Mites coexistent with neotropical hispine beetles in unfurled leaves of Heliconia: a new genus and family of the Ascoidea (Acari: Mesostigmata: Gamasina)

The genus Antennocheles gen. nov. is based on adults and nymphs of two newly described species associated with hispine beetles of the genera Chelobasis and Cephaloleia occupying unfurled leaves of Heliconia in lowland rainforest of Costa Rica. Within the superfamily Ascoidea, this taxon is so distinctive morphologically and behaviourally as to justify its own family, Antennochelidae, fam. nov. These mites bear remarkably elongated cheliceral shafts, which may extend for lengths greater than the body but are fully ensheathed in repose within the body. Other unique attributes include linear arrangement of hypostomatic setae, a pore-like structure beside the corniculus, and adults with a pair of unique sternal invaginations for enlarged muscle insertions. While undergoing their life history in water films of unfurled host leaves, the mites exhibit a slow, swimming-like behaviour in quest for prey. As leaves unfurl, adult mites run quickly off and on their hispine beetle phoronts for dispersal.

http://zoobank.org/urn:lsid:zoobank.org:pub:0876014C-1433-463B-B1A4-4CD6886F9D28     

New species of Monstrilloida (Crustacea: Copepoda) from the Eastern Tropical Pacific

Monstrilloid copepods were collected from the oceanic island Isla del Coco in the Eastern Tropical Pacific; two undescribed species were found, one of Cymbasoma and one of Monstrillopsis. The first species, represented by females only, is distinguished by the structure of its fifth legs, the antennular armature and the position of the ovigerous spines. The new Monstrillopsis, represented by male specimens, is distinguished by its genital lappets and details of the antennule armature. The isolation of this island, 532 km from the mainland, and the limited dispersal means of monstrilloids suggest potential endemism of these species. A recent record of Cymbasoma tumorifrons from the Mexican Pacific was found to represent a new species of Cymbasoma. It can be distinguished from C. tumorifrons, probably a Mediterranean form, by its body shape and antennular armature. These findings double the number of monstrilloid species known from the Eastern Tropical Pacific.     

Biology of Lissoderes Champion (Coleoptera,Curculionidae) in Cecropia saplings inhabited by Azteca ants

This paper provides an account of the biology of Lissoderes (Coleoptera, Curculionidae, Conoderinae) focusing on L. pusillus Hespenheide and L. subnudus Champion. The eggs, larvae, and pupae live inside the hollow stems of Cecropia saplings. Adult weevils chew through the stem and deposit eggs on the inner surface of the internode. The larvae feed on the parenchyma lining the hollow internodes and pupate inside the internode. Emerging adults chew their way out of the stem. Two hymenopteran parasitoids were reared from larvae and prepupae of L. pusillus: Neocatolaccus sp. (Pteromalidae) and Heterospilus sp. (Braconidae). Menozziola sp. (Diptera, Phoridae) and Conoaxima sp. (Hymenoptera, Eurytomidae) were observed parasitizing Azteca queens. Parasitism by these species may explain part of the high mortality observed in colonizing Azteca queens. Direct competition with L. pusillus and L. subnudus appears not to be a major cause of queen mortality, although possible indirect effects of the weevils remain unknown.     

An eyespot that “blinks”: an open and shut case of eye mimicry in Eumorpha caterpillars (Lepidoptera: Sphingidae)

We describe the final instars of two tropical Sphingidae caterpillars – Eumorpha phorbas and Eumorpha labruscae – from Area de Conservacion Guanacaste, northwestern Costa Rica, whose anal horn has become a posterior eyespot structure capable of rapid palpitation. When approached or harassed, the caterpillars palpitate this eyespot and produce the effect of a blinking vertebrate eye. We propose that this “blinking” is an extension of eye mimicry or at least draws attention to the eyespot, functioning to startle or intimidate would-be predators. As snakes lack eyelids and do not blink, this suggests that the blinking eye represents a more generalized (or possibly mammalian) eye. Eyespot “blinking” is probably controlled by the same musculature used to wave the anal horn in earlier instars. The extent to which this eyespot is perceived as a blinking eye, and the degree of protection from the caterpillars’ suite of potential predators, remain to be discovered.     

Lasalleistichus a new genus of Tetrastichinae (Hymenoptera: Eulophidae) from the Neotropical region,including four new species

ABSTRACT

A new genus, Lasalleistichus, is described based on material from the Neotropical region (Brazil, Costa Rica, Peru). This new genus includes four species: L. albiclava, L. albifasciatus, L. fuscicoxa, L. longicaulis, all spp. n. and described here. The group is mainly female based, males are known only for L. albiclava. There is no biological information available for this group.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:82E08F36-E2C4-42FF-AD12-11B49C272AC6     

Natural history of the terrestrial amphipod Cerrorchestia hyloraina Lindeman (Crustacea: Amphipoda; Talitridae) in a Costa Rican cloud forest

The field biology of the Costa Rican landhopper (Crustacea: Amphipoda: Talitridae) Cerrorchestia hyloraina Lindeman was investigated in the Monteverde Cloud Forest Reserve, Costa Rica. On the Pacific (leeward) side of the continental divide, local distribution follows a gradient of moisture, from densities of over 200 m^-2 in the elfin forest at 1600 m, to extremely low densities in drier forest types. Below 1400 m, the leaf litter is apparently too dry to support landhopper populations. On the Caribbean (windward) side of the continental divide, landhoppers occur well below 1400 m. A discussion of geographic distribution is included. Landhoppers prefer aged (microfaunally pre-processed) leaves as food, and move about only at night or in the mornings of heavily overcast days. Average female fecundity is seven eggs, with progressive loss of marsupium contents over time. The sex ratio is biased towards females. In cloud forest, breeding apparently is continuous throughout the year, with some increase after the beginning of the rainy season. There are 9–10 juvenile instars and 5–6 adult instars. The relationship of antennal segment number to total body length is linear.     

Helminth biodiversity of Costa Rican Anurans (Amphibia: Anura)

One hundred and sixty-three frogs representing 21 species collected in Costa Rica were examined for helminths. Those found were: one species of Digenea (Mesocoelium monas), one species of Cestoda (Cylindrotaenia americana), 15 species of Nematoda, 11 species represented by gravid individuals (Aplectana hylambatis, Aplectana incerta, Aplectana itzocanensis, Capillaria recondita, Cosmocerca parva, Cosmocerca podicipinus, Falcaustra costaricae, Hedruris heyeri, Oswaldocruzia costaricensis, Oswaldocruzia nicaraguensis, Rhabdias savagei) and four species represented by larvae (Physaloptera sp., Porrocaecum sp., Spirocamallanus sp., Ascarididae gen. sp.) and three species of Acanthocephala, one species represented by gravid individuals (Anuracanthorhynchus lutzi) and two species by cystacanths (Centrorhynchidae gen. sp. and Oligacanthorhynchidae gen. sp.). Mean helminth diversity (number of helminth species) per frog species was 2.4 ± 0.3 SE, range: 1–6. Forty-nine new host records are reported. Costa Rican frogs are infected by generalist helminths, which infect other species of frogs from Central and South America.     

Considerations about the genus Pentoniscus Richardson, 1913 (Crustacea: Isopoda: Oniscidea) with description of a new species

The status of the neotropical genus Pentoniscus Richardson, 1913 is reconsidered and a diagnosis of this genus is given. It is shown that Pentoniscus Richardson, 1913 is a valid genus and not a synonym of Philoscia Latreille, 1804 as discussed by Schultz (1968). The type species, Pentoniscus pruinosus Richardson, 1913 is redescribed and for the first time figured in detail. A new species of Pentoniscus Richardson, 1913 is described from Costa Rica, Central America, which differs remarkably from its congeners in being unpigmented and blind.     

A new species of Melanagromyza (Diptera: Agromyzidae) mining leaves of Bromelia pinguin (Bromeliaceae) in a dry forest in Costa Rica

Melanagromyza rosales, sp. nov., from Costa Rica is described and its natural history is summarized. Larvae are miners in leaves of Bromelia pinguin, a large terrestrial rosette plant. They form conspicuous longitudinal mines that may be over 1 m long. Adult emergence is virtually simultaneous for all individuals, probably triggered by temperature cues. Populations are low for many generations with brief periods of abundance.