Percentage of importance indice-production unknown: loss and solution sources identification on system

Abstract

Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.

Arthropods as possible loss or solution sources on Acacia mangium (Fabales: Fabaceae) saplings

“…The Importance Indice (I.I.) can determine the loss and solution sources on a system in some knowledge areas (e.g., agronomy), when production is known (Demolin- Leite, 2021). Events (e.g., agricultural pest) can present different magnitudes (numerical measurements), frequencies, and distributions (aggregate, random, or regular) of event occurrence, and I.I.…”

“…Events (e.g., agricultural pest) can present different magnitudes (numerical measurements), frequencies, and distributions (aggregate, random, or regular) of event occurrence, and I.I. bases in this triplet (Demolin- Leite, 2021). In general, the higher the magnitude and frequency, with aggregated distribution, the greater the problem or solution (e.g., natural enemies versus pests) for the system (Demolin- Leite, 2021).…”

II Production Unknown: a R package for application of the percentage of importance indice-production unknown

“…can determine the loss (L.S.) and solution sources (S.S.) for a system in certain knowledge areas (e.g., agronomy), when production (e.g., fruits) is known (Demolin-Leite, 2021, 2024. However, the final production of the system is not always known or is difficult to determine (e.g., degraded area recovery).…”

“…A derivation of the I.I. is the percentage of Importance Indice-Production Unknown (% I.I.-PU) that can detect the loss or solution sources when production is unknown for the system (Demolin-Leite, 2022). This new index can help in monitoring degraded area recovery.…”

“…was non-significant for damage or non-detected by L.S. on the system (Demolin-Leite, 2022). When an S.S. operates in more than one L.S., that caused damage, its ks are summed.…”