Liriomyza trifolii | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Diptera |
Family: | Agromyzidae |
Subfamily: | Phytomyzinae |
Genus: | Liriomyza |
Species: | L. trifolii |
Binomial name | |
Liriomyza trifolii (Burgess, 1880) [1] | |
Synonyms | |
Liriomyza trifolii, known generally as the American serpentine leafminer or celery leafminer, is a species of leaf miner fly in the family Agromyzidae. [4]
L. trifolii is a damaging pest, as it consumes and destroys produce and other plant products. It commonly infests greenhouses and is one of the three most-damaging leaf miners in existence today. It is found in several countries around the globe as an invasive species, but is native to the Caribbean and the Southeastern United States. [5]
L. trifolii are relatively small flies for their family. The adults typically measure less than 2 mm in length. They are mostly yellow in color, although parts of the abdomen and thorax are dark brown or grey. They typically have yellow legs. A key distinction between L. trifolii and their very similar relatives, L. sativae, are L. trifolii's dark, matte mesonotum. [5]
L. trifolii typically have a wingspan of 1.25 to 1.90 mm. Their wings are transparent and have veins in a similar pattern to that of flies in the Phytomyzinae subfamily. [5]
Originally, L. trifolii was solely found in Caribbean countries and the southeastern United States (specifically concentrated in southern Florida). [5] However, export of produce and other vegetative goods from these areas has led to the dispersion of L. trifolii to several countries in Asia along the Pacific Ocean, as well as Europe, California, and certain parts of Canada. This human-facilitated dispersion occurred mostly after L. trifolii became resistant to certain insecticides and therefore were not killed off by the exports' treatment with insecticides before and after transport. [6]
L. trifolii are naturally found in tropical and subtropical regions. However, they frequently infest greenhouses and can now be found as an invasive species in a wider variety of climates. [5] Because of this human-facilitated dispersion, L. trifolii can now be found in more temperate climates than they naturally would, although their development and survival is not as successful in the cooler climates. [5] [7]
Compared to other flies, L. trifolii have a relatively brief life cycle, ranging from 21 to 28 days in habitats they are native to. Because of this, there can be multiple generations of L. trifolii within one year in warm climates. [5] Additionally, the rate of development for L. trifolii has been shown to be temperature-dependent. Maximum pupal survival rates and oviposition rates were shown to occur at 30˚C. [7]
The eggs are typically about 1 mm long, 0.2 mm wide, and oval in shape. Initially after oviposition, the eggs are clear, but they become creamy white in color as time goes on. Eggs are laid just below the surface of the leaf; when the larvae hatch, they mine their way out of the leaf as they feed, hence the name "leaf miner". The eggs frequently fall victim to parasitoid wasps. [5]
The larvae of L. trifolii are unique from those of many other flies in their shape, as the body of L. trifolii larva does not taper at the head end. The larvae are uniform in thickness at both their anterior and posterior ends but additionally have a pair of spiracles at the posterior end. They do not have legs and are initially clear in color, but gradually become yellow as they mature. [5]
The larval instars are differentiable by the lengths of the body and mouthparts. The first instar is recognizable by a mean body length of 0.39 mm and a mouthpart length of 0.10 mm. For the second instar, the mean measurements are 1.00 mm (body) and 0.17 mm (mouth). For the third instar, the mean measurements are 1.99 mm (body) and 0.25 mm (mouth). The fourth instar is a non-feeding stage and thus is usually disregarded. [5]
Typically, at the end of the larval phase, L. trifolii drop to the soil to pupate after exiting the leaf mines they have created. Initially, the puparium is yellow, but it grows to become a darker brown over time. The puparium is typically less than 2.3 mm long and 0.75 mm wide. [5]
Adult female L. trifolii tend to live around 13 to 18 days. Male adults typically only live 2 to 3 days because they are unable to puncture plants and thus have difficulty feeding. As previously described, both males and females are typically around 2 mm in length with a wingspan around 1.25 mm. [5] After chewing a fan shape into the leaf of their host plant, adults feed on exuding sap of the host plant on which oviposition will occur. [8]
Both larval and adult female L. trifolii feed primarily on the leaves of their host plants. Larvae feed mostly on the layer of the leaf just below the epidermis, while female adults feed on liquids expelled by the leaves after the adult has punctured them. [5] [8] L. trifolii feed on a large variety of host plants, including both vegetables and ornamental plants. Studies on the flies' preferred hosts show that some of L. trifolii's most preferable hosts are chrysanthemums, Gerber daisies, and celery. When the females are placed on preferable hosts, they produce more holes and show an increased rate of oviposition. [8]
The ways in which L. trifolii signal readiness for mating are not entirely known. Researchers have not reported the presence of any sex pheromones, but L. trifolii may attract mates and signal readiness through a series of short-distance vocalization by the males. This vocalization also manifests into male L. trifolii rapidly "bobbing" up and down when nearby to females they would like to mate with. [9]
Males are typically not overly aggressive, but aggression between L. trifolii males has been observed in severely overcrowded laboratory conditions. During copulation, if a rival male approaches a pair, the mating male will repeatedly flex his wings until the rival is scared away. This is likely a display of his fitness through his wing size. [9]
Oviposition occurs within 24 hours of mating, usually during daylight hours. [5] [8] When oviposition is going to occur, the female punctures the host leaf in a tubular shape, feeding on the sap released from the leaf as she punctures. [10] Oviposition typically occurs at a rate of 35 to 39 eggs per day. Females often lay a total of 200 to 400 eggs in their lifetime when on ideal hosts such as celery. Both the rate of oviposition and the total fecundity decrease when located on less ideal host plants, such as tomatoes. [5] [8]
Eggs are typically oviposited on leaves toward the center of the host plant. Regardless of host plant, the female's first action is bending of the abdomen to position her ovipositor at the correct angle to the leaf. The ovipositor than contacts the leaf in a series of "rapid thrusts". The female punctures the leaf in either a fan shape or a tubular shape. [9] The eggs are inserted into the tubular punctures on the bottom surface of the host leaf, just below the epidermis. This is where the larva will create its mine upon hatching. [5] [10] Oftentimes, the mother will make multiple punctures before selecting the ideal spot. Oviposition rate is significantly increased for female L. trifolii located on ideal host plants such as celery. [8] [10]
The most significant natural threat to L. trifolii are parasitoid wasps. These wasps lay their eggs amongst the eggs of L. trifolii. When the wasps hatch, they typically devour the flies' nearby eggs, as is the defining characteristic of parasitoids. The most common parasitoids of L. trifolii are wasps from the families Braconidae, Eulophidae, and Pteromalidae. In the absence of insecticides, these parasitoids play a major role in keeping the L. trifolii population under control. [5]
Although predators and diseases tend to impact the L. trifolii population to an insignificant amount compared to parasitoids, both larvae and adult L. trifolii can still be at risk of predation by general predators. The most common predators of L. trifolii are ants. [5]
L. trifolii is a highly destructive pest of both produce and ornamental plants. They often infest greenhouses and inhabit shipping containers, making them an invasive species in several countries around the globe. Because of this, they are a quarantine species in several countries, meaning their host plants are isolated for testing when L. trifolii are found on them. [6] [11] L. trifolii are most destructive to floricultural crops, which are severely impacted by any insect damage. Leaf miner abundance is assessed using a variety of sampling methods, including counting mines, counting live larvae, collecting pupae, and capturing adults. [5] L. trifolii can be destructive to crops in many ways, including spreading diseases, destroying seedlings, and altering leaf production, which damages the fruits. All of these impacts on the crops decrease their value, which can be catastrophic to the industry. [9]
The spread of this pest is widely due to the fly's developed resistance to certain insecticides. This has been a major issue combatted by attempts from the Florida Fruit and Vegetable Association (FFVA) to mitigate the infestation and spread of these pests. However, due to previous spreading of L. trifolii through exported goods, L. trifolii are already a major pest of ornamentals in California. [11] [12] The California chrysanthemum industry lost approximately $93 million to damage caused by L. trifolii in the 1980s. [9] Insecticides also kill off parasitoids that inhabit the area. Thus, the use of insecticides not only damages the ecosystem, but also reduces the population of the main form of biological control for L. trifolii. [5]
The Tachinidae are a large and variable family of true flies within the insect order Diptera, with more than 8,200 known species and many more to be discovered. Over 1,300 species have been described in North America alone. Insects in this family commonly are called tachinid flies or simply tachinids. As far as is known, they all are protelean parasitoids, or occasionally parasites, of arthropods, usually other insects. The family is known from many habitats in all zoogeographical regions and is especially diverse in South America.
The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking flight. This behaviour is a source of one of their alternate names, scuttle fly. Another vernacular name, coffin fly, refers to Conicera tibialis. About 4,000 species are known in 230 genera. The most well-known species is cosmopolitan Megaselia scalaris. At 0.4 mm in length, the world's smallest fly is the phorid Euryplatea nanaknihali.
A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining insects are moths (Lepidoptera), sawflies, and flies (Diptera). Some beetles also exhibit this behavior.
The Agromyzidae are a family of flies, commonly referred to as the leaf-miner flies for the feeding habits of their larvae, most of which are leaf miners on various plants. It includes roughly 2,500 species, they are small, some with wing length of 1 mm. The maximum size is 6.5 mm. Most species are in the range of 2 to 3 mm.
Phthorimaea operculella, also known as the potato tuber moth or tobacco splitworm, is a moth of the family Gelechiidae. It is an oligophagous insect that feeds on the plant family Solanaceae and is especially known for being a major pest of potato crops. Currently farmers utilize insecticides, parasites, and sprinkler irrigation in order to prevent P. operculella from infesting their croplands.
Bactrocera dorsalis, previously known as Dacus dorsalis and commonly referred to as the oriental fruit fly, is a species of tephritid fruit fly that is endemic to Southeast Asia. It is one of the major pest species in the genus Bactrocera with a broad host range of cultivated and wild fruits. Male B. dorsalis respond strongly to methyl eugenol, which is used to monitor and estimate populations, as well as to annihilate males as a form of pest control. They are also important pollinators and visitors of wild orchids, Bulbophyllum cheiri and Bulbophyllum vinaceum in Southeast Asia, which lure the flies using methyl eugenol.
Birch leafminers are sawflies, which are closely related to bees and wasps. They are among the most common insect pests affecting birch trees in North America. The primary species affecting birch trees in North America are Profenusa thomsoni and Fenusa pumila. Areas inside the leaves are consumed by the larvae, affecting the leaves' ability to produce food. Yearly browning of birch leaves are noticed in mid July and August, but the leafminers have been feeding inside the leaf tissue since early spring.
Anthonomus eugenii is known as the pepper weevil. This beetle feeds and lays eggs on plants in the genus Capsicum and a few species in the genus Solanum. A. eugenii is native to Mexico, however, it is an important pest of Capsicum in Florida, Puerto Rico, and Central America.
The serpentine leaf miner is the larva of a fly, Liriomyza brassicae, in the family Agromyzidae, the leaf miner flies. It mines wild and cultivated plants, such as cabbage, broccoli, cauliflower and Chinese broccoli.
Bactrocera cucurbitae, the melon fly, is a fruit fly of the family Tephritidae. It is a serious agricultural pest, particularly in Hawaii.
Chloridea virescens, commonly known as the tobacco budworm, is a moth of the family Noctuidae found throughout the eastern and southwestern United States along with parts of Central America and South America.
Phytomyza ilicis, the holly leaf miner, is a leaf mining fly in the family Agromyzidae, whose larvae burrow into leaves of the holly tree leaving characteristic pale trails or leaf mines.
Empoasca decipiens is a species of leafhopper belonging to the family Cicadellidae subfamily Typhlocybinae. The adults reach 3–4 millimetres (0.12–0.16 in) of length and a are homogenously green with whitish markings on its pronotum and vertex. E. decipiens is commonly referred to as the “green leafhopper” because of its colouration. The absence of clear stripes along the forewings can easily distinguish it from the similar leafhopper species E. vitis, but distinguishing it from other leafhoppers with the same colouration requires examination under a microscope. It is present in most of Europe, in the eastern Palearctic realm, in North Africa, in the Near East, and in the Afrotropical realm. Both nymphs and adults of this small insect are considered to be a very destructive pests on field crops, vegetables and greenhouse plants.
Anastrepha suspensa, known as the Caribbean fruit fly, the Greater Antillean fruit fly, guava fruit fly, or the Caribfly, is a species of tephritid fruit fly. As the names suggest, these flies feed on and develop in a variety of fruits, primarily in the Caribbean. They mainly infest mature to overripe fruits. While thought to have originated in Cuba, the Caribbean fruit fly can now also be found in Florida, Hispaniola, and Puerto Rico.
Phytomyza horticola is a species of leaf-mining fly in the family Agromyzidae of the order Diptera. For a time it was treated as Chromatomyia horticola, but its original name has been restored after genus Chromatomyia was synonymized with Phytomyza. The species is a pest of high economic importance affecting the vegetable crops in temperate and tropical regions.
Scaptomyza flava is an herbivorous leaf mining fly species in the family Drosophilidae. In Latin, flava means golden or yellow. The fly is amber to dark brown in color and approximately 2.5 mm in length. In Europe and New Zealand the larvae are pests of plants in the order Brassicales, including arugula, brassicas, broccoli, Brussels sprouts, bok choy, cabbage, canola, cauliflower, horseradish, kale, kohlrabi, napa cabbage, nasturtium, radish, rapini, rutabaga, turnip, wasabi and watercress. In New Zealand, its range has expanded to include host species that are intercropped with salad brassicas, including gypsophila, otherwise known as baby's breath, which is in the pink family (Caryophyllaceae) and the pea in the Fabaceae. More typically, S. flava is oligophagous within the Brassicales. Scaptomyza are unusual within the Drospophilidae because the group includes species that are truly herbivorous. Other herbivorous drosophilids include D. suzukii, which attacks fruit very early during ripening and species within the genus Lordiphosa, from Africa and Asia, which also include leaf miners. Most drosophilids feed on microbes associated with decaying vegetation and sap fluxes.
Liriomyza sativae, commonly known as the vegetable leaf miner, is a species of insect, a fly in the family Agromyzidae. The larvae of this fly mine the leaves of a range of vegetables and weeds, but seem to favour plants in the families Cucurbitaceae, Fabaceae and Solanaceae.
Liriomyza huidobrensis, commonly known as the pea leaf miner, is a species of insect, a fly in the family Agromyzidae. The larvae of this fly mine the leaves and stems of peas and a range of other vegetables. It is also known as the serpentine leaf miner, but this name is also used for a closely related species, Liriomyza brassicae.
Mallophora ruficauda is a species of parasitic robber fly in the family Asilidae, endemic to South and Central America. Like other robber flies, M. ruficauda is known for its aggressive behavior and predation upon other insects, especially bees. M. ruficauda mimics a bumblebee to fool predators into thinking it has a painful sting and is not worth eating.
Anastrepha fraterculus, known as the South American fruit fly, is a fruit fly species from the genus Anastrepha. A. fraterculus is a polyphagous, frugivorous fly that is a significant pest of commercial fruit production in South America.