Attacks by predators and parasitoids on spider eggs are common. To counteract their negative effect, spiders have evolved a series of behaviours and features related to their egg sacs. In the genus Deinopis (Deinopidae) the tightly woven external layer of the egg sac seems to be an effective barrier. This layer consists of two sub-layers: the outer sub-layer is constructed of thin threads densely woven with an apparently hardened liquid that cements the threads together, and an inner sub-layer that seems to be even more compact and in which threads are not discernible. Threads of the external layer are presumably produced by the cylindrical glands, but other glands may be involved in production of the liquid substance. Fig. 3: Deinopis sp. placing her spinnerets on the outer surface of the egg sac. Note the curvature of her abdomen to reach the egg sac.
Two new species of oribatid mites of the genus Pergalumna (Oribatida, Galumnidae), P. elongatiporosa
sp. n. and P. striatiprodorsum
sp. n., are described from leaf litter of a secondary forest in Costa Rica. Pergalumna elongatiporosa
sp. n. is most similar morphologically to P. horvathorum P. Balogh, 1997 and P. sura P. Balogh, 1997, however, it differs from both by the body size, body surface ornamentation and morphology of notogastral porose areas A1 and A3. Pergalumna striatiprodorsum
sp. n. is most similar morphologically to P. hawaiiensis hawaiiensis (Jacot, 1934) and P. strigulata Mahunka, 1978, however, it differs from P. hawaiiensis by the length of interlamellar setae and surface ornamentation of the prodorsum; from P. strigulata by the surface of ornamentation of the notogaster, length of interlamellar setae and morphology of bothridial setae. An identification key to known species of Pergalumna from the Neotropical region is given.
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Micromorphology of pejibaye leaflets Bactris gasipaes (Arecaceae) var. diamonds-10.Bactris gasipaes is widely cultivated for the consumption of palm hearts and fruits. The present work describes the micro morphological characteristics of leaflets from adult plants of B. gasipaes, thornless variety Diamantes-10, collected in the Diamantes Experimental Station in Guápiles, Costa Rica. We collected 25 leaflets and analyses were performed with a combination of microscopy techniques: light microscopy, scanning electron microscopy and transmission electron microscopy to study their structure. Our results showed that leaflets have abundant epicuticular wax on adaxial and abaxial surfaces. Analyses from the epidermis indicated that it is composed of isodiametric cells, and it is also evident that hypodermis cells have rectangular shape and are larger than the other epidermal cells. We observed stomata on both surfaces, but they were more abundant in the abaxial surface. On the other hand, the epidermis showed the presence of trichomes with three different morphologies. In the parenchyma, cells are large and not well defined, and we observed the presence of astroesclereids, and compact groups of fiber bundles between parenchyma cells. The central vein has several vascular bundles, arranged in a continuous manner, and they are surrounded by sclerotic tissue; some of these fibers presented live protoplasts. All minor veins showed the same anatomy as the central vein. In these veins, the vessel elements of protoxylem and metaxylem showed scalariform ornaments on their walls. Phloem is located towards the adaxial surface of the vein and we observed sieve and companion cells surrounded by fibers and parenchyma cells. The companion cells presented branched plasmodesmata attached to a sieve element, and in these elements we found protein bodies called P-protein. The main anatomical difference in the leaflets of the var. Diamantes-10, compared to the other varieties of B. gasipaes K, is the lack of thorns; the other morphological features seem to be conserved. Rev. Biol. Trop. 64 (3): 1273-1285. Epub 2016 September 01.
Two species of oribatid mites of the genus Benoibates (Oribatida, Oripodidae), i.e., Benoibates
bolivianus Balogh & Mahunka, 1969(a) and Benoibates
minimus Mahunka, 1985, are recorded for the first time in Costa Rica. Both are redescribed in details, using drawings, images and SEM micrographs, on the basis of Costa Rican specimens. An identification key to the known species of Benoibates is given.
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