Insects Parasitoid

braconid wasp cocoons on giant leopard moth larva

the many species of parasitoid wasps chalcidoid , ichneumon wasps, followed proctotrupoidea , platygastroidea. outside these, many hymenopteran lineages contain parasitoids, such of chrysidoidea , vespoidea, , rare symphytan (sawfly) family orussidae.

hymenopteran parasitoids have remarkable life cycles. in 1 family, trigonalidae, female wasps deposit eggs small pockets cut edge of leaves ovipositor. caterpillar chewing these leaves may unknowingly swallow of eggs, , when caterpillar s gut, hatch , burrow through gut wall , body cavity. later search caterpillar s body cavity other parasitoid larvae, , these attack , feed on. trigonalids, once in caterpillar or sawfly larva, need vehicle fall prey social wasp. wasp carries caterpillar nest, , there butchered , fed wasp s young; serve host trigonalid, eggs of in butchered caterpillar. ichneumon wasp ichneumon eumerus parasitises butterfly phengaris rebeli directly seeking out, through smell, myrmica ant nests butterfly larvae parasitised, , ovipositing p. rebeli larvae. once wasps eggs hatch, feast on carcass of dead caterpillar.

megarhyssa macrurus, parasitoid, ovipositing host through wood of tree. body of female c. 2 inches (51 mm) long, ovipositor c. 4 inches (100 mm) long.

parasitoid wasps can classified either endoparasitic or ectoparasitic according lay eggs. endoparasitic wasps insert eggs inside host, while ectoparasitic wasps deposit theirs outside host s body. species of wasps attack during egg or larval stage of host, attack adult hosts. oviposition complex, depends on finding host , on evading host defense mechanisms. ovipositor long tube-like organ used inject eggs hosts. consists of genital structures segments 8 , 9 of wasp s body.

parasitoid wasps face range of obstacles oviposition, including behavioral, morphological, physiological or immunological defenses of hosts. example of immunological defense against endoparasitic wasps encapsulation of eggs. thwart immunological protection system, wasps inundate host eggs overload encapsulation response. way of hindering host s defense introduce virus interferes immune system.

some parasitoid wasps locate hosts detecting chemicals released indirect plant defenses against insect herbivores.

parasitoid wasps have specialized behavior ovipositing on hosts. example, attack ants either use horizontal or vertical alighting approach behind host. in horizontal method, wasp maintains body horizontally until grabs on ant s metasoma (upper abdomen) tarsi (lower legs). after that, places rest of legs on ant s abdomen, folds wings, , proceeds inject victim ovipositor. vertical approach more complicated, , requires more steps. wasp attaches front legs onto ant s abdomen, rotates 180 degrees becomes upside down. after that, rotates once more head , legs switch places, before inserting ovipositor.

ants aware of wasps presence, violently turn around, moving mandibles , legs in order defend against attacker. prevents wasps depositing eggs successfully. try beat such behavioral diversions, wasps close in fast inject hosts. prevent missing target when making contact host, wasp may wait ant stop moving, , attack suddenly.

other insects

the head of strepsipteran, odynerus spinipes, protruding abdomen of wasp host

the true flies (diptera) include several families of parasitoids, largest of tachinidae, along others such pipunculidae , conopidae. other families of flies include protelean species. example, phoridae parasitoidal on ants, , flesh flies, such emblemasoma auditrix, parasitoidal on cicadas, locating hosts sound.

the twisted-wing parasites (strepsiptera) consists entirely of parasitoids; sterilise hosts.

two beetle families, ripiphoridae , rhipiceridae, largely parasitoids, aleochara rove beetles. other orders include few parasitoids, such epipyropid moths, ectoparasitoids of planthoppers , cicadas. more elaborately, genus cyclotorna begins growth period parasitising plant bugs, , ends feeding on ant larvae in colonies.