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Happenings in the insect world
by Paul Cherubini
on November 21, 2023 at 11:20 PM
In March and April 2023 fourteen monarch sightings were posted on iNaturalist from Sonoma County eastward to the Sierra foothills. So we know that that the overwintered butterflies along the coast had spread E & NE across that entire area. Between June 1 - August 30 dozens of monarch sightings were also posted on iNaturalist in the area between Sonoma County and the Sierra foothills. So we know there was summer breeding across that entire area. Fall breeding in the Central Valley is not a new phenomenon. It's been known for decades that a very small percentage of female fall migrants develops eggs and goes looking for milkweed. The presence of milkweed does not cause these fall migrants to develop eggs as evidenced by the fact the vast majority of them fly over thousands of still green milkweeds during their journey to the overwintering sites yet almost none display any interest in the plants except to nectar for an hour or less if they are flowering.
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