Having things “in the bag” is usually an indication of a good situation. According to the saying, the project or objective is collected in a manageable environment and under control.
The phrase actually originates with bird and small game hunters who literally had their quarry in a bag as they headed home to prepare a meal. Today’s application is employed in business, politics, sports (but not often enough this season) and numerous other situations.
Even one of the local native insects has its objectives in the bag for at least part of its life. The Evergreen Bagworm, Thyridopteryx ephemeraeformis, is an occasional but rarely noticed larval stage of an insect pest.
Rarely noticed, Evergreen Bagworms are often found in local cedar trees.
The local bagworm comes from a large insect family with approximately 1,000 members. All of this grouping’s species’ larvae are enclosed in a bag and most species have flightless adult females.
The native bagworms will feed on over 50 locally available families of deciduous and evergreen trees and shrubs. As such its additional common names can be the eastern bagworm, common bagworm, common basket worm, or North American bagworm, depending on its meal of choice when discovered.
While several species of bagworms are found in Florida, Thyridopteryx ephemeraeformis is not encountered in the Big Bend with as great a frequency as other parts of the country. Severe infestations can damage the appearance and health of host plants, especially juniper and arborvitae types which grow in the temperate climate of north Florida.
Adult bagworms are masters at blending into the background by using earth tones to camouflage their positions. Each female remains enclosed in her bag and inside of her pupal casing throughout her life cycle in a caterpillar-like state, mates, and then becomes essentially an egg-filled sac.
The male bagworm emerges as a freely flying moth, appearing hairy and charcoal black. His diminutive wingspan measure less than an inch in length.
Neither the male nor the female adult feeds. As adults the female will live a week or two, while the male lives only one to two days.
Shortly after mating, the female lays a clutch of 500 to 1,000 eggs inside of her pupal case enclosed within her bag. The eggs are smooth and cylindrical in shape which are deposited in a mass covered with a waxy layer. The eggs will remain viable through the winter and hatch when the weather warms.
Hatching larvae are barely visible without the aid of magnification. They often disperse to surrounding plants by spinning a silky thread and drift on the wind to a new meal site.
Once a suitable host is found, the caterpillar begins feeding. Each incorporates debris into its bag, which it constructs with pieces of twigs, leaves, and silk.
The common bagworm caterpillar develops through seven phases before it transforms into a pupae. The caterpillar stage may last up to four months depending on temperature and available food.
The mature larva attaches its bag to a branch with a strong band of silk. The pupal stage generally lasts for a week to ten days before the males emerge to repeat the process.
Individuals or small groupings pose little threat, but large infestations can defoliate plants and trees. Since effective insecticide application is difficult with this species, homeowners frequently hand pick the little bags to control the population.
Alas, even the bagworms can end up in a bag not of their making.
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