Identifying Pests
Updated: Feb 26, 2022
Australia is blessed with an abundance of unique bugs, house insects and mammals that can't be found anywhere else in the world. The flipside however, is that we also have to deal with them invading our houses and properties.
Australian Cockroach
Classification
Species category: Cockroach Scientific name: Periplaneta australiasiae Family: Blattidae
Description
A large cockroach species that is similar to the American Cockroach but smaller - 30-35mm in length. It has a distinctive pale yellow ring around the pronotum and pale yellow epaulettes on the front edges of the tegmina. Regardless of its name, it is actually a cosmopolitan species that is located outside Australia also, but not common in cooler climates. Generally they like moisture and prefer warmer, humid environments but can also live in dry conditions. Unlike the American cockroach, they struggle in colder conditions. Although the main harbourages are outdoors, this cockroach will typically forage for food in the inhabited parts of buildings, along ducts, service pipes and crevices.
Behaviour
This species is nocturnal; they spend the day hiding in cracks and crevices. Generally they like moisture and prefer warmer, humid environments but can also live in dry conditions. Cockroaches are extremely fast with incredible reaction times. The Australian Cockroach has a long lifecycle and the nymphal stage can take 6-12 months, they will go through 11 moults before reaching adulthood. They are scavengers that enjoy a varied diet and tend to select a more plant based diet than other species.
Risks
Like other cockroach species, the Australian Cockroaches transmit bacteria as they walk, transferring pathogens such as salmonella and e.coli to every area they scurry across. Cockroaches also shed cuticles, faeces and other cockroach debris which are known asthma and allergy triggers. Heavy infestations can have a distinct odour.
American Cockroach
Classification
Species category: Cockroach Scientific name: Periplaneta americana Family: Blattidae
Description
The largest of the common cockroach species, it can grow up to 50mm. Reddish-brown in colour, this species can fly and its wings span the length of its body. Originating from tropical Africa, the American cockroach now has a world-wide distribution. It prefers a warm, humid, dark and well hidden environment and is often found in sewers. Typically, it will live in drains, ducts, in other underground structures and in boats. As it feeds on a large variety of foodstuffs, it will thrive wherever food is stored and prepared.
Behaviour
Gregarious and nocturnal, they spend the day hiding in cracks and crevices. Generally they like moisture and prefer warmer, humid environments but can also live in dry conditions. Cockroaches are extremely fast with incredible reaction times. Although the main harbourages are often outside of the building itself, this cockroach will typically forage for food in the inhabited parts of buildings, along ducts, service pipes and crevices.
Risks
American Cockroaches transmit bacteria as they walk, transferring pathogens such as salmonella and E.coli to every area they scurry across. Cockroaches also shed cuticles, faeces and other cockroach debris which are known asthma and allergy triggers.
German Cockroach
Classification
Species category: Cockroach Scientific name: Blattella germanica Family: Blatellidae
Description
A smaller species of cockroach, it typically measures 13-16mm in length when it reaches adulthood. It is identified by two distinct dark brown strips running down the outside edge of the pronotum. This species is a light tan brown to dark brown colour. Originating from tropical Africa, the German cockroach now has a world-wide distribution. It prefers a warm, humid, dark and well hidden environment and is found more often in sewers. It is typically also found in drains, ducts, in other underground structures, and in boats. As it feeds on a large variety of foodstuffs, it is also commonly discovered wherever food is stored and prepared. Although the main harbourages are outdoors, this cockroach will forage into the inhabited parts of buildings along ducts, services and crevices.
Behaviour
It moves with speed and equally well on both horizontal and vertical surfaces. Typically, it is faster than other cockroach species. They tend to more successfully inhabit buildings over other species. There are a number of factors which contribute to this. A shorter life cycle, coupled with an ability to constantly reproduce, accelerates population growth. German cockroaches are also faster and smaller than other species making detection even harder.
Risks
In the course of their foraging activity, the nymphs, larvae and adults can contaminate and infect foodstuffs. They secrete an odorous discharge from their body which also taints and contaminates food. Like other cockroach species, the German Cockroach transmits bacteria as they walk, transferring pathogens such as salmonella and e.coli to every area they scurry across. Cockroaches also shed cuticles, faeces and other cockroach debris which are known asthma and allergy triggers.
Oriental Cockroach
Classification
Species category: Cockroach Scientific name: Blatta orientalis Family: Blatidae
Description
This large cockroach species typically reaches 26-32mm in length during adulthood. It has a shiny deep red – to brownish-black colouring. Males and females look different because of their wing appearance, which is larger on the males. Originating from North Africa, the Oriental cockroach is now found throughout the world but less so in Europe. It prefers humid, dark and concealed harbourages, such as cellars, ducting and other underground parts of buildings. Deceptively, the harbourage may be located outside an infested area, being reached by the cockroach through under-floor cavities, ducting or drains. It is most commonly found around the ground-floor of buildings, although sometimes it can be discovered on higher levels. It is known for its love of water and in a building, can be located in sewers, drains, basements, cellars, under sinks, baths or washing machines.
Behaviour
Like the German cockroach, the main period of activity is early in the evening but unlike this species it is not a similarly accomplished climber, which means it is more commonly located at ground level. The female lays her eggs in capsules called ootheca, the life cycle can be lengthy with the nymph stage lasting from 6-12 months. This species will feed on any type of decaying organic matter, including garbage, carrying the bacteria with them on every surface that they traverse.
Risks
In the course of their foraging activity, the nymphs, larvae and adults can contaminate and infect foodstuffs. They secrete an odorous discharge from their body which also taints and contaminates food. Like other cockroach species, the Oriental Cockroaches transmit bacteria as they walk, transferring pathogens such as salmonella and e.coli to every area they scurry across. Cockroaches also shed cuticles, faeces and other cockroach debris which are known asthma and allergy triggers.
Ants
Of all insects that infest buildings, ants are the most common. There are many different species of ant. Each is unique in terms of nesting sites, habits, characteristics and feeding preferences.
All ants live in colonies, consisting of:
- An egg-laying female (Queen)
- Short-lived males and workers (sterile female)
- Foragers in gardens or kitchens (workers)
Workers are a nuisance. They forage widely in search of food and can damage food used for human consumption. In hospitals, the pharaoh ant feeds on blood, intravenous fluids and fluids associated with wounds and vomit. Materials can be damaged by ants chewing and some bite.
Identify the invader
Conduct surveys to determine the extent of the infestation and the ant species. Species identification is essential to determine the most effective bait.
Achieve long-term ant control
Successful, long-term ant control requires the destruction of the nest. This is often difficult to achieve as nests are typically located in inaccessible places. Baiting will achieve the most effective control. Foraging ants feed on the bait and transfer the active ingredient back to the rest of the ant colony. Spraying can also be used to form a perimeter barrier treatment that ants don’t like to cross, effectively keeping ants outside the premises.
Rodents
Rodents are arguably the most significant global pest for mankind. The three most common pests are: - the Black Rat - the House Mouse
They are present on every continent, causing problems that range from damage and loss in food production to structural damage and disease transmission. Rats are known vectors of many human diseases such as leptospirosis, typhoid and even salmonellosis. Rodents harbour serious livestock diseases including several bacteria and viruses.
Cleanliness is the key to control
Thoroughly inspect the area to determine the extent of infestation and the type of rodent. Control starts with good sanitation. Eliminate access to food and remove rubbish or clutter which rodents use as breeding or hiding places. Rodent-proof premises by sealing up areas where they can enter the building. Traps can also be used for smaller populations but are less effective for large populations.
Achieve efficient rodent control
Rodenticide baits placed strategically where rats roam and seek food offer efficient control. Today’s rodenticides are anti-coagulants, causing death by inhibiting blood coagulation. This process takes several days. Anti-coagulants treatments fall into two categories:
Single dose
Multi-dose
For single dose, rodents consume a lethal dose in a single feed, whereas for multi-dose, rodents must feed on the baits for several days before accumulating a lethal dose. The advantage of multi-dose is a significantly reduced risk of secondary poisoning of non-target species.
Stored Product Pets
Defining stored product pests
Stored product pests fall into two main insect orders:
- Coleoptera (beetles) - Lepidoptera (moths)
Within each group, some species are considered as primary pests, they attack the whole grain, while others follow the initial damage as secondary pests. Losses can amount to 10% or more of the commodity through spoilage or secondary fungal infection.
Understanding Primary and Secondary Pests
Primary coleopteran pests include:
- grain weevils (Sitophilusgranarius, S.zeamais, S.oryzae)
- the lesser grain borer (Rhyzoperthadominica)
- the saw-toothed grain beetle (Oryzaephilussurinamensis.)
Secondary beetle pests include:
- the flour beetles (Triboliumconfusumand T.castaneum)
The main lepidopteron pests are secondary; they feed regularly on processed foods so are more common in domestic kitchens and larders. A variety of pests infest stored grain. This may occur in succession – primary then secondary. Eggs are laid in the grain or part-processed food (flour, bran etc.) where the larvae feed through to the pupal stage. Moth larvae usually fly to a hidden site away from the food source to pupate, adults then mate and eggs are deposited on or in suitable food. Emerging beetle adults feed on grain or find shelter in the structure of the silo/warehouse prior to invading new food sources.
Flour Beetle
Classification
Species category: Stored product pest Scientific name: Tribolium Castaneum Family: Tenebrionidae
Description
There are many different species of Red Flour Beetle ranging from 2.3- 5.75mm in length. As the name suggests, they are Reddish-brown in colour or black/brown. Although small in size, they have a long body and distinctive segmented antennae with three large club-like segments at the end. They are cosmopolitan insects and found readily all across the world. Serious pests of cereal products, including grain, flour, porridge oats and rice bran. Flour beetles are most commonly encountered in bakeries, flour mills and other agricultural stored grain areas. Other products which may be attacked are oil seed, oil cake, nuts, dried fruit, spices, chocolate – even bones and other animal products.
Behaviour
The beetle lays its eggs in damaged grain and are prolific reproducers, laying 100s of eggs in a breeding season. They are not cold hardy, so only overwinter under warm conditions. They reside in the smallest of crevices, and are a particular problem in machinery where cereal and other food residues accumulate.
Risks
Flour beetles are a secondary grain pest and increase the feeding damage done by primary pests. When present in large numbers, flour beetles:
Make flour prone to moulding and will also turn the product grey.
Taint commodities with secretions from scent glands.
Spider Beetle
Classification:
Species category: Beetles & Weevils Family: Ptinidae
Description:
There are 4 key species:
1. Ptinus tectus (Australian Spider Beetle) 2. Ptinus fur (White Marked Spider Beetle) 3. Niptus hololeucus (Golden Spider Beetle) 4. Gibbium psylloides (Hump Spider Beetle)
Varying in size by species, these insects are on average 1.7-4mm in length and have a dull-brown/red body with golden hairs. The Hump Spider beetle is different and has a shiny, red-brown to black body with no hairs. Spider Beetles have 11 segmented antennae and all share a number of spider-like characteristics including a stout body, long legs and generally, a hairy appearance.
Behaviour:
Gregarious and nocturnal, Spider Beetles spend the day in cracks and crevices amongst packaging and the fabric of a building. They thrive in old buildings where they find safe harbourages. Spider beetle larvae infest all types of dry animal and vegetable matter including grain, spices and fish meal. They will scavenge on debris and bore holes in order to find a safe place to pupate. In doing so, they destroy packaging and contaminate foods. There are 2-4 generations per year in unheated conditions. All stages except eggs and young larvae can overwinter. Peak activity is reached between August and November.
Region:
The Australian Spider Beetle is Australasian in origin and now is widely distributed. Most spider beetle species are cosmopolitan and are rarely imported.
Habitat:
They enjoy dark and damp conditions and readily feed on moisture-damaged food. Infestations often originate from birds’ nests. Spider beetles are becoming increasingly common in domestic premises where they are found in attics, wall cavities and floorboard cracks. Granaries and bakeries also offer the perfect conditions and food sources. Hump Spider beetles are tolerant of cool conditions and can survive for long periods without food supplies.
Risks:
Spider beetles can reduce the quality of commodities by contaminating them with webbing and droppings. The larvae bore into packaging and the grain itself, in addition to other materials such as grain sacks, leaving behind tell-tale holes.
Grain Weevil
Classification:
Scientific name: Sitophilus granarius Family: Curculionidae
Description
There are 3 different species:
- Sitophilus granaries (Grain Weevil) - Sitophilus oryzae (Rice weevil) - Sitophilus zeamais (Maize Weevil)
Each of these species varies considerably in size but has a distinctive elongated snout which is adapted to the size of its preferred grain. Typically, they reach 2-4mm in length and have a long cylindrical body which is dark brown or nearly black in colour. Grain weevils are encountered in all temperate and warm-temperate climates. They are widely distributed around Europe. Both adults and larvae are cold-hardy. Rice and Maize weevils are widely distributed in tropical and sub-tropical areas and will be carried to temperate areas on imported commodities. The maize weevil breeds on maize in the field but the Rice weevil only breeds in stored grain. Both insects will not normally overwinter in unheated premises or grain stored at normal temperatures.
Behaviour
Grain weevils do not fly but instead, infestations often occur after being imported in grain and cereal products, also from the fabric of vehicles used to transport grain or buildings to store it. The female will lay a single egg inside the grain, where larva and pupa stages will occur, once developed, the weevil bores its way out leaving a hole in the grain. The Grain weevil can only breed in grain with moisture content of more than 9.5% and at temperature within the range 13-35C.
Risks
Grain weevils are primary grain pests, infesting undamaged grain and attacking other hard cereal products such as macaroni and spaghetti. Weevil-damaged grain is readily recognised by the presence of large holes which are the exit holes of the emerging adults. Both the adults and the larvae feed on the grain causing holes and also contamination with their excretions. Grain quality and marketability is reduced.