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Biology of Parasitoids: Parasitoid ID
part of Module 2: Parasitoids and Predators
Undergraduate 4

Additional Agriculture Flashcards




The five generally accepted steps in the parasitoid foraging behavior paradigm
1) location of host habitat
2) location of hosts within the habitat
3) acceptance of the host for egg laying
4) the suitability of hosts for development of the parasitoid
5) in some cases the parasitoid has to manipulate the host to make it suitable for offspring development.
some details about the parasitoid group Scelionidae
-Very tiny egg
-Body heavily sclerotized and usually smooth and shiny
-Valuable group in biological control. Estimated at about 7,000 species in the family. No known hyperparasitoids in the family, and they concentrate on eggs of a variety of insects and spiders. For example, several species are very effective parasitoids of green lacewing eggs, and can seriously hamper use of green lacewings in biological control. Others have been used quite effectively in biological control programs against bug pests and Lepidopteran pests.
some details about the parasitoid group Charipidae
-Hyperparasitoids of aphid parasitoids
-Smooth, shiny body,
-Abdomen laterally compressed,
-Very small wasps
-This family is essentially specialized as hyperparasitoids of parasitoids attacking Homopteran pests (aphids and Psylloids), and can be very disruptive to biological control programs against these pests. Their primary targets are Braconidae, Aphelinidae, and Encyrtidae, which we will discuss later.
some details about the parasitoid group Chrysididae
-Beautiful, metallic colors, often curled into ball when dead
-Body strongly sculptured, sclerotized
-Attack sphecoid and vespoid wasps
-Many are cleptoparasites
-These gorgeous wasps are heavily sclerotized, meaning what? They often curl into a ball when dead or disturbed. This is a defensive response. These wasps are paarsitoids of sphecoid and vespoid wasps, such as paper wasps and mud daubers. These hosts have strong defensive tools, and the Chrysidids, commonly called cuckoo wasps, are heavily armored and when attacked roll into a ball, making themselves impervious to attack. Many species are cleptoparasites, stealing the food that is placed in the host cells by the provisioning mother, and consuming the host larva to boot. Their theft of food for the host larva is why they are called cuckoo wasps, similar to the action of the cuckoo bird.
some details about the parasitoid group Evaniidae
-Abdomen attached high on thorax
-Roach egg parasitoids/ predators
-Strongly petiolate, triangular abdomen
-Evaniids are fascinating wasps that attack egg cases of cockroaches. They attack the egg cases before they harden, typically laying just one or a few eggs in the egg case. The first larval instar is a true parasitoid, but after it molts, it becomes a predator, consuming most or all of the remaining eggs in the egg case. The adults have long legs for running, and are called ensign wasps because of their rapid up-and-down movement of the abdomen that resembles a signal flag. These wasps are very distinctive, with their abdomens attached high up on the thorax, and a small triangular abdomen attached by a very petiolate propodeum.
some details about the parasitoid group Ichneumonidae
-Very large and important group with diversity of habits and host ranges: all parasitoids
-This is a huge family of parasitoids, with an estimated 100-200,000 species. The hosts of this family tend to be concentrated on larval and pupal stages of the Holometabola, or those insects with complete development. Some species attack spider egg cases, and some are egg-larval parasitoids. Some species are very important natural enemies of pests, others are hyperparasitoids, and others attack other beneficial species. Some species have extreme morphologies, such as the Megarhyssa shown here, which attacks woodboring beetles. The primitive groups are ectoparasitoids, while endoparasitism dominates in advanced taxa.
-Females often have exserted ovipositors
-Distinguishing character is second recurrent vein in wing
-Ichneumonids have a rather distinctive form, but are similar to another large family, the Braconidae, to which they are related. Differentiating these two species is done be examining the wing veins. Ichneumonidae have two recurrent veins, forming a cell
some details about the parasitoid group Braconidae
-Very large and important group with diversity of habits and host ranges
-Another very large family (estimated 60-100,00 species) of parasitoids ( a few phytophagous species), and one that is very important in biological control. Braconids attack a wide range of hosts in the Holometabola (mostly larval stages, but some pupae and adults, as well), but also in the Hemiptera, and hyperparasitism is very rare in this family. Some species are enemies of important natural enemies, such as lady beetles and lacewings. Members of this family spin cocoons at the time of pupation.
-Resemble Ichneumonids (same superfamily)
-Key character is only one recurrent vein in wing
-Distinguishing between Ichneumonids and Braconids is about the veins in the forewings. Whereas Ichneumonidae have two recurrent veins, Braconidae only have one.
some details about the parasitoid group Aphelinidae
-Tiny parasitoids of aphids, whiteflies, scales
-Valuable biological control agents
-Wild biologies
-The Aphelinidae is a family of about 2,000 species of tiny parasitoids that typically attack aphids, whiteflies, and scales. In this role they have been extremely valuable in biological control, as these host groups are also important pests in many systems. Some are also important enemies in eggs of Lepidoptera and Orthoptera, and in eggs, larvae, and pupae of Diptera. They have some very intriguing biologies. There are both ecto- and endoparasitoids in the family. It is in this family where we find the heteronomous parasitoids – those species in which males are hyperparasitoids of females of their own or another aphelinid species. In some species males and females develop on the same species, with males as ectoparasitoids and females are endoparasitoids
some details about the parasitoid group Chalcididae
-Diverse hosts, some hyperparasitoids, superparasitism common
-Chalcidids are interesting parasitoids that attack a wide variety of insect and spider hosts, although most are parasitoids of Lepidoptera. A number of species are hyperparasitoids, and superparasitism in the group is rather common, as females exhibit limited powers of host discrimination. They tend to attack only host larvae or pupae. There are about 2,000 estimated species.
some details about the parasitoid group Encyrtidae
-Important parasitoids of scales and other Homopterans
-Some hyperparasitoids, polyembryony
-These small parasitoids have been used in a number of biological control programs against scales and other Homopteran pests, as well other pests, such as gypsy moth. Some species also attack other natural enemies (such as lady beetles and lacewings). Some species are hyperparasitoids. Polyembryony is also found in this group (the Subfamily Copidosomatini), including the looper parasitoid we discussed in the last lecture, where a single egg may yield more than a thousand parasitoids, and a small subset of the larvae are defender morphs that defend their siblings from competitors, but never become adult wasps. All known species are endoparatisoids of various life stages (eggs, larvae, nymphs, pupae). The adults of these wasps are characterized by an abdominal “smile” created by a pulling forward of the abdominal sclerites on the sides.
-Look for the abdominal “smile”
some details about the parasitoid group Eulophidae
-Very diverse group; Some hyperparasitoids; Some phytophagous
-Look for 4 tarsal segments
-Very diverse family of about 5,000 species that has also been used with success in biological control. Most are primary parasitoids of (often concealed) larvae Lepidoptera, Coleoptera, Diptera, and Hymenoptera (although other orders also are attacked by some species), but some species are phytophagous, and others attack egg stages of their hosts. They have been reared from many hosts worldwide, and have been particularly useful in biological control of leafmining flies.
some details about the parasitoid group Mymaridae
-Very tiny egg parasitoids
-Especially important against true bugs
-These are extremely tiny egg parasitoids, and the family is estimated to consist of about 1,500 to 2,000 species. All are egg parasitoids, mostly of eggs that are concealed or inserted into plant tissues (Hemiptera), but also some Coleoptera are known hosts. They have been used in some biological control programs, but most host relationships are poorly known.
some details about the parasitoid group Trichogrammatidae
-Very tiny egg parasitoids
-Important in biological control
-Estimated 1-2,000 species of tiny parasitoids. All are egg parasitoids of Holometabola and Hemiptera, Orthoptera, and Thysanoptera. The taxonomy of the group is a mess, but three tarsal segments are diagnostic for the family. These parasitoids are used worldwide in release programs against crop pests, mostly Lepidopterans.
some details about the parasitoid group Tachinidae
-Largest fly family of parasitoids
-Have swollen subscutellum
-Diverse biologies, hosts
-More than 8,000 known species in this family, all of which are parasitoids. They are virtually all endoparasitoids, but some behave more as true parasites. Members of this family have been used successfully in biological control programs. Some species lay eggs in the environment for hosts to consume, some lay deposit triungulin larvae that actively search for hosts, some lay eggs on the outside of hosts that hatch shortly after deposition and the larvae enter the hosts, and some deposit larvae directly into hosts.
some details about the parasitoid group Sarcophagidae
-Large and diverse family, many parasitoids
-Lack subscutellum; often have red on abdomen; most larviporous
-Often have checkerboard pattern on abdomen
-A subset of these flies are parasitoids, mostly on Orthoptera and Lepidoptera. This family has very diverse biologies, including among the parasitoid species. Some species use phonotaxis (sound orienting) to locate their cicada hosts.
some details about the parasitoid group Carabidae
-Huge family of beetles, parasitoids (Lebiinae) of leaf beetles
-First abdominal sternum divided by hind coxae, and large hind trochanters
-The family Carabidae is a huge group with very diverse biologies, ranging from predation to parasitism to herbivory. One family, the Lebiinae, contains parasitoids of beetles in the family Chrysomelidae (the leaf beetles). Adults of these parasitoid species are predators. Some are useful parasitoids and predators of Chrysomelid pests, such as the Colorado potato beetle and the Altica flea beetle. Carabids can be distinguished by the progressive narrowing from abdomen to thorax to head, and by the large “jelly-bean” like trochanters on the legs, and the subdivision of the first abdominal segment on the underside by the hind coxae.
some details about the parasitoid group Meloidae
-Blister beetles; often find adults on flowers
-Prothorax narrower than head and abdomen
-Another group of parasitoids among the beetles is the Family Meloidae. These are interesting beetles that can induce blister formation with their defensive secretions. Unlike the Carabidae, the thorax of these beetles is narrower than the head.
-Blister beetle adults are plant feeders (some pests)
-Immature stages (triungulin) attack hosts, such as bees and wasps, or grasshoppers
-I showed you these slides in the last lecture. Blister beetles are herbivorous as adults, and some are serious crop pests. The initial immature stage is referred to as the triungulin, and they actively seek or bait hosts, which are ground-nesting bees.
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