eChapters

22.1. Aim

To estimate the fruit firmness.

22.2. Apparatus/machineries/equipments required

• Magness Taylor Pressure Tester

• Penetrometer

22.3. Theory and principle

Fruit firmness is an important feature of maturity. During ripening, fruits may soften and become too soft at the overripe stage. The changes are detected by touching or by using devices like texture analyzers and pressure testers to measure texture of fruits and vegetable.

25.1. Aim

To estimate the ash content in fresh and processed products.

25.2. Theory and principle

Estimation of ash contents is important as it gives an idea about the presence of minerals in the food samples. Determination of ash is also required to evaluate fruit chutneys as the maximum limit for ash in this product shall not exceed 5% as per FPO specifications.

25.3. Apparatus/instruments/equipment

1. Crucibles

2. Muffle furnace

3. Sensitive balance

4. Heating plate

5. Desiccators

54.1. Aim

To determine crude fibre in given samples.

54.2. Theory

Fibres can be classified into four categories like crude fibre (cellulose); acid detergent fibre (cellulose + lignin); neutral detergent fibre (cellulose + lignin + hemicelluloses) and total dietary fibre (Cellulose + lignin + hemicelluloses + pectic substances). Crude fibre is the organic residue of a sample. A fat free sample is treated with boiling sulphuric acid and subsequently with sodium hydroxide. The residue after subtraction of ash is regarded as crude fibre.

54.3. Reagents/ Apparatus/Glassware

1. 0.255 N Sulphuric acid solution

2. 0.313 N Sodium hydroxide solution

3. 10% Potassium sulphate solution

4. Ethanol

Whenever the daily maximum temperature exceeds more than average values during summer season the heat wave will occur. Similarly, whenever the daily minimum temperature falls below the average values cold wave will occur. The India Meteorological department has developed the criteria to identify the occurrence the heat waves and cold waves.

11.1 Heat Waves

Heat wave is defined as the condition when the daily maximum temperature is 45ºC or more. Based on departure from normal daily maximum temperature of 40ºC onwards the heat waves are defined as follows:

According to Thornthwaite’s method of climatic classification, six major types of climates exist in India (Fig. 14.1) as stated below:

14.1 Perhumid Regions of India (A)

These regions receive rainfall of more than 2500 mm and consist of Konkan region along Western Ghats, Kerala and most parts of northeast India covering Assam, Meghalaya, Arunachal Pradesh and Tripura etc.

14.2 Humid Regions of India (B)

These regions receive annual rainfall ranging from 2000-2500 mm and are found in areas adjoining perhumid climate.

Depending on various findings of the study, the present section put forwards some of the policies that can be implemented for using population mobility as a tool of economic development in both rural and urban areas.

• Steps must be taken to boost up the urban services sector as it is the most attractive sector for urban in-migrants. Pro-migrant policies including some economic and social benefits e.g. free health insurance, employees’ provident fund, grater loan facilities at lower rate etc. must be provided to the migrants so that it helps the labors as well as self-employed persons of urban informal sector.

8.1 Limitations

1. The research was limited to a specific geographic area.

2. The study was constrained by limitations in time and reSources.

3. The study relies on the subjective opinions of the participants, which may be influenced by their individual perspectives and biases, despite the researcher’s efforts to gather them as objectively as possible.

4. It would have been advantageous to include a broader range of relevant variables in the study.

5. A suitable statistical model could have been employed to provide thematic support for the behavior and functioning of the system.

6. The selection of variables could have been expanded by incorporating additional variables that would have demonstrated resilience in domain interactions.

Arsenic contamination is one of the serious concerns for public health throughout the world. During the weathering of rocks and minerals, which are followed by subsequent leaching and runoff, arsenic (As) is released into the soil and groundwater. Additionally, human sources can transfer it into the soil and groundwater. Depending on the geological settings, geochemistry, and geo-environmental conditions of an aquifer, different aquifers may have different adsorption and desorption processes, arsenic species, Eh, pH, solid phase dissolutions, and precipitations. Therefore, rigorous geochemical investigation for an adequate understanding of arsenic geochemistry under different hydrogeological and geo-environmental conditions of aquifers is essentially required for evolving sustainable solutions. All of the arsenic affected river plains have river routes originated from the Himalayan region. Arsenic in groundwater contamination has far-reaching consequences including its ingestion through the food chain, which are in the form of social disorders, health hazards and socioeconomic dissolution besides its sprawling movement, and exploitation of groundwater. Food crops produced with arsenic tainted water are marketed to other locations, including areas where people may eat the tainted food and be exposed to arsenic. The arsenic contamination of groundwater is a form of groundwater pollution which is due to naturally occurring high concentrations of arsenic in deeper levels of groundwater.

A farm tractor is a versatile, heavy-duty agricultural vehicle designed to perform a wide range of tasks on the farm. Tractors are a cornerstone of modern agriculture, and they come in various sizes, power ranges, and configurations to meet the diverse needs of farmers and agricultural operations. Tractors are used for tasks like plowing, planting, cultivating, harvesting, and transporting goods on the farm. They are indispensable tools that have greatly increased the efficiency and productivity of agriculture.

The choice of tractor type depends on the specific needs of the farm, the type of crops grown, the terrain, and the available budget. Farm tractors continue to evolve with technological advancements, incorporating features such as GPS guidance, advanced hydraulics, and climate-controlled cabs to enhance efficiency and operator comfort.

Resource Conservation Technologies are essential for addressing environmental challenges, reducing resource depletion, and achieving sustainability goals. By efficiently managing and preserving these resources, we can minimize negative impacts on the environment, reduce costs, and ensure that these resources are available for future generations.

Resource Conservation Technologies (RCT) are practices, methods, and technologies used in various industries, primarily in agriculture and natural resource management, to efficiently and sustainably utilize and preserve valuable resources such as water, soil, energy, and biodiversity. These technologies aim to reduce waste, minimize environmental impact, and enhance the overall productivity and sustainability of resource-dependent activities. Here are some key aspects of resource conservation technologies:

Water Conservation Technologies: RCTs for water conservation focus on efficient water use in agriculture, industrial processes, and domestic settings. Examples include drip irrigation, rainwater harvesting, and the use of sensors to optimize water application.

The study, which was conducted for nature and dynamics of farm ecology in occupational migration in some areas of West Bengal with the stipulated objectives, the following course of action can be considered in future while conduction repeating study.

• Gender dimensions on occupational migration is the future research area.

• Educational issues for families on transit could have been a very interesting area of research.

• Climate refuge; that is migration due to climate change can be an important area of research.

• Application of data analytics could be effective for modelling and simulation on occupational migration.

• The social ecology of migration itself, is a zone of future research.

The craniofacial region presents a unique challenge for implantable biomaterials because the pull of the craniofacial muscles produces variable loading in different regions. In addition, craniofacial skin loses elasticity with the age and develops subcutaneous tissue sags.

Even though surgeons are familiar with the use autogenous bone grafts for craniofacial reconstruction, the usage of alloplastic bone substitutes has increased continuously, because autogenous bone is difficult to harvest, time consuming, causes significant donor morbidity, and bone resorption, but most important thing is that the biocompatibility of current alloplastic materials are improving.

Synthetic substitute creates a new avenue for clinicians to explore as adjunct in surgical procedures. These materials may not necessarily be used solely for reconstructive procedures, but when used in the right situation in combination with autologous, allograft or other synthetic, the result have the potential for more desirable results.

1. Jefferies SR. 2014. Bioactive and biomimetic restorative materials: a comprehensive review. Part I. J Esthet Restor Dent. 26(1):14-26.

2. Sharma M, Murray PE, Sharma D, Parmar K, Gupta S, Goyal P. 2013. Modern approaches to use bioactive materials and molecules in medical and dental treatments. Int J Curr.Microbiol. App. Sci., 2(11):429-39.

3. Laskin Daniel M: Oral and Maxillofacial Surgery vol 1

4. Kay C. Dee, David A. Puleo, Bizios R. 2002. An Introduction to Tissue Biomaterial Interactions.

5. Peltola MJ, Vallittu PK, Vuorinen V, Aho AA, Puntala A, Aitasalo KM. 2012. Novel composite implant in craniofacial bone reconstruction. Eur Arch Otorhinolaryngol. 269(2):623-8

6. Kao ST, Scott DD. 2007. A review of bone substitutes. Oral Maxillofac Surg Clin North Am. 19(4):513-21, vi.

7. Nasr HF, Aichelmann-Reidy ME, Yukna RA. 1999. Bone and bone substitutes. Periodontol 2000. 19:74-86.

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.

Chlamydiosis

Chlamydiosis is an infectious disease of animals caused by Chlamydia sp. and characterized by encephalitis, polyarthritis and pneumonia in calves and abortions in cows and sheep.

Etiology

• Chlamydia psittacii

Pathogenesis

Chlamydial infection spreads through inhalation of contaminated dust from infected birds. Organism multiplies in lungs and through blood it spreads to liver, spleen, kidneys, brain, joints and placenta to cause pathology.

Characteristic symptoms

Calves

• Fever, dyspnoea

• Nasal discharge, hypersalivation

• Swelling of joints

Leptospirosis

Leptospirosis is an infectious disease of animals caused by spirocheate Leptospria sp. and characterized by widespread haemorrhage in visceral organs, nephritis, icterus, hepatitis and anemia (Fig.6.1).

Etiology

• Leptospira ictehaemorrhagae

• L. pomona

Pathogenesis

The organism is transmitted through direct contact with urine of infected animals or ingestion of urine contaminated feed or water. It can also be transmitted through aborted fetuses and infected uterine discharges. The organism enters through abraded skin and mucous membrane and reaches in blood and multiplies rapidly in blood producing septicemia and high rise in body temperature. Thereafter the organism localizes in the kidneys leading to acute or chronic nephritis. In kidneys, it multiplies in proximal convoluted tubules (PCT) and is excreted in urine which acts as source of infection.

Spongiform encephalopathy

Spongiform encephalopathy is an infectious disease of animals caused by prion proteins and characterized by presence of vacuoles in brain.

Etiology

• Prion proteins

• Sheep – Scrapie or Ovine spongiform encephalopathy

• Cattle - Bovine spongiform encephalopathy (Mad cow disease)

• Feline encephalopathy

Pathogenesis

Scrapie is also known as ovine spongiform encephalopathy. The principle means of transmission of disease is from infected mother to their lambs early in life; placental transmission has also been reported. The incubation period of disease is very long (2-5 year). The clinical form is restricted in adults. The prion proteins (PrP) occur normally in the central nervous system of all domestic animals and man bounded with neuronal surface. Animal susceptible to prion disease have a gene (PrP gene) which encodes for normal “Prion protein (PrP)” or “cellular prion protein (PrPc). In scrapie prion protein (PrPsc)/ scrapie associated fibril protein (SAI) is generated which are resistant for protease digestion. Accumulation of PrPsc in neural tissues appears to be the cause of the pathology in prion disease. When prion protein contaminated meat and bone meal are fed to the cattle as part of their concentration, the agent (prion) got introduced into cattle. Prion protein (PrP) on reaching brain slowly and progressively converted into and abnormal form (PrP sc) and this abnormal protein causes development of lesions including vacuolation in nerve cells.

Objective
After performing this experiment you will be able to learn:
How to  determine the caliper/GSM of paperboard.

Introduction

Thickness is calculated as the perpendicular distance between the two principle surfaces of paper or paperboard as measured under specified conditions. The GSM of paper may be defined as the thickness of a paper that is measured in a roundabout way. GSM stands for Gms per Square Metre - and is used to check the quality of the paper to be measured.

It is a very simple to perform test but tells a lot about the basic properties of the material which are very important to decide the quality of the material. Also, the quality of the material is measured with its GSM value. The heavier a paperboard is, the better the quality.

Principle

Packaging materials are chosen by estimating the GSM of the sample material. High Grammage defines the strength of the paper. In certain applications high Grammage is desired, where the paper will be subjected to load and harsh working conditions.

Objective
After performing this experiment you will be able to:
Calculate the Burst strength of the given paper and Board.
Introduction

Bursting strength is defined as the measure of resistance to rupture in various materials. A test specimen is held between two circular clamps and subjected to an increasing pressure from a rubber diaphragm. The rubber diaphragm keeps on expanding with the help of a controlled pneumatic pressure until the test specimen ruptures. The pressure required to rupture the specimen at the time of reading is known as bursting strength.

Principle

The bursting strength of paper, paper board, including linerboard and corrugated board, is a combined measure of properties of the sheet, like tensile strength and elongation. In general, bursting strength is dependent on the type, proportion, preparation and amount of fibres present in the sheet and their formation, internal sizing, and to some degree, the surface treatment. Since bursting strength is an empirical property, this test serves to define “standard grades” in commercial activity in combination with basis weight.

Objective
After performing this experiment you will be able to learn :
The Scuff Resistance of the Printed Sample.
Introduction

Scuff resistance or abrasion resistance is a desirable and sometimes critical property of printed materials. Abrasion damage can occur during shipment, storage, handling, and end use. The result is a significant decrease in product appearance and legibility of product information. A printed substrate's level of abrasion damage is influenced by numerous factors, including time, temperature, humidity, and shipping circumstances. This procedure offers a means of comparing printed materials' resistance to scuffs in a lab setting. The relative scuff resistance of printed inks, coatings, laminates, and substrates can also be assessed using this technique. This procedure can be changed to assess how a product—food, drink, powdered detergent, etc.—affects scuff resistance, which might happen when something spills or leaks while being transported. Labels, folding cartons, corrugated boxes, circulars, inserts, and other packaging materials with applied graphics on a flat substrate can all use this technique.

Objective
After performing this experiment you will be able to learn 
Determination of porosity of tin plate.

Introduction

Porosity in tinplate refers to the presence of tiny holes or pores in the tin coating on steel sheets used for making tin cans. These pores can expose the underlying steel to the contents of the can, potentially leading to corrosion and contamination of the food product. Ensuring minimal porosity is crucial for maintaining the integrity and safety of food packaging. Tinplate is produced by coating a thin layer of tin onto a steel sheet. This can be done through hot dipping or electroplating. The goal is to create a uniform and continuous tin layer that acts as a protective barrier against corrosion. During the coating process, imperfections such as pores or pinholes can form in the tin layer. These imperfections can occur due to variations in the coating thickness, impurities in the tin, or mechanical damage during handling and processing.When a tinplate can with porosity is filled with food, the contents can come into direct contact with the exposed steel through the pores.The acidic or basic nature of certain food products can accelerate the corrosion of the exposed steel, leading to the formation of rust.This corrosion can compromise the structural integrity of the can and potentially contaminate the food with rust particles or harmful by-products of the corrosion process. The primary function of the tin coating is to act as a physical barrier that prevents the food from contacting the steel. A continuous and defect-free tin layer ensures effective protection.Tin also provides cathodic protection to the steel. In the presence of an electrolyte (e.g., acidic food), tin acts as the sacrificial anode, corroding preferentially to the steel. However, this mechanism is only effective if the tin layer is relatively thick and the porosity is minimal.

Objective
After performing this experiment you will be able to learn:
How to do edible packaging of food sample.

Introduction

Edible Packaging – An edible film or coating is simply defined as a thin continuous layer of edible material formed on, placed on, or between the foods or food components. The package is an integral part of the food, which can be eaten as a part of the whole food product.

Edible packaging can be done in two types:

Edible coating: Edible coating are applied and formed directly on food (e.g. by spraying, immersion, and fluidization) via a coating solution. This will be a part of the food and must not provoke unwanted change (organoleptic, physical, and chemical).

Objective
After performing this experiment you will be able to learn:
Physical tests of packaging material.
I. Determination of Machine Direction 
Introduction
Machine-made paper has two directions and two sides:

Directions

a) Machine Direction: The direction in which the paper or board aligns with the flow of material on the paper machine.

b) Cross Direction: The direction perpendicular to the machine direction

Objective
After performing this experiment you will be able to learn:
Moisture content of packaging material.

Introduction

The moisture content of paper is a critical parameter that significantly affects its other properties, such as printing quality and absorbency. Maintaining an optimal moisture level is essential for ensuring the functionality and durability of the paper. For instance, double-faced corrugated boards tend to break or crack during bending operations if they are too dry.

Procedure

• Weigh the conditioned specimen and place it in a drying oven, maintained at a temperature of 103°C ± 2°C, to expel moisture. Continue heating until a constant weight is achieved.

• If the moisture content of the paper is to be determined "as received," the sample should not be conditioned.

Objective
After performing this experiment you will be able to learn:
pH value of packaging material.

Introduction

As mentioned earlier, these tests are performed to assess the suitability of the board for printing, corrosion protection, food packaging etc. The presence of acid in paper or paper possessing an acidic reaction is a property of specific importance. Not only may the presence of acid effect the aging properties of paper, but it also may act upon materials that come into contact with the paper. In addition, the sizing of paper, wet strength treatment, and dye and fillers retention, usually depend upon the addition of alum or other acidic materials to the beater furnish. Hence many appers are acidic to various degrees at the time of manufacture. pH is a measure of hydrogen ion present which depends both upon the amount of acidic material and upon its degree of ionization. Hence, pH does not measure the amount of acid present. Since it is the 'activity or ‘intensity’ of acid that is usually of most interest, the pH value is the more common test.

India is considered a pioneer in software development and a favourite destination for IT-enabled services. West Bengal is predominantly an agrarian State. Comprising only 2.7% of India’s geographical area, it supports nearly 8% of its population. There are 71.23 lakh farm families, of whom 96% are small and marginal farmers. The average size of land holding is only 0.77 ha. However, the State is bestowed with diverse natural resources and varied agro climatic conditions that support the cultivation of a wide range of crops.

The net cropped area is 52.05 lakh ha, comprising 68% of the geographical area and 92% of arable land. The cropping intensity is 184%. However, as the State is in the humid tropic and the Bay of Bengal is close by, it often must face natural vagaries like floods, cyclones, hailstorms, etc. Though the State has a surplus production of rice, vegetables and potatoes, a huge gap exists between the requirement and production of pulses, oilseeds, and maize. The deterioration of soil health due to imbalances in chemical fertilizers, the paucity of suitable improved seed varieties, inadequate farm mechanization, unorganized marketing structure, etc., is a major challenge to agricultural growth.

A student investigator confronted time constraints, such as course credit pressure, and resource constraints, such as physical, budgetary, and managerial constraints, in the current investigation. However, every effort and consideration made the study as objective and scientific as feasible. Despite the researcher’s best efforts, the study depends on the respondents’ opinions, which may or may not be devoid of their perceptions and biases.

As a result, it is a modest piece of labour that may be completed over a more extended period.

Suggestions for Future Research

• The findings of the present study warrant the need for further investigations in several directions. The following suggestions are made for further research in the following areas.

• The study was confined to one state; therefore, the results cannot be generalised to the whole country. Similar analyses can be taken up in other states to generalise the results.

Objective

The aim of this practical is to categorize insects based on their wing characteristics.

Introduction: Insect classification, as outlined by A.D. Imms (1957), divides Class Insecta or Hexapoda into two primary groups:

Group 1: Apterygota: These insects lack wings, and the absence of wings is considered primitive. Metamorphosis is minimal or absent. Adults typically possess one or more pairs of pregenital abdominal appendages. The mandible of adults usually articulates with the head capsule at a single point. This group comprises four orders:

1. Thysanura - Example: Silverfish

2. Diplura - Example: Japygids

3. Protura - Example: Telson tails or proturans

4. Collembola - Example: Springtails

Objective: The objective of this practical exercise is to understand the taxonomic features of the order Orthoptera and classify its suborders and families.

Observations: Order - Orthoptera (Orthos = straight, pteron = wing) Includes grasshoppers, crickets, and locusts.

Key Characteristics

1. Presence of wings, either fully developed, shortened (brachypterous), or absent (apterous).

2. Mouthparts are of the biting and chewing type (mandibulate).

3. Hind legs are typically enlarged and adapted for jumping.

4. Two pairs of wings, sometimes reduced or vestigial. The front wings, called Tegmina, are straight and thickened, while the hind wings are membranous.

5. Exhibits gradual metamorphosis, where nymphs closely resemble adults in essential features and habits.

Objective: The aim of this practical session is to explore the taxonomic features of the order Isoptera and classify its families.

Order: Isoptera (Iso = equal, ptera = wing) – Termites

Taxonomic Characteristics

1. Moderate-sized, social insects with thin skin, comprising various castes such as winged kings and queens, wingless kings and queens, workers, and soldiers.

2. Exhibits simple metamorphosis.

3. Mouthparts are of the typical biting and chewing type.

4. Wings are equal in size, long, narrow, membranous, and somewhat opaque.

5. Workers and soldiers of both sexes are wingless and sterile forms.

Objective: To explore the habits, habitats, and taxonomic features of the order Thysanoptera and the family Thripidae.

Order: Thysanoptera

Etymology: Thysano (fringed) + Ptera (wings) = Fringed-winged Insects (THRIPS)

Habitat: Terrestrial, commonly found in flowers

Habit: Phytophagous, feeding on plant material

Size: Minute to small, characterized by thin, slender elongated bodies

Taxonomic Characteristics

1. Antennae: Typically 6-10 segmented, with sensorial structures (cone like) on the 3rd or 4th segment.

2. Compound Eyes: Conspicuous, with 3-4 ommatidia in apterous forms and up to 150 in winged forms. Winged forms also exhibit 3 ocelli.

3. Mouthparts: Asymmetrical, lacking the right mandible. Adapted for lacerating, rasping, and sucking, with three stylets. The mouth cone, formed by the labrum, labium, and maxillae, extends ventrally between the fore coxae

Objective: To identify key characters of the order Neuroptera and explore the characteristics of the family Chrysopidae.

Order: Neuroptera

Etymology: Neuro (nerve) + Ptera (wings) = Wings with net-like patterns of veins

Common Members: Lacewings, Aphid Lions, Ant Lions, Alder Flies, Snakeflies

Key Features of Neuroptera

1. Neuroptera possess two pairs of similar-sized membranous wings with a complex, net-like pattern of veins.

2. They are relatively fragile insects and weak fliers.

3. Antennae are filiform, with or without a terminal club.

4. Both adults and larvae have chewing mouthparts, with larval mandibles being very strong and elongated. Some larval mouthparts are modified for piercing and sucking.

5. Larvae are compodiform and predaceous.

Objective: Explore and understand the key identical characteristics that differentiate the suborders Symphyta and Apocrita within the order Hymenoptera.

Objective: Identify and understand the distinctive features of the order Lepidoptera and its significance in agriculture through key families.

Objective: This practical aims to familiarize students with the essential traits of Diptera and explore the agriculturally significant families within this order.

Objective: To investigate and compare the taxonomic traits of Heteroptera and Homoptera, two suborders within the order Hemiptera, commonly known as true bugs.

Objective: To explore and compare the taxonomic traits of beetles and weevils through detailed examination and suitable examples.

Objective: Aims to investigate and understand the distinguishing features of butterflies and moths, focusing on their unique traits and examples.

Objective: This practical aims to understand the taxonomic traits of Megaloptera and Planipennia, focusing on their unique features and differences.

Objective: This practical aims to understand the taxonomic traits of Terebrantia and Tubilifera, focusing on their unique features and differences.

Objective: Aims to understand and identify the key differences between insects belonging to the suborders Nematocera and Brachycera.

Objective: This practical aims to understand the distinctive features of the insect order Mantophasmatodea and its major family, Mantophasmatidae.

Objective: To differentiate between locusts and grasshoppers based on their morphometric measurements and behavioral traits.

Objective: The order Dictyoptera includes insects like cockroaches and praying mantises with netted wings. Recognizing their unique taxonomic traits is essential for precise identification and classification.

Objective: To investigate and comprehend the taxonomic traits of family Mantidae, specifically cockroaches and praying mantises, through detailed examination and diagrammatic representation.

Objective: To explore and document the taxonomic characteristics of cockroaches belonging to the family Blattidae through detailed observation and analysis.

Objective: To explore and record the taxonomic features of insects in the family Pentatomidae through thorough examination and analysis of their morphology.

Objective: To thoroughly examine and record the fundamental taxonomic traits of insects belonging to the family Cicadellidae through detailed observation and analysis.

Objective: The objective of this practical exercise is to explore and document key taxonomic characteristics of Aphididae, focusing on specimens like cotton aphids (Aphis gossypii) and bean aphids (Aphis craccivora).