Bug of the Day

Syrphid Flies

Donna Ellis, UConn, Department of Plant Science and Landscape Architecture, 2017.

Syrphid flies are also known as hover flies or flower flies. These tiny beneficial insects are members of the insect order Diptera, which includes flies, mosquitoes, and gnats. They adults vary in size, but the common ones we often see in our area are less than ¼ inch in length. Syrphid flies have 2 wings and are sometimes mistaken for small bees due to similar markings on their abdomen, but they are flies and do not bite or sting. Syrphid flies are amazing pollinators, feeding on pollen and nectar from many annuals and perennials during the summer months. These beneficials are called hover flies because they can actually hover over plants while flying.

Syrphid flies go through complete metamorphosis, from egg to larva (the larva are technically called maggots because they are flies), on to a pupal stage, and finally to adult. As an immature larva, they can feed on many soft-bodied plant pests, such as aphids, eggs, scales, caterpillars, and leafhoppers. The larvae can be found in many colors, including green, brown, yellow, or off-white. To find their prey, larvae move their legless bodies around on plants and swing their heads until they bump into their next meal. Despite their small size, a syrphid fly larva can feed on hundreds of insects before it develops into an adult. The adults only feed on pollen and nectar. There can be a number of generations of these helpful insects during the summer months. Look for them on the flowers in your garden!

syrphid fly adult
A syrphid fly adult, also called a hover fly. These
beneficial insects are often found hovering over flowers.
Photo by Donna Ellis, UConn.
syrphid fly larva
A syrphid fly larva, or maggot.
Photo by David Cappaert, Michigan State University, Bugwood.org.
syrphid fly on flower
If you look carefully near the center of the flower,
you will see a tiny adult syrphid fly.
Photo by Donna Ellis, UConn.

References

Gardiner, M.M. 2004. Good Garden Bugs. Everything You Need to Know About Beneficial Predatory Insects. Quarry Books, Beverly, MA. 176 pp.

Walliser, J. 2014. Attracting Beneficial Bugs to Your Garden. Timber Press, Portland, OR. 240 pp.

Spittlebug: A Unique Little Insect

Spittlebug: A Unique Little Insect

By Joan Allen

spittlebug foam
Spittlebug Foam. Photo credit: Gerald J. Lenhard, Louisiana State University, Bugwood.org

Spittlebugs are common and easily recognized by the white foamy ‘spittle’ produced by the nymph or immature stage of the insects as they feed. Adults are less commonly seen but are commonly known as froghoppers (close relatives of leafhoppers, etc). Depending on the reference, there are anywhere from 30 to 60+ spittlebug species in the United States. All feed on plants, including both woody and herbaceous types. Some spittlebugs have broad host ranges and others narrow.

There is usually only one generation per year and most overwinter in the egg stage inside overwintering plant tissue where they were deposited by the females in from mid to late summer to early fall, depending on species. Hatch occurs in the spring, probably in May in Connecticut. Even though spittlebugs feed by extracting plant sap/juice through needle-like mouth parts, they seldom cause notable injury to the plant. There are a few exceptions including the meadow spittlebug (Philaenus spumarius) and the pine spittlebug (Aphrophora cribata).

The meadow spittlebug has a broad host range that includes both herbaceous and woody plants. It is reported to cause damage in clover, strawberry, mint, herbaceous ornamentals and both coniferous and broad-leaved woody plants when present in high numbers. Other common names include the common froghopper and the cuckoo spit (most common name in the UK). Eggs are laid in the stems or crevices of host plants in the fall. When they hatch in the spring, nymphs usually feed on the plant the eggs were laid on but they will move to younger more tender tissues as the plant grows. There are five nymph stages and all produce spittle as they feed.   Once the adult stage is reached, spittle is no longer produced and the adult is quite mobile, quickly jumping a long distance relative to its size when disturbed.

The froghoppers or adult stage are so-called because their bodies are somewhat wider at the rear like a frog. The name

Spittlebug nymph
Spittlebug nymph. Photo credit: David Cappaert, Bugwood.org

cuckoo spit may have come about because the spittle tends to be first seen in the spring around the same time that the first calls of the cuckoo bird are heard. Most adults are brown to green in color with only subtle markings but some species have striking coloration or patterns. The meadow spittlebug adult is quite variable in coloration.

So, about the spittle. The spittle offers some clear benefits to the nymph(s) hiding within. First, it helps prevent the soft-bodied little guys from drying out. In addition, it protects them from detection by potential parasites and predators. A single mass of spittle may be inhabited by multiple nymphs feeding in the same area on the plant. How is the spittle produced? First, the spittlebug ingests more plant sap than it needs for its nutrition/sustenance. The excess is expelled through the anus as a watery waste product. It mixes with a mucilaginous fluid produced by glands on the abdomen and air bubbles are introduced from a special canal by abdominal contractions. This is pretty interesting stuff going on in gardens, forests and meadows all around us each spring and early summer!

If you would like to get a closer look at a nymph, don’t be afraid to brush the foam carefully away from a plant and look for them inside. They will be up to ¼” long depending on their stage of development and may be yellowish, greenish or brown in color. They are elongated and generally are positioned head down. This facilitates the movement of the spittle downward to cover them. Nymphs are shy and will not be happy to be exposed. They will attempt to walk away but cannot run or fly.

Adult meadow spittlebug
Adult meadow spittlebug. Photo credit: Cheryl Moorehead, Bugwood.org

The biggest problem with spittlebugs in the garden, whether it’s an ornamental or food garden, is the unsightliness of the spittle masses. Spittle and nymphs can both be washed off the plants with a steady stream of water. On a small scale, they can be hand-removed and disposed of. Normally, no chemical controls are recommended and the spittle protects nymphs from contact insecticides. Not sure if there are enough spittlebugs to cause plants to be weakened? Look for distorted or stunted new growth, and of course numerous spittle masses on the same plant.

Lacewings

By: Donna Ellis, UConn, Department of Plant Science and Landscape Architecture, 2016.

Lacewing adult
Lacewing adult. Source: Frank Peairs (Bugwood).

Lacewings are beneficial insects that love to eat aphids, thrips, beetles, small caterpillars, and soft scales. They play an integral role in agricultural pest control, from small backyard gardens to extensive farms. Lacewings are part of the insect order Neuroptera. All immature insects in this order are predators of other insects. Lacewing adults are 8 to 25 mm long, have delicate clear wings with many veins, and at rest they hold their wings over their body. Most lacewing adults feed only on pollen, nectar, and honeydew, but one type of green lacewing will feed on small insects as an adult. There are many different types of lacewings, separated into two larger groups of green and brown lacewings.

One of the most fascinating facts about green lacewings is that

Green lacewing larvae
Green lacewing larvae. Source: Bradley Higbee (Bugwood).

females lay their eggs on ½-inch stalks, either individually or in groups. The stalks may help protect one newly-hatched larva from being eaten by another and also reduces the risk that the eggs or developing larvae may be parasitized. Lacewing larvae, the immature stage of the insect, have a pair of strong jaws to capture and feed on their prey. The larvae impale the prey with their muscular jaws and lift it high in the air. Lacewing larvae are brown in color and are sometimes described as resembling tiny alligators. Another name for a green lacewing larva is an ant lion. These insects undergo complete metamorphosis. The larvae spin silken cocoons around plant stems or leaves during the pupal stage. Adults or pre-pupae overwinter depending on the species, with most species overwintering in cocoons and adults emerging in the spring. There may be multiple generations per year.

Lacewing egg on a stalk
Lacewing egg on a stalk. Source: David Cappaert (Bugwood).

Did you know that lacewings have well-developed hearing? They can detect predators such as bats from great distances, and they will quickly drop to the ground to avoid being eaten. These beneficial insects also use their bodies to make vibrations and attract mates of the same species.

 

References

Cranshaw, W. 2004. Garden Insects of North America. Princeton University Press, Princeton, N.J. 656 pp.

Gardiner, M.M. 2015. Good Garden Bugs. Quarry Books, Beverly, MA. 176 pp.

Pfeiffer, D.G. and H.W. Hogmire. Lacewings. Mid-Atlantic Orchard Monitoring Guide, http://www.virginiafruit.ento.vt.edu/lacewings.html.

Pundt, L. 2014. Biological Control of Aphids. UConn Integrated Pest Management (IPM) website http://ipm.uconn.edu/documents/raw2/html/734.php?display=print.

The Monarch Butterfly

By: Ana Legrand, Department of Plant Science and Landscape Architecture, 2015.

Monarch on purple cone flower
Monarch on purple cone flower. Photo: Steven Katovich, USDA Forest Service

The monarch butterfly holds the record for the longest regularly repeated migration. A delicate butterfly that is able to travel between 1,200 and 2,980 miles to journey between three countries – Mexico, United States and Canada. But more on these amazing travels later. Monarchs (a.k.a Danaus plexippus for their scientific name) are bright orange butterflies with white dots on their black wing borders. They also have well-defined black veins on the wings. One can distinguish male from female butterflies by looking at the hindwings. Males have a dark spot on the hindwings while females do not.

This insect has been the inspiration of many stories and has become the symbol for many civic organizations. Its development is representative of an amazing transformation going from a single egg to a larval or caterpillar stage then to a pupa stage and finally to the adult butterfly form. Monarch caterpillars use milkweeds as their food plants. If their life cycle is intriguing then their manner of escaping harsh winter conditions is awe-inspiring. In late summer we may encounter these butterflies in what may appear a casual flight around our surroundings. However, they are engaged in a determined journey to some of the tallest mountain peaks in Mexico. In these mountains, monarchs find shelter in dense fir dominant forests. In Mexico, the fir forests are known as the ‘oyamel’ forests. Monarchs begin their voyage in summer breeding grounds in Canada and United States and fly south to avoid our harsh winters. We might take for granted our knowledge of the eastern monarch’s migration but it took a 38-year search by Frederick and Norah Urquhart to find out where the monarchs of eastern North America overwintered. The oyamel forests are found at elevations from about 9,800 to 11,000 feet above sea level on nine mountains west of Mexico City. There the butterflies form huge aggregations on oyamel firs and cypresses found also in the region. To make it through a journey of 2,980 miles, butterflies build up large quantities of body fat (yes, they too deal with that). Those that leave Canada with poor body fat reserves are less likely to reach Mexico. During their trip they stop to take nectar and in Texas and northern Mexico they really load up to make sure that their body fat reserves are good for their overwintering stay. The oyamel forests do not provide sufficient food for the millions of butterflies that assemble there.

Monarch caterpillar
Monarch caterpillar. Photo: Bruce Watt, Bugwood.org

Higher air temperatures and longer days during January and early February signal to the monarchs that it is time to leave their oyamel forests. Mating begins in January but it really peaks up during March. The butterflies that overwintered in the oyamel forests are known as the Methuselah generation because the adults survive 7-8 months. The offspring of these monarchs will not be so long-lived but survive around 4-5 weeks sufficient to leave new offspring as they keep on their journey northwards. Eventually, the great-great-great-grandchildren of the monarchs that traveled from Canada to Mexico are the ones that reach their northernmost breeding grounds during summer.

Unfortunately, these butterflies that have been able to survive such long journeys between Canada, United States and Mexico might not survive our encroachment on their habitat. Western populations of monarchs that overwinter in California face destruction of their overwintering sites as coastal land is developed. Eastern monarchs suffer increased mortality due to the loss of dense oyamel forests that provide critical microclimate protection. Other threats are loss of milkweeds for the caterpillars and impacts from climate change. In January 2015 the World Wildlife Fund in Mexico reported that the size of the 2014-2015 overwintering population was the second smallest since monitoring began in 1994. To learn more about the monarchs check out the following websites:

http://www.xerces.org/monarchs/

http://www.monarchwatch.org/

Papalotzin – documentary clip

https://www.youtube.com/watch?v=APyvV6S2p10

Monarch caterpillar feeding and pupating video

http://video.bugwood.org/browse/detail.cfm?vidnum=00000355

Acorn Weevil

Acorn weevil (Curculio sp.)

By: Joan Allen, UConn Department of Plant Science and Landscape Architecture, 2015

Jon Aspinwall photo
Adult Acorn weevil. Photo: Jon Aspinwall.

The acorn weevil is not often seen but is impressive to look at because of its long snout. The chewing mouthparts are at the end of the snout, so this long ‘beak’ does not make it difficult to feed on leaves.

Eggs are laid in green acorns on trees. Larvae feed inside and emerge after the acorns fall to the ground. They burrow into the ground where they remain for 1-3 years until they become adults, completing the life cycle. The video at the National Geographic link is great for a close-up view of adult egg-laying preparation, larval emergence, and, unfortunately, a sad ending.

Acorn weevil video.

Acorn weevil life cycle and info.

 

 

 

 

Acornweevillarva.bugwood
Acorn weevil larva. Photo Steven Katovich, USDA Forest Service, Bugwood.org

Aphids

By: Joan Allen, UConn Department of Plant Science and Landscape Architecture, 2015

15-151aphid-JAllen
Photo: Joan Allen. Notice you can see the cornices (tubes on the abdomen)

Aphids are tiny, soft-bodies insects with pear-shaped bodies. They have long legs and a pair of tube-like cornicles on the back of their abdomen. They have incomplete metamorphosis which means the newly hatched young gradually molt through several nymph stages until they become adults. Aphids are plant feeders and they suck plant juices through straw-like mouth parts. There are many species of aphid and some are important plant pests. When present in large numbers they cause plants to yellow, produce stunted or deformed new growth, or even die. In addition, aphids vector some plant viruses. Some aphids produce white waxy filaments that cover their body and give them a cottony appearance. Aphids excrete a liquid high in sugars called honeydew that drips onto leaves and other surfaces. Black fungi called sooty molds grow on the honeydew. Some ants like to eat the honeydew and will even protect the aphids from predators to preserve their food supply. These tiny insects often go unnoticed in low numbers but they have fascinating life cycles.  Many aphids live on a wood plant in winter and migrate to an herbaceous ornamental or vegetable plant for the summer. Some are happy to feed on a variety of plants while others are quite fussy and will only feed and reproduce on one. Aphids grow and multiply rapidly, with the time from hatch to reproducing adult as short as one week under favorable conditions. Check out the links for more info and images.

 

Aphid information great for all ages.

Aphids and ants: a fascinating relationship!

Aphid life cycles and habits.

Aphids feeding
Photo: Joan Allen. Aphids feeding

Lady Beetle

By: Donna Ellis, UConn, Department of Plant Science and Landscape Architecture, 2015.

Lady beetles, also known as ladybird beetles or ladybugs, are members of the insect order Coleoptera, which are insects with sheathed or covered wings. The adults range in length from 1 to 10 mm, typically have round or oval bodies often brightly colored red or orange, and may have spots or other patterns on their wing covers, known as elytra. Lady beetles can be found in many habitats, including back yard landscapes, vegetable gardens and commercial farms, fruit orchards and vineyards, and natural areas, anywhere their food sources are abundant. The adult life stage of these beneficial insects can also feed on pollen, nectar, and honeydew from garden plants.

Most lady beetles are beneficial. They are predators of soft-bodied pests such as aphids and scale insects as well as insect eggs, immature insects, and mites. There are several species of lady beetles that are pests of beans, grains, and squash, however. A number of lady beetles have been used as biological controls for agricultural pests. Vedalia beetles (Rodolia cardinalis), for example, were the first biological control agents released in the US, where they controlled cottony cushion scale in California citrus groves. The twice-stabbed lady beetle (Chilocorus stigma) is a predator of aphids and scale insects in woodlands and orchards. There are native and non-native lady beetle species in the US.

Lady beetles undergo complete metamorphosis, changing from egg to adult in approximately 8 weeks. They overwinter as adults. In the spring, after mating, female lady beetles lay yellow eggs in clusters of 5 to 30, typically on the underside of leaves and often where a food source is abundant. Eggs hatch in about 4 days and the immature lady beetles, called larvae, begin to feed on their prey. Both larvae and adult lady beetles feed on the same types of prey. The larvae do not resemble adults at all, appearing more like tiny alligators with elongated bodies that are segmented, dark in color with yellow, white or red banding or spots, and sometimes with spines. Larvae feed abundantly, with a single larva devouring up to several dozen aphids per day. The larvae molt and pass through four growth stages, or instars, during a three- to four-week period. Larvae then develop into pupae, a transitional stage occurring in 3 to 12 days from which they emerge as adult lady beetles.

Some common lady beetles in Connecticut are the multi-colored Asian lady beetle (Harmonia axyridis), the 7-spotted lady beetle (Coccinella septempunctata), and the spotted lady beetle (Coleomegilla maculata).

Asian lady beetles-Louis Tedders

Louis Tedders, USDA Agricultural Research Service, Bugwood.org

 

Multi-colored Asian lady beetles (Harmonia axyridis)

Spotted lady beetle-Whitney Crapshaw

Whitney Cranshaw, Colorado State University, Bugwood.org

 

Spotted lady beetle and eggs (Coleomegilla maculata)

Lady beeetle larva-Clemson

Clemson University – USDA Cooperative Extension Slide Series, , Bugwood.org

 

Lady beetle larva feeding on aphids

 

References

Cranshaw, W. 2004. Garden Insects of North America. Princeton University Press, Princeton, N.J. 656 pp.

University of Florida Featured Creatures http://entnemdept.ufl.edu/creatures/beneficial/lady_beetles.htm

White, R.E. 1983. Beetles. Peterson Field Guides. Houghton Mifflin Company, NY, NY. 368 pp.

Mantids

By Donna Ellis, UConn, Department of Plant Science and Landscape Architecture, 2015.

The insect that we commonly refer to as a praying mantis is also known as a mantid. Praying mantids earned their nickname because they hold their forelegs bent and raised as if in prayer. These large, beautiful predators belong to the insect order Mantodea. Adult mantids common to our area range in length from 5 to 11 cm and have a distinctive appearance. They capture and feed on prey using large grasping forelegs with spines. Mantids can turn their triangular heads 180 degrees as they search for their next meal. Two large compound eyes and three simple eyes allow them to see up to 20 meters away. They have an elongated thorax, the middle of their 3 body segments, which gives the appearance of a “neck”.

Neither of the two mantids common to the US are native species. The European mantid (Mantis religiosa) is also known as the praying mantid. There are green and brown forms, with green being more common. The drab coloration of these insects helps to protect and camouflage them from predators. The Chinese mantid (Tenodera aridifolia sinensis) is a larger species, brown in color with yellow and green striping found on the sides of the wings. Mantid egg cases sold in garden centers and from online sources are typically from Chinese mantids.

Praying mantids can be found on plants with similar coloration to their bodies and in areas where other insects can be found. Mantids are predators of many types of insects, including flies, moths, grasshoppers, and crickets. They wait quietly, poised and ready until a prospective meal is within reach, then quickly grab the unsuspecting prey with their strong forelegs. This action occurs so fast that it can’t be seen with the naked eye. Mantids will feed on both harmful and beneficial insect species. A female mantid will often eat the male after mating.

The life cycle of mantids is an incomplete metamorphosis that includes eggs, an immature stage (nymphs), and adults. Female mantids lay hundreds of eggs each in papery sacs that they attach to weed or other plant stems. The egg sac is the overwintering life stage for the species, and the reinforced papery material provides protection from the elements during the colder months. When young mantids hatch in spring, these nymphs greatly resemble their adult parents but are much smaller and without wings.

The official state insect of Connecticut is the European or praying mantis, designated in 1977.

Mantis-Allen Bridgman

Allen Bridgman, South Carolina Department of Natural Resources, Bugwood.org

 

Praying mantid

 Mantis egg case-Jim Occi

Jim Occi, BugPics, Bugwood.org

 

Praying mantid egg case

 

References

Borror, D.J. and R.E. White. 1970. Insects. Peterson Field Guides. Houghton Mifflin Company, NY, NY. 404 pp.

Cranshaw, W. 2004. Garden Insects of North America. Princeton University Press, Princeton, N.J. 656 pp.

National Geographic, Praying Mantis, http://animals.nationalgeographic.com/animals/bugs/praying-mantis/