Overwintering Physiology and Microhabitat Use of Phyllocnistis populiella (Lepidoptera: Gracilliariidae) in Interior Alaska

Abstract

We investigated the overwintering physiology and behavior of Phyllocnistis populiella Chambers, the aspen leaf miner, which has caused severe and widespread damage to aspen in Alaska over the past 10 yr. Active P. populiella moths caught in spring and summer supercooled to an average temperature of -16°C, whereas dormant moths excavated from hibernacula in the leaf litter during fall and winter supercooled to an average of -32°C. None of the moths survived freezing in the laboratory. Counts of overwintering moths in leaf litter across microhabitats in interior Alaska demonstrated that moths occurred at significantly higher density beneath white spruce trees than beneath the aspen host, several other hardwood species, or in open areas among trees. During winter, the temperature 1-2 cm below the surface of the leaf litter beneath white spruce trees was on average 7-9°C colder than beneath aspen trees, and we estimate that during at least one period of the winter the temperature under some white spruce trees may have been cold enough to cause mortality. However, the leaf litter under white spruce trees was significantly drier than the litter from other microhabitats, which may assist P. populiella moths to avoid inoculative freezing because of physical contact with ice. We conclude that in interior Alaska, P. populiella overwinter in a supercooled state within leaf litter mainly under nonhost trees, and may prefer relatively dry microhabitats over moister ones at the expense of lower environmental temperature.

Long-term impact of a leaf miner outbreak on the performance of quaking aspen

“…In Alaska, both larvae and adults feed on Populus tremuloides, the larvae consuming leaves and adults consuming extrafloral nectar. Adults overwinter and emerge in late April or May, before bud break (Wagner et al 2012). Females begin to lay eggs just as aspen leaves unfurl from buds.…”

Detecting Pest-Infested Forest Damage through Multispectral Satellite Imagery and Improved UNet++

“…The aspen leaf miner is a transcontinental pest of trembling or small tooth aspen, feeding on the poplar leaves’ epidermal cells [ 4 ]. It has wreaked havoc in the northwestern Canadian and Alaskan forests since the late 1990s, leading to a wide array of consequences [ 5 , 6 ]. Its epidemics can last for a decade or longer [ 7 ].…”

The bio-ecology of the cape grapevine leafminer,Holocacista capensis(Lepidoptera: Heliozelidae), in the Western Cape, South Africa

“…Firstly, it is important to note that these adults may inhabit alternative plant hosts such as ground cover or adjacent stands of vegetation, although no literature has explored alternative-host overwintering habits of leafmining insects. In most cases, leafminers overwinter as pupae Chen & Kang 2005), although some leafmining species have been known to overwinter in the adult form (Wagner et al 2012). Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has the ability to overwinter in the egg, pupal or adult stage, although it is believed that the larvae feed almost continuously and do not enter diapause, whilst developmental and reproductive diapause has not yet been investigated in detail (Van Damme et al 2015).…”