Defensive Strategies of a Noctuid Caterpillar in a Myrmecophytic Plant: are Dyops Larvae Immune to Azteca Ants?

Sociobiology ◽  
2018 ◽  
Vol 65 (3) ◽  
pp. 397
Author(s):  
Renato Rogner Ramos ◽  
André Victor Lucci Freitas ◽  
Ronaldo Bastos Francini

Immature stages of insects are generally susceptive to their natural enemies, but many species developed defensive and evasive mechanisms to circumvent predation. Gregarious larvae of the noctuid moth Dyops cf. cuprescens feed on leaves of young Cecropia pachystachya shrubs colonized by Azteca ants. Ants avoid contact with larval clusters, retreating to the nest when larvae are moving near the stems. Provoked encounters revealed that Dyops caterpillars present several specialized behaviors to avoid and overcome ant attacks, such as fleeing to under leaf, jumping off the leaf, curling and wriggling vigorously the anterior portion of the body, spitting droplets of oral fluids, or killing ants by pouncing them. These mechanisms allow the caterpillars to overcome ant attacks and consume leaves of ant-colonized plants. By feeding on a heavily protected plant, larvae can enjoy not only a competitor-free plant, but possibly also the enemy-free space created by the aggressive ants.

2014 ◽  
Vol 43 (6) ◽  
pp. 1465-1474 ◽  
Author(s):  
Shannon M. Murphy ◽  
John T. Lill ◽  
M. Deane Bowers ◽  
Michael S. Singer
Keyword(s):  

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 29-36
Author(s):  
V. Gremigni ◽  
M. Nigro ◽  
I. Puccinelli

The source and fate of blastema cells are important and still unresolved problems in planarian regeneration. In the present investigation we have attempted to obtain new evidence of cell dedifferentiation-redifferentiation by using a polyploid biotype of Dugesia lugubris s.1. This biotype is provided with a natural karyological marker which allows the discrimination of triploid embryonic and somatic cells from diploid male germ cells and from hexaploid female germ cells. Thanks to this cell mosaic we previously demonstrated that male germ cells take part in blastema formation and are then capable of redifferentiating into somatic cells. In the present investigation sexually mature specimens were transected behind the ovaries and the posterior stumps containing testes were allowed to regenerate the anterior portion of the body. Along with the usual hexaploid oocytes, a small percentage (3.2%) of tetraploid oocytes were produced from regenerated specimens provided with new ovaries. By contrast only hexaploid oocytes were produced from control untransected specimens. The tetraploid oocytes are interpreted as original diploid male germ cells which following the transection take part in blastema formation and then during regeneration redifferentiate into female germ cells thus doubling their chromosome number as usual for undifferentiated cells entering the female gonad in this biotype.


Author(s):  
Peter M. Kotanen

Abstract Non-native plants rarely escape damage by herbivores. Instead, upon arrival in a new region, they begin to acquire new enemies, replacing those they have lost during their migration. These herbivores can include both natives to the new region and species that have themselves been accidentally or deliberately introduced from elsewhere, potentially including examples originating from the invader's original range. Shifts of new enemies from other hosts can occur over a range of timescales, depending in part on whether evolutionary change is required, but are likely to be faster for plants that are widespread and phylogenetically related to a herbivore's original host, and faster for generalist herbivores than for specialists. The occurrence of herbivores is not necessarily uniform across an invader's range; instead, they may be less diverse or abundant in host populations that are geographically or ecologically marginal, though existing evidence is mixed. Collectively, these new suites of herbivores can affect the growth and fitness of invaders, both directly by damaging them and indirectly by attacking their competitors. Studies comparing the demographic consequences of herbivory for successful vs unsuccessful invaders may help to clarify how often such impacts limit invasiveness. The view that an invader enters 'enemy-free' space is inaccurate; instead, persistence and spread of non-native plants often may be affected by the novel and changing assemblage of herbivores that they acquire within their new distribution.


Author(s):  
Peter M. Kotanen ◽  

Non-native plants rarely escape damage by herbivores. Instead, upon arrival in a new region, they begin to acquire new enemies, replacing those they have lost during their migration. These herbivores can include both natives to the new region and species that have themselves been accidentally or deliberately introduced from elsewhere, potentially including examples originating from the invader's original range. Shifts of new enemies from other hosts can occur over a range of timescales, depending in part on whether evolutionary change is required, but are likely to be faster for plants that are widespread and phylogenetically related to a herbivore's original host, and faster for generalist herbivores than for specialists. The occurrence of herbivores is not necessarily uniform across an invader's range; instead, they may be less diverse or abundant in host populations that are geographically or ecologically marginal, though existing evidence is mixed. Collectively, these new suites of herbivores can affect the growth and fitness of invaders, both directly by damaging them and indirectly by attacking their competitors. Studies comparing the demographic consequences of herbivory for successful vs unsuccessful invaders may help to clarify how often such impacts limit invasiveness. The view that an invader enters 'enemy-free' space is inaccurate; instead, persistence and spread of non-native plants often may be affected by the novel and changing assemblage of herbivores that they acquire within their new distribution.


Zootaxa ◽  
2020 ◽  
Vol 4810 (3) ◽  
pp. 511-522
Author(s):  
GEORGE POINAR ◽  
FERNANDO E. VEGA ◽  
SCOTT A. SCHNEIDER

A new genus and species of scale insect (Hemiptera: Coccomorpha) is described from a female specimen in mid-Cretaceous Burmese (Myanmar) amber. Fossil female scales are rare and the present species, described as Paleolepidotus macrocolus gen. et sp. n., has such an unusual assortment of morphological features that it could not be assigned to any particular extant or extinct family. The small, ferruginous specimen exhibits a series of long wax pencils that extend around the body, including the head. The antennae and legs are quite long compared to other extant and extinct scale fossils. Of special interest are the protruding eyes, and a conical-triangular rostrum arising from between the forelegs; the claws with bifid apices are also unique. The ovisac contains immature stages. 


Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 197 ◽  
Author(s):  
Łukowski ◽  
Janek ◽  
Baraniak ◽  
Walczak ◽  
Karolewski

Recently in Poland, cases of host expansion have frequently been observed in the typically monophagous bird-cherry ermine moth (Yponomeuta evonymella), which has moved from its native host plant, bird cherry (Prunus padus), to a new, widely distributed plant that is invasive in Europe, black cherry (P. serotina). We attempted to verify the reasons behind this host change in the context of the enemy-free space hypothesis by focusing on parasitoids attacking larval Y. evonymella on one of three host plant variants: The primary host, P. padus; initially P. padus and later P. serotina (P. padus/P. serotina); or the new host, P. serotina. This experiment investigated if changing the host plant could be beneficial to Y. evonymella in terms of escaping from harmful parasitoids and improving survival rate. We identified nine species of parasitoids that attack larval Y. evonymella, and we found that the number of parasitoid species showed a downward trend from the primary host plant to the P. padus/P. serotina combination to the new host plant alone. We observed a significant difference among variants in relation to the percentage of cocoons killed by specific parasitoids, but no effects of non-specific parasitoids or other factors. Total mortality did not significantly differ (ca. 37%) among larval rearing variants. Changing the host plant caused differences in the structure of the parasitoid complex of Y. evonymella but did not improve its survival rate. This study does not indicate that the host expansion of Y. evonymella is associated with the enemy-free space hypothesis; we therefore discuss alternative scenarios that may be more likely.


Zootaxa ◽  
2012 ◽  
Vol 3423 (1) ◽  
pp. 45 ◽  
Author(s):  
SERGIO ANTONIO VANIN ◽  
DANIELA DE CASSIA BENÁ ◽  
FABIANO FABIAN ALBERTONI

Immatures of the Phelypera schuppeli (Boheman, 1834) (Curculionidae; Hyperinae; Cepurini) are described, illustrated and compared with available descriptions of larvae and pupae of Hyperini. Immatures and adults from midwest (Dourados, Mato Grosso do Sul; Pirenópolis, Goiás) and southeast Brazil (Bauru, São Paulo) were found on leaves of the host plant, Pachira aquatica Aubl. ( Malvaceae, formerly Bombacaceae), a tree used as an ornamental plant in many Brazilian frost-free cities. Larvae of P. schuppeli are exophytic, brightly colored, eruciform and possess abdominal ambulatory ampullae, resembling larvae of Lepidoptera. Mature larvae can spin globular lattice-like cocoons where pupation takes place. Data in the field and under laboratory conditions confirmed previously published biological observations on P. schuppeli. Additional information about defensive behaviors, process of cocoon construction and natural enemies, such as the larval predator Supputius cinticeps (Stål, 1860) (Hemiptera: Pentatomidae) and the prepupal and pupal parasitoid Jaliscoa nudipennis Bouček, 1993 (Hymenoptera: Pteromalidae), are reported.


Zootaxa ◽  
2020 ◽  
Vol 4732 (1) ◽  
pp. 99-116
Author(s):  
DANIARA COLPANI ◽  
CÉSAR JOÃO BENETTI ◽  
NEUSA HAMADA ◽  
VANDERLY ANDRADE-SOUZA ◽  
KARINE SCHOENINGER ◽  
...  

In most species of Gyrinidae, the immature stages are unknown, especially due to the difficulty in collecting the juveniles and assigning them to a particular species. Molecular association is a feasible technique that may solve this problem. Recent studies have used DNA sequence data, specifically the gene cytochrome oxidase subunit I (COI), to associate immature and adult stages, thus enabling the description of the former. The objectives of this study were (1) to describe and illustrate the immature stages of Gyrinus (Neogyrinus) rozei Ochs, 1953 including morphometric, chaetotaxic and bionomic information, and (2) to assess the usefulness of the gene COI to associate immatures and adults of Gyrinus. The studied specimens were collected in Roraima state, northern Brazil. The association of immature and adult stages was done either by rearing adults under laboratory conditions or by using DNA sequence data (COI). Eggs were described based on scanning electron microscopy; they are distinguished mainly by several features of chorion, micropyle and reticulation. Larvae of G. (N.) rozei can be distinguished from those of other Neotropical Gyrinidae by a combination of several characters, including the stipes with five robust hook-like additional setae on the dorsointernal margin, and the lacinia roughly hook-shaped. The pupa is similar to that of G. argentinus Steinhel, 1869, except for the number of setae on the body. The first record of the parasitoid wasp Melanosmicra sp. (Hymenoptera: Chalcididae) on a Gyrinus species is also provided. 


Biotropica ◽  
2014 ◽  
Vol 46 (3) ◽  
pp. 260-263 ◽  
Author(s):  
Rodrigo F. Fadini ◽  
Ana Mellado ◽  
Leidielly P. Ghizoni

1995 ◽  
Vol 69 (4) ◽  
pp. 703-707 ◽  
Author(s):  
Kazushige Tanabe ◽  
Royal H. Mapes

A well-preserved mouth apparatus consisting of jaws and a radula was found in situ within the body chamber of the goniatite Cravenoceras fayettevillae Gordon, 1965 (Neoglyphiocerataceae: Cravenoceratidae), from the middle Chesterian (Upper Mississippian) of Arkansas. Both upper and lower jaws consist of a black material. The lower jaw is characterized by a widely opened larger outer lamella and a shorter inner lamella. The upper jaw is fragmental. The radula is preserved in the anterior portion of the buccal space and comprises a series of tooth elements. Each transverse tooth row consists of seven teeth (a rhachidian and pairs of two lateral and one marginal teeth), with a pair of marginal plates. This arrangement is typical of radulae of other ammonoids of Carboniferous to Cretaceous age, coleoids, and the orthoconic “nautiloid” Michelinoceras (Silurian, Michelinocerida), suggesting a phylogenetic affinity among them.


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