Coccoidea

Description

The all Coccoidea are of the parasite S of the vegetable . They are characterized by a very extremely sexual Dimorphisme. The adult male has a single pair of wings (former), antennas and legs (uniarticulate tarsi) developed, whereas the females are Aptère rare S. Fait at the Hémiptère S, the females have only reduced appendices (they live fixed on plants, except with the state of nymph). The female resembles a larva in form of scale, Galle or covered with wax. It is not mobile and is nourished while being fixed on the stems or the sheets of certain plants of which it sucks the sap.

Coccoidea are nourished of a broad variety of Plante S, so that the majority of them are regarded as Nuisible S. Faute of food, they die at the end of one or two days .

The cochineals secrete a matter of appearance cotonneuse, made up of fine waxy filaments or waxy scales. Certain species have the reputation to have a toxic saliva.

Reproduction and life cycle

The system of reproduction within this group is very heterogeneous and includes/understands for example Hermaphrodisme and seven forms of Parthénogenèse.

The cochineals know three developmental stages:

the egg,
the nymph (mobile, with 3 larval stages L1, L2 and L3),
the adult (the female, fixed, lays many very small eggs, deposited under it, in a white wax bearing)

The annual number of generations varies according to the species and the climate.

Parasitism

In fact Parasite S seldom kill their hosts, but who can pose problem in agriculture, horticulture, sylviculture and in the orchards. Certain infestations of trees, branches and sheets by cochineals are becoming characteristic of the urbanized and very anthropized mediums. Also sometimes one finds them on adjacent objects (ex: the collars which bind the tree to the tutors).

These insects make devastations on the fruit trees and in particular the apple trees. To come ecologically to end, to pulverize a soft soap solution in which you will have added methylated spirits 1%.

Distribution

One for example counted of them 159 species in Sicily (of which about half at least are recently introduced parasites of the cultures) One counts 343 in Italy of them. The best known ones are those which parasitize the cultivated species.

They were famous not very mobile and thus at the weak risk of dissemination. They are however in Europe in full expansion on the urban trees stressed by the pollution or the urban context and perhaps via transport of parasitized seedlings. Perhaps do the birds contribute to transport eggs? The larvae seem to be able to be transported by the wind.

The pullulations of cochineals out of their natural environments are increasingly frequent, on all the continents, and they are badly included/understood.
Il is possible that a lack of water, that certain urban pollutants or a thermo-hygrometrical Couple abnormal support this parasitic insect. Another explanation can be to seek in the regression or disappearance of predatory natural of the cochineals, in particular the microphone Hyménoptère S which parasitize them and control them in nature, following the increase in the rate of Pesticide S in the air. Like all the insects stitcher-nozzles, these species (in particular introduced) are potentially dangerous for the plants, because of the viruses which they could bring, but also because of the specific absence of predator in the host country. The adult larvae or eggs or individuals are frequently introduced with the house plants, fruit and vegetables.

Natural enemies

Their principal predatory seem to be certain species of ladybird and microphone Hyménoptère S parasites. The large wasps or the ants are famous to save them and consume to them Miellat, but various hyménoptères whose Metaphicus helvolus or Metaphicus bartletti parasitizes the larval stages cochineal in a larval state or an adult state.
Diversinervus elegans (tiny wasps) parasitizes the adult or the larva. Some predatory of this insect was used in biological fight, of which for example Chilicorus renipustulatus and Chilicorus nigritus , two small ladybirds which tackle various species of cochineals (Diaspine S and Lécanine S).

Horticultural treatments

The shield, the wax which protects these insects and their eggs make them not very accessible to the external Pesticide S. The latter are aqueous solutions which slip above. One can add wetting agents to it (soft soap, liquidates crockery…) or to use insecticidal oils directly. Another very effective means (but which does not prevent the existence of resistant forms) is the use of systemic products. They are substances which will penetrate the plant and will circulate in all the system (from where the name) vascular, in other words the sap. Any insect which will consume any part of the plant (including roots) will die. It should be held account owing to the fact that the eggs do not consume anything until the blossoming: it is thus necessary to reprocess a week with 10 J afterwards against the second génération.
Obviously, it is important to be sure to treat all the plants concerned. In the event of repetition it is necessary to think of all of examining them, including sometimes the " bad herbes" …

Economic interest

Certain types played an important economic part but it declined considerably since the invention of the substances of synthesis. The cochineal is usable to produce:

- Lacquer S, like the shellac resulting from the species Kerria lacca and used to manufacture pharmaceutical dragees, the coating of some Chocolate S " who do not found in the main" and formerly among the first plastics (first discs 78 turns);

- Carmine of cochineal, produced starting from alive Dactylopius coccus on the Kermes oak in Spain then another species living on a Cactus with the Mexico).

Foot-note: the Manne which would have allowed the Hebrew to cross the desert could be the Miellat of a Cochenille.

Taxonomy

Let us tax lower: S:

Aclerididae
Asterolecaniidae
Beesoniidae
Carayonemidae
Cerococcidae
Coccidae
Conchaspididae
Dactylopiidae
Diaspididae
Electrococcidae
Eriococcidae
Grimaldiellidae
Halimococcidae
Inkaidae
Jersicoccidae
Kermesidae
Kerriidae
Kukaspididae
Labiococcidae
Lecanodiaspididae
Margarodidae
Micrococcidae
Ortheziidae
Phenacoleachiidae
Phoenicococcidae
Pseudococcidae
Putoidae
Stictococcidae

Three great types of cochineals:

Those which have a soft body, without protective shield .
Elles protects under waxy filaments

Pseudococcidés and Margarodidés:

Examples:

farinaceous Cochineal of the greenhouses (Pseudococcus adonidum)

Australian Cochineal (Icerya purchasi)

Those which have a body hardened by impregnation of wax or lacquer (lécanines, or lécanies, of the family of Lécanidés)

Exemples:

Cochineal of the dogwood (Eulecanium corni)

Cochineal of fishing (Eulecanium persicae)

Cochineal of the greenhouses (Saissetia hemisphaerica)

Cochineal of the olive-tree (Saissetia oleae)

flocculent Cochineal of the vine (Pulvinaria vitis)

Lécanie of the oak (Parthenolecanium quercifex)

Lécanie de Fletcher (Parthenolecanium fletcheri)

Lécanie of the vine (Parthenolecanium corni)

Those which have a soft body, cover of a waxy protective counting frame (Diaspididés) whose form would point out a tiny oyster shell.

Examples:

Louse of san Jose (quadraspidiotus perniciosus)

Cochineal of the fruit trees with pips (Quadraspidiotus piri and Q. ostraeiformis)

Cochineal comma of the apple tree (Lepidosaphes ulmi)

Cochineal of the pear tree (Epidiaspis leperii)

Louse of the orange tree (Chrysomphalus aonidum and C. dictyospermi)

black Cochineal of the citrus fruits (Parlatoria zizyphii), Cochineals billhook of the citrus fruits (Lepidosaphes citricola and L. gloweri)

Cochineal of the mulberry tree (Pseudolascaspis pentagona)

Examples of species

See too

Internal bonds

cochineal

External bonds

site USDA,
cohenille seen under the electron microscope, ventral face dead bond
cochineal, electronic microscopy dead bond
document of the INRA

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