Category Archives: Friday Fellow

Friday Fellow: Rhinoceros Tick

by Piter Kehoma Boll

Parasites exist everywhere and, although most of us see them as hateful creatures, more than half of all known lifeforms live as a parasite at least in part of their life. And there are likely many more yet unknown parasites around there. Today I’m going to talk about one of them, which is found in large portions of Africa.

Its name is Dermacentor rhinocerinus, known as the rhinoceros tick. As its name suggests, it is a tick, therefore a parasitic mite, and its adult stage lives on the skin of the white rhinoceros (Ceratotherium simum) and the critically endangered black rhinoceros (Diceros bicornis).

A male rhinoceros tick attached to the skin of a rhinoceros in South Africa. Credits to iNaturalist user bgwright.**

Male and female rhinoceros ticks are considerably different. In males, the body has a black background with many large orange spots. In females, on the other hand, the abdomen is mainly black with only two round orange spots and the plate on the thorax is orange with two small dark spots. Males and females mate on the surface of rhinoceroses. After mating, the female starts to increase in size while the eggs develop inside her and then drops to the ground, laying the eggs there.

A female rhinoceros tick patiently waiting for a rhinoceros to come close. Photo by Martin Weigand.**

The larvae, as soon as they hatch, start to look for another host, usually a small mammal such as rodents and elephant shrews. They feed on this smaller host until they reach the adult stage, when they drop to the ground and climb on the surrounding vegetation, waiting for a rhinoceros to pass by and then attaching to them.

Conservation efforts to preserve biodiversity are mainly focused on vertebrates, especially mammals and birds. Rhinoceroses, which are an essential host for the rhinoceros tick to survive, are often part of conservation programs and, in order to increase their reproductive success, the practice of removing parasites from their skin is common. This is, however, bad for the rhinoceros ticks. If their host is endangered, they are certainly endangered too, and removing them worsens their condition. Are parasites less important for the planet? Don’t they deserve to live just as any other lifeform? We cannot forget that nature needs more than only what we consider cute.

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More mites and ticks:

Friday Fellow: Giant Red Velvet Mite (on 22 June 2016)

Friday Fellow: Cuban-Laurel-Thrips Mite (on 28 June 2019)

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References:

Horak IG, Fourie LJ, Braack LEO (2005) Small mammals as hosts of immature ixodid ticks. Onderstepoort Journal of Veterinary Research 72:255–261.

Horak IG, Cohen M (2001) Hosts of the immature stages of the rhinoceros tick, Dermacentor rhinocerinus (Acari, Ixodidae). Onderstepoort Journal of Veterinary Research 68:75–77.

Keirans JE (1993) Dermacentor rhinocerinus (Denny 1843) (Acari: Ixodida: Ixodidae): redescription of the male, female and nymph and first description of the larva. Onderstepoort Journal of Veterinary Research 60:59–68.

Mihalca AD, Gherman CM, Cozma V (2011) Coendangered hard ticks: threatened or threatening? Parasites & Vectors 4:71. doi: 10.1186/1756-3305-4-71

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**Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

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Filed under Arachnids, Conservation, Friday Fellow, Parasites, Zoology

Friday Fellow: Eastern Eyed Click Beetle

by Piter Kehoma Boll

During the warmer nights of the year, in the eastern half of the United States, you may end up finding a nice-looking beetle that clicks when disturbed. Its name is Alaus oculatus, also known as the eastern eyed click beetle.

Eastern eyed click beetle in South Carolina, USA. Photo by Phillip Harpootlian.**

This species belongs to the family Elateridae or click beetles. All species in this family have an interesting mechanism on their thorax that allows them to jump in the air with a click, hence the name click beetle. This is used to avoid predators and also to help the beetle to right itself when it falls on its back.

Watch it click!

The eastern eyed click beetle measures about 2.5 to 4.5 cm in length and has a dark-gray to black color with many small white spots. The pronotum, the dorsal part of the anteriormost segment of the thorax, has two large black spots with a white outline that look like two eyes. These spots are actually more than black, they are superblack, meaning that they have a structure that makes them absorb more than 96% of all light in all angles.

A specimen in Philadelphia, USA. Photo by Eduardo Duenas.**

As an adult,this species is mainly nocturnal, as most click beetles, and feeds on nectar and other plant juices. They may be found inside houses, being atracted by the light of the lamps at night.

The voracious larva or wireworm of the eastern eyed click beetle. Photo by M. J. Raupp.

Different from the vegetarian habits of the adults, the larvae of the eastern eyed click beetle are voracious predators. They live in decaying wood and feed on the larvae of other beetles, especially of the family Cerambycidae, the longhorn beetles. The larvae of all click beetles have a flattened body with well marked segments and are known as wireworms. In the eastern eyed click beetle, the abdominal segments of the larva are yellow, except for the last one, which has a orange to brown tinge. The three thoracic segments have the same color, the anterior one being the widest and darkest. The head as a dark brown to black color. The pupae, on the other hand, have that miserable appearance of most insect pupae, being whitish and looking like an incomplete adult trapped in wax.

Despite being considerably popular, the eastern eyed click beetle is not a very well known species. There is a lot about its ecology that needs to be investigated.

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References:

Casari SA (2002) Larvae of Alaus myops, A. oculatus, Chalcolepidius porcatus, Hemirhipus apicalis and generic larval characterization (Elateridae, Agrypninae, Hemirhipini). Iheringia, Série Zoologia 92(2): 93–110.

Wikipedia. Alaus oculatus. Available at < https://en.wikipedia.org/wiki/Alaus_oculatus >. Access on October 4, 2019.

Wong VL, Marek PE (2019) Super black eyespots of the eyed elater. PeerJ Preprints 7:e27746v1 https://doi.org/10.7287/peerj.preprints.27746v1

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**Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

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Filed under Entomology, Friday Fellow, Zoology

Friday Fellow: Turkish Spoonwing

by Piter Kehoma Boll

Continuing the tradition that I applied on the days of the 50th and 100th Friday Fellow, today we will have two again, so that you don’t have to wait one week for the 201st.

So let’s move from the sea in northwestern Europe to the land in southeastern Europe, more precisely the Mediterranean region around the Balkans and Turkey. During May and June, you can find this species flying in meadows and fields looking for yellow flowers. Its name is Nemoptera sinuata, one of the species of the genus Nemoptera known as spoonwings or thread-winged antlions. To distinguish it from other species, I decided to call it the Turkish spoonwing.

A Turkish spoonwing visiting the yellow flowers of Achillea coarctata in Bulgaria. Photo by Paul Cools.**

Like all antlions, the Turkish spoonwing is an insect of the order Neuroptera. The adults have a pair of large oval-shaped forewings and a pair of long and thin hindwings, both of which have a pattern of black and white marks that makes it difficult to locate them against the background. They are exclusively diurnal and fly very slowly using only the forewings. When they find their favorite flowers, they feed on their pollen and nothing else, having their mouthparts adapted for this diet.

After being inseminated by a male, the female starts to lay her eggs. She perches on a flower or raceme and lays one egg every two minutes, laying up to 14 in one day and up to 70 during her 20 days of life as an adult. The eggs, which are white and spherical, fall directly to the ground.

An adult specimen in Greece. Photo by Kostas Zontanos.**

The larvae leave the eggs after about 19 days and is grey with black spots on the segments of the thorax and the abdomen. They have large jaws and bury in the soil at a depth of about 1 cm. Like other antlions, they feed on small arthropods that they capture by surprise jumping out of the soil, although the exact species eaten by them remain largely unknown. The larvae probably pupate during winter and turn into adults around May of the next year, filling the meadows again to look for yellow flowers in the sun.

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References:

Krenn HW, Gereben-Krenn BA, Steinwender BM, Popov A (2008) Flower visiting Neuroptera: mouthparts and feeding behavior of Nemoptera sinuata (Nemopteridae). European Journal of Entomology 105: 267–277.

Popov A (2002) Autoecology and biology of Nemoptera sinuata Olivier (Neuroptera: Nemopteridae). Acta Zoologica Academiae Scientiarum Hungaricae 48(Suppl. 2): 293–299.

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**Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

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Friday Fellow: Gracile Sea Spider

by Piter Kehoma Boll

We reached the 200th Friday Fellow! And to finish another group of hundred species, I will present once more a group that never appeared here, the so-called sea spiders!

The species I chose is Nymphon gracile, commonly known as the gracile sea spider. It occurs in the nothern Atlantic Ocean on the coast of Europe, especially between France and Scandinavia.

A gracile sea spider in Norway. Photo by Asbjørn Hansen.*

Like most sea spiders, the gracile sea spider has a very thin body to which four very long legs are attached. Well, long here is a relative measurement because the whole creature fits on the tip of your finger. In the anterior region, there is the head which includes the proboscis, used to ingest food, a pair of chelifores, analogous to the chelicerae of aracnids, a pair of palps and a pair of ovigers, long and thin appendages used to carry the eggs and the young. The head has four small eyes located very close to each other on a spot at the middle of the dorsum right in front of the first pair of legs and above the ovigers. The fourth pair of legs appears at the very end of the body. The abdomen is only vestigial.

Look how tiny it is. Photo by iNaturalist user gogol.**

The gracile sea spider lives in shallow waters and is often found on the shore if you pay enough attention. It feeds mainly on hydroids, i.e., small sessile cnidarians of the class Hydrozoa, and bryozoans, that it captures using its proboscis and surrounding appendices. To distribute nutrients through the body, the gracile sea spider, like other sea spiders, has a highly branched intestine, which includes branches entering the legs, probably an adaptation to the lack of a functional abdomen.

During winter, the gracile sea spider moves away from the shore and mates in deeper waters. Both males and females have their gonads inside the first segments of the legs. Thus, when the eggs start to develop in the female’s ovaries, her legs become much thicker than those of the males. When mating occurs, the male crawls under the female and captures, with his ovigers, the eggs that she releases through a single pore on the base of each leg. The male then fertilizes the eggs by releasing sperm from the pores at the base of his legs and carry them with him until early spring, when he moves back to the shore and release the juveniles on colonies of hydroids and bryozoans.

A male carrying a mass of eggs with his ovigers. The dark lines seen inside the legs and chelifores are the branches of the intestine. Photo by Julien Renoult.**

The mitochondrial genome of the gracile sea spider was the first to be sequenced for the pycnogonids. It shows a series of gene relocations compared to other arthropods, which may explain, at least partially, why this group is so unusual. We could say that the gracile sea spider, and sea spiders in general, evolved to become only legs. They are basically a bodiless group of legs!

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References:

Isaac MJ, Jarvis HJ (1973) Endogenous tidal rhythicity in the littoral pycnogonid Nymphon gracile (Leach). Journal of Experimental Marine Biology and Ecology 13(1): 83–90. doi: 10.1016/0022-0981(73)90049-X

King PE, Jarvis JH (1970) Egg development in a littoral pycnogonid Nymphon gracile. Marine Biology 7: 294–304. doi: 10.1007/BF00750822

Podsialowski L, Braband A (2006) The complete mitochondrial genome of the sea spider Nymphon gracile (Arthropoda: Pycnogonida). BMC Genomics 7: 284. doi: 10.1186/1471-2164-7-284

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*Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommerical-NoDerivs 2.0 Generic License.

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Friday Fellow: Blue Paddled Mosquito

by Piter Kehoma Boll

A common tropical disease in forested areas of South America and Africa is the yellow fever. Affecting most primate species, the yellow fever is usually transmitted by the famous mosquito Aedes aegypti, which also transmits the dengue and zika fevers, all caused by viruses of the genus Flavivirus.

But in forested areas of South and Central America, other mosquito species can also transmit the yellow fever to humans and monkeys. One of these species is Sabethes cyaneus, which I decided to call the blue paddled mosquito. This species occur from Mexico to Argentina and Brazil and, different from most mosquitos, is diurnal.

A female about to have a bloody lunch on a human in Mexico. Photo by Carlos Alvarez N.*

Even if you don’t find mosquitos nice creatures most of the time, you will have to admit that the blue paddled mosquito is a beautiful animal. The body of the adult is dark and has metallic blue shade on the dorsum and the legs, being slightly greener on the dorsum and slightly purpler on the legs. More than that, the second pair of legs have a large tuft of hair that makes it look like a pair of paddles.

But what is the function of those paddles? The first guess would be that they are sexually selected and are likely important during courtship behavior. But females also have paddles and, if they were the result of sexual selection caused by females on males, they would likely be much larger on males, which is not the case.

Another female feeding on a human, this time in Paraguay. Photo by Joaquin Movia.*

Males perform, indeed, a complex courtship ritual in front of the females using their paddled legs. When females are prepared to mate, they perch vertically on a branch and wait for males to come and dance before them. Most of the males are rejected by a female and, when she finally chooses a male, she will compulate only with him. Males, on the other hand, copulate with many females. This increases even more the idea that the paddles must have some importance on female choice.

Male (left) and female (right). Image extracted from South & Arnqvist (2008).

This is not what was found, though. When the paddles of a male are reduced in size or removed completely, he still has the same chances of getting a female than intact males. On the other hand, a female whose paddles were removed rarely attracts any male. She remains perched on her branch waiting and waiting and no male will come to dance for her. The interest that male blue paddled mosquitos have for paddles is so strong that they even approach other perched males with large paddles.

The reason why this species exhibits strong male preference and weak female preference is still a mystery but is a nice reminder that our ideas on sexual selection are not as well-established as we might think.

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References:

Hancock RG, Foster WA, Lee WL (1990) Courtship behavior of the mosquito Sabethes cyaneus (Diptera: Culicidae). Journal of Insect Behavior 3(3): 401–416. doi: 10.1007/BF01052117

South SH, Arnqvist G (2008) Evidence of monandry in a mosquito (Sabethes cyaneus) with elaborate ornaments in both sexes. Journal of Insect Behavior 21: 451. doi: 10.1007/s10905-008-9137-0

South SH, Arnqvist G (2011) Male, but not female, preference for an ornament expressed in both sexes of the polygynous mosquito Sabethes cyaneus. Animal Behaviour 81(3): 645–651. doi: 10.1016/j.anbehav.2010.12.014

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Friday Fellow: California Beach Flea

by Piter Kehoma Boll

If you are walking along the beach in the west coast of the United States, especially at night, little creatures may hop around your feet. If you look closer, you will notice that they are small crustaceans popularly known as sand hoppers or beach fleas. They belong to the order Amphipoda and there is a good chance that the ones among which you are walking belong to the species Megalorchestia californiana, popularly known as the California beach flea or long-horned beach hopper.

A female in California, USA. Photo by iNaturalist user lbyrley.*

The California beach flea occurs from the southernmost coast of Canada, around Vancouver Island, to the southern coast of the United States, around Laguna Beach. They are very large for an amphipod, reaching more than 2 cm in length, and have a typical “crustacean” color, varying from light brown to grayish. Males are slightly larger than females and have enlarged second antennae with a characteristic red coloration.

A male in California showing the enlarged red antennae and the enlarged boxing-glove-like gnathopods. Photo by Kim Cabrera.*

During the day, the California beach flea remains inside small burrows that it digs in the sand or hides under pieces of seaweed washed ashore. Females can share the same shelter but males cannot stand each other. At dusk, they move out of their shelters by the thousands and move over the sand looking for decaying organic matter on which they feed.

Several females trying to share the same shelter in Oregon, USA. Photo by Ken Chamberlain.*

The sexual dimorphism seen in this species reveals a complex sexual behavior. The enlarged antennae of the males seem to be a visual cue to other males to signal their strength. Additional to those enlarged antennae, the males also have an enlarged second pair of gnathopods or maxillipeds (legs right behind the mouth) that look like boxing gloves. Using the gnathopods, males fight each other for the possession of burrows containing many females. The male that wins the fight becomes the owner of that harem.

A male in Washington trying to invade the burrow of another male (whose antennae are visible). Photo by iNaturalist user pushtheriver.

Since both females and males leave their burrows every night to feed, harems can also be temporary. Although a male can conquer a burrow full of females, those will only return to that same place if they consider that the male is good enough to be the father of their children. This is so because females only reproduce once in their life, so it is crucial to let the best male fertilize her. More than that, females can only release their eggs soon after molting because the hardened exoskeleton prevents it during the rest of her life.

It’s not easy to be a sand hopper living on the beach in California.

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References:

Beermann J, Dick TA, Thiel M (2015) Social Recognition in Amphipods: An Overview. In: Aquiloni L, Tricarico E (Eds.) Social Recognition in Invertebrates: 85–100.

Iyengar VK, Starks BD (2008) Sexual selection in harems: male competition plays a larger role than female choice in an amphipod. Behavioral Ecology 19(3): 642–649. doi: 10.1093/beheco/arn009

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Friday Fellow: Leopard Moth

by Piter Kehoma Boll

I grew up in a house with a large backyard full of trees and other plants next to several small forest patches. As a result, moth were always very common visitors at night, especially during the warmer months. One that always called my attention was a moth with a beautiful pattern in its wings.

This is the beautiful moth that called my attention as a child. This specimen was photographed in the state of Rio Grande do Sul, Brazil, near where I grew up. Photo by Jhonatan Santos.*

Only recently I found out that its name is Pantherodes pardalaria, properly called the leopard moth. Its wings have a yellow background marked with several metallic gray spots with a black outline and a black center. Truly beautiful! A very similar pattern is found in all species of the genus Pantherodes, being the most clear characteristic that defines it.

Leopard moth in Bolivia. Photo by iNaturalist user shirdipam.*

The leopard moth occurs from Mexico to Argentina and is very common in southern Brazil. It belongs to one of the most diverse families of moth, Geometridae, characterized by their caterpilar, called inch worm, that walks as if it were measuring the ground, hence the name Geometridae (from the type genus Geometra, “earth measurer”).

Leopard moth in Southern Mexico. Photo by Roberto Pacheco García.*

I wasn’t able to find much information on the leopard moth, though. Its caterpilars seem to feed on nettles (family Urticaceae). In Mexico, the caterpilars were historically eaten as food by the Aztecs and considered a food of high value, and the practice may still occur today among some humans groups.

And that’s all I got. Despite being beautiful and easily noticed, the leopard moth is one more poorly known species.

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More butterflies and moths:

Friday Fellow: Cramer’s Eighty Eight (on 07 September 2012)

Friday Fellow: Gulf Fritillary (on 15 April 2016)

Friday Fellow: Six-Spot Burnet (on 26 August 2016)

Friday Fellow: Luna Moth (on 12 July 2019)

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References

Biezanko CM, Ruffinelli A, Link D (1974) Plantas y otras sustancias alimenticias de las orugas de los lepidopteros uruguayos. Revista do Centro de Ciências Rurais 4(2): 107–148.

Pitkin LM (2002) Neotropical ennomine moths: a review of the genera (Lepidoptera: Geometridae). Zoological Journal of the Linnean Society 135(2–3): 121–401. doi: 10.1046/j.1096-3642.2002.00012.x

Ramos-Elorduy J, Moreno JMP, Vázquez AI, Landero I, Oliva-Rivera H, Camacho VHM (2011) Edible Lepidoptera in Mexico: Geographic distribution, ethnicity, economic and nutritional importance for rural people. Journal of Ethnobiology and Ethnomedicine 7: 2. doi: 10.1186/1746-4269-7-2

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Filed under Entomology, Friday Fellow, Zoology