Ontogeny of territoriality in the desert clickerLigurotettix coquilletti (Orthoptera: Acrididae)

Field observations and experiments showed that settlement prior to reproductive maturation strongly influenced territorial success in the desert clicker(Ligurotettix coquilletti), an acridid grasshopper in which males defend individual host plants (Larrea tridentata bushes) as mating arenas. High tendencies to move and reposition among the host plants were displayed in two distinct episodes. The first occurred during early nymphal development, and it resulted in many individuals settling on high-qualityLarrea bushes. Prior work showed thatL. coquilletti that fed on foliage from these specific bushes exhibited higher relative growth rates and therefore were expected to eclose sooner. Early-eclosing males enjoyed a priority advantage in defending high-quality bushes as mating territories, and they consequently encountered more females and mated more frequently. Despite the distribution of most insects on high-quality bushes at the time of eclosion, though, a second movement episode occurred shortly thereafter. This reshuffling contrasts markedly with the site fidelity of mature adult males, most of which settle on mating territories, and it may function as a means of examining an enlarged sample of potential sites. The above results imply that territorial success of maleL. coquilletti does not result from retaining sites defended by the parents. This point is also supported by the finding that females do not oviposit particularly close to theLarrea bushes in which they reside regardless of their quality; most egg pods are deposited in bare soil midway between the bushes. Nonetheless, certain oviposition sites may be conducive to earlier hatch, and this can lead to earlier eclosion and ultimately to defense of a valuable territory. Therefore, the parental generation, through selective oviposition, may yet influence the success of their male offspring.