Beetles are common insects with four wings. The outer pair of wings are modified into stiff wing covers, protecting the inner wings. Beetles are seen throughout Arizona. You may see them on the ground, flying into your home, climbing on vegetation, plants, or rotting wood.
If you have recently seen a beetle in Arizona that you want to identify, continue reading below to find out more.
The beetles you may encounter in Arizona include:
1. Blue Fungus Beetle
The Blue Fungus Beetle (Cypherotylus californicus) is found throughout Arizona. The eggs hatch during the spring and the beetle pupates in summer. These beetles feed on Cork Fungus which is found growing on trees and logs.
These beetles have blue wing covers with black dots. The wing covers start to turn gray as the beetle ages. They grow to eighteen millimeters in length and can be found in woodlands, gardens, and fields. The larvae feed on wood-destroying fungi, making these useful beetles.
2. Convergent Lady Beetle
The Convergent Lady Beetle (Hippodamia convergens) is the most common lady beetle you will encounter in Arizona. They are a natural enemy of aphids and scales, along with other soft-bodied insects. They feed on pollen and nectar.
They are found in various habitats including forests, agricultural fields, natural parks, and grasslands. These rounded beetles can grow to eight millimeters in length. Females are larger than males.
They have bright red or orange wing covers with twelve black spots on each wing cover. The area behind the head is black with a white border. What helps you identify this lady beetle is the two white converging lines.
Larvae are black with orange spots on the abdomen and just behind the head. The larvae go through four instars (growth stages). As they grow larger they develop more orange spots.
3. Figeater Beetle
Figeater Beetles (Cotinis mutabilis) are also known as green fruit beetles. They belong to the scarab beetle family, feeding mostly on nectar, petals, and pollen. The larvae are known as crawly backs, rolling on their back to push themselves along.
Adults can grow to three centimeters in length. They are green and semi-glossy on their backs with their legs and belly being bright iridescent green. They are active during the day and congregate in breeding grounds, usually under the shade of a tree.
They prefer the fruits and sap from desert trees and cacti. They are commonly encountered in compost piles, organic mulch, and gardens. The larvae feed on decomposing matter found in compost piles, organic mulch, and manure piles.
Adult beetles feed on fruit in orchards and gardens. Their preference is sweet fruits, flowers, sap, and leaves, along with overripe fruits. This beetle is commonly seen in Arizona from June to October.
4. Giant Cactus Longhorn Beetle
The Giant Cactus Longhorn Beetle (Moneilema gigas) is native to the Sonoran Desert. This beetle’s front wings are fused to form a single hard shell. Their diet comprises prickly pear cacti and chollas.
The larvae work their way into cactus stems and rooms, killing susceptible plants. Adults feed on the surface of the cacti and are active from the middle of summer to late summer. They are mostly seen during the summer monsoon season.
This is a flightless beetle with a rounded thorax and abdomen. They mimic the noxious stink beetles.
5. Eleodes obscura
This beetle belongs to the darkling beetle species and is a common sight in Arizona. This dull black beetle can grow to three centimeters in length. The wing covers are grooved.
Their front femurs have an anterior tooth close to the tibia. They feed on dead plant matter, decaying animal remains, seeds, and roots.
6. Palo Verde Root Borer
The Palo Verde Root Borer (Derobrachus hovorei) was confused with the related species Derobrachus germinates for more than one hundred years. It was only given its name in 2007. This longhorn beetle is a common sight in Arizona and is one of the largest beetles in North America, growing to almost nine centimeters in length.
Adult beetles are brown to black with long antennae. There are visible spines on the thorax. They can fly but not very well. They tend to look awkward in flight. Adult beetles are seen during the summer months.
The adults do not eat, using their energy reserves until death, which is around one month. They are not harmful but they will give a painful bite if they feel threatened. Grubs live underground after hatching for up to three years. Grubs are often uncovered by gardeners.
The light green or cream larvae have brown heads, feeding on tree roots. They cause the branches to die. Their preference is the Palo Verde tree.
7. Western Red-bellied Tiger Beetle
The Western Red-bellied Tiger Beetle (Cicindela sedecimpunctata) grows to eleven millimeters in length. They are variable and can range from dark brown to light brown with cream-white wing covers.
You can encounter this beetle in sandy areas close to ponds, streams, springs, and lakes from May to August.
8. Glorious Jewel Scarab
The Glorious Jewel Beetle, also known as the Glorious Scarab (Chrysina gloriosa), can grow to two centimeters in length. These beetles are bright green with silver stripes on the wing covers. Adult beetles feed on juniper leaves, camouflaging themselves into the plants.
You are likely to see this beetle feeding on juniper foliage from June to August in Arizona. The larvae are abundant in decaying sycamore logs in southeastern Arizona.
9. Master Blister Beetle
The Master Blister Beetle (Lytta magister) is common from February to October. These beetles grow to just over three centimeters in length. They have red heads, legs, and prothorax. The wing covers are black.
They are seen in swarms with females laying eggs in desert soil. Larvae are insectivorous and are known to attack bee nests.
10. Armored Stink Beetle
The Armored Stink Beetle (Eleodes armata) is a desert stink beetle found in arid environments. This beetle can grow to just over three centimeters in length and is active throughout the year.
This beetle can be seen during the night in the warm summer months and during the day in the cooler winter months. These are large black beetles with a smooth sheen. Wings are elongated and often mistaken as a tail. The wing covers are fused, which means they cannot fly.
To defend themselves, they stand on their heads and omit a foul odor. Larger beetles can spray the foul odor up to fifty centimeters.
11. Beyer’s Jewel Scarab
This (Chrysina beyeri) is a Leaf Chafer Beetle that feeds on flowers and leaves, while larvae feed on compost, roots, and decaying wood. This is a green beetle with iridescent blue-purple legs.
They can grow to just over three centimeters as adults. They can be found in pine-oak, juniper, and pine forests.
12. Grant’s Hercules Beetle
The Grant’s Hercules Beetle (Dynastes grantii) belongs to the rhinoceros beetle family and is common in Arizona. It is identified by its large size and gray-white wing covers. Adult beetles can grow to six centimeters in length.
The white-gray wing covers have irregular black spots that vary in size and number. When the humidity is high, the wing covers often appear black. Females lack horns. They feed on ash trees, stripping the bark from the tree and feeding on the sap.
13. Iron Cross Blister Beetle
The Iron Cross Blister Beetle (Tegrodera aloga) can be found throughout Arizona. It has a distinctive identifying feature, a black cross on the wing covers. These beetles can grow to two centimeters in length.
They have narrow cylindrical shaped bodies with wide heads. The body is black with yellow and red spots. The spots warn predators that the beetle has cantharidin toxins. They are often seen in large groups.
Their activity times vary with some individuals being active at night and others during the day. Adults are brightly colored and gregarious. They prefer the Palo Verde tree, laying their eggs at the base of flower buds.
Larvae climb onto the backs of bees visiting the flowers. They are then taken back to the nest. Larvae eat the bee larvae, along with any provisions. The adult beetles emerge in the spring.
14. Seven-spotted Lady Beetle
The Seven-spotted Lady Beetle (Coccinella septempunctata) is a common ladybird in Arizona. They have red wing covers with three black spots on each wing cover. There is a black spot that spreads over the junction.
Larvae and adult beetles feed on aphids, along with the larvae and eggs of other beetles and butterflies. They have two generations a year with adults spending their winters in the ground litter of gardens, forest edges, and parks.
As adults, they grow to just over one centimeter in length. Their bright red coloration warns predators of their toxicity. They secrete fluid from their leg joints, which gives them a foul taste. They play dead and secrete an unappetizing substance to protect themselves against predators.
They have been introduced into North America as a biological control for aphids. They were successfully introduced in 1973 and have spread throughout the country. They out-compete native species.
15. Sunburst Diving Beetle
The Sunburst Diving Beetle (Thermonectus marmoratus) is a colorful diving beetle that dives into the water. They are brightly colored and grow to 1.5 centimeters in body length. Females are larger than males.
These are black beetles with bright golden or yellow spots. They are scavengers and predators of aquatic insects and snails. They are also known to prey on tadpoles and young fish.
These beetles are excellent swimmers spending their lives in the water. They use their hind legs to help them propel themselves through the water. An air bubble is stored beneath the wings, which enables the beetle to remain under the water for extended periods.
They can be seen in slow-moving freshwater habitats, including shallow creeks and pools. If the water dries up, they fly to find a new freshwater habitat. Their yellow spots warn predators of the foul chemical that they excrete when they feel threatened.
16. Western Rhinoceros Beetle
The Western Rhinoceros Beetle (Xyloryctes thestalus) has a long black horn that protrudes from the head. The horn is used to keep males away from a female. Females lack the horn.
They have a large, rounded pronotum with ridges on the black wing covers. Their legs have red hairs. They are harmless to humans and are not known to bite. As adults, they feed on dead roots. The larvae feed on decaying plant matter found on the forest floor.
17. Ashy Gray Lady Beetle
The Ashy Gray Lady Beetle (Olla v-nigrum) is gray or pale tan and has small black spots on the thorax and wing covers. There is a variation that is black with two red spots on the wing covers and white on the edge of the prothorax.
This lady beetle can grow to six millimeters in length and is a common visitor to gardens in Arizona.
18. Ten-lined June Beetle
Ten-lined June beetles (Polyphylla decemlineata) are also known as watermelon beetles. They are scarab beetles that are attracted to artificial lights at night. Their diet comprises foliage. They will make a hissing sound if disturbed or touched.
This beetle can grow to three centimeters in length. The males have large antennae, which are closed when they feel threatened. Wing covers have four long white stripes and the belly is covered in brown hairs.
Their brown bodies are covered with white and yellow scales. Larvae live in the soil and adults are often seen from June to August in Arizona.
19. LeConte’s Chrysina
This beetle (Chrysina lecontei) belongs to the shining leaf chafer family. This beetle does not have horns. As adults, they feed on flowers and leaves, while the larvae feed on compost, roots, and decaying wood.
Adults can grow to three centimeters in length. They are popular with collectors due to their bright green color.
20. Bloody Net-winged Beetle
The Bloody Net-winged Beetle (Lycus sanguineus) is common in Arizona. This is an elongated beetle found on flowers or plant stems. Females are larger than males with males growing to one centimeter in length.
This beetle has a triangular-shaped head with long antennae. They are brick-red and are toxic to predators. The larvae grow under leaf litter or bark.
21. Pigweed Flea Beetle
Pigweed Flea Beetles (Disonycha glabrata) grow to 6.5 millimeters in length. They are elongated with a black and yellow head and a yellow pronotum with up to three spots in the center.
They have yellow wing covers with three wide stripes on each wing cover. The marginal edge of the wing covers is black. They are commonly seen from May to September. Their diet mainly comprises pigweed. They are not a significant pest to backyard gardens.
22. Checkered Melon Beetle
The Checkered Melon Beetle (Paranapiacaba tricincta) is a skeletonizing leaf beetle, also known as a flea beetle. They are small jumping beetles that belong to the leaf beetle family.
They have enlarged hind femora, which allows them to jump when disturbed. They are dark, shiny beetles with metallic tinges. They feed on plants, eating the leaf surface, petals, and stems.
They are known to hide in the soil during adverse weather conditions. They only leave their hideout in warm or dry weather. They are considered pests for agricultural crops, including mustard and rapeseed. They carry out severe attacks during warm and dry weather.
23. Spotted Pine Sawyer
The Spotted Pine Sawyer (Monochamus clamator) is a large beetle that is brown-gray to black with white markings. They grow to twenty-four millimeters in length and can have various markings.
Some are mostly gray-white, whereas others are brown with light markings on the body. The majority of this beetle are gray to black with a white spot in the middle of the body, just at the base of the wing covers. The wing covers often have no markings.
Larvae bore into sapwood and heartwood of recently killed or dying tries. The larvae are elongated with brown heads.
24. Spotted Cucumber Beetle
The Spotted Cucumber Beetle (Diabrotica undecimpunctata), also known as the southern corn rootworm, is native to North America. It is a significant agricultural pest causing damage to crops. As larvae, they feed on the roots of emerging plants and as adults, they cause damage by eating the fruits, stems, leaves, and flowers of plants. They also spread disease.
Adult beetles lay eggs in the soil close to cucumber plants. Eggs hatch in spring and the larvae start to feed on the roots of the emerging plants. Larvae are yellow and similar to worms.
After pupation, the adults emerge. They are green-yellow with six black spots on the wing covers. Adult beetles grow to half a centimeter in length.
25. White-striped Tiger Beetle
White-striped Tiger Beetles (Jundlandia lemniscata) are flashy tiger beetles common in Arizona. They have bulging eyes with long legs. They are predators in adult and larval forms. They are large and bright.
Larvae live in burrows that can be more than one meter in depth. The larvae have large heads with hump-backs. As adults, they are fast-moving. They are fast in flight and when running on the ground.
They are commonly found on woodland paths, on sandy surfaces, and on clay banks. Adults grow to nine millimeters in length. They are brown with a prominent marginal stripe on both sides of the wing covers.
26. Lewis’ Soldier Beetle
The Lewis’ Soldier Beetle (Chauliognathus lewisi) is found in North America. It is a soft-bodied beetle with a red coat, similar to early British soldiers. They are often referred to as leatherwings.
This beetle feeds on pollen and nectar. The larvae are active and brightly colored, feeding on snails and other small creatures. As adults, they are long and black to dark brown with yellow, orange, or red patches. The head bends in a downward direction.
They have smooth wing covers with a velvet appearance. Adults can grow to twenty-eight millimeters. Larvae are cylindrical with rounded segments. The larvae are dark brown or dark yellow and can grow to eighteen millimeters in length.
27. Aloeus Ox Beetle
This beetle (Strategus aloeus) belongs to the rhinoceros beetle family and is native to North America. This species has three large horns. Females have short horns, which they use to dig in the ground.
This beetle can grow to just shy of four centimeters in length.
28. California Root Borer Beetle
The California Root Borer Beetle (Prionus californicus) is considered a pest of vine crops and orchards. They grow to just shy of six centimeters in length. The adults are red-brown with smooth wing covers.
Females are larger than males. As adults, they do not feed. They are nocturnal with the males being more active than the females. Adult beetles live for around twenty days. Females produce up to two hundred eggs, which are placed below the soil surface, and close to the roots of host plants.
The brown to cream larvae are segmented and search for roots after hatching. They burrow tunnels through the roots, consuming the tissues. The larvae move from small-diameter to large-diameter roots as they grow.
29. Ornate Checkered Beetle
The Ornate Checkered Beetle (Trichodes ornatus) is only found in North America. The larvae live in bee nests and are parasitic. The larvae feed on bee larvae and pollen. Adults feed on milkweed, yarrow, and other plants that are yellow.
Adult females grow to fifteen millimeters with males being smaller, growing to eleven millimeters. These beetles can be red and black or yellow and black with intricate patterns.
30. Carrot Beetle
The Carrot Beetle (Ligyrus gibbosus) belongs to the rhinoceros beetle family. These are one of the largest beetles you will find in Arizona growing to fifteen centimeters in length. They are harmless and do not bite or sting.
This beetle has a horn on its head that points forward from the thorax. The horns are used for fighting in males and digging in females. They have a thick exoskeleton with thick wings. They can fly but not efficiently.
This is a nocturnal beetle that hides under logs during the day. They produce a hiss if they feel threatened. The larval stage can be several years. Larvae feed on rotten wood, while adults feed on nectar, fruit, and plant sap.
31. Arizona Net-winged Beetle
The Arizona Net-winged Beetle (Lycus arizonensis) is amber with black-tipped wing covers. Females are slightly larger than males. This elongated beetle is often seen on flowers and flower stems.
Males can grow to fifteen millimeters in length with females being larger. They have triangular-shaped heads with long, thick antennae. They are brick-red, which announces that they are toxic to predators.