Rufous grasshopper

Appearance

Males range from 14 to 16 mm, while females range from 17 to 22 mm. The coloration is usually shades of brown, but features some gray, yellow, and red. The mature male has an abdomen tipped with orange-red. The female has similar coloration, but it is much less pronounced than in males. Some females are reddish purple. The club on the antenna is distinct, flattened, expanded, and apical, or at the tip. The pronotum features a central seam. The wings are present in both sexes. The forewings are longer in the males, where they reach just beyond the primary joint of the hindlegs, than in the females, where they fall short of this joint.Female behavior toward males is composed of three stages, beginning after the imaginal molt, through which the grasshopper reaches the adult phase. Which courtship stage a female is in is affected by age and whether she has mated in the past. First, there is rejection of the males, which lasts approximately four days. In this stage, the males can do nothing to induce copulation. Second, there is the two-day phase of passive acceptance without singing. Third, the female actively attracts the male by singing, and those in this state, which lasts several days, permit immediate copulation after a short courtship or without it. It is hypothesized that this active state exists as a method for individuals in populations of low densities to have a chance to copulate. It may be difficult in these populations to encounter other individuals by chance, and sounds produced by the males and females makes it easier for them to find one another. After successful copulation, she returns to a defensive state and lays eggs. After egg-laying, she once again reaches a state of passive acceptance. If she fails to mate during this stage, she will lay eggs fertilized by the previous male and return to active attraction. The cycle continues as it did at the first time entering the active phase, and follows this sequence for the rest of the adult life.

Pre-mating behaviors and the growth and development of the ovaries are controlled by the juvenile hormone-III, which is produced in the corpus allata. The production of this juvenile hormone fluctuates. Patterns of behavior are correlated with the increasing or decreasing rate of the concentration of this hormone. It is possible that the production by the corpus allata may be affected by nervous stimulation or inhibition of the glands. The hormone concentration within the hemolymph may be affected by esterases. Corpus allata activity is also affected by external factors, as it tends to be greater when mating and egg-laying are occurring, but much lower when they are prevented. When activity is lower, egg production is lower.

Behavior

Females lay eggs, usually five per egg packet, in semi-arid soil in the roots of grasses around autumn and winter. Nymphs hatch around late May, and adults appear beginning in late July. Development depends greatly on the temperature. Most are fully developed by the end of August. When autumn conditions are not too harsh,they are relatively tolerant of cold weather and adults may survive until early December. Despite this tolerance, they prefer warm weather and more individuals tend to survive through hotter summers than cooler summers.Female behavior toward males is composed of three stages, beginning after the imaginal molt, through which the grasshopper reaches the adult phase. Which courtship stage a female is in is affected by age and whether she has mated in the past. First, there is rejection of the males, which lasts approximately four days. In this stage, the males can do nothing to induce copulation. Second, there is the two-day phase of passive acceptance without singing. Third, the female actively attracts the male by singing, and those in this state, which lasts several days, permit immediate copulation after a short courtship or without it. It is hypothesized that this active state exists as a method for individuals in populations of low densities to have a chance to copulate. It may be difficult in these populations to encounter other individuals by chance, and sounds produced by the males and females makes it easier for them to find one another. After successful copulation, she returns to a defensive state and lays eggs. After egg-laying, she once again reaches a state of passive acceptance. If she fails to mate during this stage, she will lay eggs fertilized by the previous male and return to active attraction. The cycle continues as it did at the first time entering the active phase, and follows this sequence for the rest of the adult life.

Pre-mating behaviors and the growth and development of the ovaries are controlled by the juvenile hormone-III, which is produced in the corpus allata. The production of this juvenile hormone fluctuates. Patterns of behavior are correlated with the increasing or decreasing rate of the concentration of this hormone. It is possible that the production by the corpus allata may be affected by nervous stimulation or inhibition of the glands. The hormone concentration within the hemolymph may be affected by esterases. Corpus allata activity is also affected by external factors, as it tends to be greater when mating and egg-laying are occurring, but much lower when they are prevented. When activity is lower, egg production is lower.

Habitat

The rufous grasshopper is usually found in open land, particularly terrain such as meadows, pastures, and forest edges that feature tall grass. More specifically, it can often be found in chalk grassland. It has been found on southern slopes of the Alps up to approximately 8100 feet. It prefers warm environments of moisture levels ranging from dry to moist. Very common locations include regions of Europe, including Germany, Sweden, France, and the United Kingdom. In fact, it can be found across almost all of Europe and Asia, ranging from France to parts of Siberia and from Scandinavia to northern Germany.

These adept climbers prefer to avoid remaining on the ground, and instead perch on plants in sunny, elevated areas. As such they tend to live near herbaceous, taller plants and only by short plants infrequently. One situation that illustrates this preference well was the outbreak of the myxomatosis virus in rabbits in Britain in the 1950s. The rabbit population became severely depleted. As rabbits have the effect of cropping grass short to eat it, this decrease in the population led to less cropped grass. Some wildlife, such as the Large Blue butterfly, suffered immensely because of their dependence on short grass, but other organisms, like the rufous grasshopper, prospered because the lack of rabbits led to an increase in long grass.

Predators includes bats such as the greater mouse-eared bat.

Food

Grasshoppers in general, including this species, are herbivorous and subsist mainly on grasses. Scientists have gained knowledge of the diet of "G. rufus" through the use of feces as a source of DNA. It has been documented to eat plants of the genus "Bromus", the species "Holcus lanatus", and the subfamily Pooideae, all within the family Poaceae. Poaceae is a family of flowering monocots whose members are referred to as true grasses. Pooideae includes lawn grasses and cereals such as wheat and barley. "Bromus" is composed of grasses called brome grasses or cheat grasses. "Holcus lanatus", more commonly known as Yorkshire Fog or Velvet Grass, is a species of perennial pasture grass noted for its hairy texture. The rufous grasshopper has also been known to sparingly eat other plants such as rushes.

Defense

Interestingly, remating shortly after copulation is impossible for these grasshoppers. The act of copulation prompts a physiological and behavioral response in females termed “secondary defense”. During secondary defense, the female will respond to male attempts at copulation with strong, directed kicks of the hindlegs, which will deter the males and make forced mating impossible since the female may be almost twice as large as the male. This is actually advantageous for the male, as it protects his sperm from competition with other males before the pair's eggs are laid. This stage may last 3 to 4 days.

This defense is usually induced through contact of the proteins of the liquid white secretions of the white secretory tubule 1 of a male's accessory glands with the female's spermathecal duct. More specifically, this is caused by a pheromone which is spurred by a one of these proteins, of size less than 90 kDa. It can also be triggered by eggs exerting pressure against the walls of the oviduct on the pathway to oviposition. It is hypothesized that the secretion stimulates a bristle field of contact chemoreceptors where the spermathecal duct enters the endbulb. In other words, this defensive behavior is caused by both chemical and mechanical means. In terms of the four different stages of female behavior toward males, after copulation the female returns to a defensive state in which she rejects all male advances.

There are additional reasons for the inability to remate. The spermatophore actually blocks the spermathecal duct so that another spermatophore cannot physiologically be planted. Additionally, after mating is completed, the genitalia of the pair hook firmly together for 40 to 90 minutes due to the clasping reflex, which prevents other males from mating with the female before she reaches the defensive state.

Other than the loss of sexual receptivity after a copulation, refusal to mate occurs during the juvenile stage, when the insect is not yet fully sexually mature. Female grasshoppers who have not yet copulated with a male and are in the defensive state are exhibiting “primary defense”. During this phase, the females also respond to males with strong kicks of the hindlegs, but more heavily rely on escaping and evading the male.