Seasonality in the occurrence of two lepidopterous olive pests in Egypt

Abstract

Prays oleae Bern, (OM) and Palpita unionalis Hüb., (JM) are two of the most important pests in olive groves in Egypt. A 3‐year monitoring study using sex pheromone traps in semi‐arid and arid olive groves was performed. In the semi‐arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually: the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi‐arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi‐arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi‐arid one. This study shows that trapping location and fruit bearing year are characteristics that strongly affect the grove‐specific information needed to estimate correctly adult emergence and thus the timing of control measures.

A cohort-based modelling approach for managing olive moth Prays oleae (Bernard, 1788) populations in olive orchards

“…The seasonal dynamics results from both simulation years are similar to those reported in other studies (Andreadis et al, 2011;Armendáriz et al, 2007;Kavallieratos et al, 2005), namely regarding the number of P. oleae generations per year, especially on the beginning of the first flight (Hegazi et al, 2011;Kavallieratos et al, 2005;Kumral et al, 2005). These differences could be explained by distinct regions studied with different weather conditions, stated by several other case studies (Andreadis et al, 2011;Armendáriz et al, 2007;Hegazi et al, 2011;Kumral et al, 2005;Tzanakakis, 2003). In relation to the life cycle duration, the differences in each generation can be explained by the divergence in the mean temperatures occurring between years as reported in other studies (Andreadis et al, 2011;Armendáriz et al, 2007;Hegazi et al, 2011;Kumral et al, 2005).…”

“…Car population densities were similar between years (Table 4) as also was the weather data in the associated periods. The seasonal dynamics results from both simulation years are similar to those reported in other studies (Andreadis et al, 2011;Armendáriz et al, 2007;Kavallieratos et al, 2005), namely regarding the number of P. oleae generations per year, especially on the beginning of the first flight (Hegazi et al, 2011;Kavallieratos et al, 2005;Kumral et al, 2005). These differences could be explained by distinct regions studied with different weather conditions, stated by several other case studies (Andreadis et al, 2011;Armendáriz et al, 2007;Hegazi et al, 2011;Kumral et al, 2005;Tzanakakis, 2003).…”

“…P. oleae and olive tree are modeled separately but use the same weather database. Even though, P. oleae oviposition can only occur during the adult flight period and for specific olive tree phenological stages (Andreadis et al, 2011;Armendáriz et al, 2007;Bento, 1999;Bento et al, 2007;Hegazi et al, 2011;Kumral et al, 2005). The model reproduces this synchronism between P. oleae oviposition periods, namely for the Phy and Ant generation flight and the olive tree phenology (Fig.…”

“…These differences could be explained by distinct regions studied with different weather conditions, stated by several other case studies (Andreadis et al, 2011;Armendáriz et al, 2007;Hegazi et al, 2011;Kumral et al, 2005;Tzanakakis, 2003). In relation to the life cycle duration, the differences in each generation can be explained by the divergence in the mean temperatures occurring between years as reported in other studies (Andreadis et al, 2011;Armendáriz et al, 2007;Hegazi et al, 2011;Kumral et al, 2005). The variability, expressed in terms of life cycle duration and population densities, could be largely related to temperature which influence the insect and the olive tree (Armendáriz et al, Fig.…”

Methodological considerations in discriminating olive-orchard management type using olive-canopy arthropod fauna at the level of order

“…Meanwhile, P. oleae sharply declined in 2008. Other studies on this lepidopteran have found considerable interannual fluctuations (Delgado & Cuesta, 1995;Hegazi et al, 2011) related to environmental variables. The high importance of taxa such as Coleoptera and Araneae in the olive grove is also remarkable (Ruíz & Montiel, 2000;Ruano et al, 2004;Santos et al, 2007b;Rei et al, 2010;Cotes et al, 2011), hardly register significant differences in abundance among management types.…”