Hessian fly | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Diptera |
Family: | Cecidomyiidae |
Genus: | Mayetiola |
Species: | M. destructor |
Binomial name | |
Mayetiola destructor (Say, 1817) | |
Synonyms | |
Cecidomyia destructor Say, 1817 |
The Hessian fly or barley midge, Mayetiola destructor, is a species of fly that is a significant pest of cereal crops, including wheat, barley and rye. Though a native of Asia, upon its discovery it was believed to have been transported into North America in the straw bedding of Hessian troops during the American Revolution (1775–1783), thus the origin of its common name. However, the report of an inquiry made in 1788 by Sir Joseph Banks states that "no such insect could be found to exist in Germany or any other part of Europe". Nonetheless, it appears that this species, or one exactly like it in habits, had been known for at least a century prior to the American Revolution from a locality near Geneva, and also for a long time from some regions in France. [1]
The Hessian fly was described by Thomas Say in 1817. It is a very harmful insect. It mainly attacks the stem, although if it is especially hungry it will eat any part of the plant it can find.[ citation needed ]
In 1836, a severe infestation of Hessian flies resulted in a crop shortage aggravating the financial problems of farmers prior to the Panic of 1837. [2]
M. destructor is believed to have originated in the Fertile Crescent of the Middle East, parasitizing wild grass species of the tribe Triticeae. [3] With the global development of agriculture, particularly of wheat, it is now present in throughout Europe, North Africa, North America, and New Zealand. [3]
Hessian fly eggs are tiny and elliptical, being most easily recognized by their distinctive orange color. [3] Larvae resemble white cylindrical grubs similar to other members of the family Cecidomyiidae. [3] As they age, larvae also develop a translucent green stripe down the center of the back. [3] There are three larval instars, each varying in size. [3] Individuals between the first and second instars can widely differ in size, with larvae doubling in size from the first instar (0.56-1.70 mm) to the second (1.70-4.00 mm). [3] Pupae develop within the cuticle of the second instar, known as the puparium. [3] This stage is also called the flax-seed stage, as the hard, sclerotized, dark-brown cuticle the larva develops within resembles a seed of flax. [3] Adult flies are brown or black. [3] Females can sometimes be distinguished more easily due to their occasional reddish-brown coloring, a product of the eggs developing within the abdomen. [3]
The Hessian fly is a short-lived gall-forming insect, living for around 30 days. [4] Typically, multiple generations of the fly are seen, although the exact number of generations depends largely on region and its associated climate. [3] For example, in the Coastal Plains region of Georgia and South Carolina, 5-6 total generations can be observed in a year; two in fall, one in winter, and one-two in spring. [5] Females lay up to 200 eggs on wheat, but will lay on other cereals, such as oats and barley, albeit in smaller clutches. [6] [7] Eggs are most commonly laid and found in grooves on the upper side of the leaf blade in a host plant. [3] [7] Oviposition sites are carefully chosen through chemical, visual, and tactile cues, taking into account intrinsic factors that could maximize survival of offspring, such as number and depth of vascular grooves on the leaf surface. [3] [8]
After hatching, first-instar larvae migrate down to the leaf base, where they feed by attacking the abaxial surface of the sheath on the plant's youngest leaves. [7] Feeding lasts between 2-3 weeks over 2 instars, with five-day old larva consuming the greatest amount of plant fluid. [7] The second instar is largely immobile, lacking the creeping pads of the first stage. [7] Following feeding, larvae enter the third instar/pupal stage, which can last between 7-35 days. [3] Eclosure, or emergence, can be delayed if environmental conditions are not ideal, with pupae entering either aestivation or diapause if conditions are too warm or too cold respectively. [3]
Adults are the short-lived stage of life, lasting only 1-4 days. [3] During this time, females mate and oviposit on host plants. [3]
The larvae of M. destructor feed on the nutritive tissue of cereal plants [3] [7] [4] . This tissue is created by the interaction of specialized enzymes in the insect's saliva with cells in the epidermis and mesophyll of the plant, causing organelles to break down and rupture [7] . Larvae also have paired mandibles that act similarly to nematode stylets [9] , puncturing tiny holes in the epidermal wall where food can be accessed [7] .
Like in other plant-feeding cecidomyiid species, larvae have a simplified digestive system that allows for extra-intestinal digestion. [7] Lytic enzymes, present within the midgut via holocriny, act along with salivary secretions to break down complex cellulose-based plant materials into liquid sugars and proteins, which are then easily consumed by the larva. [7] While it primarily serves the purpose of transforming food into a usable form for the larva [7] , this special combination of chemicals also produces a wide range of effects in the host plant, the exact scope of which is unknown. [7] [9] One such effect is carbon/nitrogen shift. [10] As the plant interacts with the saliva of the larva, avirulence (Avr) genes in the saliva match up with similarly structured genes in the host that coordinate plant defense. [10] The resulting gene-to-gene compatibility causes changes in numerous metabolic processes, such as glycolysis and amino-acid synthesis, leading to free-containing carbon compounds being directed away from the plant and leached out as a liquid. [10] [11] These interactions can cause up to a 36% loss of free-carbon compounds and a 46% increase of free-containing nitrogen compounds. [10]
M. destructor is one of the most destructive wheat pests worldwide, hence its name. [12] This has brought it much attention from wheat breeders and genetics researchers. [12] As a result, the highest number of mapped R genes for resistance to insects in wheat are R genes for this pest specifically, with the unrelated Russian wheat aphid (Diuraphis noxia) also being of serious interest. [12]
Video describing how to identify a Hessian fly infestation in wheat: https://www.youtube.com/watch?v=aIideaTFhe0
Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing more than 150,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others.
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.
The cereal leaf beetle is a significant crop pest, described by Carl Linnaeus in 1758.
Cecidomyiidae is a family of flies known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. Cecidomyiidae are very fragile small insects usually only 2–3 mm (0.079–0.118 in) in length; many are less than 1 mm (0.039 in) long. They are characterised by hairy wings, unusual in the order Diptera, and have long antennae. Some Cecidomyiids are also known for the strange phenomenon of paedogenesis in which the larval stage reproduces without maturing first. In some species, the daughter larvae consume the mother, while in others, reproduction occurs later on in the egg or pupa.
The Culicinae are the most extensive subfamily of mosquitoes (Culicidae) and have species in every continent except Antarctica, but are highly concentrated in tropical areas. Mosquitoes are best known as parasites to many vertebrate animals and vectors for disease. They are holometabolous insects, and most species lay their eggs in stagnant water, to benefit their aquatic larval stage.
Rhagoletis mendax is a species of tephritid fruit fly known by the common name blueberry maggot. The blueberry maggot is closely related to the apple maggot, a larger fruit fly in the same genus. It is a major pest of plant species in the Ericaceae family, such as blueberry, cranberry, and huckleberry. The larva is 5 to 8 mm long, apodous, and white with chewing mouthparts. Female adults are 4.75 mm in length, males are slightly smaller. Both adults are mostly black in color with white stripes, orange-red eyes, and a single pair of clear wings with black banding. The adult female fly lays a single egg per blueberry, and when the larva hatches it consumes the fruit, usually finishing the entire berry in under 3 weeks and rendering it unmarketable. The larva then falls to the soil and pupates. Adult flies emerge, mate, and females oviposit when blueberry plants are producing fruit. Each female fly can lay 25 to 100 eggs in their lifetime.
Pollenia rudis, the common cluster fly, is a species of fly in the family Polleniidae. Pollenia rudis is also known as the attic fly, the loft fly, pollenie du lombric [French], and the buckwheat fly. During the autumn and winter months, Pollenia rudis can be found overwintering inside attics or lofts. This sluggish species can be found “clustering” near the interior windows of a warm structure.
Bactrocera cucurbitae, the melon fly, is a fruit fly of the family Tephritidae. It is a serious agricultural pest, particularly in Hawaii.
Calliphora latifrons is a species of blue bottle fly.
Mayetiola hordei,, the barley stem gall midge, is a cereal pest in Tunisia, closely related to the Hessian fly.
The Angoumois grain moth is a species of the Gelechiidae moth family, commonly referred to as the "rice grain moth". It is most abundant in the temperate or tropical climates of India, China, South Africa, Indonesia, Malaysia, Japan, Egypt and Nigeria, with its location of origin being currently unknown. It is most commonly associated as a pest of field and stored cereal grains as they burrow within the kernel grains of crop plants, rendering them unusable for human consumption. By laying eggs between the grains themselves and hatching at a later time, often during the processing, transportation or storage stages, the moth can be transported to households or countries presently free of Angoumois grain moth infestations. Thus, constant protection against the Angoumois grain moth is required for grain up till the time of consumption.
Eurygaster integriceps is a species of shield bug in the family Scutelleridae, commonly known as the sunn pest or corn bug. It is native to much of northern Africa, the Balkans and western and central Asia. It is a major pest of cereal crops especially wheat, barley and oats.
Trichopoda pennipes is a species of feather-legged fly in the dipteran family Tachinidae.
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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.
A gnat is any of many species of tiny flying insects in the dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. Certain universities and institutes also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".
Listronotus bonariensis is a species of weevil that is native to South America and is commonly known as the Argentine stem weevil. It is a pest of grasses and cereals, with the larvae being more destructive than the adult insects. It has spread to Australia and New Zealand, where it is regarded as a pest species.
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.
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