Scaevola subalpina(Goodeniaceae), a new species from Mount Mantalingahan Protected Landscape, Palawan, Philippines
BRITTONIA
Authors: Malabrigo, Pastor L., Jr.
Abstract
A new species,Scaevola subalpina, is described and illustrated from the subalpine forest of Mount Mantalingahan Protected Landscape on the island of Palawan in the Philippines. The new species is most similar toScaevola glabra, a species endemic to the Hawaiian archipelago. Both species grow at high elevations and share solitary or few-flowered inflorescences and yellow corollas but can be differentiated by flower size and structure. The flowers ofS. subalpinaare much shorter, and the corolla is half open from the base (as in most other species of the genus), whereas inS. glabrathe corolla is fused to form a tube that splits open in only the distal portion to form lobes.Scaevola subalpinais the only Phillippine-endemic of four species of the genus that are native to the Philippines. It appears to be critically endangered.
Temperature-Dependent Functional Response ofHarmonia axyridis(Coleoptera: Coccinellidae) on the Eggs ofSpodoptera litura(Lepidoptera: Noctuidae) in Laboratory
INSECTS
Authors: Islam, Yasir; Shah, Farhan Mahmood; Shah, M. Abas; Musa Khan, Muhammad; Rasheed, Muhammad Asim; Ur Rehman, Shakeel; Ali, Shahzaib; Zhou, Xingmiao
Abstract
Simple Summary Spodoptera litura(Fabricius) (Lepidoptera: Noctuidae) is a notorious and polyphagous pest of several economically important agricultural crops. It is worldwide in distribution and primarily managed through typical dependence on insecticides, which resulted in health and the environmental challenges and selected for resistance development inS. liturafield populations. Resistance caused chemical control failures andS. lituraoutbreaks around the world. This necessitated development of eco-friendly alternative approaches such as biological control. With this view, current study investigated the functional response ofHarmonia axyridis(Pallas) (Coleoptera: Coccinellidae) at various growth stages (i.e., 1st, 2nd, 3rd and 4th instars, and male and female stages) and temperatures (i.e., 15, 20, 25, 30 and 35 degrees C) againstS. lituraeggs to enable the recognition of efficient biocontrol stages that could be utilized to suppressS. liturapopulations. In our findings, egg consumption depended on the growth stage of the predator as well as temperature. All stages consumedS. lituraeggs, but more promising stages with active egg consumption were the 4th instar and adults (male and female) typically at higher temperatures (25-35 degrees C). We conclude that these stages may be exploited to suppressS. liturapopulations in fields and greenhouses. Spodoptera litura(Fabricius) (Lepidoptera: Noctuidae) is a major pest of several economically important crops with worldwide distribution. Use of insecticides is the principal strategy for its management, which has subsequently led to insecticide resistance and control failures. Functional response ofHarmonia axyridis(Pallas) (Coleoptera: Coccinellidae) at larval and adult stages was evaluated in this study, usingS. lituraeggs as the prey at various temperatures varying between 15 and 35 degrees C. Based on logistic model findings, linear parameters of various predatory stages ofH. axyridisat various temperatures were significantly negative, which indicate a type II functional response. The theoretical maximum number (T/T-h) of eggs consumed increased with increasing temperature across all predatory stages. According to the random predator equation, the coefficients of attack rate increased and that of handling time decreased as the temperature increased. The 4th instar and adult stages were superior candidates for biocontrol of the target prey, typically at higher temperatures. The maximum attack rate (0.546 +/- 0.058 h(-1)) and lowest handling time (0.189 +/- 0.004 h) were exhibited by the females at 30 and 35 degrees C, respectively, whereas these parameters were inferior for early instars. These findings clearly depict that the 4th instar and adult predators are efficient egg consumers and can serve as potential suppressors ofS. liturafield populations. The limitations of the predictions formulated by functional response trials are also discussed.