Toxoneuron

Say, 1836

Species Guides

1

Toxoneuron is a of koinobiont endoparasitoid in the Braconidae. The best-studied , Toxoneuron nigriceps, is a of the tobacco budworm (Heliothis virescens). Members of this genus develop internally within larvae, with a distinctive post-egression feeding phase where larvae feed externally on host tissues before . The genus exhibits sophisticated host manipulation mechanisms including -mediated immune suppression and teratocyte-derived physiological regulation.

Pronunciation

How to pronounce Toxoneuron: //tɒk.soʊˈnʊə.rɒn//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Habitat

Tobacco agroecosystems and associated agricultural environments where noctuid occur. Laboratory rearing occurs at 29±1°C, 60±10% relative humidity, with 14:10 L:D .

Distribution

United States; historically documented from field studies in Georgia with high rates. Laboratory colonies maintained at Texas A&M University.

Host Associations

Life Cycle

Koinobiont endoparasitoid development: and larval instars 1-3 develop internally within . First through third instar larvae feed nondestructively on host . Late third instar egresses from host (typically after host to fifth instar), then undergoes obligate external tissue-feeding phase lasting 3-4 hours while anchored to host . occurs within cocoon spun in pupation chamber; larvae require enclosed space (host-formed or artificial chamber) to successfully spin cocoons.

Behavior

Females exhibit -searching mediated by herbivore-induced plant volatiles and direct host cues. Searching time and oviposition effort are disproportionately allocated to suitable hosts over non-hosts. Larvae display distinctive post-egression feeding: after exiting host, the larva anchors its in the egress hole, curves to form a second hole in host , and feeds externally on liquefied host tissues. During this phase, larvae undergo dramatic color change (green to whitish) and near-doubling in size. Larvae can feed on presented tissues from parasitized or unparasitized hosts when normal feeding is disrupted.

Ecological Role

agent of Heliothis virescens, a major pest of tobacco, cotton, soybean, and tomato. Historical field rates estimated at 50-100% in some .

Human Relevance

Studied as a agent for agricultural pest management. Laboratory rearing methods developed including artificial chambers (gelatin capsules and microtube rack wells) for mass production.

Tags

Sources and further reading