These tiny insects (order Collembola) are usually less than 6 mm long and often gray, and have an appendage-like structure on their abdomen which allows them to jump through the air for several centimeters. Their common name, "springtail," originates from this peculiar behavior. Springtails are abundant in most soils throughout the world. They feed on many living and dead plant materials. Springtails occur in all bareroot and container nurseries in the province. Locally, there are several species, few of which have been identified. You're more than welcome to contact our memo writing services and order the assistance you need for your assignments.
In British Columbia, the globular shaped Bourletiella hortensis (Figure 80) is the most damaging species in bareroot nurseries, and can build up to alarming numbers. The insect reduces emergence of spruce (Engelmann, Sitka, and white) and western hemlock. They feed on the rising 1+0 seedlings in the spring (Figure 81), attacking the hypocotyl area between the needles and the roots, and producing small lesions that may result in deformation or mortality. These lesions can also serve as entry points for pathogenic fungi. All coniferous species are susceptible hosts during the 3-week period between germinant emergence and seedcoat shed. Springtails are no longer a threat once stems become woody. Several unidentified species of springtails have also been found on container stock, particularly on styroblocks containing algae, moss, or liverworts. Although no damage has been reported on container seedlings, springtails are important pests in other crops using artificial growing media where they may feed on root tips.
Under coastal British Columbia conditions, springtails apparently overwinter as eggs and the populations peak in mid-July, then decline to low levels by mid-September. Collembola do not undergo metamorphosis; consequently, except for small size and lack of sexual maturity, juveniles look much like adults, which are about 1.5 mm long and appear to the naked eye as blackish to dark green. The antennae are about half as long as the body and the abdomen is globular.
In bareroot nurseries, routine pre-emergent applications of herbicides usually control springtails. Their populations can be monitored by the waving of a piece of white paper over the seedbed surface. Any insects present will jump when disturbed. If large numbers are visible and damage is present, it may be necessary to apply an insecticide. Cultivation of fallow-infested soils may help destroy eggs.
Edwards, C.A. and G.W. Heath. 1965. The principles of agricultural entomology. C.C. Thomas, Springfield, Ill.
Marshall, V.G. 1978. Gut content analysis of the collembolan Bourletiella hortensis (Fitch) from a forest nursery. Rev. Ecol. Biol. Sol. 15: 243-250.
Marshall, V.G., and S. Ilnytzky. 1976. Evaluation of chemically controlling the collembolan Bourletiella hortensis on germinating Sitka spruce and western hemlock in the nursery. Can. J. For. Res. 6: 467-474.
|
Principal, locally grown hosts |
Host age and season when damage appears |
|
Nursery type and location |
|
|
|
|---|---|---|---|---|---|---|
|
Bareroot |
Container |
|||||
|
Age |
Season |
Coastal |
Interior |
Coastal |
Interior |
|
|
All spruce, western hemlock |
1+0 |
Spring through early summer |
Yes |
Yes |
Yes |
Yes |
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Figure 80. Springtail (at arrow) feeding on germinant (courtesy of V.G. Marshall).
Figure 81. Spruce seedling affected (four, right-hand-side) and unaffected (two, left-hand-side) by the springtail Bourletiella hortensis (courtesy of V.G. Marshall).
Figure 82. Life history of springtails (one or two generations per year).