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6200 Jefferson NE

Albuquerque, New Mexico 87109-3734

**Phone**: (505) 761-4400 **Fax**: (505) 761-4402

**Web site**: [www.nm.nrcs.usda.gov]{.underline}

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November 13, 2023

WATER QUALITY TECHNICAL NOTE NO. 15

SUBJECT: WATER QUALITY -- PRACTICAL INTEGRATED PEST MANAGEMENT

[Purpose]{.underline}. To distribute information on integrated pest
management.

[Effective Date]{.underline}. Effective when received.

[Explanation]{.underline}. This note presents information on integrated
pest management to be filed in the Water Quality Technical Note binder.

ROSENDO TREVIÑO III

State Conservationist

# [PRACTICAL INTEGRATED PEST MANAGEMENT]{.underline}

Draft Developed and Presented by Brad Lewis, Research Entomologist, NMSU

for NRCS Nutrient and Pest Management Training, 2002

# 

# INTRODUCTION

The purpose of the presentation is to introduce selected concepts and
elements that regional pest control advisers rely on to make pest
management decisions in New Mexico agriculture. The content of this
presentation is intended for an audience with little applied experience
in pest management. Practical Integrated Pest Management is not
exclusive of Integrated Pest Management (IPM) nor is it a management
philosophy. Practical Integrated Pest Management is merely a convenient
title used for the introduction of a collection of information related
to commonly used pest management practices. Because of the diversity and
personal interpretations of various Integrated Pest Management
definitions, several practices and techniques may or may not be part of
a specific IPM definition or program. This presentation is not meant to
replace current university guidelines and omits some crucial information
required to make appropriate pest management decisions. Regional
practices will deviate from the recommendations contained in this
presentation.

Fundamental to all pest management philosophies is determining at what
level of infestation is an arthropod pest considered an economic
problem. In 1959, Stern and others defined the concept of Economic
Injury and Economic Threshold Levels based on insect pests of
agricultural crops.

> **Economic Injury Level**: The pest density at which damage is
> quantifiable and the cost associated with that damage is equal to or
> exceeds the cost of control.
>
> **Economic Threshold Level** (action level) is the pest density at
> which suppression measures should be implemented in order to prevent
> the pest population from reaching the Economic Injury level.

Economic Threshold Level is less than the Economic Injury Level and is
the most common economic density measurement for arthropods in print.
Generally, crop advisors talk exclusively in terms of economic threshold
levels.

Pest density values for Economic Threshold Levels are different for
specific crops and specific arthropod pests. Density of an arthropod may
be represented as pests per square foot; insects per leaf, adults per
trap; adults per plant; insects per linear feet etc. The principal
components used derive Economic Threshold Levels as the damage caused by
a single or set number of pests; the cost of controlling the pest; and
the value of the crop. Typically a destructive insect feeding on a high
valued crop results in a low economic threshold value. A low valued crop
combined with a less destructive insect results in a higher Economic
Threshold Level.

Pest control advisers take a much more conservative approach to managing
pests in crops with a lower threshold level than those with higher
threshold levels. Economic Threshold Levels are extremely low for
lepidopterous pests in lettuce, cabbage, and green beans grown in the
state. The marketability of the entire crop may be lost if measurable
insect damage is observed or quantified. Because of the significant
risks and the lost cost of insecticides compared to the potential
profitability, pest control advisors are much more likely to recommend
an insecticide application when only a few pest insects are present. The
risk to benefit ratio in high value crops almost always favors reduction
in risk due to the presence of arthropod pests and favors immediate
control measures using an insecticide.

Economic Threshold Levels are higher for lepidopterous pests in cotton,
grain sorghum and wheat than for the identical pests in vegetables. The
presence of an insect pest in cotton, grain or sorghum does not normally
threaten the entire crop but rather results in yield reductions. Because
the cost of an insecticide treatment may represent a significant percent
of the profitability of grain and fiber crops, and there is less risk
for significant crop loss, pest advisers are willing to accept some crop
loss risk by not applying a pesticide until they are sure it will pay
for itself.

Economic threshold levels published in state or regional publications
are normally derived from small plot studies conducted on a limited
number of cultivars under specific environmental conditions. Although
the research results in quantifiable data, they should only be used as
guidelines. Experience with specific crop varieties, regional pest
populations, environmental conditions all contribute to determining and
refining recommended threshold levels for specific circumstances.

Simple economic threshold levels for several common New Mexico insect
pests are listed in Table l. The information in the table is presented
as a general illustration and should be noted as incomplete with respect
to the amount and specific information required before making a
decision.

> Table 1. Simple Economic Threshold Levels for selected common insect
> pests of New Mexico.

+---------+------------+----------------+-----------------------------+
| CROP    | PEST       | THRESHOLD      | NOTES                       |
|         |            |                |                             |
|         |            | LEVEL          |                             |
+---------+------------+----------------+-----------------------------+
| Alfalfa | Alfalfa    | 15-20 larvae   | Plant size dependent,       |
|         | weevil     | /sweep         | foliar insecticide,         |
|         |            |                | normally 1^st^ cutting only |
|         |            |                | economic, not normally      |
|         |            |                | present in 1^st^ year hay   |
+---------+------------+----------------+-----------------------------+
| Alfalfa | Alfalfa    | 25% damaged    | Plant size dependent,       |
|         | weevil     | stems          | foliar insecticide,         |
|         |            |                | normally 1^st^ cutting only |
|         |            | (2             | economic, not normally      |
|         |            | larvae/stem)   | present in 1^st^ year hay   |
+---------+------------+----------------+-----------------------------+
| Alfalfa | Aphids     | Greater than   | Plant size dependent,       |
|         | (pea and   | 15 per sweep   | foliar insecticides, may be |
|         | blue       |                | economic throughout the     |
|         | aphid)     |                | season, multiple            |
|         |            |                | generations per year,       |
|         |            |                | population increase         |
|         |            |                | following some insecticide  |
|         |            |                | applications                |
+---------+------------+----------------+-----------------------------+
| Chile   | Pepper     | Multiple       | Economic threshold level is |
|         | Weevil     | individuals    | variety dependent; imported |
|         |            | caught in      | pest, multiple generations  |
|         |            | pheromone trap | per year                    |
+---------+------------+----------------+-----------------------------+
| Pecans  | Pecan nut  | 3-5% egg       | Dependent on crop load and  |
|         | casebearer | infested       | price, sample nut clusters, |
|         |            | clusters       | 3 generations per year      |
+---------+------------+----------------+-----------------------------+
| Pecans  | Black      | 1 aphid per    | Sample compound leaves,     |
|         | pecan      | compound leaf  | foliar insecticides,        |
|         | aphid      |                | multiple generations/year,  |
|         |            |                | do not tolerate heat        |
+---------+------------+----------------+-----------------------------+
| Pecans  | Black      | 25/compound    | Economic problem during a   |
|         | margined   | leaf           | heavy production year       |
|         | aphid      |                |                             |
+---------+------------+----------------+-----------------------------+
| Onions  | Thrips sp. | 3-5/leaf       | Individual plant samples,   |
|         |            |                | multiple generations per    |
|         |            |                | year                        |
+---------+------------+----------------+-----------------------------+
| Cotton  | Bollworm   | 5-10% larvae   | Individual plant samples    |
|         |            | infested       | after boll development, 3 + |
|         |            | plants         | generations/year,           |
|         |            |                | populations may migrate     |
|         |            |                | from drying corn            |
+---------+------------+----------------+-----------------------------+
| Cotton  | Thrips     | 1-4/plant      | Seedling pest, individual   |
|         |            |                | seedling sampled, normally  |
|         |            |                | use insecticide at          |
|         |            |                | planting, multiple          |
|         |            |                | generations                 |
+---------+------------+----------------+-----------------------------+
| Cotton  | Pink       | 15% infested   | Consider days to harvest,   |
|         | Bollworm   | bolls          | multiple generations per    |
|         |            |                | year                        |
+---------+------------+----------------+-----------------------------+
| Corn    | So         | 20% egg or     | Individual plant samples,   |
|         | uthwestern | larvae         | two generations per year    |
|         | Corn borer | infested       |                             |
|         |            | plants         |                             |
+---------+------------+----------------+-----------------------------+

+---------+-----------+-----------------+-----------------------------+
| CROP    | PEST      | THRESHOLD       | NOTES                       |
|         |           |                 |                             |
|         |           | LEVEL           |                             |
+---------+-----------+-----------------+-----------------------------+
| Corn    | Western   | 5-7 adults per  | Individual plant samples,   |
|         | Corn      | plant prior to  | larvae controlled with      |
|         | Rootworm  | brown silk      | at-planting insecticides,   |
|         | Adults    |                 | one generation per year     |
+---------+-----------+-----------------+-----------------------------+
| Corn    | Western   | 2^nd^ year in   | Larvae controlled with      |
|         | corn      | corn and        | at-planting insecticides,   |
|         | rootworm  | presence of     | one generation per year     |
|         | larvae    | adults the      |                             |
|         |           | previous year   |                             |
+---------+-----------+-----------------+-----------------------------+
| Wheat   | Aphids    | 10/stem         | Consider dry-land vs.       |
|         | (green    |                 | irrigated, can be           |
|         | bug)      |                 | controlled with at-planting |
|         |           |                 | insecticide, multiple       |
|         |           |                 | generations                 |
+---------+-----------+-----------------+-----------------------------+
| Wheat   | Russian   | Determined by   | 50% infestation level       |
|         | Wheat     | yield           | result in 25% yield loss,   |
|         | Aphid     |                 | foliar or controlled with   |
|         |           |                 | at-planting insecticides,   |
|         |           |                 | multiple generations        |
+---------+-----------+-----------------+-----------------------------+
| Grain   | Head      | 1.5-2 per head  | Normally one generation in  |
| Sorghum | worms     |                 | grain sorghum               |
|         | (fall or  |                 |                             |
|         | earworm)  |                 |                             |
+---------+-----------+-----------------+-----------------------------+
| Grain   | Green     | Growth stage    | Leaf samples and plant      |
|         | bugs      | dependent       | observations                |
| Sorghum |           | (physical       |                             |
|         |           | damage present  |                             |
|         |           | to leaf         |                             |
|         |           | necrosis at     |                             |
|         |           | later stages)   |                             |
+---------+-----------+-----------------+-----------------------------+
| Green   | European  | Present in the  | Sweep net samples after pod |
| Beans   | corn      | field           | formation                   |
|         | borer     |                 |                             |
+---------+-----------+-----------------+-----------------------------+
| Lettuce | Corn      | Less than 1%    | Individual plant samples    |
|         | earworm   | infested plant  |                             |
+---------+-----------+-----------------+-----------------------------+
| Lettuce | Cabbage   | Less than 5%    | Individual plant samples    |
|         | loopers   | infested plants |                             |
|         | and beet  |                 |                             |
|         | armyworms |                 |                             |
+---------+-----------+-----------------+-----------------------------+

#### PEST DEVELOPMENT

Knowledge of a pest's lifecycle, feeding behavior and damage symptoms
are other key elements used by pest advisors to help predict population
emergence, time insecticide applications and quantify potential pest
problems in a crop.

The development of insects is primarily governed by temperature followed
by day length and food quality. During optimal conditions, arthropods
with a high biotic potential can develop from egg to adult in less than
10 days. Common regional arthropod pests that fall into this category
include most aphids, spider mites, and thrips. Other arthropod pests may
take from 30-40 days to develop from egg to adult. Most lepidopterous
pests fall into this category. Several economic pests found in the state
develop over a period of months or years. Western corn rootworm, a
common corn pest, may take 10 months and pecan weevil one to three years
to complete a lifecycle.

Phenology models (degree-day models) have been developed and verified
for a number of arthropod pests in New Mexico. Based on temperature, a
phenology model can be used to estimate developmental stages of specific
insects. Prior to the development of synthetic pheromones, phenology
models were the primary method of determining when to scout fields or
expect to apply pesticides to control a specific pest. Although still
used today to determine long range how fast a specific pest may develop,
pheromone traps are a more common method of determining when adult
populations are present. New Mexico State phenology models for pink
bollworm and pecan nut casebearer are found at
<http://weather.nmsu.edu/diseases.html>.

Arthropod development falls into three major categories. The two that
pest advisers are most familiar with are listed below.

1.  Gradual: Consists of egg, nymph, and adult. The nymph is similar in
    appearance and habits as the adult. Aphids, lygus and thrips are
    common examples in New Mexico.

2.  Complete: Costs of egg, larvae, pupae and adult. Larvae exhibit
    little resemblance to the adults in appearance of habits.
    Southwestern corn borer, pecan nut casebearer, alfalfa weevil,
    European corn borer, corn earworm, fall army worm, western corn
    rootworm and pepper weevils are common examples.

Generally, high biotic potential insects (potential for rapid increase
in populations) fall under gradual development while insects classified
as complete require a longer period of time to complete a lifecycle. For
some insects, where development takes place is important with respect to
scouting and control. Table 2 lists the insect stage that is most
injurious to the plant and the primary location of development.

Table 2. Injurious stages of selected common arthropod pests in New
Mexico and location of insect development.

+--------+-----------+---------------------+-------------------------+
| CROP   | PEST      | INJURIOUS           | DEVELOPMENTAL           |
|        |           |                     |                         |
|        |           | STAGE               | LOCATION                |
+--------+-----------+---------------------+-------------------------+
| A      | Alfalfa   | Larvae and adults   | Exposed on the top of   |
| lfalfa | weevil    |                     | the stem                |
+--------+-----------+---------------------+-------------------------+
| A      | Aphids    | Nymphs and adults   | Exposed on the lower    |
| lfalfa |           |                     | portion of the stem     |
+--------+-----------+---------------------+-------------------------+
| Chile  | Pepper    | Grubs (larvae)      | Inside the pods         |
|        | Weevil    |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Pecans | Pecan nut | larvae              | Inside the nut          |
|        | c         |                     |                         |
|        | asebearer |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Onions | Thrips    | Nymphs and adults   | Within the neck         |
+--------+-----------+---------------------+-------------------------+
| Cotton | Bollworm  | larvae              | Prior to bolls, exposed |
|        |           |                     | on the plant, in the    |
|        |           |                     | bolls when present      |
+--------+-----------+---------------------+-------------------------+
| Corn   | Sou       | larvae              | In the stalk            |
|        | thwestern |                     |                         |
|        | corn      |                     |                         |
|        | borer     |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Corn   | Western   | larvae              | In the soil feeding on  |
|        | corn      |                     | roots                   |
|        | rootworm  |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Corn   | Western   | adults              | exposed                 |
|        | corn      |                     |                         |
|        | rootworm  |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Corn   | Spider    | Adults, nymphs      | Underside of lower      |
|        | mites     |                     | leaves                  |
+--------+-----------+---------------------+-------------------------+
| Wheat  | Green     | Adults and nymphs   | exposed                 |
|        | bugs      |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Wheat  | Russian   | Adults and nymphs   | Hidden within a curled  |
|        | wheat     |                     | leaf                    |
|        | aphid     |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Grain  | Head      | larvae              | Exposed in the sorghum  |
| s      | worms     |                     | head                    |
| orghum |           |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Grain  | Green     | Adults and nymphs   | Underside of lower      |
| s      | bugs      |                     | leaves                  |
| orghum |           |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Green  | European  | Larvae              | Exposed prior to pod    |
| beans  | Corn      |                     | formation; inside pods  |
|        | Borer     |                     | when present            |
+--------+-----------+---------------------+-------------------------+
| L      | Corn      | larvae              | Inside lettuce heads    |
| ettuce | earworm   |                     |                         |
+--------+-----------+---------------------+-------------------------+
| L      | Cabbage   | larvae              | Exposed on the wrapper  |
| ettuce | Loopers   |                     | leaves                  |
|        | and beet  |                     |                         |
|        | armyworms |                     |                         |
+--------+-----------+---------------------+-------------------------+
| Apples | Coddling  | larvae              | Inside the apples       |
|        | Moth      |                     |                         |
+--------+-----------+---------------------+-------------------------+

SCOUTING TECHNIQUES

The examination of individual plants is the most common sampling
technique for determining the presence and quantifying insect
populations in regional crops. Other sampling techniques that are used
alone or in conjunction with plant examinations include the use of
pheromone traps, phenology models, and sweep nets.

Pheromones are chemicals that elicit a response from another individual
of the same species. Two general types of pheromones are used to help
determine the presence of an insect pest population in New Mexico. The
first type is a mating pheromone that attracts males to a trap. The
second type is an aggregation pheromone that attracts both sexes to a
trap. Various trap designs are used in the state and are most often
species specific. Although pheromone traps are the easiest method for
determining the presence of several common pests, they are not used to
determine the population density of that pest in a specific field.
Typical scouting fields is the only method of determining infestation
levels. Population densities of pests that migrate into a field are
usually higher on the edges and on the southwest side of a field
compared to the center in New Mexico. Scouting techniques should
consider sampling the entire field. Table 3 lists common scouting aids
and techniques for common insect pests in New Mexico.

## 

## Table 3. Scouting aides and techniques for common arthropod pests in New Mexico

  ----------- ---------------- ------------------- ------------------------
  CROP        PEST             SCOUTING AIDES      TECHNIQUE

  Alfalfa     Alfalfa weevil   Sweep net           25 sweeps across the
                                                   field or cut 25 stems
                                                   and shake into a bucket;
                                                   normally 1^st^ cutting
                                                   only

  Alfalfa     Aphids           bucket              Cut 25 stems and shake
                                                   into a bucket; normally
                                                   1^st^ cutting only

  Chile       Pepper Weevil    Pheromone traps     Cut immature pods from
                               (aggregation)       the top of the plant

  Pecans      Pecan nut        Magnifying lens,    Evaluate 100 nut
              casebearer       pheromone traps,    clusters for eggs and
                               degree day model    nut entry from larvae

  Onions      Thrips           none                Separate leaves and
                                                   count thrips in the neck
                                                   of the plant, season
                                                   long

  Cotton      Bollworm         Pheromone traps     Normally examine the top
                               (mating) degree day portion of the plant for
                               model               eggs and larvae; examine
                                                   bolls for entry and exit
                                                   holes; season long

  Corn        Southwestern     Pheromone traps     1^st^ generation not
              corn borer       (mating)            normally a problem.
                                                   Examine leaves (2 above
                                                   and 2 below the ear) for
                                                   eggs; look behind the
                                                   ear for frass and
                                                   presence of larvae for
                                                   second generation. Two
                                                   defined generations

  Corn        Western corn                         Count the number of
              rootworm adults                      adults found on each
                                                   plant; prior to brown
                                                   silk; not a problem
                                                   after brown silk

  Corn        Western corn                         Scout fields the
              rootworm larvae                      previous year for
                                                   presence of adults, not
                                                   a problem in 1^st^ year
                                                   corn.

  Corn        Spider mites                         Populations begin on the
                                                   underside of lower
                                                   leaves; heaviest on
                                                   edges of fields, season
                                                   long problem

  Wheat       Green bugs       bucket              Cut 25 stems and shake
                                                   in a bucket

  Wheat       Russian wheat                        Count infested stems,
              aphid                                infested plants exhibit
                                                   curled leaves and purple
                                                   in color

  Grain       Head worms       bucket              Shake sorghum heads in a
  sorghum                                          bucket

  Grain       Green bugs                           Populations begin on the
  sorghum                                          underside of the lower
                                                   leaves

  Green beans European Corn    Pheromone traps     Traps placed in the
              Borer            (mating) (Iowa      field, 25 sweeps in
                               strain) sweep net   several locations

  Lettuce     Corn earworm     Pheromone traps     Inspect individual heads
                               (mating), bucket    for eggs and larvae, can
                                                   cut heads and shake over
                                                   a bucket

  Lettuce     Cabbage loopers  bucket              Inspect individual heads
              and beet                             for eggs and larvae, can
              armyworms                            cut heads and shake over
                                                   a bucket

  Apples      Coddling Moth    Pheromone traps     Initiate insecticide
                               (mating) degree day applications several
                               model               days after positive trap
                                                   count
  ----------- ---------------- ------------------- ------------------------

### CONTROL PRACTICES

The emphasis of many current pest management guidelines is placed on
cultural, varietal and biological control measures with minimal emphasis
on the use of pesticides. In New Mexico and most agronomic regions,
pesticides remain the primary method of controlling insect pests. Crop
advisors continued use of pesticides is due primarily to their
reliability, instantaneous action and their cost effectiveness. Other
elements of pest management are not ignored but are considered when
effective.

A great deal of emphasis has been placed on biological control in
agricultural crops. Although pesticides are the dominant control method,
beneficials can play a key role in reducing pesticide applications. In
southern New Mexico cotton, beneficials can significantly reduce
bollworm populations. Generally, green bug infestations in wheat and
grain sorghum are maintained under their economic threshold levels by
beneficials. Aphid infestations in alfalfa are normally controlled by
beneficials. The serious incorporation of beneficials into a management
program, however, takes an added effort on the part of the crop advisor
and adds additional risk with respect to crop loss. More intensive
sampling and a higher level of experience are required by a crop advisor
that wants to rely primarily on beneficials. Typically, beneficials are
not a consideration for many of New Mexico's high value crops.

Arthropod pests that reach their economic threshold level do not
automatically result in a recommendation for a pesticide application.
Crop advisors consider a number of other extraneous factors. Russian
wheat aphid population levels may warrant an insecticide application in
dryland wheat; but if adequate rainfall is not expected to finish the
crop, the application is not necessary. Several years ago, it was more
economical to allow bollworm populations to develop in cotton than
control them with an insecticide. Insecticide applications directed at
bollworms resulted in reductions of beneficial populations and economic
outbreak of beet armyworms that could not be controlled with current
insecticides.

The number of registered insecticides and insecticide classes has
increased significantly over the past several years. The newer
generations of insecticides are more selective in what they kill than
the older wide spectrum pyrethroid, organophosphate and carbamate based
insecticides.