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Green beetle larvae with a white stripe running down its body.

2019 Alfalfa Weevil Activity Prediction

One of the major insect pests of alfalfa in South Dakota is the alfalfa weevil. In 2018, we received fewer reports of alfalfa weevils, which may have been a result of the cooler and wetter spring conditions. It’s possible that populations may also be lower in 2019 due to the similar spring conditions that we are currently experiencing.

Two weevil larva. Top: alfalfa weevil. Bottom: clover leaf weevil.

How to Differentiate Alfalfa Weevils From Clover Weevils

When scouting alfalfa, there are two species of weevils that are commonly observed. They are the alfalfa weevil and the clover leaf weevil. Although they are similar in size and coloration, each species has unique characteristics that can be used to identify them.

A grub that has an orange colored head and legs and a white body with a dark grey tip at the end. The grub is laying on top of the soil.

2019 June Beetle Update

In the spring of 2016, we received reports of large populations of June beetles in Central South Dakota, which indicates the start of a new cycle for the grubs. Based on these reports, it is estimated that 2019 will be the big emergence year if the 2016 adults were successful and their grubs survived.

Grassy pasture with a small hill of dirt in the foreground. There is green grass at the base of the mound.

Are Ant Mounds in Pastures Bad?

We often receive reports of large ant mounds in a pastures and rangeland. These mounds are the creation of thatching ants, which are common in South Dakota. Although these mounds are often considered a nuisance, the ants may play an important role as predators of potential pest insects.