Which species is associated with rice fields and the Sac Valley?

• A. An. freeborni
• B. An. hermsi
• C. An. punctipennis
• D. Ae. tahoensis

Answer: (A)

Species have preferred larval habitats, and rice-field environments in the Sacramento Valley provide the warm, standing water and abundant food that certain Anopheles mosquitoes need to complete their development. In this region, Anopheles freeborni is closely tied to cultivated rice fields, where irrigation ponds and flooded fields create reliable breeding sites throughout the growing season. This association with agricultural water management makes it the best fit for the Sac Valley rice-field context.

The other species have different ecological preferences. Anopheles hermsi is more commonly linked to higher-elevation conifer forests rather than cultivated fields. Anopheles punctipennis has a broader range and can exploit various stagnant waters, but it’s not the hallmark species tied specifically to rice paddies in the Sac Valley. Aedes tahoensis is an Aedes mosquito associated with different inland, often non-rice, habitats in northern California.