87-424: The Aphidiinae are a subfamily of tiny parasitoid wasps that use aphids as their hosts. Several species have been used in biological control programs of various aphids. Aphidiines are koinobiont endoparasitoids of adult and immature aphids. While the larva of the 2–3 mm long Praon leaves the hollowed shell of the aphid from below to pupate in a volcano -like cocoon , most other Aphidiinae pupate inside
174-598: A biological control agent in European fruit orchards. Several species of entomopathogenic nematode are important predators of insect and other invertebrate pests. Entomopathogenic nematodes form a stress–resistant stage known as the infective juvenile. These spread in the soil and infect suitable insect hosts. Upon entering the insect they move to the hemolymph where they recover from their stagnated state of development and release their bacterial symbionts . The bacterial symbionts reproduce and release toxins, which then kill
261-564: A biological control agent was made by Charles V. Riley in 1873, shipping to France the predatory mites Tyroglyphus phylloxera to help fight the grapevine phylloxera ( Daktulosphaira vitifoliae ) that was destroying grapevines in France. The United States Department of Agriculture (USDA) initiated research in classical biological control following the establishment of the Division of Entomology in 1881, with C. V. Riley as Chief. The first importation of
348-452: A cocoon and pupates. As adults, parasitoid wasps feed primarily on nectar from flowers. Females of some species will also drink hemolymph from hosts to gain additional nutrients for egg production. Polydnaviruses are a unique group of insect viruses that have a mutualistic relationship with some parasitic wasps. The polydnavirus replicates in the oviducts of an adult female parasitoid wasp. The wasp benefits from this relationship because
435-463: A meta-analysis was done to find such an overall trend in previously published data, if it existed. In some cases floral resources are outright necessary. Overall, floral resources (and an imitation, i.e. sugar water) increase longevity and fecundity , meaning even predatory population numbers can depend on non-prey food abundance. Thus biocontrol population maintenance – and success – may depend on nearby flowers. Parasitoids lay their eggs on or in
522-805: A natural enemy of a pest is introduced in the hope of achieving control; inductive (augmentation), in which a large population of natural enemies are administered for quick pest control; and inoculative (conservation), in which measures are taken to maintain natural enemies through regular reestablishment. Natural enemies of insects play an important part in limiting the densities of potential pests. Biological control agents such as these include predators , parasitoids , pathogens , and competitors . Biological control agents of plant diseases are most often referred to as antagonists. Biological control agents of weeds include seed predators, herbivores , and plant pathogens. Biological control can have side-effects on biodiversity through attacks on non-target species by any of
609-732: A number of recent studies pursuing sustainable methods for controlling urban cockroaches using parasitic wasps. Since most cockroaches remain in the sewer system and sheltered areas which are inaccessible to insecticides, employing active-hunter wasps is a strategy to try and reduce their populations. Pathogenic micro-organisms include bacteria , fungi , and viruses . They kill or debilitate their host and are relatively host-specific. Various microbial insect diseases occur naturally, but may also be used as biological pesticides . When naturally occurring, these outbreaks are density-dependent in that they generally only occur as insect populations become denser. The use of pathogens against aquatic weeds
696-461: A parasitoidal wasp into the United States was that of the braconid Cotesia glomerata in 1883–1884, imported from Europe to control the invasive cabbage white butterfly, Pieris rapae . In 1888–1889 the vedalia beetle, Novius cardinalis , a lady beetle, was introduced from Australia to California to control the cottony cushion scale, Icerya purchasi . This had become a major problem for
783-404: A particularly difficult plant for predators to establish on. Commercially, there are two types of rearing systems: short-term seasonal daily output with high production of parasitoids per day, and long-term year-round low daily output with a range in production of 4–1000 million female parasitoids per week, to meet demand for suitable parasitoids for different crops. Parasitoid wasps influenced
870-487: A roll of cardboard inside. Birdhouses enable insectivorous birds to nest; the most useful birds can be attracted by choosing an opening just large enough for the desired species. In cotton production, the replacement of broad-spectrum insecticides with selective control measures such as Bt cotton can create a more favorable environment for natural enemies of cotton pests due to reduced insecticide exposure risk. Such predators or parasitoids can control pests not affected by
957-612: A trained chemist and first Director of the Dominion Experimental Farms, for controlling the invasive currantworm Nematus ribesii . Between 1884 and 1908, the first Dominion Entomologist, James Fletcher, continued introductions of other parasitoids and pathogens for the control of pests in Canada. There are three basic biological pest control strategies: importation (classical biological control), augmentation and conservation. Importation or classical biological control involves
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#17328526503011044-597: A two-year period. Small, commercially-reared parasitoidal wasps , Trichogramma ostriniae , provide limited and erratic control of the European corn borer ( Ostrinia nubilalis ), a serious pest. Careful formulations of the bacterium Bacillus thuringiensis are more effective. The O. nubilalis integrated control releasing Tricogramma brassicae (egg parasitoid) and later Bacillus thuringiensis subs. kurstaki (larvicide effect) reduce pest damages more than insecticide treatments The population of Levuana iridescens ,
1131-518: A wide range of insects including caterpillars, beetle adults and larvae, and true bugs . Parasitoids are most effective at reducing pest populations when their host organisms have limited refuges to hide from them. Parasitoids are among the most widely used biological control agents. Commercially, there are two types of rearing systems: short-term daily output with high production of parasitoids per day, and long-term, low daily output systems. In most instances, production will need to be matched with
1218-533: A wide spectrum of arthropods. Entomophaga is effective against pests such as the green peach aphid . Several members of Chytridiomycota and Blastocladiomycota have been explored as agents of biological control. From Chytridiomycota, Synchytrium solstitiale is being considered as a control agent of the yellow star thistle ( Centaurea solstitialis ) in the United States. Baculoviruses are specific to individual insect host species and have been shown to be useful in biological pest control. For example,
1305-461: Is a small parasitoid wasp attacking whiteflies , sap-feeding insects which can cause wilting and black sooty moulds in glasshouse vegetable and ornamental crops. It is most effective when dealing with low level infestations, giving protection over a long period of time. The wasp lays its eggs in young whitefly 'scales', turning them black as the parasite larvae pupate. Gonatocerus ashmeadi ( Hymenoptera : Mymaridae ) has been introduced to control
1392-447: Is available to organic farmers in sachets of dried spores which are mixed with water and sprayed onto vulnerable plants such as brassicas and fruit trees . Genes from B. thuringiensis have also been incorporated into transgenic crops , making the plants express some of the bacterium's toxins, which are proteins . These confer resistance to insect pests and thus reduce the necessity for pesticide use. If pests develop resistance to
1479-677: Is effective against white flies, thrips and aphids; Purpureocillium lilacinus is used against root-knot nematodes , and 89 Trichoderma species against certain plant pathogens. Trichoderma viride has been used against Dutch elm disease , and has shown some effect in suppressing silver leaf , a disease of stone fruits caused by the pathogenic fungus Chondrostereum purpureum . Pathogenic fungi may be controlled by other fungi, or bacteria or yeasts, such as: Gliocladium spp., mycoparasitic Pythium spp., binucleate types of Rhizoctonia spp., and Laetisaria spp. The fungi Cordyceps and Metacordyceps are deployed against
1566-542: Is frequently released inundatively to control harmful moths. New way for inundative releases are now introduced i.e. use of drones. Egg parasitoids are able to find the eggs of the target host by means of several cues. Kairomones were found on moth scales. Similarly, Bacillus thuringiensis and other microbial insecticides are used in large enough quantities for a rapid effect. Recommended release rates for Trichogramma in vegetable or field crops range from 5,000 to 200,000 per acre (1 to 50 per square metre) per week according to
1653-475: Is greatest if the agent has temporal persistence so that it can maintain its population even in the temporary absence of the target species, and if it is an opportunistic forager, enabling it to rapidly exploit a pest population. One of the earliest successes was in controlling Icerya purchasi (cottony cushion scale) in Australia, using a predatory insect Rodolia cardinalis (the vedalia beetle). This success
1740-526: The Bt protein . Reduced prey quality and abundance associated with increased control from Bt cotton can also indirectly decrease natural enemy populations in some cases, but the percentage of pests eaten or parasitized in Bt and non-Bt cotton are often similar. Predators are mainly free-living species that directly consume a large number of prey during their whole lifetime. Given that many major crop pests are insects, many of
1827-548: The Ephedrini , Praini , Trioxini , Aclitini , and Aphidiini , with the latter subdivided into three subtribes. Most species reside in the Aphidiini. The Praini's loss of internal pupation is likely to be secondary. There are ~400 spp. in ~50 genera worldwide. Ephedrini Praini Trioxini Aclitini Aphidiini Parasitoid wasp Parasitoid wasps are a large group of hymenopteran superfamilies , with all but
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#17328526503011914-617: The Ichneumonidae 100,000 species, and the Braconidae up to 50,000 species. Host insects have evolved a range of defences against parasitoid wasps, including hiding, wriggling, and camouflage markings. Many parasitoid wasps are considered beneficial to humans because they naturally control agricultural pests. Some are applied commercially in biological pest control , starting in the 1920s with Encarsia formosa to control whitefly in greenhouses . Historically, parasitoidism in wasps influenced
2001-578: The Ichneumonidae . Biological pest control Biological control or biocontrol is a method of controlling pests , whether pest animals such as insects and mites , weeds , or pathogens affecting animals or plants by using other organisms . It relies on predation , parasitism , herbivory , or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs. There are three basic strategies for biological control: classical (importation), where
2088-514: The Lymantria dispar multicapsid nuclear polyhedrosis virus has been used to spray large areas of forest in North America where larvae of the spongy moth are causing serious defoliation. The moth larvae are killed by the virus they have eaten and die, the disintegrating cadavers leaving virus particles on the foliage to infect other larvae. A mammalian virus, the rabbit haemorrhagic disease virus
2175-527: The Permian , leading to a single clade called Euhymenoptera, but the parasitic lifestyle has secondarily been lost several times including among the ants , bees , and vespid wasps . As a result, the order Hymenoptera contains many families of parasitoids, intermixed with non-parasitoid groups. The parasitoid wasps include some very large groups, some estimates giving the Chalcidoidea as many as 500,000 species,
2262-480: The Pompilidae specialise in catching spiders : these are quick and dangerous prey, often as large as the wasp itself, but the spider wasp is quicker, swiftly stinging her prey to immobilise it. Adult female wasps of most species oviposit into their hosts' bodies or eggs. More rarely, parasitoid wasps may use plant seeds as hosts, such as Torymus druparum . Some also inject a mix of secretory products that paralyse
2349-579: The ants , bees , and non-parasitic wasps such as the Vespidae are not included, and there are many members of mainly parasitoidal families which are not themselves parasitic. Listed are Hymenopteran families where most members have a parasitoid lifestyle. Symphyta : Apocrita : Parasitoid wasps are considered beneficial as they naturally control the population of many pest insects . They are widely used commercially (alongside other parasitoids such as tachinid flies ) for biological pest control , for which
2436-582: The glassy-winged sharpshooter Homalodisca vitripennis (Hemiptera: Cicadellidae ) in French Polynesia and has successfully controlled ~95% of the pest density. The eastern spruce budworm is an example of a destructive insect in fir and spruce forests. Birds are a natural form of biological control, but the Trichogramma minutum , a species of parasitic wasp, has been investigated as an alternative to more controversial chemical controls. There are
2523-583: The Apocrita; it contains many families of parasitoids, though not the Ichneumonoidea , Cynipoidea , and Chalcidoidea . The Hymenoptera, Apocrita, and Aculeata are all clades, but since each of these contains non-parasitic species, the parasitoid wasps, formerly known as the Parasitica, do not form a clade on their own. The common ancestor in which parasitoidism evolved lived approximately 247 million years ago and
2610-458: The Colombian cities of Bello , Medellín , and Itagüí . The project was executed by non-profit World Mosquito Program (WMP). Wolbachia prevents mosquitos from transmitting viruses such as dengue and zika . The insects pass the bacteria on to their offspring. The project covered a combined area of 135 square kilometres (52 sq mi), home to 3.3 million people. Most of the project area reached
2697-500: The Levuana moth, a serious coconut pest in Fiji , was brought under control by a classical biological control program in the 1920s. Augmentation involves the supplemental release of natural enemies that occur in a particular area, boosting the naturally occurring populations there. In inoculative release, small numbers of the control agents are released at intervals to allow them to reproduce, in
Aphidiinae - Misplaced Pages Continue
2784-1447: The Vespidae which have secondarily abandoned the parasitoid habit. The approximate numbers of species estimated to be in these groups, often much larger than the number so far described, is shown in parentheses, with estimates for the most populous also shown in boldface , like "( 150,000 )". Not all species in these groups are parasitoidal: for example, some Cynipoidea are phytophagous . Sawflies [REDACTED] Orussoidea (parasitoid wood wasps, 85) [REDACTED] Ichneumonoidea ( 150,000 ) [REDACTED] Cynipoidea (3,000) [REDACTED] Proctotrupoidea (400) [REDACTED] Platygastroidea (4000) [REDACTED] Chalcidoidea ( 500,000 ) [REDACTED] other Superfamilies Chrysididae (jewel wasps, 3000) [REDACTED] Vespidae (wasps, hornets, 5000) [REDACTED] Mutillidae (velvet ants, 3000) [REDACTED] Pompilidae (spider wasps, 5000) [REDACTED] other families Scoliidae (560) [REDACTED] Formicidae (ants, 22,000) [REDACTED] Sphecidae (700) [REDACTED] Bembicidae (1800) [REDACTED] other families Pemphredonidae (aphid wasps, 556) [REDACTED] Philanthidae (1100) [REDACTED] Anthophila (bees, 22,000) [REDACTED] Ammoplanidae (aphid wasps, 130) The parasitoid wasps are paraphyletic since
2871-654: The above mechanisms, especially when a species is introduced without a thorough understanding of the possible consequences. The term "biological control" was first used by Harry Scott Smith at the 1919 meeting of the Pacific Slope Branch of the American Association of Economic Entomologists, in Riverside, California . It was brought into more widespread use by the entomologist Paul H. DeBach (1914–1993) who worked on citrus crop pests throughout his life. However,
2958-404: The advantage of a host that continues to grow larger and remains able to avoid predators. Many parasitoid wasps use larval Lepidoptera as hosts, but some groups parasitize different host life stages (egg, larva or nymph, pupa, adult) of nearly all other orders of insects, especially Coleoptera , Diptera , Hemiptera and other Hymenoptera. Some attack arthropods other than insects: for instance,
3045-457: The amount of land covered by the plant. Another aquatic weed, the giant salvinia ( Salvinia molesta ) is a serious pest, covering waterways, reducing water flow and harming native species. Control with the salvinia weevil ( Cyrtobagous salviniae ) and the salvinia stem-borer moth ( Samea multiplicalis ) is effective in warm climates, and in Zimbabwe, a 99% control of the weed was obtained over
3132-562: The appropriate release dates when susceptible host species at a suitable phase of development will be available. Larger production facilities produce on a yearlong basis, whereas some facilities produce only seasonally. Rearing facilities are usually a significant distance from where the agents are to be used in the field, and transporting the parasitoids from the point of production to the point of use can pose problems. Shipping conditions can be too hot, and even vibrations from planes or trucks can adversely affect parasitoids. Encarsia formosa
3219-671: The autumn allow insects to make use of their hollow stems during winter. In California, prune trees are sometimes planted in grape vineyards to provide an improved overwintering habitat or refuge for a key grape pest parasitoid. The providing of artificial shelters in the form of wooden caskets, boxes or flowerpots is also sometimes undertaken, particularly in gardens, to make a cropped area more attractive to natural enemies. For example, earwigs are natural predators that can be encouraged in gardens by hanging upside-down flowerpots filled with straw or wood wool . Green lacewings can be encouraged by using plastic bottles with an open bottom and
3306-509: The body of an insect host, which is then used as a food for developing larvae. The host is ultimately killed. Most insect parasitoids are wasps or flies , and many have a very narrow host range. The most important groups are the ichneumonid wasps , which mainly use caterpillars as hosts; braconid wasps , which attack caterpillars and a wide range of other insects including aphids; chalcidoid wasps , which parasitize eggs and larvae of many insect species; and tachinid flies , which parasitize
3393-716: The book Guangdong Xing Yu (17th century), Lingnan by Wu Zhen Fang (Qing dynasty), in Nanyue Miscellanies by Li Diao Yuan, and others. Biological control techniques as we know them today started to emerge in the 1870s. During this decade, in the US, the Missouri State Entomologist C. V. Riley and the Illinois State Entomologist W. LeBaron began within-state redistribution of parasitoids to control crop pests. The first international shipment of an insect as
3480-477: The borders of rice fields. These provide nectar to support parasitoids and predators of planthopper pests and have been demonstrated to be so effective (reducing pest densities by 10- or even 100-fold) that farmers sprayed 70% less insecticides and enjoyed yields boosted by 5%. Predators of aphids were similarly found to be present in tussock grasses by field boundary hedges in England, but they spread too slowly to reach
3567-403: The brown-tail moth, Euproctis chrysorrhoea , invasive pests of trees and shrubs. As a result, nine parasitoids (solitary wasps) of the spongy moth, seven of the brown-tail moth, and two predators of both moths became established in the US. Although the spongy moth was not fully controlled by these natural enemies, the frequency, duration, and severity of its outbreaks were reduced and the program
Aphidiinae - Misplaced Pages Continue
3654-453: The centers of fields. Control was improved by planting a meter-wide strip of tussock grasses in field centers, enabling aphid predators to overwinter there. Cropping systems can be modified to favor natural enemies, a practice sometimes referred to as habitat manipulation. Providing a suitable habitat, such as a shelterbelt , hedgerow , or beetle bank where beneficial insects such as parasitoidal wasps can live and reproduce, can help ensure
3741-741: The dead aphid and break out afterwards. These wasps are found worldwide, but are primarily found in the northern hemisphere. Several species have been introduced to countries outside of their natural range, both accidentally and purposefully for biocontrol. Although they have often been treated as a separate family, the Aphidiidae, the Aphidiinae are a lineage within the Braconidae. It is not yet clear to which braconid subfamilies they are most closely related. Ephedrini Praini Monoctonina Trioxina Aphidiina The Aphidiinae are subdivided into several tribes,
3828-595: The decades since, the same biocontrol methods that are routine on land have become common in the water. Bacteria used for biological control infect insects via their digestive tracts, so they offer only limited options for controlling insects with sucking mouth parts such as aphids and scale insects. Bacillus thuringiensis , a soil-dwelling bacterium, is the most widely applied species of bacteria used for biological control, with at least four sub-species used against Lepidopteran ( moth , butterfly ), Coleopteran (beetle) and Dipteran (true fly) insect pests. The bacterium
3915-431: The effectiveness of barn owls for this purpose, they are known rodent predators that can be used in addition to or instead of cats; they can be encouraged into an area with nest boxes. In Honduras, where the mosquito Aedes aegypti was transmitting dengue fever and other infectious diseases, biological control was attempted by a community action plan; copepods , baby turtles , and juvenile tilapia were added to
4002-401: The egg or larva in a process called encapsulation. In aphids , the presence of a particular species of γ-3 Pseudomonadota makes the aphid relatively immune to their parasitoid wasps by killing many of the eggs. As the parasitoid's survival depends on its ability to evade the host's immune response, some parasitoid wasps have developed the counterstrategy of laying more eggs in aphids that have
4089-437: The endosymbiont, so that at least one of them may hatch and parasitize the aphid. Certain caterpillars eat plants that are toxic to both themselves and the parasite to cure themselves. Drosophila melanogaster larvae also self-medicate with ethanol to treat parasitism. D. melanogaster females lay their eggs in food containing toxic amounts of alcohol if they detect parasitoid wasps nearby. The alcohol protects them from
4176-457: The evolution of parasitoidy in the order and is thought to have been a result of it. The evolution of a wasp waist, a constriction in the abdomen of the Apocrita, contributed to rapid diversification as it increased maneuverability of the ovipositor, the organ off the rear segment of the abdomen used to lay eggs. The phylogenetic tree gives a condensed overview of the positions of parasitoidal groups ( boldface ), amongst groups ( italics ) like
4263-400: The hope of setting up longer-term control and thus keeping the pest down to a low level, constituting prevention rather than cure. In inundative release, in contrast, large numbers are released in the hope of rapidly reducing a damaging pest population, correcting a problem that has already arisen. Augmentation can be effective, but is not guaranteed to work, and depends on the precise details of
4350-403: The host insect. Phasmarhabditis hermaphrodita is a microscopic nematode that kills slugs. Its complex life cycle includes a free-living, infective stage in the soil where it becomes associated with a pathogenic bacteria such as Moraxella osloensis . The nematode enters the slug through the posterior mantle region, thereafter feeding and reproducing inside, but it is the bacteria that kill
4437-528: The host or protect the egg from the host's immune system; these include polydnaviruses , ovarian proteins, and venom. If a polydnavirus is included, it infects the nuclei of host hemocytes and other cells, causing symptoms that benefit the parasite. Host size is important for the development of the parasitoid, as the host is its entire food supply until it emerges as an adult; small hosts often produce smaller parasitoids. Some species preferentially lay female eggs in larger hosts and male eggs in smaller hosts, as
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#17328526503014524-505: The host the parasitoid egg hatches into a larva or two or more larvae ( polyembryony ). Endoparasitoid eggs can absorb fluids from the host body and grow several times in size from when they were first laid before hatching. The first instar larvae are often highly mobile and may have strong mandibles or other structures to compete with other parasitoid larvae. The following instars are generally more grub-like. Parasitoid larvae have incomplete digestive systems with no rear opening. This prevents
4611-472: The host, and koinobiont, allowing the host to continue to feed, develop, and moult; or they are ectoparasitic, developing outside the host, and idiobiont, paralysing the host immediately. Some endoparasitic wasps of the superfamily Ichneumonoidea have a mutualistic relationship with polydnaviruses , the viruses suppressing the host's immune defenses. Parasitoidism evolved only once in the Hymenoptera, during
4698-436: The hosts from being contaminated by their wastes. The larva feeds on the host's tissues until ready to pupate; by then the host is generally either dead or almost so. A meconium , or the accumulated wastes from the larva is cast out as the larva transitions to a prepupa . Depending on its species, the parasitoid then may eat its way out of the host or remain in the more or less empty skin. In either case it then generally spins
4785-414: The interactions between each pest and control agent. An example of inoculative release occurs in the horticultural production of several crops in greenhouses . Periodic releases of the parasitoidal wasp, Encarsia formosa , are used to control greenhouse whitefly , while the predatory mite Phytoseiulus persimilis is used for control of the two-spotted spider mite. The egg parasite Trichogramma
4872-409: The introduction of a pest's natural enemies to a new locale where they do not occur naturally. Early instances were often unofficial and not based on research, and some introduced species became serious pests themselves. To be most effective at controlling a pest, a biological control agent requires a colonizing ability which allows it to keep pace with changes to the habitat in space and time. Control
4959-511: The level of pest infestation. Similarly, nematodes that kill insects (that are entomopathogenic) are released at rates of millions and even billions per acre for control of certain soil-dwelling insect pests. The conservation of existing natural enemies in an environment is the third method of biological pest control. Natural enemies are already adapted to the habitat and to the target pest, and their conservation can be simple and cost-effective, as when nectar-producing crop plants are grown in
5046-404: The most important groups are the ichneumonid wasps , which prey mainly on caterpillars of butterflies and moths ; braconid wasps , which attack caterpillars and a wide range of other insects including greenfly ; chalcidoid wasps , which parasitise eggs and larvae of greenfly, whitefly , cabbage caterpillars , and scale insects . One of the first parasitoid wasps to enter commercial use
5133-563: The moth strictly consumes its host plant, poison hemlock, and can exist at hundreds of larvae per individual host plant, destroying large swathes of the hemlock. For rodent pests , cats are effective biological control when used in conjunction with reduction of "harborage"/hiding locations. While cats are effective at preventing rodent "population explosions" , they are not effective for eliminating pre-existing severe infestations. Barn owls are also sometimes used as biological rodent control. Although there are no quantitative studies of
5220-520: The newly developed citrus industry in California, but by the end of 1889, the cottony cushion scale population had already declined. This great success led to further introductions of beneficial insects into the US. In 1905 the USDA initiated its first large-scale biological control program, sending entomologists to Europe and Japan to look for natural enemies of the spongy moth, Lymantria dispar dispar , and
5307-459: The parasitoid. Ants that are in a symbiotic relationship with caterpillars, aphids or scale insects may protect them from attack by wasps. Parasitoid wasps are vulnerable to hyperparasitoid wasps. Some parasitoid wasps change the behavior of the infected host, causing them to build a silk web around the pupae of the wasps after they emerge from its body to protect them from hyperparasitoids. Hosts can kill endoparasitoids by sticking haemocytes to
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#17328526503015394-422: The parasitoids in inaccessible habitats. They may also get rid of their frass (body wastes) and avoid plants that they have chewed on as both can signal their presence to parasitoids hunting for hosts. The egg shells and cuticles of the potential hosts are thickened to prevent the parasitoid from penetrating them. Hosts may use behavioral evasion when they encounter an egg laying female parasitoid, like dropping off
5481-499: The plant they are on, twisting and thrashing so as to dislodge or kill the female and even regurgitating onto the wasp to entangle it. The wriggling can sometimes help by causing the wasp to "miss" laying the egg on the host and instead place it nearby. Wriggling of pupae can cause the wasp to lose its grip on the smooth hard pupa or get trapped in the silk strands. Some caterpillars even bite the female wasps that approach them. Some insects secrete poisonous compounds that kill or drive away
5568-543: The population of weevils in the alfalfa area treated for alfalfa weevil in the Northeastern United States remained 75 percent down. Alligator weed was introduced to the United States from South America . It takes root in shallow water, interfering with navigation , irrigation , and flood control . The alligator weed flea beetle and two other biological controls were released in Florida , greatly reducing
5655-486: The practice has previously been used for centuries. The first report of the use of an insect species to control an insect pest comes from " Nanfang Caomu Zhuang " (南方草木狀 Plants of the Southern Regions ) ( c. 304 AD ), attributed to Western Jin dynasty botanist Ji Han (嵇含, 263–307), in which it is mentioned that " Jiaozhi people sell ants and their nests attached to twigs looking like thin cotton envelopes,
5742-768: The predators used in biological control are insectivorous species. Lady beetles , and in particular their larvae which are active between May and July in the northern hemisphere, are voracious predators of aphids , and also consume mites , scale insects and small caterpillars . The spotted lady beetle ( Coleomegilla maculata ) is also able to feed on the eggs and larvae of the Colorado potato beetle ( Leptinotarsa decemlineata ). The larvae of many hoverfly species principally feed upon aphids , one larva devouring up to 400 in its lifetime. Their effectiveness in commercial crops has not been studied. The running crab spider Philodromus cespitum also prey heavily on aphids, and act as
5829-526: The predatory midge Feltiella acarisuga , and a ladybird Stethorus punctillum . The bug Orius insidiosus has been successfully used against the two-spotted spider mite and the western flower thrips ( Frankliniella occidentalis ). Predators including Cactoblastis cactorum (mentioned above) can also be used to destroy invasive plant species. As another example, the poison hemlock moth ( Agonopterix alstroemeriana) can be used to control poison hemlock ( Conium maculatum ). During its larval stage,
5916-558: The reddish-yellow ant being larger than normal. Without such ants, southern citrus fruits will be severely insect-damaged ". The ants used are known as huang gan ( huang = yellow, gan = citrus) ants ( Oecophylla smaragdina ). The practice was later reported by Ling Biao Lu Yi (late Tang dynasty or Early Five Dynasties ), in Ji Le Pian by Zhuang Jisu ( Southern Song dynasty ), in the Book of Tree Planting by Yu Zhen Mu ( Ming dynasty ), in
6003-440: The reproductive capabilities of males are limited less severely by smaller adult body size. Some parasitoid wasps mark the host with chemical signals to show that an egg has been laid there. This may both deter rivals from ovipositing, and signal to itself that no further egg is needed in that host, effectively reducing the chances that offspring will have to compete for food and increasing the offspring's survival. On or inside
6090-518: The slug. The nematode is available commercially in Europe and is applied by watering onto moist soil. Entomopathogenic nematodes have a limited shelf life because of their limited resistance to high temperature and dry conditions. The type of soil they are applied to may also limit their effectiveness. Species used to control spider mites include the predatory mites Phytoseiulus persimilis , Neoseilus californicus , and Amblyseius cucumeris ,
6177-680: The spread of the plant, the cactus moth Cactoblastis cactorum , and the scale insect Dactylopius . Between 1926 and 1931, tens of millions of cactus moth eggs were distributed around Queensland with great success, and by 1932, most areas of prickly pear had been destroyed. The first reported case of a classical biological control attempt in Canada involves the parasitoidal wasp Trichogramma minutum . Individuals were caught in New York State and released in Ontario gardens in 1882 by William Saunders,
6264-466: The survival of populations of natural enemies. Things as simple as leaving a layer of fallen leaves or mulch in place provides a suitable food source for worms and provides a shelter for insects, in turn being a food source for such beneficial mammals as hedgehogs and shrews . Compost piles and stacks of wood can provide shelter for invertebrates and small mammals. Long grass and ponds support amphibians. Not removing dead annuals and non-hardy plants in
6351-579: The target of infecting 60% of local mosquitoes. The technique is not endorsed by WHO. Entomopathogenic fungi , which cause disease in insects, include at least 14 species that attack aphids . Beauveria bassiana is mass-produced and used to manage a wide variety of insect pests including whiteflies , thrips , aphids and weevils . Lecanicillium spp. are deployed against white flies, thrips and aphids. Metarhizium spp. are used against pests including beetles, locusts and other grasshoppers, Hemiptera , and spider mites . Paecilomyces fumosoroseus
6438-472: The thinking of Charles Darwin . Parasitoid wasps range from some of the smallest species of insects to wasps about an inch long. Most females have a long, sharp ovipositor at the tip of the abdomen, sometimes lacking venom glands, and almost never modified into a sting . Parasitoids can be classified in a variety of ways. They can live within their host's body as endoparasitoids, or feed on it from outside as ectoparasitoids: both strategies are found among
6525-610: The thinking of Charles Darwin . In an 1860 letter to the American naturalist Asa Gray , Darwin wrote: "I cannot persuade myself that a beneficent and omnipotent God would have designedly created parasitic wasps with the express intention of their feeding within the living bodies of Caterpillars." The palaeontologist Donald Prothero notes that religiously-minded people of the Victorian era , including Darwin, were horrified by this instance of evident cruelty in nature, particularly noticeable in
6612-578: The toxins in these crops, B. thuringiensis will become useless in organic farming also. The bacterium Paenibacillus popilliae which causes milky spore disease has been found useful in the control of Japanese beetle , killing the larvae. It is very specific to its host species and is harmless to vertebrates and other invertebrates. Bacillus spp., fluorescent Pseudomonads , and Streptomycetes are controls of various fungal pathogens. The largest-ever deployment of Wolbachia -infected A. aegypti mosquitoes reduced dengue incidence by 94–97% in
6699-492: The virus provides protection for the parasitic larvae inside the host, (i) by weakening the host's immune system and (ii) by altering the host's cells to be more beneficial to the parasite. The relationship between these viruses and the wasp is obligatory in the sense that all individuals are infected with the viruses; the virus has been incorporated in the wasp's genome and is inherited. The hosts of parasitoids have developed several levels of defence. Many hosts try to hide from
6786-462: The wasps, at the cost of retarding their own growth. Based on genetic and fossil analysis, parasitoidism has evolved only once in the Hymenoptera, during the Permian , leading to a single clade . All parasitoid wasps are descended from this lineage. The narrow-waisted Apocrita emerged during the Jurassic . The Aculeata , which includes bees, ants, and parasitoid spider wasps, evolved from within
6873-503: The wasps. Parasitoids can also be divided according to their effect on their hosts. Idiobionts prevent further development of the host after initially immobilizing it, while koinobionts allow the host to continue its development while they are feeding upon it; and again, both types are seen in parasitoidal wasps. Most ectoparasitoid wasps are idiobiont, as the host could damage or dislodge the external parasitoid if allowed to move or moult . Most endoparasitoid wasps are koinobionts, giving them
6960-491: The wells and tanks where the mosquito breeds and the mosquito larvae were eliminated. Even amongst arthropods usually thought of as obligate predators of animals (especially other arthropods), floral food sources ( nectar and to a lesser degree pollen ) are often useful adjunct sources. It had been noticed in one study that adult Adalia bipunctata (predator and common biocontrol of Ephestia kuehniella ) could survive on flowers but never completed its life cycle , so
7047-626: The wood wasps ( Orussoidea ) being in the wasp-waisted Apocrita . As parasitoids , they lay their eggs on or in the bodies of other arthropods , sooner or later causing the death of these hosts . Different species specialise in hosts from different insect orders, most often Lepidoptera , though some select beetles , flies , or bugs ; the spider wasps ( Pompilidae ) exclusively attack spiders . Parasitoid wasp species differ in which host life-stage they attack: eggs, larvae, pupae, or adults. They mainly follow one of two major strategies within parasitism : either they are endoparasitic, developing inside
7134-458: Was Encarsia formosa , an endoparasitic aphelinid . It has been used to control whitefly in greenhouses since the 1920s. Use of the insect fell almost to nothing, replaced by chemical pesticides by the 1940s. Since the 1970s, usage has revived, with renewed usage in Europe and Russia. In some countries, such as New Zealand, it is the primary biological control agent used to control greenhouse whiteflies, particularly on crops such as tomato ,
7221-400: Was introduced to Australia to attempt to control the European rabbit populations there. It escaped from quarantine and spread across the country, killing large numbers of rabbits. Very young animals survived, passing immunity to their offspring in due course and eventually producing a virus-resistant population. Introduction into New Zealand in the 1990s was similarly successful at first, but
7308-459: Was previously believed to be an ectoparasitoid wood wasp that fed on wood-boring beetle larvae. Species similar in lifestyle and morphology to this ancestor still exist in the Ichneumonoidea. However, recent molecular and morphological analysis suggests this ancestor was endophagous, meaning it fed from within its host. A significant radiation of species in the Hymenoptera occurred shortly after
7395-514: Was regarded as successful. This program also led to the development of many concepts, principles, and procedures for the implementation of biological control programs. Prickly pear cacti were introduced into Queensland , Australia as ornamental plants, starting in 1788. They quickly spread to cover over 25 million hectares of Australia by 1920, increasing by 1 million hectares per year. Digging, burning, and crushing all proved ineffective. Two control agents were introduced to help control
7482-456: Was repeated in California using the beetle and a parasitoidal fly, Cryptochaetum iceryae . Other successful cases include the control of Antonina graminis in Texas by Neodusmetia sangwani in the 1960s. Damage from Hypera postica , the alfalfa weevil, a serious introduced pest of forage, was substantially reduced by the introduction of natural enemies. 20 years after their introduction
7569-445: Was unknown until a groundbreaking 1972 proposal by Zettler and Freeman. Up to that point biocontrol of any kind had not been used against any water weeds. In their review of the possibilities, they noted the lack of interest and information thus far, and listed what was known of pests-of-pests – whether pathogens or not. They proposed that this should be relatively straightfoward to apply in the same way as other biocontrols. And indeed in
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