4.1 Weevils

The most damaging of the root pests are the weevils. Weevils are easily distinguished from other beetles by the snout-like structure that protrudes from the front of their heads [17]. Strawberry root weevils, Otiohynchus ovatus (L.), adults are approximately 6.4 mm long and brown to black in color [3, 7]. Black vine weevils,

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops DOI: http://dx.doi.org/10.5772/intechopen.82069

O. sulcatus Fabricius, are black flecked with yellow and larger at approximately 1.27 cm long [3, 7]. Adults of both species emerge in late spring and early summer and feed on leaves at night while sheltering near the base of plants during the daytime [3, 7]. They feed on the leaf margins, producing distinctive hook-shaped notches. Adults lay eggs in the fall and larvae feed on roots before burrowing deeper into the soil to overwinter. The larvae are legless, crescent shaped, creamy white to light pink grubs similar in size to the adults. As temperatures warm up in the spring, larvae again feed on roots before burrowing into plant crowns to pupate. Infested plants are dull and reddish, wilted, stunted, and extremely susceptible to stress. Injury in a field often occurs in a circular pattern. Adults emerge from these pupae to begin the cycle again.

Managing these weevil pests is difficult. Sanitizing farm equipment is important to avoid moving beetles from infested fields into fields that are not infested. Heavily infested fields should be plowed to prevent the spread of the weevil and repeated disking will continue to expose grubs to predation and weather. Soil fumigation after plowing is also effective. Two grubs per plant can cause economic damage, which makes for a low threshold [3, 7]. There are insecticides available to reduce the population of adults before they lay eggs, but efficacy is limited. Using nematodes that parasitize grubs in combination with insecticides to manage adults has shown some success. Steinernema feltiae (Filipjev) and Heterorhabditis bacteriophora (Poinar) are both commercially available and can be used in combination. Soil should be moist when nematodes are released.

#### 4.2 Strawberry rootworm

covered in hairs that can be white, various shades of yellow and orange, and black. The early instars cluster together to feed and then disperse as they grow. Mature caterpillars can be 5 cm long and look even larger because of their hairs. Salt marsh caterpillars prefer grasses and rarely occur in large enough numbers in strawberry

Strawberry - Pre- and Post-Harvest Management Techniques for Higher Fruit Quality

It is possible for other caterpillars to be seen feeding on strawberry. The lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), a serious pest of corn, is occasionally seen in strawberries, for example [3]. Various species of crickets and grasshoppers will feed on strawberry leaves, though they rarely occur in large numbers or cause enough injury to be of concern. The same is true of some species of earwigs.

Root pests are only a concern in perennial strawberry production systems [3]. The strawberry root worm, strawberry root weevil, black vine weevil, and white grubs all attack roots. These are all beetles and it is the immatures, or grubs, that feed on the roots. Injury to roots reduces the plants ability to draw water and nutrients from the soil, which can lead to reduced plant vigor, yield, and even plant death. The injury can also provide an entry point for diseases. Adults feed on leaves

The most damaging of the root pests are the weevils. Weevils are easily distinguished from other beetles by the snout-like structure that protrudes from the front of their heads [17]. Strawberry root weevils, Otiohynchus ovatus (L.), adults are approximately 6.4 mm long and brown to black in color [3, 7]. Black vine weevils,

plantings to be of concern.

Later instar salt marsh caterpillar (photo credit: M. Lopez, UF).

Figure 11.

3.9 Other chewing pests

and can, occasionally, reach damaging levels.

4. Root pests

4.1 Weevils

112

The strawberry rootworm, Paria fragaria Wilcox, is the smallest of these beetle pests [3, 19]. Both adults and grubs are only 3.2 mm long. Adults are shiny and vary from brown in color with four black splotches to completely black. They chew holes in leaves and can skeletonize leaves when infestations are severe. Adults overwinter in sheltered places such as ground litter and become active as temperatures warm in the Spring. In the northern United States, high numbers can occur in May and June, though this is uncommon [19]. These adults lay eggs in the soil that hatch into grubs, which are milky white in color and have six legs. Larvae feed on roots, which can cause plants to be stunted, and then pupate in the soil. Adults emerge from these pupae in July and August. This second generation of adults will overwinter and begin the cycle again. Insecticide applications should be timed when adults are feeding [3, 19].

#### 4.3 White grubs

White grubs, which are the larvae of Scarab beetles such as the June Beetle, Japanese Beetle, and Rose Chafer, can also be an issue in perennial strawberries [3, 20]. The grubs are C-shaped, milky white in color, have six legs, and vary in size depending on species. White grubs can grow as large as 2.5–3.8 cm long. They are a major pest of sod and can move into strawberry fields from adjacent grassy areas [3, 20]. June beetles lay their eggs in early summer. The larvae feed on roots and burrow deeper in the soil to overwinter. Larvae repeat this pattern for the next two seasons, pupating in the soil at the end of the 3rd summer. Most white grub adults have a similar 3-year life cycle [3, 20]. However, a few, like the Japanese beetle, have a 1-year life cycle. Fields planted to sod should be left fallow or planted to nonsusceptible hosts, such as squash and its relatives, for several seasons before strawberries are planted there [3, 20]. Prevention is key because grubs are difficult to control once they infest a field.

### 5. Flower pests

Strawberry bud weevils feed on and lay their eggs in strawberry buds and can cause significant yield loses. Flower thrips feed in open flowers. Tarnished plant bugs feed on both flowers and fruit. Injury to flowers can result in deformed fruit that is unmarketable. Severely injured buds and flowers may not develop into fruit. Both situations cause yield loss.

### 5.1 Strawberry bud weevil

The strawberry bud weevil, Anthonomus signatus (Say), also known as the strawberry clipper, is a highly destructive pest in perennial strawberries [3, 21]. Adult weevils are only 1/10″–1/8″ long and are copper colored with two large, black spots on the back of their wing covers. Adults become active in the Spring when temperatures reach about 60°F. Adult females chew a hole in a developing flower bud and use their long snout to feed on the pollen. They then lay a single egg in the bud and girdle or clip the pedicel, which is the stem that attaches the bud to the plant, right at the base of the bud. The buds turn brown and eventually fall to the ground. The small, opaque white, legless grub develops and then pupates in the bud. Adults emerge in June, feed on flower pollen, and then seek overwintering sites, where they stay until the following Spring. Preferred overwintering sites include mulches, brush, woods, and woodlots.

Girdled buds do not become fruit, so strawberry bud weevils can cause substantial yield loss if populations are high. Monitoring should begin once strawberry flower buds appear in the spring [3, 21]. In smaller fields, sample two feet of row from 5–10 areas of the field counting the number of cut buds in each section. For larger fields, sample five 10-foot sections of row. The threshold is one cut bud per foot of row. Two applications of insecticides should be made if the threshold is met or exceeded, one right away and the 2nd 10 days after the first.

(Orius spp. and Geocoris spp.), that are common in the strawberry system, regulate

cracking has also been attributed to thrips feeding injury.

Western flower thrips female (left) and male (right) (photo credit: E.M. Rhodes, UF).

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops

DOI: http://dx.doi.org/10.5772/intechopen.82069

strawberries have not been determined.

6.1 Spotted wing drosophila

Thrips possess a single mandible that they use to puncture plant tissue. The rest of the mouthparts are formed into a tube-like structure they use to suck up the contents of punctured tissues. Flower thrips feed on the ovaries in most flowers, which is the part that develops into fruit. In the case of strawberries, flower thrips feed on the expanding receptacle [3, 7]. Feeding injury can cause russeting or bronzing of strawberry fruit around the fruit cap. Dulling of the fruit and fruit

Monitoring for flower thrips is done by gently tapping flowers over a white piece of paper [3, 7, 8]. The thrips will resemble tiny yellow and brown dashes crawling around on the paper. Strawberries can tolerate high numbers of flower thrips, so the treatment threshold is 10 thrips per flower [3, 7]. Minute pirate bugs, Orius spp., feed on flower thrips and are commercially available although release rates in

SWD larvae, tarnished plant bugs, strawberry seed bugs, and sap beetles feed directly on strawberry fruit. SWD, tarnished plant bugs, and seed bugs can cause significant yield losses because they feed on developing and ripe fruit. Sap beetles, in contrast, prefer overripe fruit, but will chew holes in ripe fruit, which can reduce yield.

The spotted wing drosophila, Drosophila suzukii Matsumura, is a more recently introduced pest of strawberries and other thin-skinned fruits. It was first found in Santa Cruz County, California in 2008 and has since spread across the United States [22, 23] Males can be distinguished from other drosophilid species by a spot present

thrips populations.

Figure 12.

6. Fruit pests

115

Reducing overwintering sites for adult weevils is an important part of managing this pest [3, 21]. This includes plowing under old beds as soon after the end of harvest as possible and removing dead leaves and mulch from the field. Rotating a strawberry field to another crop after 3 years is also important in reducing the incidence of strawberry bud weevil injury and damage.

#### 5.2 Flower thrips

A mix of thrips species can be found in strawberry flowers. The western flower thrips (Figure 12), Frankliniella occidentalis (Pergande), feeds on strawberry flowers along with other species, primarily in the genera Frankliniella and Thrips [3, 7, 8]. They are similar in size and appearance to chili thrips. They vary in color from light yellow to dark brown, depending on species, and lack the abdominal spots present on chili thrips. Adults are blown into strawberry fields from other hosts on wind currents. Some species lay eggs in the strawberry flowers while others simply feed on the flowers. Immature thrips are smaller than adults and lack wings. Populations of flower thrips usually migrate into strawberries when flowering resources are unavailable on other host crops or weeds. In the US, the most abundant flower thrips species in the strawberry growing region is the western flower thrips, Frankliniella occidentalis (Pergande) [3, 7]. Florida has a unique flower thrips species, Frankliniella bispinosa Morgan that is common to that region [8]. Regardless, flower thrips rarely cause economic damage in strawberry. Predatory bugs

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops DOI: http://dx.doi.org/10.5772/intechopen.82069

Figure 12. Western flower thrips female (left) and male (right) (photo credit: E.M. Rhodes, UF).

(Orius spp. and Geocoris spp.), that are common in the strawberry system, regulate thrips populations.

Thrips possess a single mandible that they use to puncture plant tissue. The rest of the mouthparts are formed into a tube-like structure they use to suck up the contents of punctured tissues. Flower thrips feed on the ovaries in most flowers, which is the part that develops into fruit. In the case of strawberries, flower thrips feed on the expanding receptacle [3, 7]. Feeding injury can cause russeting or bronzing of strawberry fruit around the fruit cap. Dulling of the fruit and fruit cracking has also been attributed to thrips feeding injury.

Monitoring for flower thrips is done by gently tapping flowers over a white piece of paper [3, 7, 8]. The thrips will resemble tiny yellow and brown dashes crawling around on the paper. Strawberries can tolerate high numbers of flower thrips, so the treatment threshold is 10 thrips per flower [3, 7]. Minute pirate bugs, Orius spp., feed on flower thrips and are commercially available although release rates in strawberries have not been determined.

## 6. Fruit pests

5. Flower pests

Both situations cause yield loss.

include mulches, brush, woods, and woodlots.

5.1 Strawberry bud weevil

Strawberry bud weevils feed on and lay their eggs in strawberry buds and can cause significant yield loses. Flower thrips feed in open flowers. Tarnished plant bugs feed on both flowers and fruit. Injury to flowers can result in deformed fruit that is unmarketable. Severely injured buds and flowers may not develop into fruit.

Strawberry - Pre- and Post-Harvest Management Techniques for Higher Fruit Quality

The strawberry bud weevil, Anthonomus signatus (Say), also known as the strawberry clipper, is a highly destructive pest in perennial strawberries [3, 21]. Adult weevils are only 1/10″–1/8″ long and are copper colored with two large, black spots on the back of their wing covers. Adults become active in the Spring when temperatures reach about 60°F. Adult females chew a hole in a developing flower bud and use their long snout to feed on the pollen. They then lay a single egg in the bud and girdle or clip the pedicel, which is the stem that attaches the bud to the plant, right at the base of the bud. The buds turn brown and eventually fall to the ground. The small, opaque white, legless grub develops and then pupates in the bud. Adults emerge in June, feed on flower pollen, and then seek overwintering sites, where they stay until the following Spring. Preferred overwintering sites

Girdled buds do not become fruit, so strawberry bud weevils can cause substan-

Reducing overwintering sites for adult weevils is an important part of managing

A mix of thrips species can be found in strawberry flowers. The western flower

thrips (Figure 12), Frankliniella occidentalis (Pergande), feeds on strawberry flowers along with other species, primarily in the genera Frankliniella and Thrips [3, 7, 8]. They are similar in size and appearance to chili thrips. They vary in color from light yellow to dark brown, depending on species, and lack the abdominal spots present on chili thrips. Adults are blown into strawberry fields from other hosts on wind currents. Some species lay eggs in the strawberry flowers while others simply feed on the flowers. Immature thrips are smaller than adults and lack wings. Populations of flower thrips usually migrate into strawberries when flowering resources are unavailable on other host crops or weeds. In the US, the most abundant flower thrips species in the strawberry growing region is the western flower thrips, Frankliniella occidentalis (Pergande) [3, 7]. Florida has a unique flower thrips species, Frankliniella bispinosa Morgan that is common to that region [8]. Regardless, flower thrips rarely cause economic damage in strawberry. Predatory bugs

tial yield loss if populations are high. Monitoring should begin once strawberry flower buds appear in the spring [3, 21]. In smaller fields, sample two feet of row from 5–10 areas of the field counting the number of cut buds in each section. For larger fields, sample five 10-foot sections of row. The threshold is one cut bud per foot of row. Two applications of insecticides should be made if the threshold is met

this pest [3, 21]. This includes plowing under old beds as soon after the end of harvest as possible and removing dead leaves and mulch from the field. Rotating a strawberry field to another crop after 3 years is also important in reducing the

or exceeded, one right away and the 2nd 10 days after the first.

incidence of strawberry bud weevil injury and damage.

5.2 Flower thrips

114

SWD larvae, tarnished plant bugs, strawberry seed bugs, and sap beetles feed directly on strawberry fruit. SWD, tarnished plant bugs, and seed bugs can cause significant yield losses because they feed on developing and ripe fruit. Sap beetles, in contrast, prefer overripe fruit, but will chew holes in ripe fruit, which can reduce yield.

#### 6.1 Spotted wing drosophila

The spotted wing drosophila, Drosophila suzukii Matsumura, is a more recently introduced pest of strawberries and other thin-skinned fruits. It was first found in Santa Cruz County, California in 2008 and has since spread across the United States [22, 23] Males can be distinguished from other drosophilid species by a spot present on each wing (Figure 13a) and two pairs of combs on each foreleg that have four to ix teeth each (Figure 13b) [22]. Newly emerged males lack the wing spots but can be identified by the combs. Unlike most other drosophilid species, female D. suzukii possess a heavily sclerotized serrated ovipositor (Figure 13c and d) that allows them to lay their eggs in ripening and ripe fruit [22].

Spotted wing drosophila larvae develop in the fruit, consuming the fruit as they do so, which renders the fruit unmarketable [22, 23]. As the larvae feed, areas where they are feeding will turn brown and become soft. Sunken areas that leak juice will appear on the surface of fruit. A single larva found in a shipment of fruit can cause the entire shipment to be rejected. The injury can also make the fruit susceptible to attack by other drosophilid species and diseases.

Adult spotted wing drosophila can be monitored with traps [24]. There are several commercially available traps and baits but a bait specific to spotted wing drosophila has not yet been developed. Soapy water is used as the drowning solution in these traps. Homemade traps can provide a more cost-effective option. Any plastic container with a lid that is around the size of a peanut butter jar can be used in trap construction. Punch two or three rows of holes around the middle of the plastic container leaving a 1″ unpunched area so the trap contents can easily be poured out. The holes should be large enough to allow spotted wing drosophila to enter but not so large that bees and other pollinators can enter. String or a long twist tie can be used to create a hanger for the trap by tying it through holes on either side of the trap. An example of a home-made trap is shown in Figure 14. The most effective homemade bait is a mixture of yeast, sugar, and water. Mix 2 tsp. sugar and ¼ tsp. active dry yeast in 2/3 cup water per trap. In this case, the bait also serves as the drowning solution. Traps should be checked weekly. The contents can be

emptied into another container or dumped through a filter screen. As females often arrive earlier than males, examining the flies on the screen with a hand lens even if no flies with wing spots are present is very important. There is no threshold for spotted wing drosophila and most growers begin a spray program once flies are

Home-made spotted wing drosophila trap baited with yeast, sugar, and water mix (photo credit:

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops

DOI: http://dx.doi.org/10.5772/intechopen.82069

The only way to sample for larvae is by collecting fruit and placing them in the

Two lygus bugs are known as tarnished plant bugs, Lygus lineolaris (palisot de Beauvois) and L. hesperus Knight in the eastern and western United States, respectively [3, 7, 25]. They overwinter as adults and females begin laying eggs in the spring. Early instar tarnished plant bugs are small, bright green, and resemble aphids. They can be distinguished from aphids because they move much faster than aphids and lack cornicles on their abdomens. Nymphs develop brown markings as they mature. Adults are ¼" long and bronze/yellow or mottled brown in color. Adults resemble big-eyed bugs, Geocoris spp., which are beneficial predatory insects. As their name suggests, big eyed bugs have much larger eyes than tarnished

Both nymphs and adults feed on developing flowers and fruit [3, 7, 25]. They feed on the seeds, which stops the area around the seeds from developing, which, in turn, causes fruit to be misshapen or "cat-faced." "Cat-faced" fruit are deformed, small, and their ends are seedy. Tarnished plant bugs are a serious pest in perennial strawberries and can cause 90% yield loss if not controlled. The overwintering adults and first generation of nymphs are the most destructive to perennial

freezer. Larvae will migrate to the surface of fruit as they freeze [24]. Because strawberry fruit are large, juicy, and contain a lot of flesh relative to other berries, dissection and extraction (salt and sugar) techniques that work well with other berries are difficult to perform and do not work well. The presence of a larvae

found in traps.

Figure 14.

L. Iglesius, UF).

plant bugs.

117

6.2 Tarnished plant bugs

indicates the need for insecticide application.

#### Figure 13.

Spotted wing drosophila (a) male, (b) enlarged view of male foreleg showing the two combs, (c) female, and (d) enlarged picture of female ovipositor (photo credits: L.E. Iglesius, UF).

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops DOI: http://dx.doi.org/10.5772/intechopen.82069

#### Figure 14.

on each wing (Figure 13a) and two pairs of combs on each foreleg that have four to ix teeth each (Figure 13b) [22]. Newly emerged males lack the wing spots but can be identified by the combs. Unlike most other drosophilid species, female D. suzukii possess a heavily sclerotized serrated ovipositor (Figure 13c and d) that allows

Strawberry - Pre- and Post-Harvest Management Techniques for Higher Fruit Quality

Spotted wing drosophila larvae develop in the fruit, consuming the fruit as they do so, which renders the fruit unmarketable [22, 23]. As the larvae feed, areas where they are feeding will turn brown and become soft. Sunken areas that leak juice will appear on the surface of fruit. A single larva found in a shipment of fruit can cause the entire shipment to be rejected. The injury can also make the fruit susceptible to

Adult spotted wing drosophila can be monitored with traps [24]. There are several commercially available traps and baits but a bait specific to spotted wing drosophila has not yet been developed. Soapy water is used as the drowning solution in these traps. Homemade traps can provide a more cost-effective option. Any plastic container with a lid that is around the size of a peanut butter jar can be used in trap construction. Punch two or three rows of holes around the middle of the plastic container leaving a 1″ unpunched area so the trap contents can easily be poured out. The holes should be large enough to allow spotted wing drosophila to enter but not so large that bees and other pollinators can enter. String or a long twist tie can be used to create a hanger for the trap by tying it through holes on either side of the trap. An example of a home-made trap is shown in Figure 14. The most effective homemade bait is a mixture of yeast, sugar, and water. Mix 2 tsp. sugar and ¼ tsp. active dry yeast in 2/3 cup water per trap. In this case, the bait also serves as the drowning solution. Traps should be checked weekly. The contents can be

Spotted wing drosophila (a) male, (b) enlarged view of male foreleg showing the two combs, (c) female, and

(d) enlarged picture of female ovipositor (photo credits: L.E. Iglesius, UF).

them to lay their eggs in ripening and ripe fruit [22].

attack by other drosophilid species and diseases.

Figure 13.

116

Home-made spotted wing drosophila trap baited with yeast, sugar, and water mix (photo credit: L. Iglesius, UF).

emptied into another container or dumped through a filter screen. As females often arrive earlier than males, examining the flies on the screen with a hand lens even if no flies with wing spots are present is very important. There is no threshold for spotted wing drosophila and most growers begin a spray program once flies are found in traps.

The only way to sample for larvae is by collecting fruit and placing them in the freezer. Larvae will migrate to the surface of fruit as they freeze [24]. Because strawberry fruit are large, juicy, and contain a lot of flesh relative to other berries, dissection and extraction (salt and sugar) techniques that work well with other berries are difficult to perform and do not work well. The presence of a larvae indicates the need for insecticide application.

#### 6.2 Tarnished plant bugs

Two lygus bugs are known as tarnished plant bugs, Lygus lineolaris (palisot de Beauvois) and L. hesperus Knight in the eastern and western United States, respectively [3, 7, 25]. They overwinter as adults and females begin laying eggs in the spring. Early instar tarnished plant bugs are small, bright green, and resemble aphids. They can be distinguished from aphids because they move much faster than aphids and lack cornicles on their abdomens. Nymphs develop brown markings as they mature. Adults are ¼" long and bronze/yellow or mottled brown in color. Adults resemble big-eyed bugs, Geocoris spp., which are beneficial predatory insects. As their name suggests, big eyed bugs have much larger eyes than tarnished plant bugs.

Both nymphs and adults feed on developing flowers and fruit [3, 7, 25]. They feed on the seeds, which stops the area around the seeds from developing, which, in turn, causes fruit to be misshapen or "cat-faced." "Cat-faced" fruit are deformed, small, and their ends are seedy. Tarnished plant bugs are a serious pest in perennial strawberries and can cause 90% yield loss if not controlled. The overwintering adults and first generation of nymphs are the most destructive to perennial

strawberries because they feed during the bloom period. It is important to note that poor pollination can also cause misshapen fruit. However, fruit misshapen from poor pollination will have seeds that vary in size while those injured by tarnished plant bugs will have seeds that are uniform in size [25].

species found in North Carolina [26]. In contrast, C. fumatus Boheman, Lobiopa insularis (Castelnau), and Epuraea luteola Erichson are the most common species found in Florida strawberries [27]. In general, sap beetles are small, 1/8″–1/4″ in length, and orange to dark brown in color. Several abdominal segments protrude

Management of Strawberry Insect and Mite Pests in Greenhouse and Field Crops

Adults fly into strawberry fields from wooded areas or other protected sites after overwintering [26]. In Florida, they do not overwinter and can come into fields at anytime but are more common in February through the end of harvest in March or April [27]. Females lay their eggs on or near overripe and rotting fruit. The larvae feed on and develop inside the fruit and then pupate in the soil nearby. The adults feed on ripe fruit, chewing small holes in the fruit that can make fruit unmarketable

The best way to manage sap beetles is to practice good field sanitation [26, 27].

This chapter has reviewed the most common strawberry pests in the United States at the time this chapter was written. Pest complexes in other regions of the world will differ. It is probably inevitable that other exotic species will slip through our borders and become pests like the spotted wing drosophila and chili thrips have done. Climate change and changes in agricultural practices, such as the use of high and low tunnel systems, may change the pest complex in different areas of the United States. It is important to be aware of these things when developing an IPM

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Frequent harvests that include the removal and disposal of overripe and other unmarketable fruits usually prevent sap beetles from becoming a problem.

beyond the elytra and they have clubbed antennae.

DOI: http://dx.doi.org/10.5772/intechopen.82069

and introduce disease organisms.

7. Conclusions

program.

Author details

119

Oscar Liburd\* and Elena Rhodes

University of Florida, Gainesville, Florida, USA

\*Address all correspondence to: oeliburd@ufl.edu

provided the original work is properly cited.

Monitoring for tarnished plant bug should begin right before the start of bloom. Thirty flower clusters should be sampled evenly across the field by gently tapping them over a white piece of paper or another white surface. Nymphs will fall onto the white paper. The threshold is 0.25 nymphs before 10% bloom or more than 4 clusters infested [3, 7, 25]. The threshold rises to 0.5 nymphs per flower from mid to late bloom. There are also devices available to vacuum tarnished plant bugs off strawberry and other plants. The threshold for vacuuming is one bug per 10 plants [7].

Controlling weeds is an important part of managing tarnished plant bugs because tarnished plant bugs feed on many different weeds [3, 7, 25]. In California, the parasitoid wasp Anaphes iole Girault, which is an egg parasitoid, is available commercially [7]. Bug-vacs can be used to manage mild to moderate infestations but may also remove predatory insects and spiders from the plants [7].
