''Empoasca fabae'' belongs to family Cicadellidae and genus Empoasca within order

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

.”Lamp, W., D., Miranda, L., Culler & Alexander, L. (2011) “Host Suitability and Gas Exchange Response of Grapevines to Potato Leafhopper (Hemiptera: Cicadellidae)”. ''Journal of Economic Entomology'' 104 (4): 1316–1322. They are more commonly referred to as the potato leafhopper. In North America they are a serious agricultural pest.”Delay, B., P, Mamidala, A, Wijeratne., S, Wijerante, O, Mittapalli, J, Wang., and Lamp, W. (2012). “Transcriptome analysis of the salivary glands of potato leafhopper, Empoasca fabae”. ''Journal of Insect Physiology'' 58 (12): 1626–1634. Every year millions of dollars are lost from reduced

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponic ...

yields and on pest management. Crops that are impacted the most are

potatoes The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United ...

clover Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus ...

beans A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

apples An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...

and

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...

."Bland R.G., Jaques H.E. (2010). How to Know the Insects 3rd Edition. Waveland Press Inc. p. 163.

Appearance

Adults have pale to iridescent green bodies with 6 or 8 white spots on their

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on ea ...

. They have a distinctive white H shape mark between their head and wing base.”Dudley, J. (1921). “The Potato Leafhopper and its control”. United States Department of Agriculture: Farmers Bulletin 1225, 1–16.. Their bodies are approximately 3 mm long and have on their front wings near its tip a crossvein. Adults and nymphs move by hopping among host plants. However, only adults can fly.” Hoffman, G., D, Hogg, & Boush, M. (1991). “Potato Leafhopper (Homoptera: Cicadellidae) Life History Traits on Water-Stressed Alfalfa in the Early Regrowth and Bud Stage”. ''Environmental Entomology'' 20(4): 10581066.

Diet

They are able to feed and reproduce on at least 200 different plant species across twenty-six families. In total herb genera represent 64% of their

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

s. Adults prefer to feed on the

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

and

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

s, while the nymphs prefer the leaves.”Lamp, W., Nielsen, G., Fuentes, C., & Quebedeaux, B. (2004) “Feeding Site Preference of Potato Leafhopper (Homoptera: Cicadellidae) on Alfalfa and its Effect on Photosynthesis”. ''Journal of Agricultural and Urban Entomology'' 21 (1): 25–38 Their specialized mouth parts are able to pierce into the plant tissue and remove its

sap Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant. Sap is distinct from latex, resin, or cell sap; it is a separa ...

.”Potter, D., & Spicer, P. (1993). “Seasonal Phenology, Management, and Host Preferences of Potato Leafhopper on Nursery-Grown Maples” ''Journal of Environmental Horticulture'' 11(3): 101–106.. The ability to inhabit a wide range of hosts is due to the variation in their feeding behaviors.

Migration

''Empoasca fabae'' is a seasonal

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

species."Taylor, R., & Reling, D. (1986). Preferred Wind Direction of Long-Distance Leafhopper (Empoasca fabae) Migrants and its Relevance to the Return Migration of Small Insects. ''Journal of Animal Ecology'' 55(3): 1103–1114. If they are flying at night, it takes two or three days to reach their summer destinations. Research suggests that they are using winds as a passive means to help migrate. The direction of the winds influence their distribution within their summer range. Typically, the winds blow in a north-northeast direction towards Northern and Midwest United States. Factors such as warm temperatures and lack of

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

increases their range. Cold temperatures, major precipitation, and unsuitable environmental conditions are factors that will stop migration to continue more north. In late summer,

cold fronts A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface trough of low pressure. It often forms behind an extratropical cyclone (to the west in the Northern ...

start to appear sending cues for them to leave. As they leave they get caught up in these fronts which carry them south to southwest to their overwintering range.

Habitat and range

Winter

Due to their inability to tolerate the cold winter temperatures they must migrate south. Adults overwinter on hosts in the pine and mixed hardwood forests along the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

and in the Southern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

.”Taylor, P., & Sheilds, E. (1995). “Phenology of Empoasca fabae (Harris) (Homoptera: Cicadellidae) in its Overwintering Area and Proposed Seasonal Phenology”. ''Environmental Entomology'' 24 (5): 1096–1108. Eastern Texas and Oklahoma, Virginia, Louisiana, Florida, Georgia, South and North Carolina, Alabama, Tennessee, Arkansas, and Mississippi, have documented populations. Before migrating back to their summer range they change their hosts to

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

legumes then to new spring foliage of

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

trees.

Summer

Their summer range extends across the Midwest and eastern parts of Canada and the United States.”Medeiros, A., W, Tingey., & De Jong, W. (2004). “Mechanisms of Resistance to Potato Leafhopper, Empoasca fabae (Harris), in Potato”. ''American Journal of Potato Research'' 81(6): 431–441.. In Canada, they are found only in the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

region. They are able to inhabit a wide range of habitats.” Lamp, W., G, Nielson., & Danielson, S. (1994). “Patterns among Host Plants of Potato Leafhopper, Empoasca fabae (Homoptera: Cicadellidae.” Journal of the Kansas Entomological Society 67(4): 354-368. Only about 32% of individuals actually occupy croplands. The remaining individuals will reside in fields, woodlands, scrublands, waste places, and parks. Precipitation will deposit individuals upon plant hosts where they will quickly re-establish themselves.”Van Timmeren, S., J, Wise, C, Vandervoort., & Isaacs, R. (2011). “Comparison of foliar and soil formulations of neonicotinoid insecticides for control of potato leafhopper, Empoasca fabae (Homoptera: Cicadellidae), in wine grapes.” ''Pest Management Science'' 67(5): 560–567.

Development and reproduction

Diapause

Before migrating they mate and enter reproductive

diapause In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It ...

. ''Empoasca fabae'' begin to enter into reproductive dispause at the end of July.” Erlandson, W., & Obrycki, J. (2015). “Population Dynamics of Empoasca fabae (Hemiptera: Cicadellidae) in Central Iowa Alfalfa Fields.” ''Journal of Insect Science'' 15(1): 1-6. The entire population remains in this state for its migration and overwintering period. This diapause period ends from mid-January through February, and they begin to sexually mature.

Egg laying

During the spring migration north, the majority of the individuals are females. When they return if temperatures are above 10 °C they can start oviposition and populations grow and re-establish themselves. ''Empoasca fabae'' arrives back to their summer ranges during April or early May depending on the location.”Bentz, J., & Townsend, A. (2004). “Spatial and temporal patterns of abundance of the potato leafhopper among red maples.” ''Annals of Applied Biology'' 145(2): 157-164. During the summer months they can, on average, lay eggs over a span of 96 days.”Poos, F. (1932). “Biology of the Potato Leafhopper, Empoasca Fabae (Harris), and Some Closely Related Species of Empoasca.” ''Journal of Economic Entomology'' 25(3): 639-646. Peak population densities occur during late May to late June. Many overlapping generations appear. After this their population densities begin to decline slowly. Individuals have a tendency to aggregate as their populations increase. At the end of the summer, individuals either die or migrate south.”Taylor, P., E, Sheilds., M, Tauber., & Tauber, C. (1995). “Induction of Reproductive Diapause in Empoasca fabae (Homoptera: Cicadellidae) and Its Implications Regarding Southward Migration”. ''Environment Entomology'' 24 (5): 1086–1095.

Eggs and hatchlings

Eggs are laid on their hosts; they are transparent and small in size. Females will lay 2 or 3 eggs a day on the plant’s stem and leaf veins.”Townsend, L. (2012). “Potato Leafhoppers.” University of Kentucky. Version 2012.2. ENT facts http://www2.ca.uky.edu/entomology/entfacts/ef115.asp Retrieved 28 November 2015 The egg’s incubation period ranges from 4 through 23 days, the hatchings are called

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...

. New hatchlings are white in colour and develop their green colouring as they age. The nymphs undergo five

instars An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

before becoming adults. As they develop, they lose their skin and develop their wings. ''Empoasca fabae'' develops into adults in 8 through 37 days. Their entire lifecycle is one month long.

As a pest

Hopperburn

The visually descriptive term hopperburn is used for a distinct type of damage on plants by ''E. fabaes feeding on its hosts.”Maletta, M., M, Henninger, & Holmstrom, K. (2006). “Potato Leafhopper Control and Plastic Mulch Culture in Organic Potato Production”. ''HortTechnology'' 16 (2): 199-204. As they feed their saliva mechanically injures the

phloem Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...

and

parenchyma Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word π ...

cells. The plant also suffers damage to its

vascular cambium The vascular cambium is the main growth tissue in the stems and roots of many plants, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular plants. It produces secondary xyle ...

, and to its vascular bundles. Within 24 hours of being infested, rates of

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

, and

transpiration Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth a ...

are reduced, leaves accumulate starch, and transport of photoassimilates are reduced. The first symptoms of hopperburn is that a leaflet's margins start to curl up. As a plant's infestation increases, its leaves cup downward, and they start to turn from green to yellow."Murray, J., M, Paul., & Schaafma, A. (2001) “Determination of traits associated with leafhopper (Empoasca fabae and Empoasca kraemeri) resistance and dissection of leafhopper damage symptoms in the common bean (Phaseolus vulgaris)”. ''Annals of Applied Biology''. 139(3): 319-327. In severe infestations this leads to leaf

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

in which the leaf margins and intervein areas turn brown. Older plants completely lose their leaves. Young plants display tip-wilting and will be stunted in height. Plants that were damaged by stem feeding suffered more damage to their physiologies than those which were damaged by leaf eating. Research has shown that water-stressed plants increase nymph's development time. This causes severe hopperburn due to the increase plant stress response.

Economic impacts

Hopperburn leads to reduced plant growth and reproduction. In some heavily infested fields up to 75% of the yield is lost, it depends on what stage of development the plants are in. Obviously, this leads to reductions in crop yields and large economic losses. For example, in 1988 the losses of

crops in Northeast United States ranged from $32-$66 per hectare. The amount of crop damage is directly proportional to the population density. Most crop damage comes from the future generations of the initial arrivals back to the summer range.

Climate change

Research has indicated that over the last 62 years that they have been arriving back to their summer range earlier by ten days.” Baker, M., P, Venugopal., & Lamp, W. (2015). “Climate Change and Phenology: Empoasca fabae (Hemiptera: Cicadellidae) Migration and Severity of Impact”. ''PLoS ONE'' 10 (5): 1–12 Warmer temperatures increases the time and speed of egg hatching and nymph development.”Sidumo, A., E, Sheilds., & Lembo, A. (2005). “Estimating the Potato Leafhopper Empoasca fabae (Homoptera: Cicadellidae) Overwintering Range and Spring Premigrant Development by Using Geographic Information System.” ''Journal of Economic Entomology'' 98 (3): 757–764. There is increasing concern that

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

will shift the overwintering and summer ranges more northward. This will exacerbate the problem of pest management and increase economic losses. .

Pest management

Usually, crop detection of ''E. fabae'' is too late as hopperburn is the first visual symptom of a major infestation. Regular crop inspections with a sweep net are essential to help reduce massive economic losses. Another visual cue is the death of leaves with small pits holes throughout them resulting from their eggs. Host expansion is likely caused from the loss of natural resistance through extensive

plant breeding Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. The goals of plant breeding are to produce cro ...

. Currently, the only effective method that exists for controlling ''E. fabaes infestations is the heavy application of

insecticides Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

. Short-lived insecticides such as carbaryl are commonly used; however they require costly reapplications. Research is indicating the possibility of being able to control populations by increasing ''E. fabaes natural enemies as part of pest management plan.”Erlandson, W., & Obrycki, J. (2010). “Predation of Immature and Adult Empoasca fabae (Harris) (Hemiptera: Cicadellidae) by Three Species of Predatory Insects.” ''Journal of the Kansas Entomological Society'' 83(1): 1-6. Percent mortality has been shown to be highest in individuals in younger instars. Research has shown that natural resistance and pesticide use are just as effective, but neither is capable to fully contain populations.Ghidiu, G., D, Douches., K, Flecher., & Coombs, J. (2011). “Comparing Host Plant Resistance, Engineered Resistance, and Insecticide Treatment for Control of Colorado Potato Beetle and Potato Leafhopper in Potatoes.” ''International Journal of Agronomy'' 11(6): 516–523 To create more effective management programs and reduce pesticide use it is essential to understand their dispersion, temporal and spatial patterns.

References

{{Taxonbar, from=Q2972255 Hemiptera of North America Empoascini Insects described in 1841