When viewed over a period of years, the frequency and type of seasonal occupancy of overwintering monarch butterflies, Danaus plexippus plexippus (Linnaeus, 1758), at California winter groves are good indicators of whether grove conditions are being maintained, declining, or recovering. The contribution of a winter grove to the next generation of butterflies depends on the stability of grove conditions for winter aggregations. Knowing the trend of grove conditions allows proactive management of winter groves for overwintering butterflies.

Phenacoccus peruvianus Granara de Willink, in Granara de Willink & Szumik, 2007, the bougainvillea mealybug (Hemiptera: Coccomorpha: Pseudococcidae), is recorded from California and North America for the first time. Comparison of the morphology of the adult females from California with those described from South America, found a closer match with specimens from Argentina than with those from Peru. The adult male is described for the first time and compared with that of Phenacoccus solenopsis Tinsley, 1898. A table listing all 36 known host plant families in California is appended, 28 of which are new. DNA sequences from the COI and 18S portions of the genome were analyzed and compared with those available for specimens of P. peruvianus introduced to Europe and those of other congeners, confirming conspecificity between the Californian and European specimens and displaying interspecific genetic differences from other known Phenacoccus species within the range of values so far known to occur within the genus.

A survey of arthropods visiting flowers of California pipevine, Aristolochia californica Torr. (Aristolochiaceae), was conducted during 2017 and 2018. Collecting produced 1725 individuals in 75 terminal taxa. Over the two years, a residential backyard produced more terminal taxa (70) and individuals (1539) than flowers in an upland grassland (27 terminal taxa, 186 individuals). Diptera: Mycetophilidae were the dominate arthropod group attracted to the flowers, accounting for 77.8% of visitors and represented by 17 genera and 28 morphospecies, with Mycetophila Meigen, 1803 being most diverse with 12 morphospecies. The superfamily Sciaroidea (Keroplatidae, Mycetophilidae, Sciaridae) had 33 morphospecies and 1505 specimens representing 87.2% of the total arthropods. The arthropods could be grouped into the following guilds: potential pollinators, fluid feeders, predators, parasites, scavengers and temporary residents.

In lowland areas, carabid beetles show diurnal or nocturnal activity patterns depending on habitat type. However, the diel activity patterns of carabid beetles in alpine areas are poorly understood. We conducted field studies in the alpine area of Mt. Hakusan in central Japan to determine the diel activity patterns of carabid beetles according to habitat type and ground surface temperature. Using baited pitfall traps, we collected samples every three hours over a 24-hour period in the summers of 2015 and 2016 in Pinus scrub, snowbed, and fellfield sites. In both years, the numerically dominant species were Pterostichus janoi Jedlicka, 1952 in the Pinus scrub, Bembidion sp. in the snowbed, and Bembidion sp. and Colpodes xestus (Bates, 1883) in the fellfield. Carabid beetles on alpine Hakusan showed activity patterns that varied depending on habitat type or ground surface temperature. Bembidion sp. showed diurnal activity patterns in the snowbed but nocturnal activity patterns in the fellfield when the diurnal temperature range was large. However, this species was active throughout the day and night in these habitats when the diurnal temperature range was small. By contrast, P. janoi in the Pinus scrub and C. xestus in the fellfield were mainly active nocturnally in both years, regardless of temperature fluctuations. Because alpine areas are generally characterized by harsh and changeable climates, some alpine carabids such as Bembidion sp. are probably adapted to show versatile activity patterns in response to changeable microclimatic conditions.