Additional exercises can be accessed by clicking on the links to the left. A glossary and chapters on supplies and laboratory techniques are also available. Terminology and phylogeny used in these exercises correspond to usage in the Invertebrate Zoology textbook by Ruppert, Fox, and Barnes Hyphenated figure callouts refer to figures in the textbook. Callouts that are not hyphenated refer to figures embedded in the exercise.
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Description Back to Top Pillbugs are nocturnal isopods. During the day they can be found in dark, humid places such as under fallen leaves, rocks, or logs. They are terrestrial crustaceans that live their entire lives on land. Pillbugs feed mainly on decaying plant leaves and other decomposing materials. Life Cycle Back to Top Eggs: The eggs are carried in a marsupium brood pouch on the ventral underside surface of the female and can reach a diameter of 0.
Eggs hatch after three to four weeks. Females may produce one to three broods every year and each brood is composed of to eggs. While in the marsupium, both the eggs and the young survive on nutrients received through marsupial fluid Capinera Figure 3. Pillbug, Armadillidium vulgare Latreille , adult and young. Photograph by Lyle J. Buss , University of Florida.
This first molt allows them to gain the seventh segment of their pereon the thoracic structure in crustaceans. The second molt takes place two weeks later and allows the seventh pair of legs to generate, originating from the newest thoracic segement. The pillbugs continue to molt every one to two weeks for the next 18 weeks. When molting, the posterior portion of the body sheds first and then the anterior portion sheds around three days later Capinera Adult: The adult ranges in color from gray to brown and reaches 8.
Compound eyes are located on the side of the cephalothorax the head-like region in isopods composed of the fused head and thoracic segment Figure 4. The body of Armadillidium vulgare is made up of a thorax known as the pereon with seven segments and an abdomen the pleon with uropods appendages arising from the last segment of the abdomen. Pillbugs have seven pairs of legs, one pair for each segment of the thorax.
Males and females can be distinguished by looking at the ventral underside plane. Males have copulatory organs on the anterior portion of the thorax and females have a pouch for brooding the marsupium , if they are pregnant. Adults can live for two to five years.
Figure 4. Pillbug adults, Armadillidium vulgare Latreille. Photograph by James Castner, University of Florida. Pillbugs are nocturnal and require humid conditions during the day. Pillbugs are generally found in soil with sowbugs, millipedes, and earthworms.
Their preferred soil habitat is composed of organic matter and has a neutral to alkaline pH. Pillbugs are least likely to be found in soil that has been tilled, is too wet, or has an acidic pH Capinera Pillbugs have also been found feeding on seedlings and some plant roots, leading to occasional minor pest status.
Plants with damage to green leaves by Armadillidium vulgare Latreille include Picris echioides and Silybum marianum in the grasslands of California Paris Additionally, Armadillidium vulgare Latreille was found to cause damage to tomato, radish, lettuce, mustard, pea, and bean crops Pierce Armadillidium nasatum has been reported feeding on cucumber plants and fruit Goats Economic Importance and Damage Back to Top A study was conducted on the effects of the detritivorous behavior consumption of dead plant material of the pillbug in the hydric hardwood forest of central Florida.
Pillbugs may also be found inside of homes, but are not known to cause any damage, only annoy people by being present inside their residences. Management Back to Top Preventing the establishment of pillbugs in unwanted areas is the best management strategy. Pillbugs traveling inside a home can easily be swept up and taken outside.
To prevent their re-entry, ensure any floor level cracks and door entries are sealed. Cultural controls for preventing pillbugs from causing damage to seedlings or vegetables and fruit on the soil, may include avoiding overwatering leading to moist soil conditions and removing decaying plant material that may serve as a host area for the isopods. Chemical controls include insecticide bait, dust, granular, and liquid formulations Capinera Genetica Capinera JL.
Handbook of vegetable pests. Academic Press, San Diego. Effects of the exotic crustacean, Armadillidium vulgare Isopoda , and other macrofauna on organic matter dynamics in soil microcosms in a hardwood forest in central Florida. Florida Entomological Society Howard HW. The distribution at breeding time of the sexes of the woodlouse, Armadillidium vulgare Latreille, Isopoda. Crustaceana Pillbugs, sowbugs, centipedes, millipedes and earwigs.
McDaniel EI. Insect and allied pests of plants grown under glass. McDaniel, E. Greenhouse insects. Ziegler A, Suzuki S. Sperm storage, sperm translocation and genitalia formation in females of the terrestrial isopod Armadillidium vulgare Crustacea, Peracarida, Isopoda.
Arthropod Structure and Development Authors: Julie A. Franklin, Morgan A.
There is no nauplius stage, which most crustaceans have. Instead, embryos hatch as immaturely developed adults. After release from the oviduct, they are stored in the marsupium, a fluid-filled pouch present in reproducing females. Eggs are enclosed in both an inner vitelline membrane composed of protein fibers and species-specific sperm receptors and an outer chorion. This structure is hypothesized to regulate ion and acid exchange for the developing embryo. Egg size increases with the size of the mother. When the yolk is fully consumed, the dorsal organ atrophies and the embryo undergoes blastokinesis.
Interesting Facts about A. Sowbugs have two appendages on the posterior end of their bodies. These tail-like appendages are not present in pillbugs. Pillbugs, on the other hand, can roll into a ball when they perceive a threatening stimuli.
They are usually found in moist areas such as decomposing leaf matter and soil. Armadillidium vulgare is the most abundant species in Europe and has been introduced worldwide. However, the vast majority of species are endemic to small regions close to the Mediterranean Sea , in much lower numbers than common species such as A. Description[ edit ] Unlike other terrestrial arthropods such as insects and spiders, pill bugs do not have a waxy cuticle that would reduce evaporation from their bodies. Pill bugs also use modified lungs, called pseudotrachea, for respiration, and the lungs must remain moist to function. Individual pill bugs typically live for two or three years, and females brood eggs once or twice each summer. Several hundred eggs are brooded at a time in the marsupium, a pocket on the ventral side of the female pill bug.