Diaprepes Root Weevil Control: Helpful Tips

Do you have an infestation of the diaprepes root weevil on your ornamentals or citrus plants? In this article, we will help you understand their life cycle and how to get rid of them.

It is great to have citrus trees like lemon, orange, grapefruit, etc., in your yard. Not only do they look good, but the fruits are delicious and healthy.

But if you don’t keep your citrus and ornamental plants safe from the Diaprepes root weevil, they will wither away in no time with minimum yield.

This article will help you identify these weevils and how to keep them away from your beloved trees.

What Is Diaprepes Root Weevil?

The Diaprepes root weevils originated from the Caribbean and were introduced to Florida in the 60s. Later on, they spread to parts of Southern California and Texas as well.

The adult weevils grow from ⅜ to ¾ inches in length. They have black bodies with long patterns that look like stripes of white, orange, red, or yellow color.

Both adult females and males feed on plant leaves. They lay their eggs in the ground. When the eggs hatch, the larvae consume the roots of plants over a 9-18 month-long duration.

These larvae usually chew out the root crown area, which causes the host plant to die.

Lifecycle

Adult Diaprepes root weevils have a relatively long life cycle; they live around 135-147 days.

This cycle starts when the females lay around 5,000 eggs after mating in later summer or spring. They deposit these eggs in clusters of 30-260 eggs between or inside a pocket made between the edges of leaves.

The females build these pockets using a gelatinous mixture that they produce to glue two edges together. You can identify eggs by their uniform white color, which turns dark just before hatching.

It takes around 7-10 days for these eggs to hatch. Once the larva comes out, they go into the soil to eat the roots of citrus trees.

After getting enough food and nutrition, the larvae go into the pupation stage. The pupa stays in the soil for around 30 days.

During spring, the new adults emerge from the soil using their mandibles to tunnel out of the underground pupa.

The lifecycle of these weevils depends highly on the soil temperature. If the soil is too hard and dry, new adults won’t be able to emerge from it.

What Damage Does it Cause?

The adult weevils usually feed on tender young leaves. On rare occasions, they consume fruits like papaya. The larvae, on the other hand, feed on the roots of various ornamental and citrus plants.

They eat up both structural and fibrous roots (tubers), stunting root growth and eventually causing extensive damage to the plants.

In some plants like sweet potatoes, these pests directly consume the tubers. When it comes to citrus plants, they start by feeding on the small roots, and as they grow, they shift to the larger roots.

Control Measures

Due to their root-feeding nature, these weevils can cause massive damage to highly economical trees like citrus, palm, roses, birch, guava, and more.

Therefore it is essential to control their population to prevent infestations. Mentioned below are a few tips and tricks that you can use to remove these beetles from your yards.

Adults

Ground Traps

Since the new adults emerge from the ground, setting up ground traps can be an effective way of keeping their numbers in check.

You can use a Tedders trap to monitor the number of adult weevils in different tree canopies.

Foliar Contact Insecticides

With the use of a foliar spray, you can apply specific applications of Brigade to the emergence spots of the new adult beetles.

You can use other chemicals like carbaryl and zeta-cypermethrin as well for effective results.

These chemicals are great for killing adult beetles which is why you must spray them near the emerging spots from late May to early June.

The number of weevils emerging from the ground is the highest during these months.

Larvae

Chemical Barriers

Since the larvae attack the roots of various trees, chemical barriers can be highly effective against them.

A dry chemical insecticide is added to the soil around the plant, which kills the larval population when they come in contact with it.

This barrier is applied from the trunk to the dripline under the soil to get the best results.

Landscape fabrics

Once the eggs hatch, the larvae drop from the leaves to the soil and resides there for a few months before emerging.

To prevent the larvae from going inside the soil, you can use a landscape fabric that will act as a barrier between the soil and the larvae.

These fabrics allow water to pass to the ground so that the plants get enough of it to grow, but do not let the larvae fall directly on the soil.

Parasitic Nematodes

These pests can also be eliminated using parasitic nematodes, which are an effective form of biological control for most garden pests.

The nematodes Heterorhabditis Indica and Steinernema Riobravis are great for attacking and killing these root weevils.

The good thing about them is that once they kill the weevils, they die due to hunger. This prevents them from attacking trees and other insects.

You can purchase nematodes as biopesticides and apply them using micro-irrigation.

Frequently Asked Questions

Wrap Up

The Diaprepes root weevils are a major threat to your ornamental and citrus tree plantations.

Although these beetles are not harmful and poisonous, it is best to keep them away from your yard, as they will end up killing most of the plants. Use the methods mentioned here to get rid of these insects.

Thank you for reading the article.