 = Mole cricket = 
 
 Mole crickets are members of the insect family Gryllotalpidae , in the order Orthoptera ( grasshoppers , locusts and crickets ) . Mole crickets are cylindrical @-@ bodied insects about 3 – 5 centimetres ( 1 @.@ 2 – 2 @.@ 0 in ) long , with small eyes and shovel @-@ like forelimbs highly developed for burrowing . They are present in many parts of the world and where they have been introduced into new regions , may become agricultural pests . 
 Mole crickets have three life stages , eggs , nymphs and adults . Most of their life in these stages is spent underground but adults have wings and disperse in the breeding season . They vary in their diet ; some species are vegetarian , mainly feeding on roots , others are omnivores , including worms and grubs in their diet , while a few are largely predacious . Male mole crickets have an exceptionally loud song ; they sing from a sub @-@ surface burrow that opens out into the air in the shape of an exponential horn . The song is an almost pure tone , modulated into chirps . It is used to attract females , either for mating , or for indicating favourable habitats for them to lay their eggs . 
 In Zambia , mole crickets are thought to bring good fortune , while in Latin America they are said to predict rain . In Florida , where Scapteriscus mole crickets are non @-@ native , they are considered pests , and various biological controls have been used . Gryllotalpa species have been used as food in West Java , Vietnam , and the Philippines . 
 
 = = Description = = 
 
 Mole crickets vary in size and appearance , but most of them are of moderate size for an insect , typically between 3 @.@ 2 and 3 @.@ 5 cm ( 1 @.@ 3 and 1 @.@ 4 in ) long as adults . They are adapted for underground life and are cylindrical in shape and covered with fine , dense hairs . The head , forelimbs , and prothorax are heavily sclerotinised but the abdomen is rather soft . The head bears two threadlike antennae and a pair of beady eyes . The two pairs of wings are folded flat over the abdomen ; in most species , the fore wings are short and rounded and the hind wings are membranous and reach or exceed the tip of the abdomen ; however , in some species the hind wings are reduced in size and the insect is unable to fly . The fore legs are flattened for digging but the hind legs are shaped somewhat like the legs of a true cricket ; however , these limbs are more adapted for pushing soil , rather than leaping , which they do rarely and poorly . The nymphs resemble the adults apart from the absence of wings and genitalia ; the wingpads become larger after each successive moult . 
 
 = = Taxonomy and phylogeny = = 
 
 The Gryllotalpidae are a monophyletic group in the order Orthoptera ( grasshoppers , locusts and crickets ) . Cladistic analysis of mole cricket morphology in 2015 identifies six tribes , of which four were then new : Indioscaptorini ( Scapteriscinae ) , Triamescaptorini , Gryllotalpellini and Neocurtillini ( Gryllotalpinae ) , and two existing tribes , Scapteriscini and Gryllotalpini , are revised . The group name is derived straightforwardly from Latin ' gryllus ' , cricket , and ' talpa ' , mole . 
 Within these subfamilies , genera include : 
 Gryllotalpa 
 Gryllotalpella 
 Leptocurtilla 
 Neocurtilla 
 † Pterotriamescaptor 
 Indioscaptor 
 Scapteriscus 
 Neoscapteriscus 
 Triamescaptor 
 † Archaeogryllotalpoides 
 † Cratotetraspinus 
 † Marchandia 
 † Palaeoscapteriscops 
 Mole cricket fossils are rare . A stem group fossil , Cratotetraspinus , is known from the Lower Cretaceous of Brazil . Two specimens of Marchandia magnifica in amber have been found in the Lower Cretaceous of Charente @-@ Maritime in France . They are somewhat more abundant in the Tertiary amber of the Baltic and Dominican regions ; impressions are found in Europe and the American Green River Formation . 
 Mole crickets are not closely related to the " pygmy mole crickets " , the Tridactyloidea , which are in the grasshopper suborder Caelifera rather than the cricket suborder Ensifera . The two groups , and indeed their resemblance in form to the mammalian mole family Talpidae with their powerful front limbs , form an example of convergent evolution , both developing adaptations for burrowing . 
 
 = = Behavior = = 
 
 Adults of most species of mole cricket can fly powerfully , if not with agility , but males do so infrequently . The females typically take wing soon after sunset , and are attracted to areas where males are calling , which they do for about an hour after sunset . This may be in order to mate , or they may be influenced by the suitability of the habitat for egg @-@ laying , as demonstrated by the number of males present and calling in the vicinity . 
 
 = = = Life cycle = = = 
 
 Mole crickets are hemimetabolous meaning they undergo incomplete metamorphosis ; when nymphs hatch from eggs , the nymphs increasingly resemble the adult form as they grow and pass through a series of up to ten moults . After mating , there may be a period of one or two weeks before the female starts laying eggs . She burrows into the soil to a depth of 30 cm ( 12 in ) , ( 72 cm ( 28 in ) has been seen in the laboratory ) , and lays a clutch of 25 to 60 eggs . Neoscapteriscus females then retire , sealing the entrance passage , but in Gryllotalpa and Neocurtilla species , the female has been observed to remain in an adjoining chamber to tend the clutch . Further clutches may follow over several months , according to species . Eggs need to be laid in moist ground and many nymphs die because of insufficient moisture in the soil . The eggs hatch in a few weeks , and as they grow , the nymphs consume a great deal of plant material either underground or on the surface . The adults of some species of mole cricket may move as far as 8 kilometres ( 5 @.@ 0 mi ) during the breeding season . Mole crickets are active most of the year , but overwinter as nymphs or adults in cooler climates , resuming activity in the spring . 
 
 = = = Burrowing = = = 
 
 Mole crickets live almost entirely below ground , digging tunnels of different kinds for the major functions of life , including feeding , escape from predators , attracting a mate ( by singing ) , mating , and raising of young . 
 Their main tunnels are used for feeding and for escape : they can dig themselves underground very rapidly , and can move along existing tunnels at high speed both forwards and backwards . Their digging technique is to force the soil to either side with their powerful , shovel @-@ like forelimbs , which are broad , flattened , toothed and heavily sclerotised ( the cuticle is hardened and darkened ) . 
 Males attract mates by constructing specially @-@ shaped tunnels in which they sing . Mating takes place in the male 's burrow ; the male may widen a tunnel to make room for the female to mount , though in some species mating is tail @-@ to @-@ tail . Females lay their eggs either in their normal burrows or in specially @-@ dug brood chambers which are sealed when complete in the case of the genus Neoscapteriscus or not sealed in the case of genera Gryllotalpa and Neocurtilla . 
 
 = = = Song = = = 
 
 Male mole crickets sing by stridulating , always underground . In Gryllotalpa gryllotalpa the song is based on an almost pure tone at 3 @.@ 5 kiloHertz , loud enough to make the ground vibrate 20 cm all round the burrow ; in fact the song is unique in each species . In Gryllotalpa gryllotalpa the burrow is somewhat roughly sculpted ; in Gryllotalpa vineae , the burrow is smooth and carefully shaped , with no irregularities larger than 1 millimetre . In both species the burrow takes the form of a double exponential horn with twin openings at the soil surface ; at the other end there is a constriction , then a resonating bulb , and then an escape tunnel . A burrow is used for at least a week . The male positions himself head down with his head in the bulb , his tail near the fork in the tunnel . 
 Mole crickets stridulate like other crickets by scraping the rear edge of the left forewing , which forms a plectrum , against the lower surface of the right forewing , which has a ratchet @-@ like series of asymmetric teeth : the more acute edges face backwards , as do those of the plectrum . The plectrum can move forwards with little resistance ; but moving it backwards makes it catch each tooth , setting up a vibration in both wings . The sound @-@ producing stroke is the raising ( levation ) of the wings . The resulting song resembles the result of modulating a pure tone with a 66 Hertz wave to form regular chirps . In G. vineae , the wing levator muscle , which weighs 50 milligrams , can deliver 3 @.@ 5 milliWatts of mechanical power ; G. gryllotalpa can deliver about 1 milliWatt . G. vineae produces an exceptionally loud song from half an hour after sunset , continuing for an hour ; it can be heard up to 600 metres away . At a distance of 1 metre from the burrow , the sound has a mean power over the stridulation cycle of up to 88 decibels ; the loudest recorded peak power was about 92 decibels ; at the mouths of the burrow , the sound reaches around 115 decibels . G. gryllotalpa can deliver a peak sound pressure of 72 decibels and a mean of about 66 decibels . The throat of the horn appears to be tuned ( offering low inductive reactance ) , making the burrow radiate sound efficiently ; the efficiency increases when the burrow is wet and absorbs less sound . Mole crickets are the only insects that construct a sound @-@ producing apparatus . Given the known sensitivity of a cricket 's hearing ( 60 decibels ) , a night @-@ flying G. vineae female should be able to detect the male 's song at a range of 30 metres ; this compares to about 5 metres for a typical Gryllus cricket that does not construct a burrow . 
 The loudness of the song is correlated with the size of the male and the quality of the habitat , both indicators of male attractiveness . The loudest males may attract 20 females in one evening , when a quieter male may attract none . This behaviour enables acoustic trapping : females can be trapped in large numbers by broadcasting a male 's song very loudly . 
 
 = = = Food = = = 
 
 Mole crickets vary in their diets ; some like the tawny mole cricket are herbivores , others are omnivores , feeding on larvae , worms , roots , and grasses , and others like the southern mole cricket are mainly predacious . As well as consuming roots underground , mole crickets leave their burrows at night to forage for leaves and stems which they drag underground before consumption . 
 
 = = = = Predators , parasites and pathogens = = = = 
 
 Besides birds , toads and insectivorous mammals , the predators of mole crickets include subterranean assassin bugs , wolf spiders , and various beetles . The South American nematode Steinernema scapterisci kills Neocapteriscus mole crickets by introducing bacteria into their bodies , causing an overwhelming infection . Steinernema neocurtillae is native to Florida and attacks native Neocurtilla hexadactyla mole crickets . Parasitoid wasps of the genus Larra ( Hymenoptera : Crabronidae ) attack mole crickets , the female laying an egg on the external surface of the mole cricket , and the larva developing externally on the mole cricket host . Ormia depleta ( Diptera : Tachinidae ) is a specialized parasitoid of mole crickets in the genus Neoscapteriscus ; the fly 's larvae hatch from eggs inside her abdomen ; she is attracted by the call of the male mole cricket and deposits a larva or more on any mole cricket individual with which she comes in contact . Specialist predators of mole cricket eggs in China and Japan include the bombardier beetle Stenaptinus jessoensis whereas in South America they include the bombardier beetle Pheropsophus aequinoctialis ( Coleoptera : Carabidae ) ; the adult beetle lays eggs near the burrows of mole crickets , and the beetle larvae find their way to the egg chamber and eat the eggs . Fungal diseases can devastate mole cricket populations during winters with sudden rises of temperature and thaws . The fungus Beauveria bassiana can overwhelm adult mole crickets and several other fungal , microsporidian and viral pathogens have been identified . Mole crickets evade predators by living below ground , and vigorously burrowing if disturbed at the surface . As a last @-@ ditch defence , they eject a foul @-@ smelling brown liquid from their anal glands when captured ; they can also bite . 
 
 = = Distribution = = 
 
 Mole crickets are relatively common , but because they are nocturnal and spend nearly all their lives underground in extensive tunnel systems , they are rarely seen . They inhabit agricultural fields and grassy areas . They are present in every continent with the exception of Antarctica ; by 2014 , one hundred and seven species had been described and more species are likely to be discovered , especially in Asia . Neoscapteriscus didactylus is a widespread pest species , originating in South America it has spread to the West Indies and New South Wales in Australia . Gryllotalpa africana is a major pest in South Africa ; other Gryllotalpa species are widely distributed in Europe , Asia and Australia . They are native to Britain ( as to western Europe ) , but the former population of G. gryllotalpa may now be extinct in mainland Britain , surviving in the Channel Islands . 
 
 = = = Invasive mole crickets , and their biological control = = = 
 
 Invasive species are those that cause harm in their newly occupied area , where biological control may be attempted . The first @-@ detected invasive mole cricket species was Neoscapteriscus didactylus , a South American species reported as a pest in St. Vincent , West Indies as early as 1837 ; by 1900 , it was a major pest of agriculture in Puerto Rico . It had probably slowly expanded its range northwards , island by island , from South America . The only biological control program against N. didactylus was in Puerto Rico , and it succeeded in establishing the parasitoid wasp Larra bicolor from Amazonian Brazil . In 2001 , N. didactylus in Puerto Rico seemed to be a pest only in irrigated crops and turf . Small scale experimental applications of the nematode Steinernema scapterisci were made in irrigated turf , but survival of the nematode was poor . Very much later , this same species was reported as a pest in Queensland , Australia , presumably arriving by ship or plane . The next @-@ detected invasive species was in the late 19th century in Hawaii , probably by ship . It was named as Gryllotalpa africana , but was probably G. orientalis . It attacked sugarcane and was targeted with Larra polita from the Philippines in 1925 , apparently successfully . 
 The next detection was in Georgia , USA , and at that time was assumed to be N. didactylus from the West Indies . It was in fact three South American Neoscapteriscus species , N. abbreviatus , N . vicinus , and N. borellii , probably arrived in ship ballast . They caused major problems for decades as they spread in the southeastern USA.Scapteriscus mole cricket populations had built up since the early decades of the 20th century and damaged pastures , lawns , playing fields and vegetable crops . From the late 1940s chordane had been the insecticide of choice to control them , but when chordane was banned by the U.S. EPA in the 1970s , ranchers were left with no economic and effective control method . Especially to aid Florida ranchers , a project that became known as the UF / IFAS Mole Cricket Research Program was initiated in 1978 . In 1985 , a multi @-@ authored report was published on accomplishments . In 1988 , an account was published on prospects for biological control , and in 1996 an account of promising results with biological control . The program ended in 2004 after 25 years of running monitoring stations , and in 2006 a summary publication announced success : a 95 % reduction in mole cricket numbers in northern Florida , with biological control agents spreading potentially to all parts of Florida . Efforts to use Larra bicolor as a biological control agent in Florida began by importing a stock from Puerto Rico . It became established in a small area of southeastern Florida but had little effect on Neoscapteriscus populations . A stock from Bolivia became established in northern Florida and spread widely ( with some help ) to most of the rest of the state and neighboring states . Its survival depends upon the availability of suitable nectar sources . 
 Once it was discovered that gravid female Ormia depleta flies are attracted to the song of Neoscapteriscus males in South America , a path to trap these flies at synthetic mole cricket song was opened . Experimentation then led to a rearing method . Laborious rearing of over 10 @,@ 000 flies on mole cricket hosts allowed releases of living fly pupae at many sites in Florida from the far northwest to the far south , mainly on golf courses , and mainly in 1989 @-@ 1991 . Populations were established , began to spread , and were monitored by use of synthetic mole cricket song . Eventually it was discovered that the flies had a continuous population from about 29 degrees North all the way south to Miami , but that the flies failed to survive the winter north of about 29 degrees . Shipment and release of the flies to states north of Florida was thus a wasted effort . As the flies had been imported from 23 degrees South in Brazil and could not overwinter north of 29 degrees North in Florida , it was investigated in 1999 whether flies from 30 degrees South in Brazil might survive better in northern Florida , but they did not . 
 The third biological control agent to target Neoscapteriscus in Florida was the South American nematode Steinernema scapterisci . Small @-@ scale releases proved it could persist for years in mole @-@ cricket @-@ infested sandy Florida soils . Its use as a biopesticide against Neoscapteriscus was patented , making it attractive to industry . Industrial @-@ scale production on artificial diet allowed large @-@ scale trial applications in pastures and on golf courses , which succeeded in establishing populations in several counties , and these populations spread , but sales were disappointing , and the product was withdrawn from the market in 2014 . 
 
 = = = As pests = = = 
 
 The main damage done by mole crickets is as a result of their burrowing activities . As they tunnel through the top few centimetres of soil they push the ground up in little ridges , increasing evaporation of surface moisture , disturbing germinating seeds and damaging the delicate young roots of seedlings . They are also injurious to turf- and pasture @-@ grasses as they feed on the roots of the grasses , leaving the plants prone to drying @-@ out and damage by use . 
 In their native lands , mole crickets have natural enemies that keep them under control . This is not the case when they have been accidentally introduced to other parts of the world . In Florida they are considered pests and are described as " a serious problem " . A University of Florida Entomology report suggests that South American Neoscapteriscus mole crickets may have entered the United States at Brunswick , Georgia in ship 's ballast from southern South America around 1899 , but were at that time mistakenly believed to be from the West Indies . One possible remedy is biological pest control using the parasitoidal wasps Larra bicolor . Another remedy that has been successfully applied is use of the parasitic nematode Steinernema scapterisci . When this is applied in strips across grassland , it spreads throughout the pasture within a few months and not only controls the mole crickets , but remains infective in the soil for future years . 
 
 = = In human culture = = 
 
 
 = = = Folklore = = = 
 
 In Zambia , Gryllotalpa africana is held to bring good fortune to anyone who sees it . In Latin America , Scapteriscus and Neocurtilla mole crickets are said to predict rain when they dig into the ground . In Japan in the past they seem to have been associated with the worms / corpses / bugs that announce a persons sins to heaven in the Koshin / Koushin belief — see the spirit ghoul shokera / shoukera . 
 
 = = = As food = = = 
 
 Gryllotalpa mole crickets have sometimes been used as food in West Java and Vietnam . In Thailand mole crickets ( Thai : กระชอน ) are valued as food in Isan . They are usually eaten fried along with sticky rice . 
 In the Philippines , they are served as a delicacy called Camaro in the province of Pampanga and are a tourist attraction . They are also served in parts of Northern Luzon . 
 
 