Judul: Aktivitas Perilaku Meghimatium bilineatum dan Deroceras laeve pada daun bawang (Allium fistulotum) di Kawasan Pertanian Agropolitan Cipanas.
Abstrak: Meghimatium bilineatum and Deroceras laeve are gastropod without shells. These animals live as pests in horticultural commodities (such as Allium fistulotum). This study aims to determine the behavioural activities of the M. bilineatum and D. laeve on Allium fistulotum in Agropolitan Agricultural Regions, Cipanas. The observed behavioural activities are their emerging, locomotion, feeding, returning to their hideout and mating. Observations were carried out from 18:00 in the twilight until 6:00 in the morning for 20 days. The results of this study indicated that the M. bilineatum’s behavioural emerging activity was peaked at 19:00, locomotion activity peaked at 19:00 and 02:00, feeding activity peaked at 23:00 pm, and returning to their hideout peaked at 03:00, while mating activity was not too often found. For D. laeve’s emerging activity, locomotion activity, feeding activity, returning to their hideout peaked at 18:00, at 18:00 and 04:00, at 22:00, and respectively, at 05.00. Meanwhile mating activity of this slug is not too obvious.
Keyword: Meghimatium bilineatum, Deroceras laeve, behavioural activity, Agropolitan Region

Judul: Perilaku Kawin dan Siklus Reproduksi Deroceras laeve, Filicaulis bleekeri, dan Meghimatium bilineatum (Mollusca: Gastropoda)
Abstrak: Deroceras laeve, Filicaulis bleekeri and Meghimatium bilineatum are members of Gastropoda (Mollusca) that live as pest. However they are potential for protein source of animal livestock. Mating behavior and reproductive cycle of those were inspected for 42 days. The mating phase of F. bleekeri and M. bilineatum started from touching each other with tentacle or touching another slug’s body or tail with tentacle, slug come closer to other which will be the partner, stuck each other position, and withdrawal. The mating phase of D. laeve investigated slug touched body or tail another slug with tentacle. Mating behavior of M. bilineatum and F.bleekeri which stick each other position was the longest mating duration (average 281,4 second and 561,9 second respectly) during 42 days observation. D. laeve produced 264 eggs, took average incubation period for 14 days and had hatching percentage 60.98%. The fecundity per individual is 0.31/day.
Keyword: Deroceras laeve, Filicaulis bleekeri, mating behaviour, Meghimatium bilineatum, slug egg

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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