Sustainability of Mahogany Production in Plantations: Does Resource Availability Influence Susceptibility of Young Mahogany Plantation Stands to Hypsipyla robusta Infestation?

Abstract

Hypsipyla robusta Moore (Lepidoptera: Pyralidae), like many other moth species, shows selectivity when choosing host plants for its eggs. Four Meliaceae species (Khaya grandifoliola, K. ivorensis, Swietenia macrophyla, and Entandrophragma cylindricum) were established in a moist semideciduous forest in Ghana to study this selectivity at 12 and 21 months after planting. The analysis of variance (ANOVA) at a P -value of 0.05 was used to test the significance of differences in infestation by H. robusta between the species. H. robusta attacks were recorded by month 12 after planting in the field, and only Khaya spp. was attacked, with attacks evident on 15.5% of K grandifoliola and 6.6% K. ivorensis. Saplings in blocks closer to an older H. robusta infested K. grandifoliola stand had more infestation compared to saplings further away. The mean percentage of K. grandifoliola attacked was 38.9%, 38.9%, 13.3%, and 7.4% in 4 different plots located increasingly further away from the older infested plantation. A similar trend was found in K. ivorensis with 28.4%, 7.1%, 0.0%, and 0.0% in the plots located increasingly further away from the infested stand. These results indicate a higher number of shoot borer attacks at the edge of the plantation and in proximity to other infested plantations. After 21 months, the fastest-growing species and the fastest-growing individuals within the species were the most infested. K. grandifoliola recorded the fastest growth and most attacks followed by K. ivorensis and S. macrophylla. E. cylindricum recorded the least growth and no H. robusta infestation. After 21 months, the mean percentages of trees attacked were 59.1%, 23.7%, 5.6%, and 0.0% for K. grandifoliola, K. ivorensis, S. macrophylla, and E. cylindricum, respectively. Within species, the fastest-growing saplings experienced the most attacks. A positive correlation was observed between the plant size and H. robusta attacks (R2 = 0.76). Attacks resulted in the death of the apical shoot and the proliferation of multiple shoots in only the Khaya spp., with K. ivorensis recording a lower number of shoots than K. grandifoliola. These proliferated shoots were also attacked, and a positive correlation was observed between the number of proliferated shoots and H. robusta attacks (R2 = 0.84). These findings will assist plantation developers, forest managers, and investors in mahogany plantations to devise integrated pest management strategies to reduce the impact of Hypsipyla attacks on their plantations.

Modelling Climatically Suitable Areas for Mahogany (Swietenia macrophylla King) and Their Shifts across Neotropics: The Role of Protected Areas

“…For example, a forest inventory conducted in native populations of Mahogany in the province of Pastaza yielded that 93% of the sampled seedlings indicated signs of herbivory in 50% of their leaves [154]. This demonstrates that the species presents a great vulnerability to herbivores that limits its growth and the survival of individuals in its populations [29,30]. Research focused on the phytosanitary control of Mahogany indicated that the most relevant biological threat to the species would be the insect Hypsipyla grandella (Lepidoptera: Pyralidae) [155,156].…”

“…This species presents a slow growth, and therefore an ineffective natural regeneration, a period of 30 years being necessary for it to be able to develop completely [28]. In addition, it presents a great vulnerability to climatic conditions that affect its germination or pests that limit its growth [29,30]. For all these reasons, it is considered vulnerable to extinction according to the IUCN evaluation categories and is one of the most threatened forest species in the world [31,32].…”

Rasio keuangan, ukuran perusahaan, dan arus kas aktivitas operasi mempengaruhi return saham: Investigasi pada perusahaan sektor properti dan Real Estate, Tbk

“…Salah satu tujuan investor dalam berinvestasi, baik investasi riil pada aktiva berujud maupun investasi keuangan adalah mendapatkan keuntungan di dalam bentuk peningkatan nilai asetnya (Darko et al, 2022;Koesoemasari et al, 2022). Sebagai manusia yang rasional, pilihan investasi yang dilakukan investor adalah investasi yang memberikan return yang tinggi, dengan tentu saja memperhatikan risiko yang menyertai investasi tersebut.…”

Integrated pest management of Hypsipyla robusta shoot-tip borer (Lepidoptera: Pyralidae) in Chukrasia tabularis (Sapindales: Meliaceae)

“…The larvae of H. robusta bore into the shoot tips and form tunnels in the stem resulting in loss of apical dominance, deformation of the crown, and reduction in merchantable wood (Nuraeni and Nuroniah 2020, Tra et al 2021, Darko et al 2022). Forest companies in Vietnam are concerned because tree height is being reduced by 20–30% in young trees (Chi 2020, Tra et al 2021).…”

“…Forest companies in Vietnam are concerned because tree height is being reduced by 20–30% in young trees (Chi 2020, Tra et al 2021). Severe damage from shoot-tip borers is a major obstacle to the expansion of plantations of susceptible hosts in many countries (Cunningham et al 2005, Opuni-Frimpong et al 2008, 2022, Darko et al 2022).…”