A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives. Thus, an elephant is unobjectionable in its natural habitat but a pest when it tramples crops.
Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the superfamily Coccoidea. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.
Weaver ants or green ants are eusocial insects of the family Formicidae. Weaver ants live in trees and are known for their unique nest building behaviour where workers construct nests by weaving together leaves using larval silk. Colonies can be extremely large consisting of more than a hundred nests spanning numerous trees and containing more than half a million workers. Like many other ant species, weaver ants prey on small insects and supplement their diet with carbohydrate-rich honeydew excreted by small insects (Hemiptera). Weaver ant workers exhibit a clear bimodal size distribution, with almost no overlap between the size of the minor and major workers. The major workers are approximately 8–10 mm (0.31–0.39 in) in length and the minors approximately half the length of the majors. Major workers forage, defend, maintain, and expand the colony whereas minor workers tend to stay within the nests where they care for the brood and 'milk' scale insects in or close to the nests.
Vachellia cornigera, commonly known as bullhorn acacia, is a swollen-thorn tree native to Mexico and Central America. The common name of "bullhorn" refers to the enlarged, hollowed-out, swollen thorns that occur in pairs at the base of leaves, and resemble the horns of a steer. In Yucatán it is called "subín", in Panamá the locals call them "cachito". The trees are commonly found in wet lowlands
Aonidiella aurantii or red scale is an armored scale insect and a major pest of citrus. It is thought to be a native of South China but has been widely dispersed by the agency of man through the movement of infected plant material. In the United States it is known as California red scale. It was first found in California between 1868 and 1875, apparently brought there on planting material imported from Australia.
Vachellia drepanolobium, commonly known as whistling thorn, is a swollen-thorn acacia native to East Africa. The whistling thorn grows up to 6 meters tall. It produces a pair of straight spines at each node, some of which have large bulbous bases. These swollen spines are naturally hollow and occupied by any one of several symbiotic ant species. The common name of the plant is derived from the observation that when wind blows over bulbous spines in which ants have made entry/exit holes, they create a whistling noise.
The tree pangolin is one of eight extant species of pangolins, and is native to equatorial Africa. Also known as the white-bellied pangolin or three-cusped pangolin, it is the most common of the African forest pangolins.
Tetraponera is a genus of ants in the subfamily Pseudomyrmecinae that are commonly known as slender ants and are characterized by their arboreal nature and slender bodies. The 86 described species of Tetraponera all live in hollow structures of plants and trees, such as thorns or branches; these hosts are known as myrmecophytes. Tetraponera species are closely related to the New World genus of ants Pseudomyrmex, but differ in their relationships with host plants.
The black bean aphid is a small black insect in the genus Aphis, with a broad, soft body, a member of the order Hemiptera. Other common names include blackfly, bean aphid, and beet leaf aphid. In the warmer months of the year, it is found in large numbers on the undersides of leaves and on the growing tips of host plants, including various agricultural crops and many wild and ornamental plants. Both winged and wingless forms exist, and at this time of year, they are all females. They suck sap from stems and leaves and cause distortion of the shoots, stunted plants, reduced yield, and spoiled crops. This aphid also acts as a vector for viruses that cause plant disease, and the honeydew it secretes may encourage the growth of sooty mould. It breeds profusely by live birth, but its numbers are kept in check, especially in the later part of the summer, by various predatory and parasitic insects. Ants feed on the honeydew it produces, and take active steps to remove the aphid's enemies. It is a widely distributed pest of agricultural crops and can be controlled by chemical or biological means. In the autumn, winged forms move to different host plants, where both males and females are produced. These mate and the females lay eggs which overwinter.
Coccus viridis is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as green scale or sometimes coffee green scale because it is a major pest of coffee crops throughout the world.
Thonningia is a monotypic genus of flowering plants in the family Balanophoraceae containing the single species Thonningia sanguinea. It is distributed throughout much of southern and western Africa, particularly the tropical regions. Common names for the plant include ground pineapple. A familiar plant to humans, it has an extremely long list of common names in many African languages. Many names are inspired by the resemblance of the plant's inflorescence to a pineapple or palm tree. Some of the names can be translated as pineapple of the bush, duiker's kolanut, and crown of the ground.
Crematogaster carinata is a species of ant in the tribe Crematogastrini. It was first described by Gustav Mayr in 1862. It is native to Central and South America, where it is a common species, forming large colonies in the canopy of the forest.
Azteca alfari is a species of ant in the genus Azteca. Described by Carlo Emery in 1893, the species is widespread in Mexico, Central and South America. This ant has a mutualistic relationship with a Cecropia tree. The specific name alfari honours a Costa Rican zoologist Anastasio Alfaro.
Tetraponera rufonigra, is a species of ant belonging to the subfamily Pseudomyrmecinae. It is distributed across Asia, and Africa. Commonly called the Bi-coloured Arboreal ant, they are arboreal and build small nests which are excavated holes usually in dried parts of trees. They are active hunters and hunt small insects. They have a well developed sting and when stung can cause allergic reactions in human beings.
Saissetia coffeae, known generally as hemispherical scale, is a species of soft scale insect in the family Coccidae. Other common names include the helmet scale and coffee brown scale.
Tetraponera penzigi, is a species of ant of the subfamily Pseudomyrmecinae, which can be found in East Africa. It forms an obligate symbiosis with the whistling thorn, a dominant tree in some upland areas of East Africa.
Barteria fistulosa is a species of tree in the family Passifloraceae, native to tropical Central Africa. The tree has an association with an aggressive species of ant with a very painful sting, which lives in its hollow branches and twigs, and gives rise to its common name of "ant tree".
Tetraponera tessmanni is a species of ant in the subfamily Pseudomyrmecinae, which is native to tropical Central Africa, where it inhabits the hollow stems of the liana Vitex thyrsiflora.
Vitex thyrsiflora is a species of woody vine in the family Lamiaceae. It is native to tropical West and Central Africa. Its hollow stem is used as a home by an aggressive species of ant.
An ant garden is a mutualistic interaction between certain species of arboreal ants and various epiphytic plants. It is a structure made in the tree canopy by the ants that is filled with debris and other organic matter in which epiphytes grow. The ants benefit from this arrangement by having a stable framework on which to build their nest while the plants benefit by obtaining nutrients from the soil and from the moisture retained there.
