A Novel Insect Overwintering Strategy: The Case of Mealybugs.

Insects have limited ability to regulate their body temperature and have thus required a range of strategies to withstand thermally stressful environments. Under unfavorable winter conditions, insects often take refuge under the soil surface to survive. Here, the mealybug insect family was selected for the study.

Parasitoid competitive displacement and coexistence in citrus agroecosystems: linking species distribution with climate.

The introduced parasitoid wasp Aphytis melinus, the most widespread natural enemy of the California red scale (Aonidiella aurantii) and the superior competitor, has displaced the native Aphytis chrysomphali from most citrus areas of the Mediterranean basin and other citrus areas all over the world. However, our extensive survey data on the scale parasitoid populations collected in 2004-2008 show that in large citrus areas of eastern Spain both parasitoids coexist. Using field data from 179 orchards spatially divided in five citrus-producing agroecosystems, we examined the mechanisms that could explain displacement or coexistence between both Aphytis species in relation to weather conditions.