Diplura

Synonyms Dicellura, Entotrophi, Entognatha Common name diplurans Elongate apterygotes head with long many-segmented antennae, compound eyes, and ocelli absent, mouthparts entognathous thoracic segments distinct, legs with unsegmented tarsus abdomen 10-segmented, most pregenital segments with styli, eversible vesicles on some abdominal segments, cerci present as either long multiannulate or forcepslike structures, gonopore between segments 8 and 9. More than 800 species of this widely...

The

PLECOPTEROID, BLATTOID, AND ORTHOPTEROID ORDERS FIGURE 7.17. A proposed phylogeny of Orthoptera. FIGURE 7.17. A proposed phylogeny of Orthoptera. The superfamily Gryllacridoidea is a primitive superfamily that contains nearly 1500 species. Its members are usually somewhat cricketlike in appearance, with longish cerci. However, they may be distinguished from true crickets because males lack a stridulatory mirror on the tegmen, and females have a laterally compressed, not needlelike, ovipositor....

Corpora Allata

Typically the corpora allata are seen as a pair of spherical bodies lying one on each side of the gut, behind the brain (Figure 13.4A,B). However, in some species, the glands may be fused in a middorsal position above the aorta, or each gland may fuse with the corpus cardiacum on the same side. In larvae of cyclorrhaph Diptera the corpora allata, corpora cardiaca, and molt glands fuse to form a composite structure, Weismann's ring, which surrounds the aorta. Each gland receives a nerve (NCA I)...

Supella Supellictilium

Chapter 7 In members of the suborder Blattodea the head is covered with a large, shield shaped pronotum the legs are identical and the gizzard is strongly dentate. Included in this group are two families, POLYPHAGIDAE (about 190 species) and CRYPTOCERCIDAE (nine species in the genus Cryptocercus). The Polyphagidae is a widely distributed family that includes the most primitive living cockroaches. They are generally small (2 cm or less in length) and often have a hairy pronotum. Some inhabit...

Arthropod Evolution

Branchinecta sp., a fairy shrimp. From R. D. Barnes, 1968, Invertebrate Zoology, 2nd ed. By permission of the W. B. Saunders Co., Philadelphia. FIGURE 1.5. Branchinecta sp., a fairy shrimp. From R. D. Barnes, 1968, Invertebrate Zoology, 2nd ed. By permission of the W. B. Saunders Co., Philadelphia. swimmeret (forward swimming) FIGURE 1.6. Crayfish. Ventral view of one side to show differentiation of appendages. eyes, elongate trunk that bears many pairs of legs, articulation of the...

The Panorpoid Orders

A single superfamily, Eriocranioidea, containing three very small families, is included in this group. The ERIOCRANIIDAE (20 holarctic species) are diurnal, iridescent moths with a short proboscis. They appear to feed on sap exudates. Larvae are leaf miners in chestnut, oak, birch, and hazel. Pupation takes place in a cocoon buried in soil. Among the features that characterize members of this suborder are adults (after eclosion) with non-functional (often reduced) mandibles, maxilla without a...

Insects Whose Products Are Commercially Valuable

The best-known insects in this category are the honey bee (Apis mellifera), silkworm (Bombyx mori), lac insect (Laccifer lacca), and pela wax scale (Ericerus pela). The honey bee originally occupied the African continent, most of Europe (except the northern part), and western Asia, and within this area the usefulness of its products, honey and beeswax, has been known for many thousands of years. Though the discovery of sugar in cane (in India, about 500 B.C.) and in beet (in Europe, about 1800...

Zygentoma

Synonyms Thysanura (sensu stricto), Common name silverfish, firebrats Ectotrophi (in part), Ectognatha (in part) Small or moderately sized, dorsoventrally flattened apterygote insects head with long mul- tiannulate antennae, compound eyes small or absent, ocelli absent (except Lepidotrichidae), ectognathous chewing mouthparts, mandible with dicondylic articulation, maxillary palp 5-segmented legs with 2-4 tarsal segments abdomen 11-segmented but with 10th segment

Insects And Humans

Deacon (1983), Khetan (2001), and authors in the volumes edited by Burges and Hussey 777 (1971), Burges (1981), Kurstak (1982), Anderson and Canning (1982), Maramorosch and Sherman (1985), Baker and Dunn (1990), Gaugler and Kaya (1990), Bedding etal. (1993), Hunter-Fujitaetal. (1998), Rechcigl andRechcigl (2000), Koul andDhaliwal (2002), Metz (2003), and Upadhyay (2003) discuss the potential and use of microorganisms as insect pest control agents. The genetic bases for management of insect pest...

Info

Chapter 8 This widespread group contains only about 20 species, all in the family PIESMATI- DAE. Though these phytophagous bugs superficially resemble Tingoidea, morphological studies confirm that they are closely related to the Lygaeoidea (in which they are sometimes included). About 80 of the more than 3600 species of Lygaeoidea belong to the family LY-GAEIDAE, a widely distributed group whose members are usually found on the ground, among vegetation, or under stones or low plants, where they...

Ametabolous Development

In Thysanura (and other primitive hexapods), which as adults remain wingless, the degree of change from juvenile to adult form is slight and is manifest primarily in increased body size and development of functional genitalia. Juvenile and adult apterygotes inhabit the same ecological niche, and the insects continue to grow and molt after reaching sexual maturity. The number of molts through which an insect passes is very high and variable. For example, in the firebrat, Thermobia domestica,...

The Hemipteroid Orders

A water boatman. Sigara atropodonta Vf. ff The 15 species of Thaumastocoroidea are arranged in a single family, THAUMASTO-CORIDAE. Most species of these phytophagous bugs are Australian, though others occur in India, South America, Cuba, and Florida. About 1800 species of Tingoidea are known, the vast majority of which are included in the family TINGIDAE (lacebugs). Members of this cosmopolitan family are easily recognized by the lacelike pattern on the dorsal surface...

Pheromones

Chapter 13 Pheromones are chemicals messages produced by one individual that induce a partic ular behavioral, physiological, or developmental response in other individuals of the same species. Like hormones, they are produced in small quantities indeed, they are referred to in older literature as ectohormones, a term that may take on renewed significance following the discovery that in termites juvenile hormone apparently serves also as a pheromone that regulates caste differentiation (Section...

External Structure

Chewing Mouth Parts Insect

Simplified sectional diagram through the insect head showing the general arrangement of the parts. From R. E. Snodgrass, Principles of Insect Morphology. Copyright 1935 by McGraw-Hill, Inc. Used with permission of McGraw-Hill Book Company. Neuroptera and Coleoptera with the exceptions mentioned below , Mecoptera, primitive Hymenoptera, and larval Ephemeroptera, Trichoptera, and Lepidoptera. However, the basic arrangement may undergo great modification associated with specialized...

Structure of the Thorax

Wing Bearing Segment

In the evolution of the typical insectan body plan there have been two phases associated with the development of the thorax as the locomotory center in the first the walking legs became restricted to the three thoracic segments, and in the second articulated wings were formed on the meso- and metathoracic terga. Accompanying each of these developments were major changes in the basic structure of the secondary segments of the thoracic region. These changes were primarily to strengthen the region...

The History of Insect Classification

Wilson and Doner l937 have fully documented the many schemes that have been devised for the classification of insects, and it is from their account that the following short history is mainly compiled. Papers marked with an asterisk are cited from Wilson and Doner's review. Only the major developments i.e., those that have had a direct bearing on modern schemes have been included, though it should be realized that a good many more systems have been proposed. Insect systematics may be considered...

Hio

Cording to Snodgrass 1957 , the evidence from embryonic and postembryonic development does not support assumption 2 but indicates that the genitalia arose primitively on the tenth abdominal segment. Cerci. Paired cerci occur in Diplura, Microcoryphia, Zygentoma, Ephemeroptera, Zygoptera a suborder of the Odonata , Plecoptera, the orthopteroids and blattoids, and Mecoptera. It is generally agreed that the cerci Figure 3.31 are true appendages of the 11th segment, although frequently all traces...

Xco

Stenodictya Ephemeroptera Larva

Insects were already well established by the Lower Devonian, some 80 million years earlier than previously assumed. This conclusion agrees with a molecular clock study indicating that insects arose in the Early Silurian about 430 million years ago , with neopteran forms present by about 390 million years ago Gaunt and Miles, 2002 . By the Upper Carboniferous period, when conditions became suitable for fossilization, almost a dozen paleopteran and neopteran orders had evolved. Most authors,...

Phylogeny and Classification

Paleoptera

In contrast to that of the other paleopteran order, the Ephemeroptera, the fossil record of the Odonata is remarkably extensive. Carpenter 1992 suggested that the aquatic juvenile stage and the tendency of adults to remain near water would favor the fossilization of these generally robust insects. According to Carpenter 1992 , the earliest odonates from the Permian belonged to the entirely fossil suborders Protanisoptera and Archizy-goptera. Other suborders include the Triadophlebiomorpha...

Abdominal Appendages

Bee Stinger Anatomy

Generally the only appendages seen on the abdomen of an adult pterygote insect are those on the genital segments the external genitalia and the cerci. In the apterygote groups i i jS FIGURE 3.30. Postgenital segments of a female grasshop- .V ovi i itoi- per. From R. E. Snodgrass, Principles of Insect Morphology. Y- Copyright 1935 by McGraw-Hill, Inc. Used with permission of there are, in addition, appendages on a varied number of pregenital segments. All of these 85 may be considered as primary...

Key to the Orders of Insects

The following key, modified from Brues et al. 1954 , is in accordance with the classification used in this book. A few comments are necessary regarding its use. The key is suitable for use with the adult and most larval forms of insects. However, the larval forms of the endopterygote orders are often difficult to identify and, if at all possible, they should be allowed to metamorphose to the adult stage. In some cases it is important to know the original habitat of the specimen, and care should...

Naming and Describing Insects

For a variety of reasons but most obviously the enormous diversity within the class Insecta and economic considerations, insect taxonomists usually work within fairly narrow boundaries. Only by doing this can they acquire the necessary familiarity with a particular group including knowledge of the relevant literature to determine whether the specimen they are examining has been described and named or may be new to science. Even after a particular group has been chosen for study, there are...