Dark sword-grass

Naming

The moth gets its scientific name from black markings on its forewings shaped like a letter "Y" and resembles the Greek letter upsilon.

Behavior

In a given year, the number of generation differs based on location and weather conditions. In Canada, there are 1–2 generations, while in the United States, there are 2–4 per year. This species is abundant in warmer temperatures during the late spring in May–June and early fall in September–October, while they are more abundant in cooler temperature during the summer in June–July. One life cycle lasts between 35–60 days.Calling behavior is the act of females releasing sex pheromone in preparation for mating. Calling behavior increases within the first 3 days after eclosion but decreases as the females grow older. As well, as the females grow older, they onset time of calling behavior occurs earlier. Calling earlier allows older females to have increased mating success as they normally produce less sex pheromone and need to appear more attractive than younger females. The amount of sex pheromone in the body and calling behavior are coordinated on a time-scale.

Habitat

This species is a seasonal migrant that travels north in the spring and south in the fall to escape extreme temperatures in the summer and winter. The migration patterns reflect how reproduction occurs in the spring and ceases in the fall.

Reproduction

Females release sex pheromones to attract males for mating. Pheromone production and release in females and pheromone responsiveness in males is dependent on the juvenile hormone and pheromone biosynthesis activating neuropeptide. In the span of 2 months, the moth progresses through the life-cycle stages egg, larvae, pupa, and adult. Throughout this time period, this moth faces the risk of predation and parasitism, such as by "Hexamermis arvalis" or by the parasite "Archytas cirphis".

Predators

Several species of wasps prey on the black cutworm. Larvae parasitized by "Meteorus leviventris," a type of parasitoid, eat 24% less vegetation and cut 36% fewer seedlings. Other parasitoids include several fly species such as "Archytas cirphis, Bonnetia comta, Eucelatoria armigera" and "Sisyropa eudryae." Ground beetles also eat black cutworm larvae. Ants, specifically "Lasius neoniger" also prey on this species and feed on "A. ipsilon" eggs"."

Migration

"A. ipsilon" are seasonal migratory insects that travel south in the fall to escape harsh cold temperatures and travel north in the spring to escape extremely warm weather. Therefore, changes in thermoperiod as well as photoperiod may influence the onset of migration patterns in this species. Before migration southward in the fall, the reproductive system in both females and males shuts down to prevent copulation before winter. In the spring and early summer, though, before migration north, females release sex pheromones soon after eclosion. In one study, female moths collected in late April-early May were 100% mated.