Assistant Cooperative Extension Specialist University of California-Davis Davis, California, United States
Bagrada bugs are Pentatomid Hemipterans that are known for their high rates of mating, and damage on certain crops. They are a pest species that feeds on cruciferous plants such as broccoli, cauliflower, and kale. They are native to Africa and have been introduced to the United States for around 10 years. Studying their mating behavior is key for understanding these bug’s life histories and their management as pests. We set up laboratory experiments to test how the bug’s social environment affects mating behaviors such as mate guarding and copulation time. Bugs were placed in 15cm petri dishes, where the sex ratio is the factor being manipulated. Within these mating arenas, 3 different ratios were tested (4 males, 8 females; 6 males, 6 females; and 8 males, 4 females). The bugs were filmed for 6 hours and copulation time, mate guarding time, and mate guard interruption for each mating event was recorded. These data were quantified, and analyzed to reveal patterns on how the bagrada bug’s social environment can influence mating behaviors.We found that when female ratios are higher, copulation times were lower, and mate guarding was less prevalent. This is due to males choosing to expend fewer resources on mating when there is an abundance of females. And when male ratios were higher, we saw longer mate guarding time and more instances of mate guard interrupting.
