Home Invasion – Asian Lady Beetle or Seven Spotted Lady Beetle

Home Invasion – Asian Lady Beetle or Seven Spotted Lady Beetle

What is taking over my dwelling?

The Multicolored Asian lady beetle (Harmonia axyridis) was introduced from Asia and intentionally and quickly established itself over the entire United States.

A Comparison 

The Multicolored Asian Lady Beetle (MALB) adults can be distinguished from other lady beetle species by a pair of white, oval markings behind the head that form a black M-shaped pattern.  Most adults have nineteen black spots on their forewings, but variability is common and spots may be missing. Adult MALBs consist of several color patterns (morphs), varying from solid orange to red with black spots.

This species is often mistaken for the seven spotted lady beetle (Coccinella septempunctata), which was introduced from Europe. Both species are usually found feeding on the same insect host and plants.

Both species tend to overwinter in large numbers. However, the Seven Spotted Lady Beetle overwinters under rocks, abandoned shrubs and forest edges. In contrast, the MALB is attracted to light and often aggregate and overwinter in dwellings, entering through cracks or crevices.

Due to the onset of winter and scarcity of food, MALB is more noticeable November to January in north Florida. As a result, they are a nuisance during the flight period, aggregating in walls and other parts of dwellings.

Once they enter your dwelling and experience warmth, they fly around and annoyance progresses. They produce a yellow, viscous, foul-smelling defensive substance when disturbed. The defensive substance usually leaves spots on furniture and the foul odor lingers in the air.

The solution

  • Seal building or caulked entry point to prevent infestation.
  • If beetles get inside your dwelling, a black light trap can be used.
  • Vacuum cleaners can be used to remove them, though, while effective, it will result in some spotting and foul odor.

In conclusion, though a nuisance, lady beetles are considered to be valuable natural enemies and should be tolerated and conserved when possible.

Supporting information for this article can be found in the UF/IFAS EDIS publications:  

EENY204/IN361: Multicolored Asian Lady Beetle, Harmonia axyridis Pallas (Insecta: Coleoptera: Coccinellidae) (ufl.edu) and EENY170/IN327: Ladybirds, Ladybird beetles, Lady Beetles, Ladybugs of Florida, Coleoptera: Coccinellidae (ufl.edu)

How to Manage Citrus Leafminer in Your Backyard

How to Manage Citrus Leafminer in Your Backyard

By Danielle Sprague & Dr. Xavier Martini

Citrus is one of the most cherished fruit trees in the Panhandle. Citrus owners are well aware that every year the main damage to their trees come from citrus leafminer (CLM). CLM is a small moth and its larvae feeds between the tissue layers of new leaf growth, causing serpentine mines to form under the leaf cuticle (Fig. 1). The feeding damage results in leaf curling and distortion, and severe infestations of CLM on young trees can retard the growth of trees. Another threat concerning CLM in Florida is that the mines provide an open wound for citrus canker to enter, a bacterial disease that has been found recently in the Florida Panhandle, Georgia, and Alabama.

Citrus leaf miner adult (picture Lyle Buss). (B) Citrus leaves with citrus leafminer mines (picture: Xavier Martini)

Chemical Control

Most commercial growers deal with CLM in young trees by a soil application of systemic insecticide before the flush season, followed by a foliar insecticide when the systemic drench’s toxicity is declining. Homeowners, however, have limited access to these chemistries. Garden systemic insecticides that include imidacloprid (Bayer’s Tree & Shrub Insect Control™, Merit®, etc.) and dinotefuran (Greenlight Tree and Shrub Insect Control™, Safari®, etc.) are among the few options for CLM control. For the best efficacy, those insecticides should be applied two weeks before the start of the flushing season to allow time for the insecticide to move from the roots into the canopy. To avoid leaching of insecticide away from the root zone, soil applications should be made within a 24-hour period without rain. Citrus trees usually have several flushes per year, depending upon cultivar, climate, and crop load. However, in the Florida Panhandle, most citrus cultivars have two major flushes in May and September.

Importantly, systemic insecticides are only efficient against CLM for small immature trees; therefore, the only products labeled for use against CLM on mature trees are foliar sprays. Horticultural oils or insecticides with spinosad (such as Monterey® Garden Insect Spray) are some options available for homeowners. However, achieving leafminer control with foliar applications on mature trees is challenging due to unsynchronized flushing of trees. Foliar applications should be timed with the appearance of the first visible leaf mines. In any case, be sure to READ THE LABEL and follow all the label directions.

Cultural practices, and non-insecticidal methods.

For isolated trees in a backyard, cultural practices and control through mass trapping are usually sufficient to control CLM and insecticide use is not recommended, especially for mature trees. One of the basic cultural practices is to remove any stems that grow below the bud union or from the rootstock, also called ‘suckers’ (Fig. 2). Those rootstock shoots compete with the scion shoots and are great reservoirs for CLM; removing them will help reducing CLM population. On isolated trees, mass trapping using CLM pheromone provide good results (Fig. 3). The mass trapping method is constituted of a delta trap baited with a lure that emits a large quantity of CLM sex pheromone. CLM males are attracted by the odor and are captured in the delta trap’s sticky liner. Those traps are commonly used by growers to monitor CLM populations, but for homeowners they are sufficient to control CLM on a single tree. This trap and a lure method should protect a single tree for approximately 3 months. Finally, the last option is the use of biological control.  Several natural enemies are predators or parasitize CLM. In some case, biological control can reduce CLM populations by 90%. Primary predators of CLM include ants, lacewings, and spiders, as well as a parasitic wasp, Ageniaspis citricola that was introduced into Florida and has become established (Fig. 4).

New growth from the rootstock (called ‘suckers’, red arrow) are a source for CLM infestation and should be removed.
Baited pheromone trap for citrus leafminer (picture Danielle Sprague).
Citrus leafminer serpentine mine parasitized with Ageniaspis citricola larvae (picture Lyle Buss).

Friend or Foe – Horned Passalus beetle

Friend or Foe – Horned Passalus beetle

Have you ever been strolling through your garden and decide to rearrange or remove a log? You might be amazed or intimidated by the sight of a dark shiny creature with large mandibles (mouth parts).  But don’t be alarmed- it is the Horned Passalus, Odontotaenius disjunctus.  This beetle also is known by many other common names including the Betsy Beetle, Bess Bug, Patent Leather Beetle, Jerusalem Beetle, Horn Beetle, and Peg Beetle.  

This beetle is a widely distributed from mid-Florida to Massachusetts, Southern Texas to Minnesota, and Nebraska.  Beetles are easily recognized due to their large size, ranging between 30 and 40 mm (1.2 and 1.6 inches) in length. They are known to have pre-social activities, where both males and females perform the same duties of processing decaying wood and protecting larvae.

Friend or foe?

Horned Passalus Beetles are beneficial decomposers of decaying wood or logs, often found in large numbers to efficiently complete the task!  However, they are medically harmless and not considered a pest of urban structures. Horned passalus beetles are considered to be beneficial insects as these beetles help decompose deadwood by chewing the pulp and then expelling the frass.

Musically inclined or just a talkative beetle?

The phrase “crazy as a Betsy Bug” may refer to the sounds that these insects make — The adults are able to produce at least 17 different calls (Stridulation) as they communicate with other beetles or when disturbed/agitated, which are audible to humans.

Life cycle/ Developmental stage.

Using its large mandibles, the horned passalus cuts into fallen logs and creates tunnels where the eggs are deposited and hatched into white grubs (larvae) that have up to three instars. They appear to only have two pairs of legs, but a third pair is present and reduced. Only the first two pairs are used for movement. These grubs usually retain a distinctive C-shaped position when not active.

As pupae begin to form they become pearly white with a rainbow sheen. As the pupae age, they lose their rainbow sheen and can range in color from off white to earth-toned. Adult beetles aggregate and compete for sections of fallen wood.  

Nuptial flight or defense?

Newly mature adults will leave the parent log and participate in a nuptial flight, one of the only instances of their wing use. During observations of the nuptial flight, adults were found to be susceptible to light attractants such as light traps and street lights. At the end of the nuptial flight, adults will seek out a new log to start another aggregation.

For more information, please contact your local county extension office.
Supporting information for this article can be found in the UF/IFAS EDIS publications/websites below: horned passalus – Odontotaenius disjunctus (Illiger) (ufl.edu); EENY 487/IN879: Horned passalus, Odontotaenius disjunctus (Illiger) (Insecta: Coleoptera: Passalidae: Passalinae) (ufl.edu) and Odontotaenius disjunctus (tamu.edu)

Gulf Fritillaries

Gulf Fritillaries

October is an important month for butterflies. The monarchs are making their epic migration towards Mexico, gracing us with their presence as they stop to feed on saltbush or lantana plants along the coast. But our homegrown orange-and-black butterfly is showing up everywhere right now, too. The Gulf fritillary (Agrautis vanillae) is a smaller species, but also features bright orange wings with black stripes and spots. Their caterpillars come dressed for Halloween, too—they are a deep orange color with black legs and spikes. While the caterpillar is not venomous to any potential predators, the spikes are quite intimidating and serve a protective function.

A gulf fritillary butterfly gathering nectar from a similarly brilliant orange flower. Photo credit: Carrie Stevenson, UF IFAS Extension

Fritillary (name from the Latin “chessboard”) eggs are bright yellow and laid primarily on varieties of passionflower vines, which the caterpillars feed voraciously upon. Passion vine is an important host plant for the zebra longwing as well, which is Florida’s state butterfly.

Gulf fritillaries are found in all 67 Florida counties, and may live throughout the southeastern United States, Mexico, and central and south America. They are found in varied habitats but prefer open, sunny spots in fields, forests, and gardens. The butterfly’s wing shape puts them into the “longwing” category, as their elongated wings spread wider than other species.

Caterpillar of the Gulf fritillary butterfly on corkystem passionflower. Photo credit: Jaret C. Daniels, University of Florida.

In the fall, fritillaries migrate to the warmest ends of their range. By spring, they move slightly north into North Carolina or interior Alabama.

Plant of the Week:  Mistflower (Conoclinium coelestinum)

Plant of the Week:  Mistflower (Conoclinium coelestinum)

October is the premier wildflower month in the Panhandle.  Nighttime temperatures drop, days shorten, pollinators emerge, and many native plants explode into flower.  Of all the native fall-flowering Panhandle wildflowers, maybe the most striking is currently in full bloom, the Mistflower (Conoclinium coelestinum)! 

Photo credit Bill Boothe / Natural Encounters

Mistflower is a low growing, spreading native perennial (1-2’ in height) found in sunny, moist areas of meadows and near rivers, ponds, and creeks throughout much of the United States from New York to Florida and even west as far as Texas and Nebraska.  This common native wildflower is conspicuously one of the few native plants in our area that has blue flowers, making Mistflower easy to spot in a sea of yellow, orange, purple, pink, and white wildflowers.  The flowers appear as little puffs of purply-blue due to the lack of ray florets (think the outer yellow “petals” of sunflowers), possessing only disk florets (think the inner part of sunflower heads) with long blue, fuzzy-appearing stamens.   Mistflower is attractive to more than just wildflower watchers as well, it’s a magnet for nectar-seeking butterflies as well; Eastern Swallowtails, Great Purple and Juniper Hairstreaks, and others are often found feeding on the flowers. 

Great Purple Hairstreak butterfly on Mistflower. Photo credit Bill Boothe / Natural Encounters.

As lovely as Mistflower is in the wild, it’s probably best left for folks enjoy there, especially those who prefer an orderly yard.  Mistflower will indeed grow great in moist areas of pollinator gardens and landscapes, requiring only ample sunlight and rainfall, but it is very aggressive.  Its spreading nature via its rhizomatous root system and prolific seed production often lead to it becoming a weedy nuisance in more manicured landscapes.  But, if chaos and fall bursts of blue erupting at random throughout your garden don’t bother you, by all means, seek out Mistflower for purchase through seed catalogs and local native nurseries.  For more information on Mistflower and other fall-blooming native wildflowers, contact us at the UF/IFAS Calhoun County Extension office!  Happy Gardening.

North Florida Goldenrod

North Florida Goldenrod

Autumn Blooms

The days are getting shorter, the sun setting earlier each day, and the temperatures are beginning to dip.  All the signs are there, we’ve reached autumn which means it’s time for many roadside wildflowers to begin their bloom cycle.  Surely, you’ve seen them as you drive down the road, small colorful patches in the ditch or as almost blinding yellows across vast fields. The vibrant yellow in this latter example is that of goldenrod (Solidago spp.).  A name attributed to many plants in Asteraceae better known as the Daisy family, they serve to feed pollinators when other plants begin to fade.  Two of the most common in the panhandle are seaside goldenrod (Solidago sempervirens) and Canada goldenrod (Solidago canadensis).

Coastal Goldenrod

Seaside goldenrod will be most prevalent in the coastal counties along the panhandle. It thrives on beach dunes in tidal marshes and disturbed coastal areas. Tolerance to saline soils and sea spray allow growth in these environments.  A clumping perennial, it grows to 6.6 feet clumping with a 1.6 foot spread.  The flowers of this plant bloom in autumn on a spiked inflorescence as tubular disk florets. They are pollinated by several types of insects and birds. This plant was used as far back as the Roman times to treat several medical conditions.

Photo: Joshua Criss

Inland Goldenrod

Canada goldenrod is found in Florida almost exclusively in the panhandle with a few pockets as holdouts in the peninsula.  Not as common along the coast, this plant prefers to take hold in ditches and open meadows.  At 1-7 feet tall with it spreads via underground stems known as rhizomes.  Rhizomatous plants such as these are traditionally difficult to control and may become weedy in some situations. Yellow ray style flowers present in clusters at the end of stems on drooping panicles. Pollen form this plant is often blamed for fall allergies, but does not tend to travel far on the wind making this an unlikely source. As with the seaside goldenrod, this plant was used traditionally as a medicine in ancient times. 

Photo: Joshua Criss

Summing it up

Goldenrod along with many autumn blooming wild flowers may be something you’ve put very little thought into.  They are proven winners in terms of late season pollinator support. Often overlooked in the home landscape, plants like goldenrod may bring a new twist to your home gardens.  They require little water and fertilizer and grow well in our area.  For more information on Florida wildflowers, see these Ask IFAS documents, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.