نتایج جستجو برای: overwintering population
تعداد نتایج: 695225 فیلتر نتایج به سال:
Eggs of temperate Aedes albopictus populations are cold hardy and can diapause, but tropical populations are not cold hardy and cannot diapause. Heterozygotes possess intermediate diapause and cold hardiness. Males of a tropical strain from Malaysia with a distinctive genetic marker were released into an existing temperate population in East St. Louis, Illinois. Subsequent egg samples from the ...
Many migratory songbirds follow circuitous migratory routes instead of taking the shortest path between overwintering and breeding areas. Here, we study the migration patterns in Swainson's thrush (Catharus ustulatus), a neartic-neotropical migrant songbird, using molecular genetic approaches. This species is presently separated into genetically distinct coastal and continental populations that...
The most effective management program for soybean cyst nematode, Heterodera glycines, is a crop rotation that uses nonhost crops and resistant soybean cultivars. However, little is known about the effects of rotation crops and overwintering on H. glycines biology. These experiments were initiated to determine the effects of seven alternative crops on H. glycines' ability to infect and mature on...
Seasonal variations in the supercooling point, survival at low temperatures and sugar content were studied in fieldcollected codling moth larvae. The supercooling point of field-collected larvae decreased significantly from a mean value of –13.4°C in August 2004 (feeding larvae) to –22.0°C in December 2004 (overwintering larvae). Survival at –20°C/24 h was 0% during early autumn, whereas it inc...
The overwintering survival and development of Drosophila suzukii Matsumura were investigated in California's San Joaquin Valley. Drosophila suzukii were exposed to overwintering conditions in cages hung in a citrus orchard, and the pupae were buried in the soil. Eggs exposed from late November to January did not survive; a low percentage (<3%) of larvae and pupae developed into adults. Survival...
Field studies over 3 yr demonstrated that overwintering populations of the Colorado potato beetle in upstate New York and on Long Island are composed of adults from both the first and second summer generations. The two populations from the climatically different regions differ in their responses to environmental factors that influence voltinism. The critical photoperiod for aestival diapause in...
The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during the winter to survive the cold. Recent published reports have highlighted that overwintering individuals use hydrocarbon markings deposited on surfaces by conspecifics to orient toward aggregation sites. In the current study, monthly GC-MS analyses revealed seasonal modifications in the chemical pr...
A fundamental goal of evolutionary ecology is to understand how asymmetric competition influences phenotype expression, yet few studies have quantified the relative effects of intraand interspecific competition on phenotypes. We examined the effects of intraand interspecific larval competition on both discrete and continuous phenotype expression of the facultatively paedomorphic mole salamander...
A new species, Haplothrips heliotropica, is described from Argentina causing severe damage to the leaves of Heliotropium amplexicaule (Boraginaceae), a South American plant that is now a serious weed of pastures in Australia. Observations are presented on the host specificity, seasonal population changes and overwintering of this thrips. The genus Haplothrips includes more than 230 species worl...
In early August 1995, Aedes albopictus was detected in a light trap collection at a coastal location of Monmouth County, NJ. Larval surveillance indicated the species was breeding in a variety of containers over an area of at least 1.0 km2. This New Jersey record currently represents the northernmost breeding population of Ae. albopictus on the eastern seaboard. The collection site is very clos...
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