*Corresponding author: gconstante@espam.edu.ec

Gonzalo Bolívar Constante Tubay

Ernesto Gonzalo Cañarte Bermudez

Luis Alberto Duicela Guambi

José Bernardo Navarrete Cedeño

Rev. Fac. Agron. (LUZ). 2022, 39(4): e223950

ISSN 2477-9407

DOI: https://doi.org/10.47280/RevFacAgron(LUZ).v39.n4.05

Crop Production

Associate editor: Dra. Lilia Urdaneta

University of Zulia, Faculty of Agronomy

Bolivarian Republic of Venezuela

Keywords:

Insect pest

Solanaceae

Infestation

Severity

Cultural practices

Interaction between the incidence of Prodiplosis longila Gagné (Diptera: Cecidomyiidae) and

management practices in tomato crops in Manabí, Ecuador

Interacción entre la incidencia de Prodiplosis longila Gagné (Diptera: Cecidomyiidae) y prácticas

de manejo en cultivos de tomate en Manabí, Ecuador

Interacção entre a incidência de Prodiplosis longila Gagné (Diptera: Cecidomyiidae) e as práticas

de gestão nas culturas de tomate em Manabí, Equador

Escuela Superior Politécnica Agropecuaria de Manabí. Av.

10 de Agosto y G. Centeno. Calceta, Ecuador.

Instituto Nacional de Investigaciones Agropecuarias.

Estación Experimental Portoviejo. Km 12 vía Santa Ana.

Cantón Portoviejo, Ecuador.

Received: 02-05-2022

Accepted: 08-10-2022

Published: 02-11-2022

Abstract

The insect pest Prodiplosis longila Gagné (Diptera: Cecidomyiidae),

causes severe losses to the tomato crop in Ecuador, in the provinces of

Manabí, Pichincha, Carchi, Cotopaxi, Azuay, and Chimborazo, where the

main producing areas of this solanaceous crop in the country are located.

The objective of this research was to study the interaction of the incidence

of this pest with tomato crop management practices. The evaluations were

carried out in twenty-ve production units in different cantons of Manabí:

in Bolívar (two), Portoviejo (eight), Rocafuerte (ve), Santa Ana (one),

Sucre (three) and Tosagua (six). Each unit had an area of 2500 m

, where

25 plants were randomly marked and the number of healthy, infested

and damaged shoots was recorded, as well as the number of healthy and

damaged fruits. In addition, a survey was applied to growers to determine

the management practices carried out during the crop cycle. Descriptive

analysis, signicance tests, hierarchical clustering and chi-square tests were

carried out. It was determined that in the cantons of Portoviejo, Tosagua

and Rocafuerte, infestations did not exceed 13 % and a severity of up to 15

%, reaching 25 % of damaged fruit in Tosagua. The agronomic practices

applied were trellising, drip and gravity irrigation, collection of infested fruit

and chemical insecticides. There was an interaction with P. longila between

infested fruit collection and trellising, which inuenced its infestation and

severity, respectively. These incidences were signicantly high at harvest,

where highly toxic insecticide applications were substantially increased

indiscriminately.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2022, 39(4): e223950. October-December. ISSN 2477-9407.2-7 |

Resumen

La plaga insectil Prodiplosis longila Gagné (Diptera:

Cecidomyiidae), provoca severas pérdidas al cultivo de tomate en

Ecuador, en las provincias de Manabí, Pichincha, Carchi, Cotopaxi,

Azuay y Chimborazo, donde están las principales áreas productoras

de esta solanácea en el país. El objetivo de esta investigación fue

estudiar la interacción de la incidencia de esta plaga con las prácticas

de manejo del cultivo de tomate. Las evaluaciones se efectuaron en

veinticinco unidades productivas, en diferentes cantones de Manabí:

en Bolívar (dos), Portoviejo (ocho), Rocafuerte (cinco), Santa Ana

(uno), Sucre (tres) y Tosagua (seis). Cada unidad tuvo un área de

2500 m

, en donde se marcaron aleatoriamente 25 plantas, y se

registró número de brotes sanos, infestados y con daño; así como,

números de frutos sanos y dañados. Además, se aplicó una encuesta

a los productores para determinar las prácticas de manejo realizadas

durante el ciclo del cultivo. Se efectuaron análisis descriptivos,

pruebas de signicación, conglomerados jerárquicos y chi cuadrado.

Se determinó que en los cantones Portoviejo, Tosagua y Rocafuerte,

presentaron infestaciones no superiores al 13 % y una severidad hasta

el 15 %, alcanzando Tosagua el 25 % de frutos dañados. Las prácticas

agronómicas aplicadas fueron, tutoreo-amarre, riego por goteo y

gravedad, recolección de frutos infestados e insecticidas químicos.

Entre la recolección de frutos infestados y tutoreo-amarre existió una

interacción con P. longila, que inuyó en su infestación y severidad,

respectivamente. Estas incidencias fueron signicativamente altas en

la cosecha, donde se incrementaron sustancialmente las aplicaciones

de insecticidas altamente tóxicos en forma indiscriminada.

Palabras clave: Plaga insectil, solanácea, infestación, severidad,

prácticas culturales.

Resumo

A praga Prodiplosis longila Gagné (Diptera: Cecidomyiidae),

causa graves perdas à cultura do tomate no Equador, nas províncias

de Manabí, Pichincha, Carchi, Cotopaxi, Azuay e Chimborazo,

onde se localizam as principais zonas produtoras desta cultura de

solanáceas no país. O objectivo desta investigação foi o de estudar

a interacção da incidência desta praga com as práticas de gestão

das culturas de tomate. As avaliações foram realizadas em vinte e

cinco unidades de produção em diferentes cantões de Manabí: em

Bolívar (dois), Portoviejo (oito), Rocafuerte (cinco), Santa Ana

(uma), Sucre (três) e Tosagua (seis). Cada unidade tinha uma área de

2500 m

, onde 25 plantas foram marcadas aleatoriamente, e o número

de rebentos saudáveis, infestados e danicados foi registado, bem

como o número de frutos saudáveis e danicados. Além disso, foi

aplicado um inquérito aos cultivadores para determinar as práticas

de gestão levadas a cabo durante o ciclo de cultivo. Foram realizadas

análises descritivas, testes de signicância, agrupamento hierárquico

e testes de qui-quadrado. Foi determinado que nos cantões de

Portoviejo, Tosagua e Rocafuerte, as infestações não excederam 13

% e uma severidade até 15 %, chegando a Tosagua a 25 % dos frutos

danicados. As práticas agronómicas aplicadas foram: aramação,

irrigação por gotejamento e gravidade, colheita de frutos infestados

e insecticidas químicos. Houve uma interacção entre a recolha de

fruta infestada e a lavoura com P. longila, o que inuenciou a sua

infestação e severidade, respectivamente. Estas incidências foram

signicativamente elevadas na colheita, onde as aplicações de

insecticidas altamente tóxicos foram substancialmente aumentadas

indiscriminadamente.

Palavras-chave: Praga de insectos, solanáceas, infestação,

severidade, práticas culturais.

Introduction

Tomato (Solanum lycopersicum L.) is a vegetable in high demand,

since its consumption is associated with its important nutritional

properties (Arroyo et al., 2018), therefore its cultivation has increased

worldwide (Trust Funds for Agricultural Development [FIRA],

2017). In Ecuador, 91 % of the production areas are located in the

provinces of Imbabura, Manabí, Pichincha, Carchi, Cotopaxi, Azuay,

and Chimborazo. In Manabí, in 2021, 35 ha were established with a

production of 319 t and an average yield of 9.02 t.ha

-1

(Agricultural

Public Information System [SIPA], 2021).

In Ecuador, Prodiplosis longila Gagné (Diptera: Cecidomyiidae)

constitutes the main pest of economic importance of the tomato crops,

limiting production and protability of the crop, since the costs for its

control represent up to 50 % of the total production cost (Cañarte et

al., 2015; Polo, 2017).

The damage of P. longila is caused by its larva in the rst instars

(Cardona et al., 2010), with losses of up to 100 % of production

(Cañarte et al., 2015). In the ower, it affects the epidermal cells of

the ovary, pistils, and stamens (Peña and Mead, 2016). The female

oviposits on the plant epidermis, without perforating the tissues, in

protected areas such as closed buds, ower buds, and at the base of

the fruits (Díaz, 2011), where upon hatching, the newly emerged

larvae feed on these tender tissues, scraping the surface of the bundle,

whose damage turns it blackish and in young fruits causes necrotic

scars that deform the base, taking away its commercial value (Geraud

et al., 2022).

The biological cycle of P. longila is 11 to 24 days, distributed

in three larval instars (2-3 days), pre-pupa (2-3 days), pupa (6-7

days) and adult (1-2 days), except for certain eld or laboratory

variations (Valarezo et al., 2003; Díaz, 2011; Geraud et al., 2022).

It is a multivoltine species, which develops 18 to 22 generations per

year, depending on environmental conditions of temperature, relative

humidity and precipitation (Díaz, 2011).

The control of P. longila is almost exclusively chemical, with

extremely toxic insecticides, such as metamidophos (Valarezo et

al., 2003; Polo, 2017; Chirinos et al., 2020), triazophos (Fernández,

2016), benfucarb (Polo, 2017), methomyl (Polo, 2017; Chirinos et

al., 2020) applied during the crop cycle, including the harvest stage.

The use of this type of insecticides generates environmental pollution

and ecological imbalance (Hernández et al., 2015), affecting human

health (Lindao et al., 2017), which affects the quality of life of the

producer (Bravo et al., 2020).

In view of this situation, the implementation of sustainable

integrated management programs should be considered, which

include: 1) biological control through the action of predators,

parasitoids and pathogens (Díaz, 2011; Cedano and Cubas, 2012),

2) genetic control with the use of cultivars that are harmless to the

attack of P. longila (Mena et al., 2014), 3) cultural control (Cañarte

et al., 2015), 4) ethological (Camborda et al., 2015), in order to

reduce or eliminate insecticide applications, which are responsible

for the increased incidence of this species as a tomato pest, due to

the elimination in the eld of one of its natural biological controllers

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Bolívar et al. Rev. Fac. Agron. (LUZ). 2022, 39(4): e2239503-7 |

(Synopeas sp.), which was reported by Geraud et al. (2022)

parasitizing the larvae of P. longila in the tomato crop in Ecuador.

Consequently, the objective of this research was to determine the

interaction between the incidence of the pest and the agronomic and

phytosanitary practices applied by producers in tomato crops in six

cantons of the province of Manabí, Ecuador.

Materials and methods

This research was developed in crops established by tomato

growers in open elds, where a single production cycle was evaluated

between March 2019 and January 2020, in the cantons of Bolívar,

Portoviejo, Rocafuerte, Santa Ana, Sucre, and Tosagua (gure 1). The

province of Manabí is at coordinates 40°40’00 “S and 80°05’00 “W

(National Geospatial-Intelligence Agency [NGA], 2022).

Figure 1. Location of the study area in cantons of the province of

Manabí, Ecuador.

Implementation of the study

It was framed in two areas: an analysis of the infestation and

severity of damage of P. longila, for which 25 tomato production

units were identied in the province of Manabí, considering the

cantons: Bolívar (2), Portoviejo (8), Rocafuerte (5), Santa Ana (1),

Sucre (3), and Tosagua (6). In each one, an observation area of 2500

was delimited, within which, a minimum of 25 tomato plants

were randomly marked 10 days after being established in the eld for

statistical support (Badii et al., 2008). The varieties established in the

province were Margot and Acerado, as well as the Zodiac, Prieto, and

Revolución hybrids, all of which are cultivars genetically susceptible

to P. longila. The information required during the development of

the crop (ni = 25) was evaluated in these materials. For this purpose,

analysis of optimal sample size was not applied, since it is a nite

population, where the variance of the qualitative characteristics is

unknown (Bernal, 2006).

Additionally, the phytosanitary management program used by the

producer to control the pest was considered. For this, the estimated

universe of tomato producers in Manabí was assessed through an

analysis of the planting area in the 24 cantons of the province of

Manabí, which is 139 ha (SIPA, 2021). For the present study, six

cantons with the highest production of this vegetable were delimited,

with an approximate planting area of 60 ha, and the average size of

the production units was 2 ha. These data allowed to estimate the

population of growers (30). Badii et al. (2008), mentioned that

for the statistical support of the survey data, the calculation of the

optimal sample size [Formula 1], which estimated a total number of

25 growers to be surveyed, with a 95 % probability of success and a

margin of error of 10 %, should be carried out.

Formula: [1]

Where:

N= tomato producers (30)

Z = probability of making a mistake in the decision Z=1.96 for

α=0.05)

p = hit = 0.05

q = not right = 0.95

d = maximum error accepted by the researcher (0.1)

Data recording

The incidence data of P. longila and severity of damage caused

by this pest on apical shoots, and fruits were taken from 25 tomato

plants, in addition, cultural practices carried out on each crop were

recorded. Field evaluations were performed every 15 days during

the crop cycle. The variables evaluated were: the number of shoots

(healthy, infested, and damaged) and the total number of healthy and

damaged fruits by P. longila.

With this information, the percentages of infestation and severity

(shoot and fruit damage) were calculated by applying the formulas

described by González et al. (1995):

Infestation (I%)

N° of shoots with presence of P. longifila larvae/plant

I%= (100)

N° total of shoots/plant

Severity-damage (S%)

N° of shoots with damage,with and sithout the

present of P. longifila larvae/plant

S%= (100)

N° total of shoots/plant

Through a survey applied to the producers, the cultural practices

carried out during the crop cycle (pruning, trellising, irrigation, and

collection of infested fruits) and phytosanitary practices (applications

of insecticide) were established.

Statistical analysis

The descriptive analysis was performed, and to establish

signicant differences in infestation and severity, the non-parametric

Friedman test was used (Amat, 2018). To determine the similarities

and differences between the agronomic practices applied in tomato

crops in the six cantons, cluster analysis was performed. This is a

multivariate statistical technique that seeks to group elements (or

variables) trying to achieve maximum homogeneity in each group,

and the greatest difference between groups (De la Fuente, 2011).

The Euclidean distance was used to dene similarity. Ward’s method

was used for clustering and cophenetic correlation to determine the

validity of the test. To demonstrate the level of relationship between

optimal

𝑁. 𝑍

𝛼/2

.𝑝.𝑞

𝑑

(

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)

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.𝑝.𝑞

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2022, 39(4): e223950. October-December. ISSN 2477-9407.4-7 |

Damage severity (%) of Prodiplosis longila

Regarding the behavior of P. longila by canton, the Friedman

test at 95 %, determined signicance in the severity levels of P.

longila in tomato crops in the six cantons. Portoviejo, Tosagua,

and Rocafuerte showed similar damage to apical shoots up to 15 %

(table 2). This percentage is lower than those reported by Valarezo

et al. (2003), who indicated damage to apical shoots greater than 70

and 80 % in Portoviejo and Santa Ana, respectively, during the dry

season in the owering and fruiting stages. Regarding the severity

of P. longila in fruits per plant, Portoviejo, Tosagua, and Bolívar

showed up to 25 % damage, in contrast to the other cantons that did

not exceed 9 % in both variables.

Similarly, signicant differences were established at 95 %,

in the phenological stages, where the harvest reached an average

damage of 31 %, and in the vegetative, owering, and fruiting

stages, affectation was recorded at 5 %. The average number of

fruits damaged by P. longila per plant was 14 % (table 2). These

percentages are greater than those reported by Valarezo et al.

(2003), who reported values of 11 % in fruits of tomato cultivars

for industrial use, and those reported by Cardona et al. (2010),

who established that 2.3 % of the total production was damaged

by this insect. These results could be associated with the chemical

management of the pest by growers, which is similar to the 30

applications reported by Cañarte et al. (2015), and which also

contrasts with the 45 sprays recorded by Chirinos et al. (2020)

during the crop cycle.

Through the survey carried out, it was possible to identify

the agronomic practices applied in each of the tomato plantations

evaluated. With the information recorded, a hierarchical cluster

analysis (ACJ) was performed, which indicated that these practices

were similar in the cantons of Tosagua, and Rocafuerte, approaching

this group Portoviejo (gure 1).

Table 2. Severity of Prodiplosis longila in apical shoots by phenological stages and in fruits, depending on insecticide applications in

cantons of Manabí, Ecuador.

Cantons

Severity (%) / phenological stages Damaged fruits/ plants(%) Application of insecticides

Vegetative Flowering Fruiting Harvest x

Portoviejo (n= 8) 1.1 2 11 44 15a 19 a 29

Tosagua (n= 6) 0.3 3 8 46 14a 25 a 32

Rocafuerte (n= 5) 0.2 3 9 39 13a 7,8 b 29

Sucre (n= 3) 0 0 1 34 9 b 8 b 38

Santa Ana(n= 1) 0 0 0 21 5 b 7 b 24

Bolívar (n= 2) 0 0 2 4 1 b 12 a 32

Means x̄ 0.3 b 1 b 5 b 31 a 10 14 31

P> 0.05 probability of 95 %.

agronomic practices, infestation, and severity, a contingency table

was made, relying on the Chi-square statistic at 95 % condence to

know the signicance level at 95 % (De la Fuente, 2016).

Results and discussion

Infestation (I%) of Prodiplosis longila

The non-parametric Friedman test at 95 %, determined

signicance in the levels of infestation of P. longila in the tomato

crops of the six cantons. Rocafuerte, Tosagua, and Portoviejo

showed similar signicance, reaching up to 4 % infestation,

differing from the other cantons which did not exceed 2 % (table

1). These percentages contrast with those reported in Portoviejo,

and Santa Ana by Valarezo et al. (2003), whose infestation values

ranged from 50.5 % and 45.6 % respectively, with an intensive

insecticide application regime, highlighting that, in Santa Ana,

without insecticide application, infestation reached 70.5 %.

In relation to the population dynamics of P. longila according

to the phenological stages of the crop, during the vegetative and

owering stages, no larvae were observed in the production units

sampled, and the attack began during fruiting (0.8 %), which

increased at harvest stage (7.78 %) (table 1). However, it is known

that tomato emits abundant sprouting during its production cycle,

which makes it vulnerable to attack by P. longila (Díaz, 2011;

Cañarte et al., 2015; Geraud et al., 2022). During this research, low

average infestations were recorded, which are possibly related to

the high frequency of pesticide application (31 applications/average

cycle), results that coincide with those of Valarezo et al. (2003) and

Cardona et al. (2010), who recorded very similar infestations under

very similar conditions.

Table 1. Infestation of Prodiplosis longila in apical shoots by phenological stage and cantons, depending on insecticide applications, in

Manabí, Ecuador.

Cantons

Infestation(%) / phenological stage Application of insecticides

Vegetative Flowering Fruiting Harvest x

Rocafuerte (n= 5) 0 0 1.6 11.4 4 a

Tosagua (n= 6) 0 0 0.33 12.17 3 a

Portoviejo (n= 8) 0 0 1.25 11.13 3 a

Sucre (n= 3) 0 0 0 7 2 b

Santa Ana (n= 1) 0 0 0 4 1 b

Bolívar (n= 2) 0 0 1.5 1 0.6b

Means x̄ 0 b 0 b 0.8 b 7.78 a 2.23 31

P> 0.05 probability of 95 %.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Bolívar et al. Rev. Fac. Agron. (LUZ). 2022, 39(4): e2239505-7 |

The similarity of the cultural activities carried out in Santa Ana

and Sucre, places them in the same group, bringing Bolívar closer to

this cluster (gure 1).

Figure 1. Similarity in the application of practices of pruning,

trellising, drip irrigation, and collection of

fruits infested by Prodiplosis longifila in tomato

crop management in cantons of Manabí, Ecuador.

Diagnosis

According to the contingency matrix of categorical data and

Pearson’s Chi-squared statistic at 95 % probability, a relationship was

established between the agronomic practices of collection of infested

fruits, and trellising with the level of infestation and severity (high,

medium, low) of P. longila, respectively (table 3).

The practice of collecting infested fruits resulted in a low

infestation of P. longila in 36 % of the producers. This cultural

practice contemplated within the MIP allows interrupting the

biological cycle of the pest (Martínez, 2010), since, when collecting

tomato fruits with fresh lesions and larvae, it reduces the population

of P. longila and minimizes its pupe stage (Díaz, 2011). Regarding

trellising, 44 % of growers recorded low infestation, 28 % had a

medium infestation and 8 % had a high infestation. This practice

associated with pruning, allows the tomato crop to have greater light

penetration and aeration, unfavorable conditions for the establishment

of P. longila, which needs a dark environment with little ventilation

(Valarezo et al., 2003). This cultural practice, which is based on

preventing pest attack, and reducing damage (Díaz, 2011), could have

inuenced the level of severity of P. longila.

Table 4 shows the insecticides applied on the tomato crop. A

total of 21 chemical groups and 37 active ingredients were used,

predominantly phosphorous, neonicotinoids, and tetramic acids.

Triazofos, pirimiphos-methyl, and spirotetramat were the most

commonly applied in the phenological stages, particularly at harvest.

There is the application of insecticides banned in Ecuador, such as

methamidophos (Agrocalidad, 2020). Some of these insecticides

are of extremely and highly toxic categories, being applied after

transplanting, with a maximum of three controls/week in the

vegetative stage and four sprays/week from owering to harvest,

without observing the toxicological deciency of the products, which

uctuate in 8 to 21 days between the last application and harvest, as

noted by Reinoso (2015).

These results indicate that tomato agroecosystems in Manabí are

seriously disturbed, since the appearance of P. longila in Manabí

in 1988 (Valarezo et al., 2003), many producers indiscriminately

use extremely toxic insecticides to combat it (Cañarte et al., 2015).

According to Chirinos et al. (2020), this dependence on chemical

Table 3. Relationship between agronomic practices and the infestation and severity of Prodiplosis longila in six cantons of Manabí,

Ecuador.

Variables Infestation Total Pearson’s

chi-squared

test

Severity Total Pearson’s

chi-squared

test

Categories Low Medium High Low Medium High

Collection of infested fruits

Yes 9 1 0 10

0.008*

6 3 1 10

0,508No 4 9 2 15 6 5 4 15

Total 13 10 2 25 12 8 5 25

Drip irragation

Yes 8 6 2 16

0.541

6 6 4 16

0,369No 5 4 0 9 6 2 1 9

Total 13 10 2 25 12 8 5 25

Gravity irrigation

Yes 6 4 0 10

0.463

7 2 1 10

0,196No 7 6 2 15 5 6 4 15

Total 13 10 2 25 12 8 5 25

Tresilling

Yes 11 7 2 20

0.523

11 7 2 20

0,043*No 2 3 0 5 1 1 3 5

Total 13 10 2 25 12 8 5 25

Pruning practices

Yes 10 7 2 19

0.659

10 7 2 19

0,106No 3 3 0 6 2 1 3 6

Total

13 10 2 25 12 8 5 25

P> 0.05 probability of 50 %.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2022, 39(4): e223950. October-December. ISSN 2477-9407.6-7 |

Table 4. Insecticides applied to combat Prodiplosis longila in tomato crop by phenological stages in six cantons of Manabí, Ecuador.

Chemical groups i. a.

*Toxic

level

Application of insecticides

Vegetative Flowering Fruiting Harvest

Phosphorates

Triazofos Ib 11 16 15 18

Pirimiphos-methyl III 12 11 12 15

Methamidophos Ib 6 7 6 6

Malathion III 2 5 6 5

Profenofos II 6 5 3 3

Dimethoate II 2 3 3 3

Chlorpyrifos II 1 2 1

Acephate III 1

Neonicotinoids

Imidacloprid III 7 4 8 8

Acetamiprid III 8 8 8 13

Clothianidin III 1 1 2

Tetramic Acids Spirotetramat III 11 14 12 13

Avermectin

Abamectin II 6 3 10 9

Emamectin + benzoate III 1 2 4 4

Pyrethroid + Nitroguani-

dines

Lambdacyhalotrin+ Thiame-

thoxam

II 8 7 8 8

Naturalyte

Spinetoram-J-L IV 5 7 4 8

Spinosad A and D IV 1

Carbamates

Benfuracarb II 2 5 4 5

Methomyl Ib 3 5 1 4

Thiodicarb II 1 2 4

Carbosulfan II 2 2 1

*Toxic level: Ib Extremely; II Highly; III Moderately; IV Slightly.

Literature cited

Agrocalidad (2020). Plaguicidas prohibidos en el Ecuador. Coordinación General

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Conclusions

The levels of infestation and severity of P. longila in the

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The practices widely used by tomato growers in the study area are

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There was a relationship between the agronomic practices of

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