Relationship between male moths of Cryptoblabes gnidiella (Millière) (Lepidoptera: Pyralidae) caught in sex pheromone traps and cumulative degree-days in vineyards in southern Uruguay
Mara Valeria Vidart
0
Mara Valentina Mujica
0
Mara Victoria Calvo
0
Felicia Duarte
0
Carlos Mara Bentancourt
0
Jorge Franco
Iris Beatriz Scatoni
0
0
Department of Plant Protection, Faculty of Agronomy, University of the Republic
, Ave. E. Garzn 780, Montevideo 12900,
Uruguay
Cryptoblabes gnidiella (Millire) (Lepidoptera: Pyralidae) has been known in Uruguay for 30 years and only in vineyards, despite being polyphagous. In recent years, this pest has caused sporadic but serious damage on some grapevine cultivars. Understanding the insect's phenology and developing a monitoring program are essential aspects of integrated pest management. We monitored males using sexual pheromone traps on four cultivars of vine, Pinot noir, Tannat, Gewrztraminer, and Cabernet Sauvignon, in two vine-growing establishments in the Department of Canelones and compiled data on the accumulated effective temperatures for the southern area of Uruguay. We determined that this species undergoes three generations per year and overwinters without diapause as larvae on dried grapes remaining after harvest. Using the proportion of cumulative male moths caught from December to May from 2003-2007 on the four cultivars and the sum of effective temperatures above two previously-published lower-threshold temperatures for development, 12.26C and 13C, statistically significant logistic models were estimated. Predictions based on the resulting models suggested that they would be acceptable tools to improve the efficiency of integrated management of this pest in Uruguay.
-
Background
In Uruguay, vineyards have undergone sustained plant
replacement. In the past 20 years, most of the country's
8,000 hectares of vineyards have been replaced by newer,
healthier, and higher-quality grapevine cultivars.
Eightynine percent of the wine growing area is concentrated in
southern Uruguay, especially in Canelones Department
(MGAPDIEA 2011). Unlike in other wine-producing
areas of the world, pests have been a minor problem in
Uruguay's vineyards, eliminating the need for widespread
applications of insecticides (Bentancourt and Scatoni
1999).
Cryptoblabes gnidiella (Millire) (Lepidoptera: Pyralidae)
has become a sporadic pest in Uruguay capable of causing
significant damage to some grapevine cultivars in certain
years and areas (Bentancourt and Scatoni 2006). This
polyphagous moth, is native to the Mediterranean regions of
Europe and reported from Africa, Asia, New Zealand,
North and South America (Bagnoli and Lucchi 2001,
Ioriatti et al. 2012). It has been known in Uruguay for
30 years, but only reported from vineyards (Scatoni and
Bentancourt 1983). Since its appearance, it has displaced in
importance two other grape pests: Argyrotaenia sphaleropa
(Meyrick) and Bonagota salubricola (Meyrick)
(Lepidoptera: Tortricidae). The larvae feed on grape cluster,
especially at the end of season when the fruits are already
mature. Feeding damage produces conditions conducive to
the development of rots. The economic losses become
more significant when harvest is delayed, due to an increase
in population and a potential additional generation. Also,
rainfall and high humidity create conditions suitable for rots
causing further deterioration of the clusters (Bentancourt
and Scatoni 2006).
Knowing pest phenology is an essential aspect of
developing a management program. The identification of the sex
pheromone of C. gnidiella provided a monitoring tool for
adults now widely used (Bjostad et al. 1981, Anshelevich
et al. 1993). Monitoring of adults as well as degree-days
(DD) allows the prediction of pest phenological events for
management purposes. Numerous reports have correlated
species catches with DD for several species of Lepidoptera;
as an example, these relationship have been studied for
Lobesia botrana (Lepidoptera: Tortricidae), the main
vineyard pest in Europe (Del Tio et al. 2001, Milonas et al.
2001). The thermal constant and lower thresholds of
development for C. gnidiella were determined by Avidov and
Gothilf (1960) for Israel and by Ringenberg et al. (2005) for
Brazil. There is, however, no information available about
the relationship between DD and catch levels.
Understanding a pest's phenology and monitoring its
populations are essential aspects of integrated pest
management. The objective of this research was to better
understand the phenology of this insect in Uruguay and
the damage it inflicts on cultivars with different maturity
dates to develop a forecasting system that uses
pheromone traps and the accumulation of effective
temperatures. For these purposes, populations growth models
were run for each cultivar and for all cultivars.
Materials and methods
Study sites
The study was carried out in two vineyards, 10 km apart,
in Canelones Department, which represents our country's
wine production. One was located in Juanic (3458'S,
5625'W) and the other in Progreso (3468'S, 5621'W).
The first being a 200 hectares vineyard and the second 50
hectares. Both (...truncated)