Sampling for Insects

Insects are the most successful and enduring life form on earth and are known to have existed for over 400 million years. They are the most dominant multicellular life form on earth and are represented all over, from the poles to the equator, from the sea surface to the highest peaks and from the deserts to rain forests. It is estimated that insects comprise about half of the earth’s 1.5 million known species (Chapman, 2013; McGavin, 2007). Gullan and Cranston (2014) stated that it was very important for man to study insects while noting that the high species richness in insects is attributed to their small sizes and a limitation imposed by their method of gas exchange through tracheae. According them, insects are important for nutrients recycling, plant propagation including pollination and seed dispersal, maintenance of plant community composition and structure amongst many others. More so, many insects are threatened with extinction which in case of the pollination ones could lead to reducing pollination, hence a decrease in ecosystem biodiversity (Sieg et al., 2018). However, insects can also have devastating effects on humans as about one-sixth of all crops grown in the world are lost to herbivorous insects and the plant diseases they transmit (Chapman, 2013).

Sampling these insects is therefore of utmost importance to both man and the environment. Sampling is a fundamental component of any experimental based research program in the discipline of entomology, whether conducted in the laboratory, greenhouse, or field. It is also important in the description, measurement, and quantification of insect’s population dynamics in order to understand the community or population ecology of a given species or to develop decision aids for the Integrated Pest Management. A population census is highly desirable, but no one would have the time and resources to count all the insects in a given area. That is why it is important for us to consider drawing a sample from the population and using this sample to have estimates of the population density (Naranjo, n.d).

TABLE OF CONTENTS

INTRODUCTION.. 1

DEFINITIONS. 2

II-1. Sampling. 2

II-2. Sample. 2

II-3. Pest2

GOALS FOR SAMPLING.. 2

SAMPLING EQUIPMENT. 3

Equipment used for sampling Base equipment:3

Collecting nets. 4

Killing Jars and liquid killing agents. 4

Sifters. 5

Aspirators and suction devices. 5

Beating sheets. 6

a)    Traps. 6

Pheromones and other attractants. 6

V. SAMPLING TECHNIQUES AND POPULATION ESTIMATION.. 6

A. Sampling Techniques. 6

V-1. Transect line sampling. 7

V-2. NETS. 8

V-2.1. Sweep net8

V-2.2. Aerial net9

V-2.3. Aquatic nets. 10

V-3. TRAPS. 10

V-3.1. Malaise Trap. 10

V-3.2. Bait Traps. 12

V-3.3. Light Trap. 12

V-3.4. Flight Intercept traps (FITs)13

V-3.5. Pitfall Trap. 14

V-3.6. Sticky traps. 15

V-4. Marked Release Recapture. 16

B. Making population estimate from samples (Krebs, 2014; Sallam, n.d)16

VI. AN OVERVIEW OF SOME COMMON PESTS AND THE PROPOSED TECHNIQUES OF SAMPLING FROM LITERATURE.. 17

VI.1. Common soil or ground pests causing plant diseases are. 17

VI-2. Flying insects Pests. 19

VI.3. Agricultural pests. 21

VI.4. Pests of veterinary importance. 24

VII. CONCLUSION.. 25

VIII. REFERENCES. 26