Parasitoids

Question 1

define Parasitoid

Answer 1

An organism whose young develop on or within another organism, eventually killing it

Question 2

which insect orders have parasitoids

Answer 2

• Hymenoptera
• Diptera
• Coleoptera
• Neuroptera
• Lepidoptera
• Trichoptera
• Strepsiptera

Question 3

Tachinid Flies

Answer 3

• Diptera: Tachinidae
• Common, resemble houseflies
• Oviposition can be direct or indirect
• Can be solitary or gregarious
• Biological control
• endoparasitoids - eggs are put inside the host

Question 4

explain the Eulophidae family

Answer 4

• Superfamily = Chalcidoidea
• Wide range of hosts
• 4 subfamilies: Tetrastichinae, Entedoninae, Euderinae, Eulophinae

Question 5

Eulophidae subfamily - Tetrastichinae

Answer 5

• Abundant in all geographic regions
• Can be strongly sexually dimorphic → two generations of dimorphic forms

Question 6

Eulophidae subfamily: Tetrastichinae - explain their sexual dimorphism

Answer 6

• Form 1 (1st gen): feed on hemolymph; variant type females/males
• form 1 lays second batch of eggs → (2nd gen) “normal” morphs
• Form 2 (1st gen): feed on solid material; “normal” females/males

Question 7

Family Ichneumonidae

Answer 7

• Order Hymenoptera
• Parasitize spiders or their egg sacs

Question 8

Family Ichneumonidae - morphology

Answer 8

• 16+ antennal segments
• Distinct wing venation
• Range from 3-40 mm

Question 9

family Ichneumonidae - Zatypota percontatoria

Answer 9

• Habitat: woodlands in the northern hemisphere
• Host: arachnids of the Theridiidae family

Question 10

Zatypota percontatoria - Parasitization strategy

Answer 10

• Hosts are similar in size to parasitoid
• Preference to juveniles and females
• Female wasp oviposits eggs into spider’s abdomen

Question 11

Zatypota percontatoria - larva lifecycle

Answer 11

• Endoparasitic and ectoparasitic behavior as koinobionts
• After hatching, larva will feed off nutrients in hemolymph as spider continues to forage, but eventually will burst from the spider’s abdomen, still feeding from hemolymph

Question 12

Zatypota percontatoria: larva lifecycle - Neuroparasitic behavior

Answer 12

• Influences behavior to prevent spider from attacking larva
• Inducing overwintering behavior 24-48 hours prior to entering pupal stage so that the spider will make the cocoon for it
• Prior to entering cocoon, larva will consume the spider

Question 13

Zatypota percontatoria - Adult stage

Answer 13

Solitary behavior, feeds off nectar

Question 14

Parasitoids in Coleoptera

Answer 14

• Carabidae are parasitoids and are generally only ectoparasitoids during their larval stage.
• They are ectoparasitoids on pupae of other beetles or in one case on young millipedes

Question 15

define Ectoparasitoid

Answer 15

a parasitoid that as an egg is laid in its hosts habitat and eats the host from the outside rather than being laid inside the host and eating it from the inside out.

Question 16

Parasitoid Carabidae (Ground Beetles) Life Cycle

Answer 16

• Carabids development overall is through four stages
• First an egg, then a larval stage next is a pupae stage and finally and adult
• There are four instars where the carabid beetle gets larger.
• The oviposition strategy is to lay the eggs directly into the hosts habitat

Question 17

Parasitoid Carabidae (Ground Beetles) Life Cycle - Specifics in the larval stage

Answer 17

• During the larval stage there are three phases.
• The first is after emerging from the egg the larvae now free-living (living without a parent) locates its host.
• Once the host is located the larvae feed on it. While feeding the larvae molts up to four times.