Delayed-dispersal
Guides
Anelosimus studiosus
tangle web spider, cobweb spider, social cobweb spider
Anelosimus studiosus is a subsocial tangle web spider in the family Theridiidae, distributed across much of North and South America from temperate to tropical regions. The species exhibits striking social polymorphism, with two distinct behavioral phenotypes: social spiders that live communally in large cooperative colonies, and asocial solitary individuals that defend individual territories. Social colonies involve multiple adult females sharing web maintenance, brood care, and cooperative prey capture without aggression. The frequency of the social phenotype increases at higher latitudes, correlating with colder temperatures where delayed juvenile development and maternal mortality risks favor communal living. Despite behavioral differences, the two phenotypes interbreed freely and produce viable offspring.
Xyleborus affinis
sugarcane shot-hole borer
Xyleborus affinis is a highly widespread ambrosia beetle native to the American tropics, now found in tropical and subtropical regions worldwide. It cultivates symbiotic fungi in galleries bored into decaying wood, feeding exclusively on these fungal gardens. The species exhibits facultative eusociality with delayed dispersal of adult offspring, who assist with nest maintenance and brood care. Females are the dispersing sex and are strongly attracted to ethanol and specific host plant volatiles. Despite frequent association with declining trees, it primarily colonizes wood already in early decay rather than causing primary mortality.