eChapters

Objective: To identify agriculturally important insect orders and understand their key morphological characteristics relevant to their impact on agriculture.

Code of Ethics was observed by International Commission on Zoological Nomenclature for renaming of homonyms. The commission had issues declarations or opinions from time to time, which together constitute the start of a code of ethics in the field of nomenclature. The first Declaration of the international Commission was as follows:

• When it is noticed by any zoologist that the generic name or specific name published by any living author as new is in reality a homonym, and therefore unavailable under articles 34 and 36 of the Rules of Nomenclature, the action is for said person to notify the said author of the facts, and give said author an opportunity to propose a substitute name.

• When the author of a newly discovered generic or specific homonym is dead, the discoverer is free to rename the genus or species as he likes. It is common practice to rename the category after the author of the homonym. However, this practice was never universal and it is not a matter of ethics.

Quadrangle: A cell immediately beyond the arculus (Odonata, Zygoptera).

Quadrat: A four-sided defined area from which a sample is collected, used in population determination.

Quadrivoltine: Four life cycles per year.

Qualitative defenses of plants: Toxins and small-molecular-weight compounds (such as alkaloids) that are active against the physiological systems of phytophagous insects; complex, digestibility-reducing substances (such as tannins) that reduce the ability of insects to feed on plants.

Quantitative specificity: In serology, the principle that a given kind of antibody will react more strongly, under comparable conditions, with the particular kind of antigen used in its formation than with any other substance (cf. Antibody, Antigen, and Precipitin reaction).

Ultra low volume spraying (ULV): The application of pesticides in extremely concentrated or undiluted form using 10 liters or less per hectare (1 gal per acre); highly concentrated pesticide applied without dilution at a rate of 0.5 gallons per acre or less.

Umbilical cord: The cord containing blood vessels supported by connective tissue that unites the embryo or fetus of a mammal with the mother during development in the uterus. (L. umbilicus = navel).

Ungulate: Having hoofs, as a deer or (L. ungula = hoof).

Unguligrade: Walking or adopted for walking on hoofs. (L. ungula = hoof + gradior = to step).

Ungue: Pretarsal claw.

Unguiculate: Having claws, as a cat. (L. unguis = claw).

Xerophyte: Plant adapted for survival in desert or physiologically dry soil.

Xylem: The water-conducting woody tissue in vascular plants.

Xylomycetophagy: Cultivation and feeding upon symbiotic fungi growing in woody tree tissues; for example, some Scolytidae.

Xylophage (adj. xylophagous): An eater of wood.

Xylophagy: Feeding on xylem tissues.

Yellow fever: An infectious, mosquito-transmitted viral disease.

A pesticide is any material intended to prevent, destroy, repel, or mitigate any pest, which is defined as a living organism that occurs where it is not wanted or that causes damage to crops, humans, or other animals. There are many different types of pesticides, each is meant to be effective against specific pests. The term “-cide” comes from the Latin word “to kill.”

A pesticide may be referred to by several different names, which can cause confusion. The same pesticide may be referred to by a number of different names, or different pesticides may have similar names.

The grasshoppers are widely distributed throughout the country and may be seen in abundance during monsoon season. For the generalized morphological description, this insect has been considered as the most suitable representative of class insects because its structural details are not much variable. Apart from this, being larger, it can be studied easily. The generalized insect body is divided into 3 distinct body regions: a head, a thorax and an abdomen. Grouping of body segments into distinct regions is known as Tagmosis and the body regions are called Tagmata.

The Head

When two or more chemicals can be used in combination or mixed safely, they are said to be compatible. These combinations can be a pesticide mixed with another non-pesticide chemical, or can be two or more pesticides that are combined in the same tank mix. The reasons for combining pesticides are:

1.To control different types of pests with a single application. Often, several types of pests need to be controlled at the same time. It is generally more economical to combine the pesticides needed and make a single application.

2.To provide superior control than that obtained from one pesticide. Applicators at times combine active pesticides to kill a pest that has not been effectively controlled by either chemical alone. Many combinations are quite effective, but in most cases it is not known if the improved control is a result of an additive effect or a synergistic action of the combined chemicals on different segments of the pest population. One should always check the label prior to verify the safety and legality of mixing pesticides.

3.To increase the effectiveness of one of the chemicals. As mentioned above, this is called synergism. The material added to increase the effectiveness of the primary chemical is called a synergist. The synergist may not necessarily be pesticidal by itself, but increases the effectiveness of the pesticide with which it is combined.

The label on the pesticide container is the principal source of information about a product. The label has all the fundamental information that is required. If you need information about a pesticide, do not rely on memory as it is very easy to make a mistake. Read the label every time before using a pesticide. The lay-out of the pesticide label varies between countries. However, every label on a pesticide container from a reputable manufacturer or source will have the following information:

The best learning situation requires one specimen and set of tools per two students for studies. Students working in pairs have ample opportunity to fully participate in the dissection and to carefully examine the specimen. They are also able to share and discuss their observations during and after the dissection.

Requirements: Dissecting pan with wax pad, dissecting pins, forceps, hand lenses and scissors

Procedure

Place the specimen in the dissecting pan ventral side up. Use scissors to cut through the exoskeleton‘s ventral side from the head to the posterior end of the abdomen.

Jet: Liquid emitted from a nozzle orifice (in USA = nozzle).

JH: An abbreviation of juvenile hormone.

Johnston’s organ: A sense organ similar to a chordotonal organ, located in the second antennal segment of most insects; functions in sound reception in some Diptera (Fig. 153); an organ in the pedicel of the antenna, consisting of a cluster of chordotonal sensilla.

Kairomone: A chemical produced by an individual of one species that has a beneficial effect on the recipient individual of another species; a chemical that is adaptively favourable to the receiving organism; an interspecific messenger substance that benefits the receiver but not the releaser (e.g., attractants, excitants); an interspecific chemical messenger that benefits the receiver but not the emitter; a communication chemical that benefits the receiver and is disadvantageous to the producer; see also Allomone; Synomone.

Karyological character: A character involving chromosome structure or number (cf. Taxonomic character).

Keeled: With an elevated ridge or carnia.

Keratin: The inert exoskeleton protein of vertebrate animals forming skin, hair, feathers, claws, nails, scales, etc.; similar in structure and function to the arthropod chitin.

Keratolytic: Pertaining to or promoting loosening or separation of the outer layer of the skin.

Pesticide Resistance

Resistance to pesticides may be defined as ‘a heritable change in the sensitivity of a pest population that is reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for that pest species.

Requirements: Dissecting pan with wax pad, dissecting pins, forceps, hand lenses and scissors

Procedure

Place the specimen in the dissecting pan ventral side up. Use scissors to cut through the exoskeleton‘s ventral side from the head to the posterior end of the abdomen.

Pull the cut sides apart and observe the internal organs. Pin the sides of the insect to the dissecting pan. The observation of the reproductive systems of males and females are as follows:

Female reproductive system

The main functions of the female reproductive system are egg production and storage of male spermatozoa until the eggs are ready to be fertilized. The basic components of the female system are paired ovaries, which empty their mature oocytes (eggs) via the calyces (Calyx) into the lateral oviduct which unite to form the common (median) oviduct.

The pesticides-one amongst the most important inputs in the crop production contributed a lot to minimize the losses to crop yield. In India, on an average, 33 % of crop loss occurs due to pests and disease and runs to an estimated Rs 1.40000 crore. Pesticide is an essential in the farmers struggle to protect their crops. Pesticides consumption in India reported to 288g/ha is very low compared to global average of 900g/ha. Excessive, irrational and indiscriminate use of these pesticides causes many negative consequences, mainly the famous 3 R viz; Resistance, Resurgence and Residue aspects.

Requirements: Insecticides of different types

Insecticide chemicals in their “raw” or unformulated state are not usually suitable for pest control. These concentrated chemicals and active ingredients may not mix well with water, may be chemically unstable, and may be difficult to handle and transport. For these reasons, manufacturers add inert substances, such as clays and solvents, to improve application effectiveness, safety, handling, and storage. Inert ingredients do not possess Insecticidal activity and are added to serve as a carrier for the active ingredient. Manufacturers will list the percentage of inert ingredients in the formulation or designate them as “other ingredients” on their labels.

Definition

Adjuvants are chemicals incorporated in a pesticide formulation or added to the tank mix, to increase effectiveness and safety. They generally have no effect on pests in themselves.

Strobilurins are a group of chemical compounds used in agriculture as fungicides. They are part of the larger group of QoI inhibitors, which act to inhibit the respiratory chain at the level of Complex III.Some common Strobilurins are azoxystrobin, kresoxim-methyl, picoxystrobin, fluoxastrobin,oryzastrobin, dimoxystrobin, pyraclostrobin and trifloxystrobin. Strobilurins represented a major development in fungus-based fungicides. They were extracted from the fungus Strobilurus tenacellus. They have a suppressive effect on other fungi, reducing competition for nutrients; theyinhibit electron transfer inmitochondria,disrupting energy metabolism and preventing growth of the target fungi. Strobilurins are miracle fungicides ever developed with novel mode of action & mobility that qualifies the Unique New Generation Fungicides controlling Pathogen from diverse class.