Defoliators
> Larch Casebearer
Pest: Larch Casebearer (Coleophora laricella (Hubner))
Order: Lepidoptera
Family: Coleophoridae
Host Plants: All species of Larch (Larix).
Description:
Caterpillars of this species are very small and one of their
first actions is to cut off a needle tip of the host, hollow it
out, reinforce the inside with silk, and then crawl inside. This
light brown, cigar-shaped case is then carried around on their backs
for the remainder of the larval period. Larvae feed on the foliage
beginning when it is emerging from the bud and into June (Approximately
75 -350 GDD). New needle tips can appear scorched or damage can
proceed to complete defoliation, depending on population size. Repeated
years of defoliation are extremely stressful for the host and may
cause mortality. Usually, however, in the Northeast, damage is limited
to the aesthetic.
Life Cycle:
Larvae over-winter on the stems, branches and trunk of the host
tree. In the spring, they will crawl to the newly emerging needle
tips to feed. Pupation occurs in late-May
into early June and the adult moths will be flying by late-June
into early July. Eggs are laid on the needles and new caterpillars
appear soon thereafter (Approximately 2375 - 2805). Newly emerged
caterpillars make cases for themselves but do not create much injury
to the host during that year. Before the needles fall from these
deciduous conifer hosts, the larvae will migrate to the woody portions
of the plant to over-winter. There is one generation per year. GDD
for the adult flight period is approximately: 700-1200.
Management Strategies:
The caterpillars are very cryptic and are only detectable to the
trained eye. New injury in the spring is obvious and should be monitored
for and detected prior to it becoming severe. Branches can be lightly
shaken for the presence of adult moths during their flight period.
Adults are grayish and have a wingspan of only 8 mm.
Images:
| 
A larch casebearer caterpillar within its "case" on the foliage
of the host plant. (R. Childs)
The tiny brownish-gray needles, that are attached to the healthy
emerging needles, are actually the larch casebearer caterpillars
in their cases and ready to feed. (R. childs)
|
Defoliators
index:
Asiatic Garden Beetle 
Bagworm
Cankerworms
Eastern Tent Caterpillar
Fall Webworm
Forest Tent Caterpillar
Gypsy Moth
Japanese Beetle
Larch Casebearer
Lily
Leaf Beetle
Mimosa Webworm
Viburnum Leaf Beetle
Winter
Moth - ID & Management
UPDATED! Winter
Moth Overview
Winter
Moth Project - Biological Control in MA
Questions
about downloading files followed by the
symbol? Click
here for more info.
|
