Insect bites and stings

Definition

Insect bites and stings can cause an immediate skin reaction. The bite from fire ants and the sting from bees, wasps, and hornets are usually painful. Bites caused by mosquitoes, fleas, and mites are more likely to cause itching than pain.

Alternative Names

Bedbug bite; Bee sting; Bites - insects, bees, and spiders; Black widow spider bite; Brown recluse bite; Flea bite; Honey bee or hornet sting; Lice bites; Mite bite; Scorpion bite; Spider bite; Wasp sting; Yellow jacket sting

Considerations

In most cases, bites and stings can be easily treated at home. However, some people have a severe allergic reaction to insect bites and stings. This is a life-threatening allergic reaction known as anaphylaxis, and it requires urgent emergency care. Severe reactions can affect the whole body and may occur very quickly, often within minutes. These severe reactions can be rapidly fatal if untreated. Call 911 if you are with someone who has trouble breathing or goes into shock.

Some spider bites, like those of the black widow or brown recluse, are also serious and can be life-threatening. Most spider bites, however, are harmless. If bitten by an insect or spider, bring it for identification if this can be done quickly and safely.

Symptoms

The non-emergency symptoms vary according to the type of insect and the individual. Most people have localized pain, redness, swelling, or itching. You may also feel burning, numbness, or tingling.

First Aid

For emergencies (severe reactions):

1. Check the person's airway and breathing. If necessary, call 911 and begin rescue breathing and CPR.
2. Reassure the person. Try to keep him or her calm.
3. Remove nearby rings and constricting items because the affected area may swell.
4. Use the person's Epi-pen or other emergency kit, if they have one. (Some people who have serious insect reactions carry it with them.)
5. If appropriate, treat the person for signs of shock. Remain with the person until medical help arrives.

The Insect Body

It is very difficult to provide a simple answer to the question: What external features characterise an insect? This is because the class Insecta is full of exceptions. It is not easy to produce a typical body plan for what most insects look like, but there are some very general features that most insects possess.

Insect features:
The insect body is divided into three main parts, the head, thorax and abdomen.
Insects have no internal skeleton, instead they are covered in an external shell (exoskeleton) that protects their soft internal organs.
No insect has more than three pairs of legs, except for some immature forms such as caterpillars that have prolegs. These are appendages that serve the purpose of legs.
The typical insect mouth has a pair of lower jaws (maxillae) and upper jaws (mandibles) which are designed to bite. There are many variations to this structure, as many moths and butterflies have tubular sucking mouthparts, many bugs and other blood-sucking insects have sucking stabbing mouthparts and some adult insects simply don't have functional mouthparts.
Insects have one pair of antennae located on the head
Most insects have one or two pairs of wings although some insects such as lice, fleas, bristletails and silverfish are completely wingless.

Information regarding Insect Repellents

Repellents are an important tool to assist people in protecting themselves from mosquito-borne diseases.

CDC recommends the use of products containing active ingredients which have been registered by the U.S. Environmental Protection Agency (EPA) for use as repellents applied to skin and clothing. EPA registration of repellent active ingredients indicates the materials have been reviewed and approved for efficacy and human safety when applied according to the instructions on the label.

Repellents for use on skin and clothing:

CDC evaluation of information contained in peer-reviewed scientific literature and data available from EPA has identified several EPA registered products that provide repellent activity sufficient to help people avoid the bites of disease carrying mosquitoes. Products containing these active ingredients typically provide reasonably long-lasting protection:

• DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-benzamide)
  
• Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester )
  
• Oil of Lemon Eucalyptus* or PMD (Chemical Name: para-Menthane-3,8-diol) the synthesized version of oil of lemon eucalyptus
  
• IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester)

EPA characterizes the active ingredients DEET and Picaridin as “conventional repellents” and Oil of Lemon Eucalyptus, PMD, and IR3535 as “biopesticide repellents”, which are derived from natural materials. For more information on repellent active ingredients see (http://www.epa.gov/pesticides/health/mosquitoes/ai_insectrp.htm).

Published data indicate that repellent efficacy and duration of protection vary considerably among products and among mosquito species and are markedly affected by ambient temperature, amount of perspiration, exposure to water, abrasive removal, and other factors.

In general, higher concentrations of active ingredient provide longer duration of protection, regardless of the active ingredient, although concentrations above ~50% do not offer a marked increase in protection time. Products with <10%>

These recommendations are for domestic use in the United States where EPA-registered products are readily available. See CDC Travelers’ Health website for additional recommendations concerning protection from insects when traveling outside the United States.

Repellents for use on clothing:

Certain products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear, and are registered with EPA for this use. Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other arthropods and retains this effect after repeated laundering. The permethrin insecticide should be reapplied following the label instructions. Some commercial products are available pretreated with permethrin.

EPA recommends the following precautions when using insect repellents:

• Apply repellents only to exposed skin and/or clothing (as directed on the product label.) Do not use repellents under clothing.
• Never use repellents over cuts, wounds or irritated skin.
• Do not apply to eyes or mouth, and apply sparingly around ears. When using sprays, do not spray directly on face—spray on hands first and then apply to face.
• Do not allow children to handle the product. When using on children, apply to your own hands first and then put it on the child. You may not want to apply to children’s hands.
• Use just enough repellent to cover exposed skin and/or clothing. Heavy application and saturation are generally unnecessary for effectiveness. If biting insects do not respond to a thin film of repellent, then apply a bit more.
• After returning indoors, wash treated skin with soap and water or bathe. This is particularly important when repellents are used repeatedly in a day or on consecutive days. Also, wash treated clothing before wearing it again. (This precaution may vary with different repellents—check the product label.)
• If you or your child get a rash or other bad reaction from an insect repellent, stop using the repellent, wash the repellent off with mild soap and water, and call a local poison control center for further guidance. If you go to a doctor because of the repellent, take the repellent with you to show the doctor.

European Red Mite

Life History

Overwintering eggs occur in clusters on roughened areas of bark on twigs and smaller branches, often on the undersides of fruit spurs and at forks of small branches. Eggs hatch at the pink bud stage, and young mites feed upon the opening flowers and developing leaves. The mites continue to feed upon leaves during the spring and summer, increasing in numbers in response to warm temperatures. There may be as many as 6-7 generations per year. Populations generally decline by mid-August, and females lay overwintering eggs during August and September.

Monitoring

Dormant season - Collect 5 fruit spurs per tree on 20 trees selected at random from each hectare of orchard. Count or estimate the number of eggs on the terminal 4-cm of each spur, starting at the base of the bud.

Summer Monitoring is especially important if you apply Sevin thinning sprays and either Assail or Admire, or both, each season. The combination of Sevin thinning sprays and more that 2 applications of either Assail or Admire, or both, can greatly increase the risk of mite flare-ups in the current or subsequent year. Assail and Admire increase egg production in mites. Examine leaves throughout the orchard to assess average numbers of active European red mites and predatory mites. Inspections every week or two are desirable to evaluate population trends and tree response. Numbers of both plant-feeding and predatory mites may be determined either by hand lens examination or through one of the mite counting services. Check with your crop management advisor for addresses of these monitoring services.

Control

Cultural - Healthy, well-maintained trees will tolerate higher mite populations than weak or stressed trees.

Biological - Several species of predatory insects and mites attack all stages of plant-feeding mites to keep populations below damaging levels in most tree fruits. Pear trees cannot tolerate high enough numbers of plant-feeding mites to support the predatory mites needed in integrated control. Chemicals applied for controlling other pests and diseases may upset the ratio of plant-feeding to predatory mites, reducing the effect of biological control. Therefore all pesticides and application rates recommended for integrated mite control in apple are selected to conserve predatory mites.

Chemical - If predatory mites are present in orchards and not exposed to harmful sprays (such as pyrethroids and many Sevin thinning sprays), summer sprays of miticides are not usually necessary.

Pesticide resistance management - It is important to alternate products from different chemical classes or with different modes of action to avoid the development of resistance.

Early season - If an average of over 50 European red mite eggs per spur is present in the dormant sample, apply dormant oil during the 15 mm green-bud to tight-cluster bud stage. This spray is especially important to integrated control because it favours survival of predatory mites and apple rust mite. Oil has a physical effect on mite eggs. A physical control method is not susceptible to resistance development. A well-applied oil spray will keep European red mites at a low level until summer.

Assassin Bug

Assassin Bugs

One large family of these bugs (the Reduviidae) are predatory and feed on the body juices of other animals, mainly other insects. These are called assassin bugs because of their habit of hiding in ambush for their prey. The rostrum of an ordinary plant-feeding bug is tucked
flat against the underside of the head, but that of an assassin bug is curved outwards from the head. This is a very useful feature by which to identify predatory bugs. They are able to swing their rostrum forwards as they catch and pierce their prey. Once the prey is held and punctured, a salivary secretion is pumped into a canal running down between the fine stylets. This secretion immobilises the prey and dissolves its internal tissues into a pre-digested ‘soup’ that the
assassin bug can then suck up. At the end of the meal, all that is left of the prey is a dry, empty shell.

The common Assassin Bug

Assassin bugs are widely distributed throughout Australia. The common species responsible for bites in coastal Queensland is Pristhesancus plagipennis. It can be found in most urban gardens,
where it lurks among the foliage. It is sometimes called the ‘beekiller’, because a favourite food is the honey bee, but it will feed on any insect it can catch. The one illustrated is about to impale a
small jewel beetle with its rostrum.
Adults of P. plagipennis are 25-30 mm long and yellowish brown. The females lay clusters of long, reddish eggs attached by their ends to twigs. From these eggs hatch tiny spider-like babies with red bodies and black legs. They are sometimes confused with Redbacked
Spiders but they have only six legs, not eight. As they grow and moult they become a speckled colour. Eventually they reach full size and moult into the plain brown adult.