Psytalla is a genus of insects belonging to the assassin bugs. Species within this genus include: Psytalla ducalis Psytalla dudgeoni Distant, 1919 Psytalla horrida Psytalla incognita Distant, 1919 Psytalla johnstoni Distant, 1919 Psytalla samwelli Distant, 1919
The wheel bug is in the family Reduviidae, which consists of assassin bugs. The species is one of the largest terrestrial true bugs in North America, reaching up to 1.5 inches in length in their adult stage. However, males are smaller in terms of their width when compared to females. A characteristic structure is the wheel-shaped pronotal armor, they are predators upon soft-bodied insects such as caterpillars, Japanese beetles, the cabbage worm, orange dogs, tent caterpillars, the Mexican bean beetle, all of which they pierce with their beak to inject salivary fluids that dissolve soft tissue. Wheel bugs are most active in daylight, though they may engage in predatory behaviors at night in areas illuminated by lights; because most of their prey are pests, wheel bugs are considered as beneficial to the garden as ladybugs. Wheel bugs are common in eastern North America, but are confirmed to occupy areas of Mexico and Guatemala, they are camouflaged and shy, residing in leafy areas and hiding whenever possible.
Habitats of the wheel bug include sunflowers, cotton, trunks of locust trees, various fruit and tree groves. They have membranous wings, allowing for clumsy, noisy flight which can be mistaken for the flight of a large grasshopper; the adult is gray to brownish gray in color and black shortly after molting, but the nymphs have bright red or orange abdomens. It was taxonified in 1831 by Carl Wilhelm Hahn. Regardless of the prevalence of the wheel bug in many habitats, the information compiled concerning the species is haphazard and incomplete; the wheel bug has a characteristic dorsal crest, shaped like a cog. It moves and flies and in flight produces a noisy buzzing sound; as with other assassin bugs, its proboscis arises from the anterior end of its long, tubular head and unfolds forward when feeding. It possesses two scent glands that can be ejected from its abdomen in reaction to being disturbed; the scent produced by it is not as powerful as that produced by the stink bug, but is still strong enough to be detected by humans.
Wheel bugs exhibit armored forewings and membranous hind wings which allow the wheel bug to take flight. As a result of its incapacity to move swiftly, wheel bugs rely upon camouflage, the effect of their punishing, segmented proboscis, or the excretion of unpleasant odors in order to evade predation. In addition, wheel bugs feature cephalization in the form of a pair of long antennae which project from the head. Wheel bugs initiate pinning their prey with their front legs; the bug plunges its beak into its victim before injecting it with enzymes, paralyzing it and dissolving its insides, proceeds to drain the resulting fluids. The wheel bug is noted to be vicious in the wild, cannibalistic behaviors between them have been noted. Additionally, the species is capable of disseminating auditory clicking signals by creating friction between its proboscis and thorax; the purpose of this sound is unknown, may serve as a means of communication between members of the species. The reproductive cycle of the wheel bug initiates in autumn.
When a pair of wheel bugs encounter each other and have coitus, the female will lay 40-200 small, cylindrical eggs, die. The eggs will hatch in the next spring into eight millimeter long red nymphs, which will undergo 5 molts until they reach the adult stage the following summer. Females lay eggs at a low elevation on trees, bushes and other objects. Secreted glue serves as an adhesive. After the nymphs hatch, the average length of each molt is 18.8 days, though the 5th and final molt prior to the adult stage is the longest. Eggs hatch in the beginning of May and mature into adults by July. Overall, it takes 94 days for nymphs to reach maturity. However, the phenology of this life cycle varies based upon the climate which the population occupies. For instance, communities in warm climates may not overwinter as eggs. In a laboratory test conducted of wheel bugs at the Southern Illinois University Entomology Collection in 1997 and 1998, research revealed that the species’ eggs face the daunting threat of being infected by parasitic organisms, namely Ooencyrtus Johnsoni and Anastatus Reduvii.
Of the 12 clusters of eggs monitored in the lab, 10 were ravaged by parasites which prevented the eggs from hatching normally. The proboscis develops in the early molts, allowing the wheel bug to practice predatory habits in its nymphal stages. Alternatively, the distinctive wheel unique to the species derives only after the wheel bug reaches the adult stage following the final molt. Wheel bugs are regarded by organic gardeners because they consume a variety of insects and their presence indicates a healthy, pesticide-free ecosystem. "They're the lion or the eagle of your food web," Dr. Michael J. Raupp, an entomologist at the University of Maryland, notes. "They sit on top. When you have these big, ferocious predators in your landscape, that tells me that this is a healthy landscape, because all these other levels in your food web are intact."Though wheel bugs are a welcome agent of pest control, they prey on several ecologically beneficial species, such as lady beetles and honey bees. The species is indifferent concerning the presence and interruption of humans.
Although evidence suggests that wheel bugs can be domesticated in controlled environments, if provoked or mishandled, they may att
Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey by stealth or by strategy, rather than by speed or by strength. Ambush predators sit and wait for prey from a concealed position, launch a rapid surprise attack; the ambush may be set by hiding in a burrow, by camouflage, by aggressive mimicry, or by the use of a trap. The predator uses a combination of senses to assess the prey and to time the strike. Nocturnal ambush predators such as cats and snakes have vertical slit pupils, helping them to judge the distance to prey in dim light. Different ambush predators use a variety of means to capture their prey, from the long sticky tongues of chameleons to the expanding mouths of frogfishes. Ambush predation is distributed in the animal kingdom, spanning some members of numerous groups such as the starfish, crustaceans, insects such as mantises, vertebrates such as many snakes and fishes. Ambush predators remain motionless and wait for prey to come within ambush distance before pouncing.
Ambush predators are camouflaged, may be solitary. Pursuit predation becomes a better strategy than ambush predation when the predator is faster than the prey. Ambush predators use many intermediate strategies. For example, when a pursuit predator is faster than its prey over a short distance, but not in a long chase either stalking or ambush becomes necessary as part of the strategy. Ambush relies on concealment, whether by staying out of sight or by means of camouflage. Ambush predators such as trapdoor spiders on land and mantis shrimps in the sea rely on concealment and hiding in burrows; these provide effective concealment at the price of a restricted field of vision. Trapdoor spiders excavate a burrow and seal the entrance with a web trapdoor hinged on one side with silk; the most well-known door is the cork-type, thick and beveled to fit the opening. The other is a simpler sheet of silk and dirt; the top of the door is camouflaged with bits of debris such as twigs and rock, making it difficult to detect.
The spider spins trip wires, that radiate out of the burrow entrance. When the spider is using the trap to capture prey, its chelicerae hold the door shut on the end furthest from the hinge; the vibrations of passing prey are conducted by the silk and alert the spider whereupon it throws open the door, ambushes the prey and returns with it down the tube. Many ambush predators make use of camouflage so that their prey can come within striking range without detecting their presence. Among fishes, the warteye stargazer buries itself nearly in the sand and waits for prey; the devil scorpionfish lies buried on the sea floor or on a coral head during the day, covering itself with sand and other debris to further camouflage itself. The tasselled wobbegong is a shark whose adaptations as an ambush predator include a flattened and camouflaged body with a fringe that breaks up its outline. Many ambush predators attract their prey towards them before ambushing them; these animals are classified as aggressive mimics.
The promise of nourishment as a way of attracting prey. The alligator snapping turtle is a well-camouflaged ambush predator, its tongue bears a conspicuous pink extension that can be wriggled around. Some snakes employ caudal luring to entice small vertebrates into striking range; the zone-tailed hawk, which resembles the turkey vulture, flies among flocks of turkey vultures suddenly breaks from the formation and ambushes one of them as its prey. There is however some controversy about whether this is a true case of wolf in sheep's clothing mimicry. Flower mantises are aggressive mimics, resembling flowers convincingly enough to attract prey that come to collect pollen and nectar; the orchid mantis Hymenopus coronatus attracts its prey, pollinator insects, more than flowers do. Crab spiders are coloured like the flowers they habitually rest on, but again, they can lure their prey away from flowers; some ambush predators build traps to help capture their prey. Lacewings are a flying insect in the order Neuroptera.
In some species, their larval form, known as the antlion, is an ambush predator. Eggs are laid in the earth in caves or under a rocky ledge; the juvenile creates a small, crater shaped trap. The antlion hides under a light cover of earth; when an ant, beetle or other prey slides into the trap, the antlion grabs the prey with its powerful jaws. Some but not all web-spinning spiders are sit-and-wait ambush predators; the sheetweb spiders tend to stay with their webs for long periods and so resemble sit-and-wait predators, whereas the orb-weaving spiders tend to move from one patch to another. Ambush predators must time their strike carefully, they need to detect the prey, assess it as worth attacking, strike when it is in the right place. They have evolved a variety of adaptations. For example, pit vipers prey on small birds, choosing targets of the right size for their mouth gape: larger snakes choose larger prey, they prefer to strike prey, both warm and moving. The deep-sea tripodfish Bathypterois gra
In biological classification zoology, the type genus is the genus which defines a biological family and the root of the family name. According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal family-group taxon is a nominal genus called the'type genus'; the type genus for a family-group name is the genus that provided the stem to, added the ending -idae. Example: The family name Cricetidae has as its type genus the genus Cricetus Leske, 1779. In botanical nomenclature, the phrase "type genus" is used, unofficially, as a term of convenience. In the ICN this phrase has no status; the code uses type specimens for ranks up to family, types are optional for higher ranks. The Code does not refer to the genus containing that type as a "type genus". Example: "Poa is the type genus of the family Poaceae and of the order Poales" is another way of saying that the names Poaceae and Poales are based on the generic name Poa. Principle of Typification Type Type species
An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
In anatomy, the term rostrum is used for a number of phylogenetically unrelated structures in different groups of animals. In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes, it is a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. Among insects, the rostrum is the name for the piercing mouthparts of the order Hemiptera; the long snout of weevils may be called a rostrum. Gastropod molluscs proboscis. Cephalopod molluscs have hard beak-like mouthparts referred to as the rostrum. Invertebrate rostrums In mammals, the rostrum is that part of the cranium located in front of the zygomatic arches, where it holds the teeth and nasal cavity; the beak or snout of a vertebrate may be referred to as the rostrum. Some cetaceans, including toothed whales such as dolphins and beaked whales, have rostrums which evolved from their jawbones; the narwhal possesses a large rostrum. Some fish have permanently protruding rostrums. Billfish use rostrums to stun prey.
Paddlefish, goblin sharks and hammerhead sharks have rostrums packed with electroreceptors which signal the presence of prey by detecting weak electrical fields. Sawsharks and the critically endangered sawfish have rostrums which are both electro-sensitive and used for slashing; the rostrums extend ventrally in front of the fish. In the case of hammerheads the rostrum extends both laterally; the upper jawbones of some fish have evolved into rostrums Beak Nostril Snout
Insects in the subfamily Phymatinae are called ambush bugs after their habit of lying in wait for prey, relying on their superb camouflage. Armed with raptorial forelegs, ambush bugs capture prey ten or more times their own size, they form a subgroup within the assassin bugs. Phymatinae are 5–12 mm long. In Phymata, the scutellum is triangular and shorter than the pronotum. In Macrocephalus, the scutellum extends to the tip of the abdomen. Phymatinae have a large fore femur and clubbed antennae; the forewing membranes sometimes lack distinct cells. The antennae have four segments. There are two ocelli; the beak has three segments. The tarsi have three segments; the rear half of the abdomen expands beyond the edges of the wings. The name Phymatinae is derived from the Greek phymata meaning "swollen", which refers to the enlarged abdomen and femora; the subfamily Phymatinae was given family-level status and this classification is still used in some textbooks. Based on cladistic analyses, ambush bugs are part of the family Reduviidae.
The Phymatinae include the following genera: Amblythyreus Lophoscutus Kormilev, 1951 Macrocephalus Swederus, 1787 Phymata Latreille, 1802 Themonocoris Glossopelta Carcinocoris Chelocoris Microtomus Neocentrocnemis Ptilocnemus Agdistocoris Agreuocoris Bakerinia Cnizocoris Diurocoris Eurymnus Extraneza Goellneriana Hoberlandtiana Kormilevida Metagreuocoris Narina Oxythyreus Parabotha Paragreuocoris