An instar is the stage of an insect between one moult and the next. A caterpillar typically passes through five or six larval instars before pupating; an aphid has four nymphal instars. Each instar is larger and, often, harder to kill. Oregon State Extension advises targeting corn earworm while larvae are small, before they bore into hemp buds.
In practice
Instar matters for timing. Bt-class sprays act when eaten and work best on first and second instars still feeding on the surface; late instars inside colas are out of reach. Scout for eggs and tiny larvae after moth flights, not for damage.
Don't confuse with
- Generation: egg to egg, several instars long.
- Pupa: the non-feeding stage after the last larval instar.
Small soft-bodied sap-sucking insects of the family Aphididae that cluster on stems and leaf undersides, excrete sticky honeydew and multiply rapidly by live birth.Helicoverpa zea, a moth caterpillar that bores into developing cannabis flowers outdoors, leaving frass that triggers bud rot; growers call it budworm.Hemp is cannabis grown for fibre, seed or other uses and, in many laws, defined as Cannabis sativa with no more than 0.3% THC by dry weight.The dense, elongated cluster of flowers that forms at the end of a stem or branch; the main cola tops the leader.The mobile first-instar nymph of a mealybug or scale insect; the only stage without protective wax, so the stage contact sprays hit best.A record of survival and egg-laying at each age for a cohort of pests at set conditions, from which development time, fecundity and r_m are calculated.A soil bacterium whose crystal proteins kill caterpillars after they eat treated leaves; subspecies kurstaki and aizawai are the strains used against budworms.
