Clavate Tortoise Beetle: Essential Facts Uncovered

The Clavate Tortoise Beetle (Plagiometriona clavata) is a fascinating small insect with unique features. Found in North America, these beetles captivate observers with their vibrant colors, which range from brilliant brassy green to golden brown. The peculiar dome-shaped body, resembling a miniature turtle’s shell, further adds to their allure.

One fascinating characteristic of these beetles is their textured surface. They have a rough and tuberculate skin, setting them apart from other species in the subfamily Cassidinae. They mainly feed on plants from the Convolvulaceae family, such as morning glories and bindweeds, but can also be found munching on plants from the Solanaceae family, like tomatoes, beans, and peppers.

Clavate Tortoise Beetle Classification

Order Coleoptera

Clavate Tortoise Beetles, scientifically named as Plagiometriona clavata, belong to the Order Coleoptera. Coleoptera, known as beetles, comprises a diverse group of insects that currently includes over 350,000 described species worldwide.

Some features of beetles include:

  • Hardened wing covers, known as elytra
  • Chewing mouthparts
  • Well-developed hind wings for flight

Suborder Polyphaga

Within Coleoptera, Clavate Tortoise Beetles are classified under the Suborder Polyphaga. Polyphaga represents the largest and most diverse group of beetles, accounting for almost 90% of the described species within Coleoptera.

Superfamily Chrysomeloidea

Clavate Tortoise Beetles are part of the Superfamily Chrysomeloidea. This superfamily includes mainly leaf beetles and long-horned beetles known for their vibrant colors and patterns.

Family Chrysomelidae

Chrysomelidae, or leaf beetles, is the family in which Clavate Tortoise Beetles belong. With over 35,000 species, this family is known for:

  • Feeding on leaves, stems, and flowers of plants
  • Usually being small to medium-sized beetles

Subfamily Cassidinae

The Clavate Tortoise Beetle is a member of the Subfamily Cassidinae, also known as tortoise beetles. Key characteristics of this subfamily are:

  • Broad, flat bodies with a tortoise-like appearance
  • A unique “fecal fork” feature in their larvae

Genus Helocassis

Lastly, Clavate Tortoise Beetle falls under the Genus Helocassis. Synonyms for Plagiometriona clavata include:

  • Cassida clavata
  • Coptocycla clavata
  • Deloyala clavata
  • Helocassis clavata

Comparison Table

Feature Beetles (Order Coleoptera) Clavate Tortoise Beetle (Subfamily Cassidinae)
Appearance Hardened wing covers (elytra), diverse shapes and sizes Broad, flat body resembling a tortoise shell
Diet Varies greatly (plant, fungi or animal matter) Primarily plant feeders (leaves, stems, flowers)
Size Ranges widely from less than 1mm to over 100mm Generally small to medium-sized beetles
Diversity Over 350,000 described species worldwide Over 3,000 species within Cassidinae

The classification helps us understand how Clavate Tortoise Beetle is related to the broader group of beetles by examining its unique characteristics and features at each taxonomic level. By looking into its classification, we can better appreciate how this small, distinct beetle fits within the diverse and fascinating world of insects.

Physical Description

Size

The Clavate Tortoise Beetle is a small insect, typically measuring around 6-8 mm in length.

Some key features include:

  • Petite stature
  • Compact body shape

Color

These beetles display a translucent greenish-yellow color, often with a mottled pattern on their elytra.

Pronotum

The pronotum (the plate-like structure covering the thorax) is:

  • Broad
  • Convex
  • Heavily sculptured

Elytra

Elytra are the hardened forewings that protect the beetle’s hindwings and abdomen. In Clavate Tortoise Beetles, the elytra are:

  • Dome-shaped
  • Translucent
  • Patterned with irregular spots and markings

Hindwing

The hindwings of the Clavate Tortoise Beetle are:

  • Membranous
  • Folded beneath the elytra when at rest

These wings facilitate flight, allowing the beetle to easily move between host plants.

Abdomen

The abdomen of the Clavate Tortoise Beetle is:

  • Enclosed by expansions of the pronotum and elytra
  • Well-protected from predators
Feature Description
Size 6-8 mm in length
Color Translucent greenish-yellow
Pronotum Broad, convex, heavily sculptured
Elytra Dome-shaped, translucent, patterned
Hindwing Membranous, folded beneath elytra
Abdomen Enclosed and well-protected

Distribution and Habitat

North America

Clavate Tortoise Beetles can be found in various parts of North America, including the United States and Mexico.

Florida

In Florida, these beetles are particularly common, thriving in warm and humid environments.

Range

The range of the Clavate Tortoise Beetle extends through the southern United States, and down into Mexico, adapting to different habitats across this region.

Host Plants

  • Morning glory: A favorite food source for Clavate Tortoise Beetles, as they feed on the leaves.
  • Sweet potato: Another preferred plant, beetles consume the plant’s foliage, potentially causing damage.

Overall, considering the vast distribution and various host plants included, it’s clear that the Clavate Tortoise Beetle is a versatile and adaptable insect.

Biology and Ecology

Life Cycle

The life cycle of the Clavate Tortoise Beetle includes four stages: egg, larva, pupa, and adult. They typically prefer plants from the family Solanaceae as hosts1.

Larva

Larvae of the Clavate Tortoise Beetle have a unique appearance, with their head to the right and an anal fork with feces held above the larva2.

Pupa

In the pupa stage, the beetle undergoes a significant transformation as it develops into its adult form. This stage occurs within the host plant’s leaves.

Fecal Fork

Larvae use a fecal fork, a structure at their rear, to carry their fecal matter. This acts as a form of camouflage and protection from predators2.

Camouflage

Clavate Tortoise Beetles exhibit remarkable camouflage in both larval and adult stages. Adults display brilliant brassy green, golden, and brown colors, which help them blend with their surroundings1.

Behavior

These beetles are known for their secretive behavior, spending most of their time within the host plant, making them difficult to spot.

Season

The seasonal occurrence of Clavate Tortoise Beetles is not entirely understood. However, they generally depend on the availability of suitable host plants on which they can feed and lay their eggs.

Diet and Host Plants

Leaf

Clavate tortoise beetles feed on leaves of plants, particularly those in the nightshade family (Solanaceae) 1. They consume the leaf tissue, leaving behind characteristic holes or skeletonized veins.

Nightshade Family

The nightshade family of plants, Solanaceae, is a favorite host for the clavate tortoise beetle. A few of these plants include:

  • Potato leaves
  • Eggplant
  • Jimsonweed

Food

These beetles’ diet consists largely of foliage from the nightshade family of plants, which provide nourishment for both adults and larvae.

Potato Leaves

Clavate tortoise beetles are known to feed on potato leaves, potentially causing adverse effects on potato crops. Potato leaves are one of the more common host plants for these beetles in North American gardens.

Eggplant

Eggplants, another nightshade plant, also serve as a source of food for the clavate tortoise beetle. This can result in damaged eggplant plants in gardens and farms.

Jimsonweed

Jimsonweed is an additional host plant for these beetles in the Solanaceae family. Similar to potato leaves and eggplants, the beetles will feed on this plant’s foliage, causing potential harm.

Comparison of Host Plants:

Host Plant Nightshade Family Potential Damage
Potato Leaves Yes Moderate-high
Eggplant Yes Moderate
Jimsonweed Yes Moderate-low

In conclusion, the clavate tortoise beetle mainly feeds on plants in the nightshade family, such as potato leaves, eggplant, and jimsonweed. Their consumption of these plants can cause varying levels of damage to the plants, making them a potential concern for gardeners and farmers.

Interactions with Humans

Entomology Studies

The Clavate Tortoise Beetle is an insect that interests many entomologists due to its unique appearance and characteristics. Researchers study this beetle for:

  • Coloration: Its brilliant brassy green, golden, and brown colors
  • Shape: Dome-shaped with a conical peak near the middle

Insecta Collection

Insect collectors often include the Clavate Tortoise Beetle in their Insecta collections due to its visually appealing nature and intriguing features such as:

  • Length: 6.5 to 7.5 mm
  • Width: 5.5 to 6.3 mm
  • Markings: Dark markings seen in dead specimens
Feature Clavate Tortoise Beetle Comparison Insect
Size 6.5-7.5 mm (length)
5.5-6.3 mm (width)
Color Brassy green, gold, brown
Shape Dome-shaped

Note: The comparison insect has not been provided; please fill in the information accordingly.

Footnotes

  1. Clavate Tortoise Beetle – Plagiometriona Clavata 2 3

  2. Clavate Tortoise Beetle 2

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Clavate Tortoise Beetle

 

Subject: Odd leaf-eating bug in Maine
Location: Coastal Maine, USA
June 17, 2012 9:26 pm
I found this creature yesterday on a leaf. It’s smaller than a dime. Can you tell me what it is?
Thank you!
Signature: Zach

Clavate Tortoise Beetle

Hi Zach,
This is a Clavate Tortoise Beetle.  Since they feed on the leaves of tomato plants and related plants in the family, including peppers, eggplant and other cultivated plants, Clavate Tortoise Beetles attract more attention than the average Leaf Beetle.

Letter 2 – Clavate Tortoise Beetle

 

Quarter inch diameter wierd bug
July 21, 2009
Hi,
The first time i saw one of these, i just thought it was a strange growth on the leaf. They always seem to be on tomato plants. I was looking closely at this one, and after touching it a few times, it moved. I touched it again and it flew to another plant. I went and got my camera and got this picture. The clear like ring around it is actually the wings, or wing covers, i’m not sure. The antennai are facing down in the picture.
packrat
central Pennsylvania

Clavate Tortoise Beetle
Clavate Tortoise Beetle

Dear packrat,
This is a Clavate Tortoise Beetle, Plagiometriona clavata.  We also just posted a photo of the larva which is a spiny green creature that never completely sheds its exoskeleton.  The dried remnants of the cast of skin stay attached to the spiny larva.  The Tortoise Beetles are a tribe of the Leaf Beetle family Chrysomelidae.  Beetles are characterized as having two different sets of wings.  The outer wings are usually hardened and are termed the elytra.  The soft flying wings are protected under the elytra and only exposed during flight.  The elytra on the Clavate Tortoise Beetle which forms a carapace does contain clear areas and BugGuide describes the markings as:  “most noticeable feature in adult, covering much of the carapace, is a dark brown irregular patch shaped like a teddy bear, with the front and back “legs” of the “bear” extending to the outer margins of the elytra, and the “head” of the “bear” extending onto the pronotum.

Letter 3 – Clavate Tortoise Beetle

 

Very interesting bug I found
May 27, 2010
Hi there. I am writing from Oswego, NY which is straight north of Syracuse, NY on Lake Ontario. I am often outside taking pictures of various bugs, plants, flowers and anything cool I can find in the swamps and woods. Most of what I find is rather common….Until I found this little guy. It was about a cm wide. It has clear panels all around its shell. It has a hard shell and which is split down the middle and opens up like a beetle and has wings underneath. It also has small little antennas. So I definitely think it’s a type of beetle but no one I know has any idea what it is or has seen anything like it.
My mom often writes into your site and mentioned that I should show you the pictures. She is in the woods all the time as she does wild edible and Mycology walks and this one was new to her also. Curious to know if anyone has an idea what this cool little guy is. My mom mentioned it could be perhaps a young beetle of some type, not fully grown yet, as they can often look so different between growing stages.
Thanks so much for any information.
TJ
Oswego, New York

Clavate Tortoise Beetle

Dear TJ,
It truly warms our heart to hear that What’s That Bug? is bringing family generations together through an understanding of the natural sciences.  This is a Clavate Tortoise Beetle, Plagiometriona clavata, a species that is found over much of North America.  Both adults and the green spiny larvae feed on solanaceous plants in the tomato family, including jimsonweed and nightshade.

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