted Bug

can cause slight discoloration to the layers or fruit clusters, and they may surface of the fruit that should be of no hide or fly when startled. Handpick and concern to backyard gardeners. crush the bugs or brush them off plants into soapy water. Wear gloves because MANAGEMENT of the odor they will emit when han- During most years, leaffooted bug dled. A handheld vacuum dedicated populations are low enough that dam- to catching the bugs can be effective age to gardens is tolerable and damage at reducing numbers, if used regularly. to landscape plants is negligible. When It is especially important to remove outbreaks occur, a variety of methods the bugs as early in the season as pos- will likely be needed to manage this sible, when the very young nymphs are pest, which may include removing tightly clustered together, and morning Figure 10. The Gryon pennsyl- overwintering sites or the use of weed is best to reduce movement and flight. vanicum lays its eggs inside of the eggs host removal, row covers, physical Be sure to also destroy the egg masses of leaffooted bug. Parasitoid eggs hatch removal, natural enemies, and insec- found on the underside of leaves. into larvae that develop into adults ticides. Achieving good control will within the leaffooted bug egg. likely require some combination of For late-season infestations in pome- (D. Haviland, UCCE Kern Co. ) these methods. granate trees, prune trees so that there is a space between tree limbs and the Insecticides. Insecticides are rarely Remove Overwintering Sites. Adult ground. Leaffooted bug nymphs can bugs overwinter in woodpiles, under needed for leaffooted bug control be- easily be knocked out of the tree using the bark of eucalyptus, juniper, or cause small blemishes on most fruit are a stick, by physically shaking the tree cypress, and in outbuildings. Large tolerable in gardening situations and numbers may pass the winter in culls limbs, or using water from a pressure because landscape plants are rarely of fruit such as pomegranates. Remove nozzle on a garden hose. Once bugs fall damaged. Also, because they are pri- these overwintering sites where possi- on the ground, they can be smashed. marily seed feeders, leaffooted bugs ble or inspect them for leaffooted bugs. This method is effective against nymphs are most common on garden plants but will not dislodge eggs. It is less near harvest, when the application of Weed Removal. Weedy areas serve as a effective against adults, which are able pesticides to fruits that are going to be to fly away. For this reason, this method food source for leaffooted bugs during consumed is undesirable. In addition, should be repeated once every 1 to 2 winter and spring, when fruits are not most insecticides available to home- weeks as necessary, until the majority available. Try to eliminate such areas owners only have temporary effects on near your garden or keep weedy areas of the bugs have disappeared. Laying a the leaffooted bug. closely mowed. white ground cover beneath the plant can aid in seeing the insects when using However, in severe cases, insecticides Row Covers. Covering plants with a this control method. row cover material can prevent feed- can be considered as a last resort. If needed, insecticides will be most effec- ing by leaffooted bugs. A row cover Natural Enemies. Native egg parasites, tive against small nymphs. Therefore, is a light, permeable material, usually such as the tiny wasp, Gryon pennsyl- monitor infested plants for egg masses made of polypropylene or polyester. vanicum (Figure 10), if not disrupted, Row covers are sometimes used to may reduce leaffooted bug populations and try to make insecticide applica- extend the harvest season past the first by killing the eggs before they hatch. tions when small nymphs are present. few frosts but are also valuable for Adult leaffooted bugs may be parasit- The most effective insecticides against preventing damage by a wide range of ized by certain tachinid flies, such as leaffooted bug are broad-spectrum, pests. Covers must be applied early, be- pennipes, which lays its eggs pyrethroid-based insecticides, such as fore bugs arrive and lay eggs on plants; on the sides of large nymphs or adults permethrin. However, these products otherwise, bugs will be trapped inside. of several species of true bugs. Leaf- are quite toxic to bees and beneficial Unfortunately, row covers will prevent insects. Insecticidal soap or botanicals, pollinators and beneficial insects from footed bug predators include birds, such as neem oil or pyrethrin, may reaching plants. Some garden plants spiders, and assassin bugs. Although provide some control of young nymphs like tomatoes are self-pollinating, but they may control only a small number or may build up if of the bugs, natural enemies are impor- only. If insecticides are used close beneficial insects are excluded. tant to preserve because they control to harvest, make sure to observe the other pests as well. Avoiding use of days-to-harvest period indicated on Physical Removal. Thoroughly exam- persistent broad-spectrum insecticides the insecticide label; and wash the fruit ine plants for all stages of the pest, dai- and assuring pollen and nectar sources before eating. ly to several times per week. The bugs for adult beneficials are important ways may be hidden inside dense foliage to protect natural enemies.

◆ 3 of 4 ◆ May 2014 Leaffooted Bug

REFERENCES Buss, L.J., S.E. Halbert, and S.J. Johnson. 2013. Pest Alert: Leptoglossus zonatus - A new leaffooted bug in Florida (He- miptera: Coreidae). Available online at www.freshfromflorida.com/Divi- sions-Offices/Plant-Industry/Plant- Industry-Publications/Pest-Alerts/ Pest-Alerts-Leptoglossus-Zonatus-A- New-Leaffooted-Bug-In-Florida.

Chi, A.A. and R.F. Mizell III. Western leaffooted bug. University of Florida web site. Available online at http:// entnemdept.ufl.edu/creatures/citrus/ leptoglossus_zonatus.htm.

Taylor, S. 2009. Leptoglossus clypealis Heidemann, 1910: (: Pentato- momorpha: Coreidae). Univ. of Illinois at Urbana-Champaigne, Illinois Natural History Survey. Available online at http://www.inhs.uiuc.edu/~sjtaylor/ AUTHORS: Chuck Ingels, UCCE To simplify information, trade names of products coreidae/Leptoglossus_clypealis.html. Sacramento and David Haviland, UCCE have been used. No endorsement of named products Kern Co. is intended, nor is criticism implied of similar products that are not mentioned. Bentley, W. J., R. H. Beede, K. M. Daane, This material is partially based upon work and D. R. Haviland. 2012. Insects and TECHNICAL EDITOR: M. L. Flint supported by the Extension Service, U.S. Department EDITOR: K. Beverlin of Agriculture, under special project Section 3(d), Mites from UCIPM Integrated Pest Man- Integrated Pest Management. agement Guidelines: Pistachio. UC ANR This and other Pest Notes are available at Publication 3461. Available online at www.ipm.ucanr.edu. Produced by UC Statewide Integrated Pest Management Program http://www.ipm.ucdavis.edu/PMG/ University of California, Davis, CA 95618-7774 r605100511.html. For more information, contact the University of California Cooperative Extension office in your county. See your telephone directory for addresses Grafton-Cardwell, E. E., D. Carroll, W. J. and phone numbers, or visit http://ucanr.org/ce.cfm.

Bentley, D. R. Haviland and V. Walton. University of California scientists and other 2013. Insects and Mites from UCIPM qualified professionals have anonymously peer Integrated Pest Management Guidelines: reviewed this publication for technical accuracy. The ANR Associate Editor for Pest Management Pomegranate. UC ANR Publication 3474. managed this process. Available online at http://www.ipm. WARNING ON THE USE OF CHEMICALS ucanr.edu/PMG/r621100111.html. Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed, away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Zalom, F. G., C. Pickel, W. J. Bentley, D. Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans. R. Haviland, and R. A. Van Steenwyk. Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens containing fruits or vegetables ready to be picked. 2012. Insects and Mites from UCIPM Do not place containers containing pesticide in the trash or pour pesticides down the sink or toilet. Either use Integrated Pest Management Guidelines: the pesticide according to the label, or take unwanted pesticides to a Household Hazardous Waste Collection Almond. UC ANR Publication 3431. site. Contact your county agricultural commissioner for additional information on safe container disposal and for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers Available online at http://www.ipm. by following label directions. Never reuse or burn the containers or dispose of them in such a manner that ucanr.edu/PMG/r3300411.html. they may contaminate water supplies or natural waterways.

ANR NONDISCRIMINATION AND AFFIRMATIVE ACTION POLICY STATEMENT It is the policy of the University of California (UC) and the UC Division of Agriculture & Natural Resources not to engage in discrimination against or harassment of any person in any of its programs or activities (Complete nondiscrimination policy statement can be found at http://ucanr.edu/ sites/anrstaff/files/183099.pdf). Inquiries regarding ANR’s nondiscrimination policies may be directed to Linda Marie Manton, Affirmative Action Contact, University of California, Agriculture and Natural Resources, 2801 Second Street, Davis, CA 95618, (530) 750-1318.

◆ 4 of 4 ◆