Class 5: Insects

[The Insects and Arachnids]

INSECTS

Oviparous animals, undergoing metamorphoses, able to have wings, and possessing, in the perfect state, six articulated limbs, two antennae, two faceted eyes, and a horny skin.

Respiration by aerated trachaea which extend to all the parts; no system of circulation; two distinct sexes; one single reproductive act in a lifetime.

Observations

This has extremely numerous animals and a very different order of things from the 4 preceding classes.

In the place of modulations in the progressive complexity of the organic structure in animals, once we arrive at the insects, in this matter we have made quite a considerable leap.

They have:

• true heads which are always distinct
• very remarkable eyes (although still very imperfect)
• articulated limbs arranged in 2 rows
• the symmetrical form of paired and opposing parts which nature will use from this point on right up to and including the most perfect animals.

In the interior, they have a complete but very imperfect nervous system of nerves which end a a longitudinal ganglionic chord.

The area where the sensations meet appears very fractured.

The senses are few and very obscure.

They have a real muscular system and distinct sexes which, however, can provide only a single fertilization (as with the plants).

They do not have a circulatory system.

It is necessary to go higher in the animal chain to find this improvement in organic structure.

The property of all insects is having wings in their perfect state, so that those which lack them have been deprived only by an abortion which has become habitual and constant.

Observations

The genera have been reduced to fewer.

Interest in studying the subject and the simplicity and the clarity of the method seemed to me to demand this reduction, which is not going to harm at all an understanding of the objects.

To use all the particular details which one could seize upon in the characteristics of animals and plants in order to multiply genera to infinity is to clutter up and obscure science instead of serving it.

It makes the study of science so complicated and difficult, that it would become impossible to practice it, except for those who wished to dedicate their entire lives to learning the immense nomenclature and the minute characteristics used to make distinctions among animals.

A. SUCKING INSECTS

Their mouths display a sucker furnished or lacking a sheath

First Order: Apterous Insects

A proboscis with two valves and articulated in three places, containing a sucking organ with two bristles The wings have usually aborted in both sexes; legless larvae; immobile nymph in a cocoon.

Flea

Second Order: Dipterous Insects

A non-articulated proboscis, straight or with an elbow, sometimes retractile. Two bare wings membranous and veined; two balancers; vermiform larvae, most often without feet

Hippobosca (Horse Fly) Oestrus

Stratiomys Syrphus Anthrax Fly

Stomoxe Myopa Conops

Empis Bombylus Asilus Taon Rhagio

Cousin Tipula Simulium Bibio

Third Order: Hemipterous Insects

Sharp articulated beak, curved under the chest serving as a sheath for a sucker with three bristles. Two wings hidden under membranous elytra; larvae with six feet; the nymph moves and eats.

Dorthesia Cochinea Psylla Aphids Aleyrodes Thrips

Cicada Fulgora Tettigonia

Scutellera

Pentatoma Bed Bugs Coraeus Reduvius Hydrometra Gerris

Nepa Notonecte Nancoris Corixa

Fourth Order: Lepidopterous Insects

A two-part sucker, lacking a sheath, like a tubular proboscis, and folded up as a spiral when inactive. Four membranous wings, covered with colour scales like flour. The larvae have eight to sixteen limbs, inactive chrysalis.

(1) With subulate or setaceous antennae

Petrophorus Orneodes Cerastoma Tinea Noctua Phalaena

Alucita Adella Pyralis

Hepialus Bombyx

(2) Antennae swollen somewhere along their length

Zygoena Butterfly

Sphinx Sesia

(B) BITING INSECTS

Their mouths display mandibles, most often accompanied by jaws

Fifth Order: Hymenopterous Insects

Mandibles and a three-sectioned sucker more or less extended, the base of which is enclosed in a short sheath. Four bare wings (membranous, veined, unequal); in the female the anus is equipped with a sting or apparatus for boring; immobile nymph.

(1) Females equipped with a sting in the anus

Bee Monomelites Nomads Eucera Andrena

Wasp Polistes

Ant Mutilla Scolia Tiphia Bembex Crabro Sphex

(2) Females equipped with a boring apparatus in the anus

Chrysis Oxyurus

Leucopsis Chalcis Cinips Diplolepis Ichneumon

Evania Foene

Urocere Oryssus Tenthredo Clavellair

Sixth Order: Neuopterous Insects

Mandibles and jaws; four naked wings (membranous and reticulated); lengthened abdomen, lacking a sting or boring apparatus; six-footed larva; variation in the metamorphoses.

(1) Inactive nymphs

Perla Nemoura Frigania

Hemerobius Ascalaphus Myrmeleon

(2) Active nymphs

Nemopterea Panorpa Psocus Termes

Corydalis Chauliodes

Raphidia Ephemera

Agrion Aeshna Libellula

Seventh Order: Orthopterous Insects

Mandibles, jaws, and galeae covering the jaws; two straight wings, longitudinally folded and cover by two almost membranous elytra; larvae as in the perfect insect, but having neither wings nor elytra; active nymph.

Grasshopper Acheta Locust Truxalis

Mantis

Phasma Spectrum

Cricket Cockroach Earwig

Eighth Order: Coleopterous Insects

Mandibles and jaws; two membranous wings, transversely folded in repose and under two hard or coriaceous shorter elytra; six-footed larvae; scaly head and eyeless; inactive nymph.

(1) Two or three parts in every tarsal

Pselaphus

Lady-bird Eumorphus

(2) Four parts in every tarsal

Erotylus Cassida Chrysomela Galeruca Leptura Stencorus Saperda Necydalis Callidium Cerambix Sprionus Spondilus

Bostrichus

Crioceris Clythra Griborus

Mycetophagus Trogossita Cucujus

Bruchus Attelabus Brentus Curculio Brachycerus

(3) Five parts in the tarsals of the first pair of feet and four on those of the third pair.

Opatrum Tenebrio Blaps Pimelia Sepidium Scaurus Erodius Chiroscelis

Helops Diaperis

Cistela

Momrdella Rhipiphorus Pyrochroa Cossiphus Notoxus Lagria Cercoma Apalus Horia Mylabris Cantharis Meloe

(4) Five parts on every tarsal

Lymexylon Telephorus Malachius Melyris Lampyris Lycus Omalysus Drilus

Melasis Buprestis CLick beetle

Ptinus Death-watch Ptinus

Staphylinus Ips. Dermestes Anthrenus Byrrhus Hister. Sphoeridinus

Trox. Cetonia

Oxyporus Poederus —–Cicindela Elaphrus Scarites Manticora Carabus Dyticus

Hydrophilus Gyrinus Dryops Clerus.

Necrophorus Carrion-beetle Nitidula Goliathus Cockchafter Lethrus Geotrupes Copris Scarabaeus Passalus Lucanus