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What kind of eggs are these?
Found outside on a window, when I removed them via scraping, whitish oozy fluid came out. I've seen this before but they've been appearing more frequently, always appear in a straight line and are brown.
This is in Malaysia, in South East Asia. More specifically Johor. The entire line measured about 1 inch, and in terms of individual egg size, 0.3 inches.
This eggs belong to Mictis profana which is a species of insect in the family Coreidae known by the common names crusader bug and holy cross bug. It is distributed in Australia, Indonesia, and the Indo-Pacific.
Flies 101: Different Types of Flies and the Threats they Pose
Flies are a common pest around the world – with more than 120,000 kinds of flies found globally, and 18,000 of those found throughout North America. Although flies have short lifespans, they are able to quickly reproduce in large numbers and are also capable of spreading various dangerous diseases, including malaria, salmonella and tuberculosis.
Where do flies come from?
Flies typically hatch outside and then make their way into our homes through structural weak spots, such as damaged weather stripping or torn screens covering windows and doors. Around the home, flies can lay their eggs in garbage cans, compost piles, excrement, and rotting organic material. Female flies can lay between 75 to 150 eggs at a time, which if compressed together only adds up to roughly the size of a pea, making them extremely difficult to identify.
Houseflies are widespread because they reproduce quickly and in large numbers. At times, they have been known to move up to 20 miles from where they were hatched, but they usually stay within one mile of their birthplace. Fruit flies, another common fly type, are usually found within the home because of their attraction to food waste like overripe or rotten produce. They typically enter the house as hitchhikers on produce and other food brought in from the outside. Horse flies are not commonly found inside and do not feed indoors, but sometimes enter homes by accident through open windows and doors.
Types of Flies
The house fly is the most common type of fly found in and around homes. They can be found worldwide and are widespread throughout the United States.
House flies are typically gray in color and have four black stripes on their thorax. Adult house flies are about 1/8-1/4” long. They have slightly hairy bodies, a pair of wings and compound red eyes that contain thousands of individual lenses, giving them wider vision. House flies do not have teeth or a stinger.
House fly eggs resemble small grains of rice. The eggs hatch into larvae, also known as maggots, which range in size from about ¼-3/8” long. Maggots are cream colored with a greasy appearance. When entering the pupal stage, maggots develop dark, hard outer shells, legs and wings, ultimately emerging as full-grown adult flies.
Depending on conditions, it can sometimes take as little as six days for a house fly to develop from egg to adult. Similar to various other pests, the house fly experiences a four-phase life cycle, which begins when a fertilized female house fly finds a suitable location to lay her eggs, oftentimes on feces, rotting meat and food or garbage. Female house flies usually only mate once but are capable of producing between 350-900 eggs in their lifetime. Their larvae, known as maggots, are pale-whitish. These legless larvae feed at the egg-laying site for three to five days. At the conclusion of this period, maggots seek out a dark, dry and cool environment to develop in. Over the course of three to six days, the pupae develop legs and wings, and grow into fully-grown adult house flies. After two to three days, the adult female house flies are fully ready and able to reproduce, restarting the life cycle. Adult house flies typically live 15-25 days.
Since house flies don’t have teeth, they can only feed on liquids. However, they use their sponging mouthparts to liquefy many solid foods through spitting or regurgitation. Their tongues are shaped like straws to suck up the food. House flies feed on a wide variety of substances such as human food, animal carcasses and garbage. They are particularly attracted to pet waste because of its potent odor.
Although house flies do not bite, they are capable of transferring more than 100 different pathogens, including salmonellosis, typhoid and tuberculosis. This kind of fly can contaminate food surfaces by spreading disease organisms picked up on their legs and mouths when feeding on trash, feces and other decaying substances. They also defecate constantly, which further spreads bacteria.
Fruit flies are found throughout the United States and are known for their ability to rapidly reproduce. They can be found indoors year-round, and depending on the conditions, their lifespans can last 25 to 30 days.
Adult fruit flies are typically 3 to 4 mm long and appear to be brown or tan in color. They usually have red eyes, but some fruit flies have darker eyes. They have a tan thorax with a black and grey abdomen. Fruit flies have six legs and are small and oval in shape with antennae.
Fruit flies are attracted to and eat rotting food matter, especially fruits and vegetables, and any fermenting liquids, like beer, liquor and wine. They are also attracted to and sometimes breed in dark, moist and unsanitary environments like drains, garbage disposals and trash bins. Fruit flies are able to reproduce very quickly, making them difficult to control. Female fruit flies can lay around 500 eggs, which can hatch in as little as 24 hours. Similar to other fly species, fruit flies have a four-stage lifecycle, which can be completed in as little as a week in ideal conditions.
Not only are fruit flies a nuisance pest, but they are also capable of contaminating food with harmful bacteria and disease-causing pathogens, since they are typically found in unsanitary conditions, just like house flies.
This type of fly likely received their common name because they are notorious pests of horses and other mammals. They are commonly found in both suburban and rural areas near bodies of water, which serve as breeding sites, and where mammal hosts are most abundant.
Horse flies have a gray or blackish body and are 10 to 30 mm long. They usually have wings lacking dark areas, but some species have entirely dark wings. They have large eyes that are usually green or purple with horizontal stripes. Horse flies have six legs and are stout-bodied and without bristles. They also all have short antennae.
Adult horse flies are fast, strong fliers and capable of flying for more than 30 miles, though they generally do not disperse widely. They most often attack moving and dark objects. Horse flies often rest on paths and roads, especially in wooded areas, where they wait for potential hosts. Horse flies are attracted to light and will sometimes congregate at windows. They are most evident on windless, hot and sunny days. Larvae develop in wet soil close to bodies of water.
Female horse flies feed on blood aggressively, while males do not consume blood but rather feed on pollen and plant nectars. Female bites can be painful because their mouthparts are used for tearing and lapping up blood, rather than just sucking like mosquitoes.
Unlike the other kinds of flies, horse flies are not known to be vectors of disease or capable of transmitting harmful disease-causing bacteria. They do, however, have painful bites that can cause allergic reactions. They are also persistent and will continue to bite their host until they either succeed in procuring their blood meal or are killed. Female horse flies are even known to chase their intended targets for short periods of time.
The best method for preventing flies in the home is through vigilant sanitation, including removing trash daily, ensuring all counter surfaces are kept clean, checking that all windows and screens are properly screened, and any decaying food matter is properly disposed of. If you have animals, stay on top of waste removal by emptying litter boxes and picking up around the yard for dog waste.
If a fly infestation is suspected, it’s important to contact a licensed pest control professional to conduct an inspection, specifically looking for any places where fly eggs may have been deposited. Once the breeding site is eliminated, the pest professional will develop a house fly treatment plan based on the circumstances of the infestation.
Tick Prevention Tips
Learn how to keep yourself and your family safe from tick bites before heading outdoors this summer.
West Nile Virus and EEE
While differing in many ways, extreme cases of these two mosquito-borne diseases can cause serious health consequences.
Unusual Places Bed Bugs Hide
From purses to stuffed animals, bed bugs can hide in some unusual places.
What is a plankton? If you have watched SpongeBob SquarePants, you might have heard of these small organisms.
A plankton technically is just an organism that lives in water and that cannot propel themselves. For example, a jellyfish is a plankton.
However, usually plankton are very small and/or microscopic. Two most commonly categories of plankton are zooplankton (animal) and phytoplankton (algae/plant-like protist). Some zooplankton are some of our favorite ocean animals that have just hatched from eggs.
Plankton are a food to many estuary and ocean animals and are at the bottom of the estuary food chain.
A Lotta Mola
The mola, or ocean sunfish, looks like an animal cracker someone bit in half. At 5,000 pounds, though, this temperate and tropical water animal is the world’s heaviest bony fish.
It’s also the heavyweight egg producer, releasing 300 million eggs over a spawning season. (Related: "See Which Animals Have the Most Enormous And Tiniest Babies.")
So how do you count 300 million eggs free-floating in the ocean?
Marine biologists would likely have “counted a small number of eggs,” from a female mola ready to ovulate, says Kathleen Cole, a marine biologist at the University of Hawaii at Mānoa.
Scientists weigh a specific number of eggs, then repeat the process to get an accurate average, then weigh all the eggs to get a total estimate, Cole says.
Selina Heppell, head of the Department of Fisheries and Wildlife at Oregon State University, says other fish known to have high numbers of eggs include sturgeon (up to 2.5 million eggs for Atlantic sturgeon) and large tuna (bluefin tuna can produce 10 million eggs a year).
“The largest fish with the most eggs also tend to be older, experienced females that have high fertility rates,” Heppell says. (Can we hear it for older, experienced females?)
As the females grow, their larger ovaries can hold more eggs “so if the fish doubles in length,” the number of eggs will “multiply by 30 or 60,” Coleman says. It’s understood among those who fish not to take large females, “because in some species the largest females are equivalent 30 or even 60 small females.”
And those eggs are often more likely to hatch, Heppell says.
Many eggs of spawning fish don’t make it.
The tiny mola eggs “have very, very small chances of survival,” Heppell says. “Even species with lots of eggs can be overfished or reduced by climate change.”
In a stable population, Heppell says, each adult replaces itself, so those 300 million eggs should produce two adult mola. Yet, the mola is still listed as vulnerable by the International Union for the Conservation of Nature, partly due to accidental capture by fisheries targeting other species.
Food for Phyllium giganteum
Giant Leaf Insects eat leaves of bramble, oak and rose species. Do not feed the fresh new leaves, especially not of bramble. The older, darker colored leaves are much better. Young nymphs cannot eat from undamaged leaves, so you should cut of the edges of the leaves before you feed it to them. How to place foodplants in a stick insects cage can be read here.
A young nymph of the Giant Leaf Insect Phyllium giganteum
Materials and Methods
A survey in the post-tsunami affected areas was explored in a random fashion during February to April 2005. Some freshwater sites had changed into brackish-water sites. The denatured and polluted water sites that formed had become breeding areas for Cx. sitiens. The collection stations were set at Phang Nga Naval Base, Ban Keuk Kuk, Ban Bang Ka Ya and Ban Nam Khem, Phang Nga province.
Natural breeding habitats
Surveys of breeding places of Cx. sitiens were carried out and mosquito species and aquatic predators were determined as well as some quality parameters of the breeding water, such as pH, conductivity, total dissolved solids, dissolved oxygen, salinity and temperature. The water quality was recorded using a Sension 156 Portable Multiparameter Meter (HACH, www.hach.com). Identification of the collected mosquitoes was based on adults emerging from the pupae.
Collection stations were established at all study sites to determine the biting cycle of the mosquito studies. The biting cycles were conducted outdoors between 1800–2400 hours, by human landing catch. Mosquito counts were made hourly for 45 minutes by two groups, each with two persons, for three periods of time during 3 consecutive nights from Nov. to Dec. 2005. All mosquitoes were identified as to species by using a standard dissecting microscope and taxonomic keys ( Bram 1967 Ratanarithikul et al. 2005). Female Cx. sitiens mosquitoes were transferred into paper cups with screen tops (approximately 50 mosquitoes per cup) and cotton wool soaked with 10% sugar solution was offered as a food. These cups were placed in a cooler covered with a wet towel. Ice packing was used to keep them cool and provide humidity during transportation.
Biology Laboratory colonization of Culex sitiens
The mosquitoes were reared individually to get single colonies using a modified procedure ( Panicker et al. 1981 Limsuwan et al. 1987). After returning to the laboratory, the female mosquitoes were released into a 30×30×30 cm cage as starting colonies and the females were given a blood meal from a golden hamster by placing it inside a mosquito cage overnight. The engorged females were transferred into paper cups (approximately 15 individuals per cup) and cotton wool soaked with 10% sugar solution was offered as food. About three or four days after feeding, each mosquito was transferred to a plastic cup containing 15 ml natural water which was carried from the field at the collecting areas for oviposition. Egg rafts were separated individually in plastic cups with the same natural water to observe hatchability. On the following day, the number of eggs that hatched were scored from 20 egg rafts. The number of eggs in each raft, the duration of different larvae instars, pupae and adults recorded every day. The larvae were reared in a plastic trays with about 1000 ml of natural water (from field study area) per tray. A mixture of Powered Fish 2000 (White Crane Aquarium Co. Ltd. (www.whitecranev88.com) and water was provided as larval food. Food was added to each plastic rearing tray at each of the 4 instars, 0.5, 1.0, 1.5 and 2.0 ml respectively. Numbers of male and female mosquitoes that emerged were counted and recorded, cotton wool soaked with 10% sugar solution was provided as food for the adults. The insectarium used was not air-conditioned, the temperature and relative humidity were recorded and measured. The rearing temperature was 30.8 ± 0.5°C (range 29–31°C) with approximately 68.2 ± 3.1% (64–70%) relative humidity.
Observations on longevity
The longevity of eggs, larvae, pupae and adults was assessed. Thirty of each of the newly emerged males and females were kept separate in paper cups covered with screen tops, with cotton wool soaked with 10% sugar solution provided as food. These sugar pads were provided regularly and changed every day until the adults died. Paper cups were checked daily and dead mosquitoes were counted and removed until all of mosquitoes died. The sex ratio of the adult male and female was also determined.
American Cockroaches Facts & Information
Length: Adults can be slightly more than 50 mm (3 inches) long.
Color: Adult American cockroaches are reddish brown or mahogany colored. The area behind their heads is outlined with a yellow band.
Female American cockroaches make protective cases for their eggs. These cases are capsule-shaped. After forming a capsule, the roach deposits it in a warm, humid area. An average American roach egg capsule contains about 16 eggs.
When the eggs hatch, the tiny nymphs come out of the capsule. As they grow, the baby cockroaches shed their skins. If there is plenty of food, American cockroaches can develop from egg to adult in as little as 5½ months.
Behavior & Diet
Both male and female American cockroaches can fly. The wings develop when the roaches become adults.
American cockroaches normally live outdoors. They prefer warm, damp areas like flowerbeds, and under mulch. In many parts of the United States people call them “palmetto bugs” because they live on trees. American cockroaches are very common in sewer systems of many American cities.
American cockroaches enter homes to find water or food. They can easily pass under doors if the weather stripping is damaged. Basement windows and garages are also common entryways. When American cockroaches enter homes, they often go to bathrooms, kitchens, laundry rooms and basements.
Outdoors, American cockroaches eat leaves, tiny wood particles, fungi and algae. They also eat small insects. Indoors, American cockroaches forage under appliances, in drains, in kitchen cabinets and on the floor. They eat crumbs, scraps of food and spilled food that they find. They will also eat pet food that is left out overnight.
Signs of American Cockroach Infestation
Homeowners may see these active cockroaches. American roaches can run very fast, and they usually scurry into a dark area. If they are startled, American roaches may even fly.
American cockroaches leave their droppings in the dark areas where they hide. Homeowners may find these droppings in basements, in pantries or behind appliances.
American cockroach droppings are small, and sometimes people mistake them for mouse droppings. American cockroach droppings have ridges on the sides and they are blunt on the ends. Mouse droppings have pointed ends. Since mice groom themselves, mouse droppings often have hairs embedded in them.
American cockroach egg cases are about 38 mm long. They are dark-colored—reddish or blackish brown. Homeowners often find these egg cases in basements, in laundry rooms or kitchens. The egg cases may be under cabinets or behind appliances. American cockroaches also deposit their egg capsules behind stored items in garages and sheds.
Cockroaches produce a chemical called an “aggregation pheromone.” The odor of this chemical causes the roaches to stay together in groups. Some people describe the odor of these pheromones as having a “musty” smell. As the roach population starts to grow, people with sensitive noses may begin to notice this odor.
How Did I Get American Cockroaches?
American cockroaches enter home to find water or food. They can easily pass under doors if the weather stripping is damaged. Basement windows and garages are also common entryways. When American cockroaches enter homes, they often go to bathrooms, kitchens, laundry rooms and basements.
How Serious are American Cockroaches?
Cockroaches are filthy pests. They can spread disease, contaminate our food and cause allergies and even asthma. Cockroaches can pick up germs on their legs and bodies as they crawl through decaying matter or sewage and then transfer these germs to food or onto food surfaces. According to the World Health Organization (WHO), they are proven or suspected carriers of the organisms causing diarrhea, dysentery, cholera, leprosy, plague, typhoid fever and viral diseases such as poliomyelitis.
Orkin encourages people to help reduce cockroach populations by removing all food and unnecessary water sources, sealing all cracks and crevices, vacuuming and removing shelter sites like cardboard and paper. To effectively manage a serious cockroach infestation, you must correctly identify the type of cockroach causing the infestation, which is why it is important to contact a pest control professional.
How Do I get Rid of American Cockroaches
The Orkin Man™ is trained to help manage American cockroaches. Since every home is different, the Orkin technician will design a unique program for your situation.
Keeping American cockroaches out of your home is an ongoing process, not a one-time treatment. Orkin’s exclusive A.I.M. solution is a continuing cycle of three critical steps—Assess, Implement and Monitor.
The Orkin Man™ can provide the right solution to help keep American cockroaches in their place … out of your home.
Assess the situation
Your Orkin technician will do a thorough inspection of your home—inside and outside. There are several things the technician will do during the inspection:
- Locate areas of American cockroach activity.
- Identify the causes of the American cockroach problem.
- Look for entryways that American cockroaches could be using to get into your home.
Since “cookie-cutter” treatments aren’t always effective, the technician will customize the treatment to the situation. He can select from a variety of tools and techniques to help keep American cockroaches out of your home:
- Exclusion–Nonchemical methods such as caulking or door sweeps help keep American cockroaches from entering your home.
- Landscape modification—If American roaches are living around your home, it may be necessary to remove dead leaves or rake mulch away from the foundation. The technician will point out these opportunities.
- Gel or granular bait—These are applied in areas where American cockroaches will eat them but children or pets cannot reach them.
- Insect growth regulator—Applied into cockroach hiding places, these interfere with the cockroaches’ normal development.
- Residual insecticides—Applied into cracks and crevices, these help keep American cockroaches from hiding in the treated areas. The technician may also apply liquid insecticide outdoors to help keep American cockroaches from coming inside.
Every time the technician returns to your home, he or she will make an inspection. There are several things he will do during the inspection:
- Confirm that previous treatment was effective.
- Check for new American cockroach activity.
- Identify changes to the home or landscape that could make your home vulnerable to American cockroach invasion.
The Orkin Man™ can provide the right solution to keep American cockroaches in their place … out of your home. For more information or to schedule an inspection, please contact your local Orkin branch office.
Convenient, Lasting and Affordable Treatment
The Orkin Man™ can work around your schedule. In many cases, treatments will be made on the outside—sometimes with no need for you to be at home.
Keeping American cockroaches out of your home is an on-going collaborative process, not a one-time event. Orkin’s A.I.M. solution is the ideal way to help keep these pests where they belong—outside your home.
While it might seem easy to quote a service price online, in fact it really is almost impossible. Since every home is unique, no two treatment plans should be exactly the same. The best way to prescribe an effective treatment plan and to quote an accurate price is by having a trained professional complete a comprehensive inspection.
The American cockroach is also commonly known as the water bug, flying water bug or palmetto bug. These large cockroaches can grow to exceed 50 cm in length. Although the American cockroach is a major pest in the United States, they are native to the tropical climates of Africa. Some evidence has suggested that the American cockroach was brought to North America aboard ships.
American Cockroach Illustration
They are a peridomestic species and live primarily outdoors. In southern states, they are common in shady, humid areas like flowerbeds and around trees. In northern areas, they are usually found in sewers and drains. Climate changes or food shortage can cause them to move indoors.
When they move indoors, American cockroaches prefer to live in moist, humid environments. They can also survive in dry areas with sufficient food and water sources. These insects favor temperatures between 70 and 80 degrees Fahrenheit. When an American cockroach population infests a human home, the insects are drawn to food storage and preparation areas, as well as moist locations. In industrial settings such as restaurants and bakeries, they can be found in boiler rooms and steam tunnels. In residential and commercial buildings, the American cockroach typically infests basements and landscaping.
American cockroaches are moderate flyers. They also gather together in open spaces, while other domestic cockroaches tend to hide in cracks and crevices. They do enjoy sweet foods, but prefer decaying material.
Butterflies are oviparous, meaning they lay eggs. They breed as many animals do—eggs from the female insect are fertilized by sperm from the male. The female butterfly stores the male’s sperm in a bursa, or sac, until she is ready to lay eggs. Depending on the species, females lay eggs one at a time, in clusters, or in batches of hundreds. Butterflies lay an average of between 100 to 300 eggs, although some species may only lay a few dozen, others can lay as many as a thousand or more.
Billions of Brood X Cicadas Are About to Get Loud
A big event in the insect world is approaching. Starting sometime in April or May, depending on latitude, one of the largest broods of 17-year cicadas will emerge from underground in a dozen states, from New York west to Illinois and south into northern Georgia. This group is known as Brood X, as in the Roman numeral for 10.
For about four weeks, wooded and suburban areas will ring with cicadas' whistling and buzzing mating calls. After mating, each female will lay hundreds of eggs in pencil-sized tree branches.
Then the adult cicadas will die. Once the eggs hatch, new cicada nymphs fall from the trees and burrow back underground, starting the cycle again.
There are perhaps 3,000 to 4,000 species of cicadas around the world, but the 13- and 17-year periodical cicadas of the eastern U.S. appear to be unique in combining long juvenile development times with synchronized, mass adult emergences.
These events raise many questions for entomologists and the public alike. What do cicadas do underground for 13 or 17 years? What do they eat? Why are their life cycles so long? Why are they synchronized? And is climate change affecting this wonder of the insect world?
We study periodical cicadas to understand questions about biodiversity, biogeography, behavior and ecology — the evolution, natural history and geographic distribution of life. We've learned many surprising things about these insects: For example, they can travel through time by changing their life cycles in four-year increments. It's no accident that the scientific name for periodical 13- and 17-year cicadas is Magicicada, shortened from "magic cicada."
As species, periodical cicadas are older than the forests that they inhabit. Molecular analysis has shown that about 4 million years ago, the ancestor of the current Magicicada species split into two lineages. Some 1.5 million years later, one of those lineages split again. The resulting three lineages are the basis of the modern periodical cicada species groups, Decim, Cassini and Decula.
Early American colonists first encountered periodical cicadas in Massachusetts. The sudden appearance of so many insects reminded them of biblical plagues of locusts, which are a type of grasshopper. That's how the name "locust" became incorrectly associated with cicadas in North America.
During the 19th century, notable entomologists such as Benjamin Walsh, C.V. Riley and Charles Marlatt worked out the astonishing biology of periodical cicadas. They established that unlike locusts or other grasshoppers, cicadas don't chew leaves, decimate crops or fly in swarms.
Instead, these insects spend most of their lives out of sight, growing underground and feeding on plant roots as they pass through five juvenile stages. Their synchronized emergences are predictable, occurring on a clockwork schedule of 17 years in the North and 13 years in the South and Mississippi Valley. There are multiple, regional year classes, known as broods.
Safety in Numbers
The key feature of Magicicada biology is that these insects emerge in huge numbers. This increases their chances of accomplishing their key mission aboveground: finding mates.
Dense emergences also provide what scientists call a predator-satiation defense. Any predator that feeds on cicadas, whether it's a fox, squirrel, bat or bird, will eat its fill long before it consumes all of the insects in the area, leaving many survivors behind.
While periodical cicadas largely come out on schedule every 17 or 13 years, often a small group emerges four years early or late. Early emerging cicadas may be faster-growing individuals who had access to abundant food, and the laggards may be individuals that subsisted with less.
If growing conditions change over time, having the ability to make this kind of life cycle switch and come out either four years early in favorable times or four years late in more difficult times becomes important. If a sudden warm or cold phase causes a large number of cicadas to make a one-time mistake and come out off-schedule by four years, the insects can emerge in sufficient numbers to satiate predators and shift to a new schedule.
Census Time for Brood X
As glaciers retreated from what is now the U.S. some 10,000 to 20,000 years ago, periodical cicadas filled eastern forests. Temporary life cycle switching has formed a complex mosaic of broods.
Today there are 12 broods of 17-year periodical cicadas in northeastern deciduous forests, where trees drop leaves in winter. These groups are numbered sequentially and fit together like a giant jigsaw puzzle. In the Southeast and the Mississippi Valley there are three broods of 13-year cicadas.
Because periodical cicadas are sensitive to climate, the patterns of their broods and species reflect climatic shifts. For example, genetic and other data from our work indicate that the 13-year species Magicicada neotredecim, which is found in the upper Mississippi Valley, formed shortly after the last glaciation. As the environment warmed, 17-year cicadas in the area emerged successively, generation after generation, after 13 years underground until they were permanently shifted to a 13-year cycle.
But it's not clear whether cicadas can continue to evolve as quickly as humans alter their environment. Although periodical cicadas prefer forest edges and thrive in suburban areas, they cannot survive deforestation or reproduce in areas without trees.
Indeed, some broods have already become extinct. In the late 19th century, one brood (XXI) disappeared from north Florida and Georgia. Another (XI) has been extinct in northeast Connecticut since around 1954, and a third (VII) in upstate New York has shrunk from eight counties to one since mapping first began in the mid-1800s.
Climate change could also have far-reaching effects. As the U.S. climate warms, longer growing seasons may provide a larger food supply. This may eventually change more 17-year cicadas into 13-year cicadas, just as past warming altered Magicicada neotredecim. Large-scale early emergences occurred in 2017 in Cincinnati and the Baltimore-Washington metro area, and in 1969, 2003 and 2020 in the Chicago metro area — potential harbingers of this kind of change.
Researchers need detailed high-quality information to track cicada distributions over time.
Help Count the Cicadas Near You
Citizen scientists play a key role in this effort because periodical cicada populations are so large and their adult emergences only last a few weeks.
Volunteers who want to help document Brood X's emergence this spring can download the Cicada Safari mobile phone app, provide snapshots and follow our research in real time online at www.cicadas.uconn.edu. Don't miss out — the next opportunity won't come until Broods XIII and XIX emerge in 2024.
This article is republished from The Conversation under a Creative Commons license. You can find the original article here.
John Cooley is assistant professor of ecology and evolutionary biology at the University of Connecticut. He has received funding from the National Science Foundation and National Geographic. Chris Simon is a professor of ecology and evolutionary biology at the University of Connecticut. She receives funding from the National Science Foundation.
Ministry of Agriculture, Food and Rural Affairs
|History:||Replaces OMAFRA Factsheet 03-075, Management of Thrips in Greenhouse Crops, and OMAFRA Factsheet 03-077, Biology of Thrips in Greenhouse Crops|
|Written by:||Graeme Murphy - Greenhouse Floriculture IPM Specialist/OMAFRA Gillian Ferguson - Greenhouse Vegetable IPM Specialist/OMAFRA and Les Shipp - Greenhouse Entomologist/Agriculture and Agri-Food Canada|
Table of Contents
Thrips are a major pest of greenhouse crops in Ontario. A number of thrips species are commonly found including western flower thrips (Frankliniella occidentalis), eastern flower thrips (Frankliniella tritici), onion thrips (Thrips tabaci), and Echinothrips. However, western flower thrips is the predominant species and the most difficult to control.
Figure 1. Comparison between adult western flower thrips (right) and adult Echinothrips (left).
Adult western flower thrips are approximately 1-2 mm in length and generally yellowish-brown in colour. Identification to the species level is difficult (especially among western flower thrips, eastern flower thrips and onion thrips) because they are so small and their colour varies. Adults are the only stage that can be identified to species. Identification should be done by specialists.
The life cycle consists of five stages: egg, larval, prepupal, pupal and adult. Female adult western flower thrips live up to 30 days and lay 2-10 eggs per day. At 20°C, development from egg to adult takes approximately 19 days. At 25°C, it takes 13 days. The eggs are inserted into soft plant tissues, including flowers, leaves, stems and fruit. In sweet pepper, egg hatch gives the leaves a speckled appearance, with the degree of speckling corresponding to the number of hatched eggs. The larval stage (see Figure 2) consists of 2 instars that feed and develop on the leaves, flowers and fruit. The prepupal and pupal stages often complete their development on the ground or growing medium, but pupation can also take place on the plant. The pupa (see Figure 3) is a non-feeding stage during which the wings and other adult structures form.
Figure 2. First and second larval instars plus adult of western flower thrips.
Figure 3. Pupal stage of western flower thrips.
The adults are weak fliers, usually taking short flights from leaf to leaf or plant to plant. Nevertheless, they disperse rapidly throughout the greenhouse. Adult thrips can be transported on wind currents and will enter the greenhouse through vents and doorways. At all stages they may be dispersed on workers' clothing and on infested plants, growing media or farm implements.
The adult and larval stages feed by piercing the plant surface with their mouthparts and sucking the contents of plant cells. This causes white or brown spots on the leaves where the plant cells have been destroyed. These spots are also speckled with dark fecal droppings from the thrips.
In cucumber (see Figure 4) and tomato, thrips damage is noticed first on the lower leaves. In sweet pepper (see Figure 5), it is evident in the upper youngest leaves. Heavy infestations reduce the ability of the plants to photosynthesize, reducing the yield. On vegetable flowers, thrips feeding creates silvery white streaks on the petals. Fruit damage varies according to the crop. For instance, in cucumber fruit, feeding creates severe distortion and curling as well as white streaks (see Figure 6). Feeding on sweet pepper (see Figure 7) causes silvery or bronze streaks or spots on the fruit. Thrips also feed on the calyx, causing it to turn up and expose the fruit to bacterial infections. On tomato, thrips may lay eggs in the fruit, creating ghost-spotting (see Figure 8). Ghost-spotting can also occur with sweet pepper and cucumber.
Figure 4. Thrips feeding damage on cucumber leaves.
Figure 5. Thrips feeding damage on pepper leaves.
Figure 6. Thrips feeding damage on cucumber fruit.
Figure 7. Egg-laying scars and feeding damage on sweet pepper.
Figure 8. Thrips egg-laying scars on tomato
Western flower thrips has a host range of hundreds of plant species, including many major commercial floriculture crops. Damage includes feeding scars and leaf distortion (see Figures 9 and 10). Thrips are particularly attracted to flowers, where they cause damage such as streaking and scarring of petals, distortion of flowers and flower buds and incomplete petal expansion (see Figures 11 and 12).
Figure 9. Thrips feeding damage on roses. (Photo credit: Colleen Teerling, Agriculture and Agri-Food Canada)
Figure 10. Thrips feeding damage on chrysanthemum leaves.
Figure 11. Thrips feeding damage on chrysanthemum.
Figure 12. Thrips feeding damage on gerbera.
Western flower thrips is the most important vector of a group of viruses called tospoviruses. Tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV) are the most common tospoviruses in greenhouse crops. In Ontario, TSWV is generally found in vegetable crops and some ornamental crops such as chrysanthemum, while INSV is more common in ornamental crops. In vegetables, symptoms of this disease vary according to the host, cultivar and stage of plant development, but it can severely reduce or even stop plant growth. Other general symptoms include stunting, bronzing and curling of the leaves, and distortion of affected plant areas. In addition, infected fruit are misshapen and ripen unevenly, often with a necrotic ring pattern (see Figures 13 and 14).
Figure 13. TSWV symptoms on pepper fruit.
Figure 14. TSWV symptoms on pepper leaves.
In ornamental crops, many different species serve as hosts for INSV. Symptoms and susceptibility vary widely (see Figures 15-20) but include:
- ring spots and line patterns on leaves
- necrotic lesions
- black streaking on veins and stems
- death of growing points and crown
- plant death in some crops (e.g., gloxinia)
Figure 15. INSV symptoms on kalanchoe: concentric ring patterns.
Figure 16. INSV symptoms on Aphelandra: necrotic leaf lesions.
Figure 17. INSV symptoms on cineraria: stem lesions.
Figure 18. INSV symptoms on gloxinia: ring spots and leaf lesions.
Figure 19. INSV symptoms on gloxinia: extreme necrosis leading to death.
Figure 20. INSV symptoms on Exacum: complete plant collapse.
Monitoring the population levels of western flower thrips is critical for successful pest management. In vegetable crops, monitoring should begin during propagation and continue after transplanting. In floriculture crops, thrips can be present at damaging levels year-round, although populations are usually smaller during winter. Commercially available blue or yellow sticky traps can be used to monitor the population densities of adult thrips (see Figure 21). Blue traps are more attractive to western flower thrips, although yellow traps are more attractive to other pests such as whiteflies and aphids. Your choice depends on how many pests you need to monitor, the susceptibility of the crop to thrips and/or tospoviruses and your need to detect thrips populations at low levels.
Figure 21. Sticky cards: blue (left) and yellow (right)
When setting up a monitoring program, use 1 trap per 100-200 m 2 . The exact number will depend on the layout of the greenhouse. A large open range will require a lower total density of cards than a greenhouse made up of a several smaller areas. Place the sticky cards in a grid pattern throughout the greenhouse. Check the traps weekly and record the average number of thrips per trap. Be aware that this is not an absolute measure of the population rather, it measures increases and decreases in thrips numbers throughout the year. As you become more aware of how the numbers on sticky cards relate to the population in the crop, you can use the monitoring data to help you make pest management decisions. In greenhouse ornamentals, visually inspecting simple flowers, such as impatiens, can provide good estimates of thrips numbers in the crop. However, in more complex flowers, visual counts can be less reliable. In sweet pepper and cucumber crops, precision-level sampling programs have been developed for monitoring adult western flower thrips in the flowers. These sampling programs vary the number of samples taken according to the population level of the pest and accurately predict the pest density to set precision levels. Contact the OMAF Greenhouse Pest Management Specialist or your IPM Consultant for more detailed information before implementing your monitoring program.
Sanitation is the first and most important step in implementing an effective pest management program. Effective sanitation will reduce or even eliminate thrips as a pest problem. For example, in cut roses, removing all flower buds (including non-marketable flowers) can significantly reduce thrips populations in that crop. Cultural control measures also include maintaining a healthy crop and an optimal greenhouse environment (such as 80% relative humidity), creating less favourable conditions for a rapid increase in the density of thrips populations.
An influx of outside pests, including thrips, can overwhelm your greenhouse IPM program, making it difficult to plan ahead. To prevent this, use screens to restrict the movement of insects into the greenhouse. For more information on screening, see the OMAF Factsheet Screening of Greenhouses for Insect Exclusion.
Because thrips have developed resistance to most registered pesticides, biological control is now the primary strategy for controlling thrips in greenhouse crop production. Biological control agents include predatory mites such as:
- Neoseiulus (= Amblyseius) cucumeris
- Amblyseius swirskii
- Iphesius (= Amblyseius) degenerans
- Stratiolaelaps scimitus (= Hypoaspis miles)
- Gaeolaelaps gillespiei
- Gaeolaelaps aculeifer (= Hypoaspis aculeifer)
- minute pirate bugs (Orius insidiosus)
- nematodes (Steinernema feltiae)
- the fungal insect pathogen Beauveria bassiana
N. cucumeris (see Figure 22) and A. swirskii are the most extensively used predatory mites and look very similar. These mites control western flower thrips on the foliage by feeding on the first instar larvae. A. swirskii can also feed to a lesser extent on second instar thrips. As such, it takes a number of weeks for their impact to be seen in the greenhouse, and it is unlikely that they will completely eliminate thrips populations. The life cycle for N. cucumeris is completed in approximately 10 days at 20°C and 6 days at 25°C. A. swirskii has a higher optimal temperature for development than A. cucumeris and performs better in summer conditions. Its development time is similar to that of A. cucumeris but depends on the number and type of prey available.
Figure 22. Adult and egg of Neoseiulus cucumeris.
Predatory mites should be introduced at the beginning of the crop or as soon as thrips are detected. Sanitation at the beginning and end of a cropping season is extremely important and will delay any thrips infestation until the biological control agents can be effective. Regular introductions of either N. cucumeris or A. swirskii are necessary, either by dispersing bran mixed with mites on plants or growing medium or by hanging a slow-release rearing sachet on plants (see Figure 23). The sachet system provides a continuous release of mites to the plant and should be replaced monthly. In ornamental production, many growers are now using new slow-release mini-sachets, which reduce the cost substantially and can be used on individual containers (e.g., hanging baskets or even 15-cm pots). Applying a supplemental food source such as apple pollen to chrysanthemum may help A. swirskii to get established when thrips levels are low. The number of introductions depends on the crop and level of thrips infestation (contact the OMAF Greenhouse Pest Management Specialist or your IPM Consultant). Control of the thrips should be achieved in 5-9 weeks. When using N. cucumeris or A. swirskii, it is important to maintain at least 70% relative humidity in the greenhouse and avoid using any persistent pesticides for several months before introducing the mites.
Figure 23. Methods for introducing predatory mites: directly on the plants (top), using a bag rearing system (middle) and piling bran on rockwool cubes or other growing medium (bottom).
Orius is effective in controlling thrips (see Figure 24). Unlike N. cucumeris and A. swirskii, Orius will feed on all stages of thrips. It is often found in the flowers, where it feeds on pollen as an alternative food source. Because pollen is not often present in ornamental crops, Orius is not as effective in flower crops as it is in vegetables. However, recent research has shown ornamental peppers can be used as a banker plant for Orius in other ornamental crops, allowing a population to establish, develop and disperse within the greenhouse. Some ornamental and vegetable growers are using this strategy to take advantage of the control potential offered by Orius. Development time for Orius from egg to adult is 31 days at 20°C and 19 days at 25°C. Orius enters reproductive diapause when there are less than 12 hr of light per day. Thus, Orius is only effective as a biological control agent from March to September.
Figure 24. Adult Orius preying on western flower thrips.
Orius is best released when the pest level is low. One or two releases are usually enough to provide thrips control in approximately 3-5 weeks, depending on the level of thrips and the type of host crop. For greenhouse vegetable crops, Orius is most successfully used on peppers and cucumber. Introduce adults in several locations where they can naturally disperse by flying throughout the greenhouse. Flower sampling is the best method to monitor the presence of Orius.
Iphesius degenerans (see Figure 25) differs from N. cucumeris and A. swirskii in its appearance and its ability to tolerate less humid conditions. It is dark and very agile. Because it reproduces very well on pollen, it performs best in crops with a pollen source (e.g., greenhouse peppers) but is unlikely to be the best option for floricultural crops.
Figure 25. The predatory mite Iphesius degenerans.
Stratiolaelaps scimitus and Gaeolaelaps gillespiei (see Figure 26) are soil-dwelling predatory mites that feed on a variety of soil organisms, including thrips pupae. Apply either of these to the growing medium (e.g., rockwool, peat mixes) once only, at the beginning of the crop. Although it is difficult to determine the exact impact of these predators on a thrips population, research has estimated they can kill up to 30% of pupae. Because they are unlikely to provide enough control on their own, they are better used in combination with other predators.
Figure 26. The predatory mite Stratiolaelaps scimitus.
Nematodes are frequently used by ornamental growers in Ontario. Research in Ontario and Europe has shown that they effectively control thrips pupae when applied to the growing medium on a weekly basis. To reduce costs, this is best done by overhead application in propagation, when the plants are pot tight.
Beauveria bassiana is a fungal pathogen of thrips. It is usually mixed in water and applied as a spray. Like many fungi, it is more effective under high humidity. Therefore, to treat ornamentals, it is most often applied in propagation. In vegetables, it can be either sprayed onto the crop or distributed via bumble bees that are supplied with hives specially equipped with dispensing trays. These trays contain Beauveria bassiana spores that are diluted with a powdered carrier. The bees must walk through the trays to leave the hives. In the process, some of the spore mixture sticks to their bodies. The spores become distributed in the crop when the bees fly in search of nectar and pollen and when they pollinate the crops. When thrips come into contact with spores on the crop surface, they become infected and die.
- Begin applications early, before the thrips population grows too large. Thrips are more easily managed when population levels are low.
- Although it is important to rotate chemical classes, use only one chemical class for the duration of the thrips' life cycle. This generally means using a different class every 2-3 weeks, depending on the time of year.
- Apply pesticides in early morning or late afternoon, when flight activity of thrips is at a peak. This increases exposure of the thrips to the pesticides.
For more information:
This Factsheet was authored by Graeme Murphy, Greenhouse Floriculture IPM Specialist, Economic Development Division, OMAF, Vineland Gillian Ferguson, Greenhouse Vegetable IPM Specialist, Economic Development Division, OMAF, Harrow and Les Shipp, Greenhouse Entomologist, Agriculture and Agri-Food Canada, Harrow.