Basic background and biology of the blue alfalfa aphid:

The blue alfalfa aphid (Acyrthosiphon kondoi Shinji) was first identified by entomologists in the spring of 1975 in the Imperial Valley of California. Since then it has become widespread throughout the state and has become established in Arizona, Nevada, New Mexico, and as far east as Kansas and Oklahoma. Both adults and nymphs feed on photosynthetic fluids from the leaves and stems of the alfalfa plant. Low to moderate populations of blue alfalfa aphid (BAA) may cause little to no visible yellowing of plants. Blue alfalfa aphid feed in the new growth, at the tips and young leaves. After prolonged feeding, leaves will eventually turn yellow,...

The blue alfalfa aphid, Acyrthosiphon kondoi Shinji was first identified by entomologists in the spring of 1975 in the Imperial Valley of California. Since then it has become widespread throughout the state and has become established in Arizona, Nevada, New Mexico, and as far east as Kansas and Oklahoma. Both adults and nymphs feed on photosynthetic fluids from the leaves and stems of the alfalfa plant. Low to moderate populations of blue alfalfa aphid may cause little to no visible yellowing of plants. Blue alfalfa aphid feed in the new growth, at the tips and young leaves. After prolonged feeding, leaves will eventually turn yellow, starting at the veins, leaves will curl and wilt, and turn necrotic...

Introduction

Alfalfa (Medicago sativa L.) has been cultivated in California since it was first introduced from Chile in 1850. Alfalfa yields can be reduced by several species of insects, such as leafhoppers in the genus Empoasca. These leafhoppers are highly polyphagous and capable of successful reproduction on over 200 plant species in 25 different families. In alfalfa hay in California there is a complex of three species of Empoasca leafhoppers (ELH) that are nearly identical in appearance and behavior. These include the potato leafhopper, Empoasca fabae (Harris), the garden leafhopper, Empoasca solana DeLong, and the Mexican leafhopper,...

One of the most damaging pests of alfalfa is the pocket gopher.  A recent study estimated that, when present, pocket gophers resulted in an 8.8% loss in revenue.  The damage that pocket gophers cause to alfalfa can be quite varied but includes consumption of tap roots and above-ground vegetation that can result in reduced vigor and/or mortality of alfalfa plants, loss of irrigation water down burrow systems, and chewing on underground irrigation lines.  Pocket gopher mounds can result in additional problems including serving as weed seed beds, burying of plants, and causing damage to farm equipment.

A number of options are currently available for controlling pocket gophers but most control centers on toxic baits,...